Traction accumulator, in particular for a motor vehicle, with lithium ion secondary cells and manufacturing process of a traction accumulator dissipating heat

The present invention deals with a traction accumulator of an elongate design, in which the lithium-ion secondary cells arranged side by side form an accumulator module. In other words, the present invention deals with a traction accumulator, in particular for a motor vehicle such as a passenger car, according to the preamble of claim 1.

The present invention also deals with a production process for a traction battery, how a traction battery can deal with its thermal energy, in particular with its charging heat generated during electrical charging, in particular a method according to the preamble of claim 15.

technical field

Electric vehicles, in particular for road use, are known from the literature and from small series, which have a large number of electrochemical secondary cells, preferably based on lithium-ion, to a high-voltage (e.g. 400 volts to 850 volts) power source and electrically connect mechanically. The focus in the development of suitable traction accumulators is, among other things, on the technical difficulties<ul id="ul0001" list-style="bullet" compact="compact"><li>the desired high energy density (measured e.g. in Wh per liter of battery volume),</li><li>to the lowest possible weights per electrical capacity (measured e.g. in kilograms per farad),</li><li>to a thermal conductivity that is as balanced as possible (measured e.g. in watts per meter and Kelvin) and</li><li>to an acceptable temperature gradient (measured e.g. in Kelvin per meter).</li></ul>

With traction accumulators, the difficulty still arises that if they are to be B. are installed in a passenger vehicle, should be as mechanically stable as possible, especially torsionally rigid. The demands contradict each other, at least in part. Mechanically stable traction accumulators are usually heavier and therefore have a lower energy density per gram than lighter accumulators, e.g. B. in the field of consumer electronics.

In the field of traction accumulators, the present invention deals with the subject of how an accumulator module can be connected that represents an acceptable compromise between the conflicting requirements.

A secondary cell design presented in numerous publications is the prismatic cell, which is often used for lithium-ion accumulators in the mobile sector as well as in the motor vehicle sector. Due to the desired short charging times for charging a traction accumulator, considerations are made as to how the heat generated when charging the accumulators can be discharged as cheaply as possible.

Here it can be considered which of the accumulator types, of which there are such types as pouch cells, prismatic cells and hard cover modules, among others, can be the most promising candidate for an optimized design. The individual types can be illustrated using the patent literature.

State of the art

the<patcit id="pcit0001" dnum="US2014154549A1"><text>US 2014/154 549 A1 (Applicant: GrafTech International Holdings, Inc.; Filing date: 08/13/2012</text></patcit>) shows a stacked arrangement with a heat sink to which the heat from the accumulator cells is to be supplied via thermal transfer sheets. Again<figref idref="f0001">figure 1</figref> the<patcit id="pcit0002" dnum="US2014154549A1"><text>US 2014/154 549 A1</text></patcit> can be seen, a mechanical strength of the stack is only generated by a frame-like housing.

the<patcit id="pcit0003" dnum="US2016049704A1"><text>US 2016/049 704 A1 (applicant: GrafTech International Holdings Inc.; priority date: 04.06.2012</text></patcit>) describes a stacked arrangement of prismatic-shaped accumulators, which are clamped on one side in a heat sink by means of heat distribution plates and are intended to transfer the heat generated during charging to the heat sink. The cells (secondary cells) shown in the figures are also referred to in the art as pouch cells because of their laminated packaging. The cells themselves are made of a material in which the focus is not on mechanical stability but on electrochemical functionality. Therefore, the one in the<patcit id="pcit0004" dnum="US2016049704A1"><text>US 2016/049 704 A1</text></patcit> proposed stack not be particularly mechanically stable due to the flexible graphite layer, among other things.

the<patcit id="pcit0005" dnum="US2016056427A1"><text>US 2016/056 427 A1 (Applicant: LG Chem, Ltd.; Filing date: May 15, 2013</text></patcit>) also starts from the pouch cells, whereby a stabilizing cartridge frame is arranged between two pouch cells over the entire area between the two cells. That is, the mechanical stability is generated by the multiple use of stabilizing frames.

the<patcit id="pcit0006" dnum="DE60308598T2"><text>DE 603 ​​08 598 T2 (patent owner: Nissan Motor Co., Ltd.; date of issue: September 27, 2006</text></patcit>), also published as<patcit id="pcit0007" dnum="EP1376718A2"><text>EP 1 376 718 A2</text></patcit>, deals with pouch cells. These are optimized in their dimensions according to various criteria. Almost countless variants for individual dimensions are listed here, in particular in tabular form. A reader of<patcit id="pcit0008" dnum="EP1376718A2"><text>EP 1 376 718 A2</text></patcit> comes to the most varied of proportions without knowing which proportion is actually to be given preference in pouch cells.

the<patcit id="pcit0009" dnum="US8231996B2"><text>US 8,231,996 B2 (patent holder: Keith Howard, Sheau-Pyng Lin; Date of issue: 08/20/2009</text></patcit>) deals with round cells and allegedly offers suitable dimensions and ratios for these cells.

In the<patcit id="pcit0010" dnum="DE102009046801A1"><text>DE 10 2009 046 801 A1 (Applicant: SB LiMotive Company Ltd.; Disclosure date: May 19, 2011</text></patcit>) describes a battery cell in which a length belonging to a base area is greater than the height of the battery cell body defined by the side area, at least in an extent that is intended to be the maximum extent. The bottom surface should serve as a contact surface for a connected cooling system. Terminals of the battery cell can be arranged on two opposite side faces. There is also a burst pressure opening on the side face, preferably below the terminal and valved. A division of the battery cell by partitions into cell units serves to conduct heat via the partitions from the interior to the surface of the battery cell.

the<patcit id="pcit0011" dnum="DE102005031504A1"><text>DE 10 2005 031 504 A1 (applicant: DaimlerChrysler AG; disclosure date: January 11, 2007</text></patcit>) deals with a traction battery based on lithium, in which the heat sink for a stack of prismatic modules is the focus of the considerations. The individual cells inside a module are separated from each other by bars. A recess is arranged in each of the webs. Cooling ribs connected to a central heat sink should protrude into the recesses of the webs. This design with webs and cooling fins projecting into them should make it possible to produce the housings of the individual modules using casting manufacturing processes.

A U-shaped cold plate wrapped around an electrochemical stack, as in FIG<patcit id="pcit0012" dnum="US2014272513A1"><text>US 2014/272 513 A1 (Applicant: GM Global Technology Operations LLC; Filing date: 03/13/2013</text></patcit>) can increase mechanical stability, but it also increases the overall weight of the enclosed stack.

A similar approach, but not using a liquid coolant, is discussed in<patcit id="pcit0013" dnum="US2016197386A1"><text>US 2016/197 386 A1 (applicant: LG Chem, Ltd.; priority date: 08/28/2013</text></patcit>) presented, in which two cap-like half housings should completely cover stack-like flat cells, whereby the heat dissipation should be improved in that, after assembly, a thermoplastic synthetic resin is injected into the interior space containing the stack via filling openings in the caps.

the<patcit id="pcit0014" dnum="EP2064758B1"><text>EP 2 064 758 B1 (patent owner: LG Chem, Ltd.; priority date: 09/18/2006</text></patcit>) shows in pictures a stack made up of flat cells, which is covered on three sides by electronic circuit boards instead of a housing, whereby the sides covered with metal plates are equipped with a rail system so that two stacks can be pushed together over the rails. The stacks are freely accessible outside the circuit board or metal plate cover. With intended no-load and also operating voltages in the three-digit volt range, such a modular design should raise concerns about the lack of protection against accidental contact.

In the two patent applications<patcit id="pcit0015" dnum="US2012129024A1"><text>US 2012/129 024 A1 (patent applicant: Cobasys, LLC; priority date: 18.11.2010</text></patcit>) and<patcit id="pcit0016" dnum="WO2016053403A1"><text>WO 2016/053 403 A1 (applicant: Johnson Controls Technology Company; priority date: September 30, 2014</text></patcit>) shows how individual modules can be mechanically connected to form larger accumulators.

the<patcit id="pcit0017" dnum="DE102009058809A1"><text>DE 10 2009 058 809 A1 (Applicant: Valeo Klimasysteme GmbH; Disclosure date: June 22, 2011</text></patcit>) or your subsequent registration<patcit id="pcit0018" dnum="EP2377141A1"><text>EP 2 377 141 A1 (applicant: Valeo Klimasysteme GmbH; disclosure date: June 22, 2011</text></patcit>) and the<patcit id="pcit0019" dnum="DE102009058810A1"><text>DE 10 2009 058 810 A1 (applicant: Valeo Klimasysteme GmbH; disclosure date: June 22, 2011</text></patcit>) deal with how a component can be created for a battery that is used either as a cooling device or as a combined cooling and heat transfer component and should be as simple as possible to produce. Certain complicated geometries should be able to be produced by an extrusion process or by an extrusion process.

Monolithic housing body with integrated liquid channel should according to the<patcit id="pcit0020" dnum="DE102016113597A1"><text>DE 10 2016 113 597 A1 (Applicant: Ford Global Technologies, LLC; Disclosure date: February 16, 2017</text></patcit>) can be produced by extrusion. In a housing body, which comprises two side parts and a base, a battery array can be arranged on the base of the housing as a battery pack. The floor should be designed in such a way that it can both support the battery array and thermally treat the heat generated by the battery cells. In addition, thermally resistant and electrically insulating spacers can be present between the battery cells. Battery cells are held together by frictional force due to cell compression during assembly. Glue can also be used as an alternative. During extrusion, liquefied material is formed, so that at least the energy to reach the melting point of the material used has to be applied during production.

the<patcit id="pcit0021" dnum="DE102011107007A1"><text>DE 10 2011 107 007 A1 (Applicant: Volkswagen AG; Disclosure date: January 10, 2013</text></patcit>) is also working on the design of a cooling plate for a traction battery and comes to the conclusion that the cooling plate with integrated cooling channels should be made of light metal using an extrusion process. the<patcit id="pcit0022" dnum="DE102015214661A1"><text>DE 10 2015 214 661 A1 (Applicant: Volkswagen AG; Disclosure date: January 10, 2013</text></patcit>) presupposes the knowledge of<patcit id="pcit0023" dnum="DE102011107007A1"><text>DE 10 2011 107 007 A1</text></patcit> continues to the effect that the cooling plate of a battery cell of a traction battery can temper the battery cell if the cooling plate is an extruded profile that has reproducible, uniform cooling channels. The aim here is to work with cross sections that are as straight as possible.

the<patcit id="pcit0024" dnum="WO2008034584A1"><text>WO 2008 034 584 A1 (applicant: MAGNA STEYR FAHRZEUGTECHNIK AG &amp; CO KG; publication date: March 27, 2008</text></patcit>) describes a modular battery unit with at least two battery cells and with a heat sink arranged between the battery cells and clinging to the side of the battery cells, through which a cooling medium flows and which, on the one hand, removes the heat generated in the battery cells in a suitable manner and, on the other hand, supports the battery cells. There are also two cover caps that can be arranged on the heat sink. The top caps should be designed as die-cast parts; the heat sink of the battery pack shall be made by extrusion.

In an energy storage device according to<patcit id="pcit0025" dnum="DE102015222138A1"><text>DE 10 2015 222 138 A1 (Applicant: AUDI AG; Disclosure date: May 11, 2017</text></patcit>) individual walls can consist of a panel-shaped extruded profile. Such an extruded profile can also have cooling pipe coils for a coolant circuit. An outer wall of a cooled housing or a wall lying in the interior of the housing can thus be formed, with which storage cells or storage cell modules are intended to be thermally coupled on one or both sides.

the<patcit id="pcit0026" dnum="WO2009080175A1"><text>WO 2009 / 080 175 A1 (applicant: Daimler AG; priority date: December 20, 2007</text></patcit>) describes a spaced, open frame housing made from an extruded profile, inside which cells are stacked on a wall and electrically connected via this wall and insulated from the housing.

In the<patcit id="pcit0027" dnum="DE102012000871A1"><text>DE 10 2012 000 871 A1 (Applicant: Li-Tec Battery GmbH; Disclosure date: July 18, 2013</text></patcit>) cell housings for electrochemical cells are described, with which an energy store that can be cooled by a coolant can be constructed. The cell housing should be equipped with coolant channels. An essentially meandering cooling channel can be formed over almost the entire first housing side wall. Such first housing side walls of adjacent cell housings are intended to be connected to one another in a battery, with a common coolant channel being formed. Sealing parts or sealing strips are used for sealing.

From the<patcit id="pcit0028" dnum="US2012237805A1"><text>US 2012 237 805 A1 (Applicant: Dana Canada Corporation; Publication date: 09/20/2012</text></patcit>) results in a battery cell cooler. A battery cell cooler through which a liquid coolant can flow is inserted between adjacent battery cells. With different flow geometries in the cooling plates, such as "dimples", ribs and large flow reversal radii for the flow, favorable flow conditions and the mechanical stability achieved by the structure of the components are to be achieved. In addition, z. B. the escape of air from the system can be facilitated by a favorable design of the reversal radii.

the<patcit id="pcit0029" dnum="US2016329538A1"><text>US 2016/ 329 538 A1 (Applicant: A123 Systems LLC.; Date of publication: November 10, 2016</text></patcit>) deals with a battery shock protection system. Each battery cell has a positive terminal and a negative terminal. Various wall parts or partition walls of housings can be connected to one another by tongue and groove curves that can be plugged into one another. In addition, it should also be possible to plug separate housings together, with additional free spaces being provided between these connection areas. This US application also proposes incorporating compliant foam sheets between the battery cells to serve to limit relative movement between cell bank components and to facilitate assembly of cell banks into the housing by compressibility of the sheets.

In the<patcit id="pcit0030" dnum="US2015200429A1"><text>US 2015/ 200 429 A1 (Applicant: Simplo Technology Co., Ltd.; Date of publication: July 16, 2015</text></patcit>) describes a battery module with a heat dissipation device. The heat dissipation device has plate-like, identical cooling elements to be arranged in layers. These are presented in four different exemplary embodiments. Accordingly, the heat dissipation device to be inserted between spaced battery cells can be folded with U-turns. In accordance with a further exemplary embodiment shown in the document, a number of connecting channels, which are also referred to as expandable fluid channels, can be connected to a base with an inlet and outlet fluid channel. The name comes from the fact that a connection to the two adjacent battery cells should be possible through the expansion of the fluid channels via their side walls. Such an arrangement is based on the<figref idref="f0009">figure 10</figref> proposed for a battery cell array, which comprises a plurality of battery cells in two spatial directions.

Some of the publications examined describe battery packs that are only conditionally suitable for the rough use in motor vehicles. With other designs, it seems as if mechanical stability is bought at the expense of components that cause the accumulator to increase in weight significantly.

Technical difficulties

There is a need for an arrangement of electrochemical cells that is sufficiently mechanically stable and has an acceptably low weight per stored energy. The ideal would be a battery design that can still offer a short charging time thanks to the high charging currents that can be set and the associated heat generation. In other words, with the aim of bringing electric drives more successfully into road traffic, there is a desire to create better energy storage devices that at least partially overcome the known disadvantages, which particularly limit the possible applications in the form of fully electric vehicles.

invention description

The present invention solves the problem according to the invention by a device according to claim 1. The present invention also solves the problem according to the invention by a method according to claim 15. Advantageous developments can be found in the dependent claims.

Traction accumulators are such electrochemical secondary cells, ie electrochemical cells that can be repeatedly charged and discharged and are suitable for mobile use in vehicles. Traction accumulators for motor vehicles are of particular interest. This includes passenger cars.

There are many types of electrochemical secondary cells. One possible design is the stacked, prismatic secondary cells. This differ z. B. the pouch cells presented above. Another design are the round cells, which are preferably arranged parallel to one another along their lateral surfaces, often aligned in the same direction, and are combined to form a package arranged in one plane.

A type of secondary cell that gets its name from the materials or ions that are installed or present in the secondary cells are lithium-ion accumulators. In fact, as a rule, a material or ion specification for one of the two electrodes of a basic cell, a secondary cell or for an electrolyte becomes the naming specification. The category of lithium-ion accumulators includes a whole group of chemically active, film-like half-cells and the electrolytes suitable for them.

As reference parts or common assemblies, a lithium secondary battery generally includes a positive electrode, a negative electrode, a separator, and a nonaqueous electrolytic solution containing e.g. B. may contain lithium salt.

For example, the positive electrode can be created through the following two steps:<ul id="ul0002" list-style="bullet"><li>first step: applying a mixture of a positive electrode active material, a conductive agent and a binder to a positive electrode current collector and</li><li>second step: drying the mixture.</li></ul>

A filler can also be added to the mixture as required.

Common nomenclatures are used below to characterize the composition of chemically synthesizable substances with regard to the elements forming the substances and their relative frequency, in particular with regard to their molarity. This information can also be referred to as chemical formulas or molecular formulas of chemical compounds.

The positive electrode active material may e.g. B. be one or more of the following:<ul id="ul0003" list-style="bullet" compact="compact"><li>a layered compound such as a lithium cobalt oxide (LiCoO₂) or</li><li>a lithium nickel oxide (LiNiO₂) or</li><li>a compound in which one or more transition metals are replaced,</li><li>a lithium manganese oxide represented by a chemical formula Li_1+xMn_2xO₄ (with x = 0 to 0.33) or</li><li>a lithium manganese oxide such as LiMnO₃, LiMn₂O₃ or LiMnO₂,</li><li>a lithium copper oxide (Li₂CuO₂),</li><li>a vanadium oxide such as LiV₃O₈, LiFe₃O₄, v₂O₅ or Cu₂V₂O₇,</li><li>a Ni-based lithium nickel oxide, according to a chemical formula LiNi_1-xM_xO₂ (where M = Co, Mn, Al, Cu, Fe, Mg, B or Ga and x = 0.01 to 0.3),</li><li>a lithium-manganese compound oxide represented by a chemical formula LiMn_2xM_xO₂ (where M = Co, Ni, Fe, Cr, Zn or Ta and x = 0.01 to 0.1) or a chemical formula Li₂Mn₃MON₈ (where M = Fe, Co, Ni, Cu or Zn),</li><li>LiMn₂O₄, where Li is partially replaced by alkaline earth metal ions in a chemical formula,</li><li>a disulfide compound or</li><li>feet₂(MoO₄)₃.</li></ul>

Conductive agent is optionally 1 to 30% by weight based on the total weight of the compound including the positive electrode active material, depending on the addition. In particular, the conductive means should have high conductivity. The conductive agent is selected so that it does not induce a chemical change in a battery to which the conductive agent is applied. It is suitable for example<ul id="ul0004" list-style="bullet" compact="compact"><li>graphite such as natural graphite or artificial graphite,</li><li>Carbon black or industrial carbon black, also known as "carbon black",</li><li>Cracked soot, such as B. acetylene black, Ketjen black, channel black, especially channel black,</li><li>Furnace soot, such as B. Furnace Black,</li><li>lamp black, such as B. Lamp Black or Buzzer Black,</li><li>carbon black,</li><li>conductive fiber(s) such as carbon fiber(s) or metal fiber(s);</li><li>metallic powder such as carbon fluoride powder, aluminum powder or nickel powder;</li><li>conductive whiskers, such as zinc oxide or potassium titanate,</li><li>conductive metal oxide such as titanium oxide.</li></ul>

Conductive materials such as polyphenylene derivatives can be used as the conductive agent.

The binder is a component that forms or supports the bond between the active material and the conductive agent and the attachment to the current collector. The binder is generally added in an amount of 1 to 30% by weight based on the total weight of the composition including the positive electrode active material. Examples of the binder are:<ul id="ul0005" list-style="bullet" compact="compact"><li>polyvinylidene fluoride,</li><li>polyvinyl alcohol,</li><li>carboxymethyl cellulose (CMC),</li><li>Strength,</li><li>hydroxypropyl cellulose,</li><li>regenerated cellulose,</li><li>polyvinylpyrrolidone,</li><li>tetrafluoroethylene,</li><li>polyethylene,</li><li>polypropylene,</li><li>ethylene propylene diene terpolymer (EPDM),</li><li>sulfonated EPDM,</li><li>styrene butadiene rubber,</li><li>fluororubber and</li><li>various copolymers.</li></ul>

The filler is an optional component used to restrain the positive electrode from expanding. There is no particular limitation on the filler as long as it causes no chemical changes in a battery to which the filler is applied and comprises or is made of at least a fibrous material. Examples of the filler are olefin polymers such as polyethylene and polypropylene, as fibrous material or fibrous materials such. B. glass fiber or carbon fiber into consideration.

The negative electrode can be manufactured by applying and drying a negative electrode active material on a negative electrode current collector. The components described above may optionally be selectively added to the negative electrode active material to further improve the properties thereof.

As the active material of the negative electrode, for example, carbon can be used, such as. B. non-graphitizing carbon or a graphite-based carbon, a metal compound oxide is usable, such as Li_xfeet₂O₃ (0 ≦ x ≦ 1), Li_xWHERE₂ (0 ≦ x ≦ 1), Sn_xme_1-xme_yO_e.g (The components can be specified, for example, with a selection from the following: Me as Mn, Fe, Pb, Ge; Me' as Al, B, P, Si, Group 1, 2 and 3 elements of the periodic table, halogen; 0≦x≦1;1≦y≦3;1≦z≦8), lithium metal, lithium alloys, silicon-based alloys, tin-based alloys, metal oxides such as SnO, SnO are also suitable₂, PbO, PbO₂, pb₂O₃, pb₃O₄, Sb₂O₃, Sb₂O₄, Sb₂O₅, GeO, GeO₂, bi₂O₃, bi₂O₄ or bi₂O₅, conductive polymer such as polyacetylene, or a Li-Co-Ni based material.

This means that suitable materials can be combined with one another for the desired fields of application in order to make the electrodes particularly efficient.

The separator is interposed between the positive electrode and the negative electrode. As the separator, for example, an insulating thin film with high ion permeability can be used. Preferably, the thin film has high mechanical strength. In preferred embodiments, the separator can optionally have a pore diameter of 0.01 μm to 10 μm. A thickness of the separator between 5 μm and 300 μm is particularly advantageous. An olefin polymer, for example, can be used as the material for the separator. The material may be provided as a sheet or as a nonwoven. Polypropylene, which has chemical resistance and hydrophobicity, is particularly advantageous. Glass fiber(s) or polyethylene offer favorable properties for the separator. In embodiments where a solid electrolyte, such as a polymer, is used as the electrolyte, the solid electrolyte can also function as a separator.

The non-aqueous lithium salt electrolytic solution comprises a polar organic electrolytic solution and at least one salt of lithium. As the electrolytic solution, a nonaqueous liquid electrolytic solution, an organic solid electrolyte, or an inorganic solid electrolyte can be used. The electrolyte can contain chemically different components.

As examples of the non-aqueous liquid electrolytic solution, non-protic organic solvents such as N-methyl-2-pyrrolidinone, propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, gamma-butyrolactone, 1,2-dimethoxyethane, tetrahydroxy franc, 2-methyltetrahydrofuran, dimethyl sulfoxide, 1,3-dioxolane, formamide, dimethylformamide, dioxolane, acetonitrile, nitromethane, methyl formate, methyl acetate, phosphoric acid triester, trimethoxymethane, dioxolane derivatives, Sulfolane, methylsulfolane, 1,3-dimethyl-2-imidazolidinone, propylene carbonate derivatives, tetrahydrofuran derivatives, ether, methyl propionate and ethyl propionate can be mentioned.

Polyethylene derivatives, polyethylene oxide derivatives, polypropylene oxide derivatives, phosphoric acid ester polymers, polyreaction lysine, polyester sulfide, polyvinyl alcohols, polyvinylidene fluoride and polymers with ionic dissociation groups can be mentioned as examples of suitable organic solid electrolytes.

Examples of suitable inorganic solid electrolytes are nitrides, halides or sulfates of lithium (Li) with common chemical abbreviations for their composition such as Li₃N, LiI, Li₅NO₂, Li₃N-LiI-LiOH, LiSiO₄, LiSiO₄-LiI-LiOH, Li₂SiS₃, Li₄SiO₄, Li₄SiO₄-LiI-LiOH and Li₃PO₄-Li₂S-SiS₂ to be named.

The lithium salt is a material that is easily soluble in the non-aqueous electrolytes mentioned above. For example, the lithium salt may comprise one or more of the following: LiCl, LiBr, LiI, LiClO₄, LiBF₄, LiB₁₀class₁₀, LiPF₆, LiCF₃SO₃, LiCF₃CO₂, LiAsF₆, LiSbF₆, LiAlCl₄, CH₃SO₃Li, CF₃SO₃Li, (CF₃SO₂)₂NLi, chloroborane lithium, lower aliphatic carboxylic acid lithium, lithium tetraphenylborate and imido compounds.

With a selection from the materials mentioned for electrolytes, the electrolyte can be adjusted particularly well to the selected electrode material. As a result, good operating properties, such as favorable charging/discharging characteristics for rechargeable batteries or electrical energy storage cells, can be set.

In addition, to further improve the charging and discharging properties and as a flame retardant, for example, pyridine, triethyl phosphite, triethanolamine, cyclic ether, ethylenediamine, n-glyme, hexaphosphoric triamide, nitrobenzene derivatives, sulphur, quinoneimine dyes, N-substituted oxazolidinone, N,N-substituted imidazolidine, ethylene glycol dialkyl ether, ammonium salts, pyrrole, 2-methoxyethanol, Aluminum trichloride or the like can be added to the non-aqueous electrolytic solution. The non-aqueous electrolytic solution may additionally contain halogen-containing solvents such as carbon tetrachloride and ethylene trifluoride for the flame retardant property. Furthermore, in order to further improve the high-temperature resistance, the nonaqueous electrolytic solution may additionally contain carbon dioxide gas.

The electrochemical secondary cells of the traction accumulator, which are lithium-ion cells, are advantageously realized as prismatic secondary cells that are stacked with one another, or—in an alternative embodiment—as round cells. In the case of prismatic cells, not only are the cells stacked one below the other, but in the secondary cells—according to an advantageous embodiment—a first electrode, an active area of ​​the electrolyte and a second electrode are planar and parallel to one another over the entire surface arranged. A longitudinal section can be carried out through a secondary cell, regardless of whether it is a round cell or a prismatic cell. If the cell is (imaginatively) cut, a basic shape that is rectangular but elongated comes to the fore. A single secondary cell appears rod-shaped, almost like flat steel.

The individual sides of the basic form can be designated by long side, high side and width. The three sides long side, high side and width characterize the shape of the individual cells. The long side is the longest side on the secondary cell case. The high side is at right angles to the long side. The high side also has a length, which can also be referred to as height. The basic form has two long sides and two high sides. In the case of prismatic cells in particular, the long side is several times longer than the high side. Due to the stacked arrangement of the individual components of the secondary cell, the secondary cell can have the smallest extent in the direction of its width. Advantageously, the longest side that can be observed on the base is at least three times as long as the top of the base. If an active area, which is delimited by long side and high side, in depth, ie in width, continued, results in a first conversion volume of a single cell. The active area can also be referred to as an active area or as an active element. The conversion volumes of the single cell are placed next to each other, parallel to each other. If the conversion volumes are put together, a total module volume of the traction accumulator results. The individual conversion volumes can be separated by housing or a wall of a housing to the individual cells or cell stacks, the cell housings.

Several individual cells can also be connected in series to provide a higher voltage.

Several individual cells can be combined to form a module or an accumulator (sub-)package. These secondary cells can be combined in one housing.

Both an individual cell and a group of individual cells can be placed or combined in one housing. In the same way, several cells, in particular cells combined in housings, such as cell packs, can also be combined in a module housing. A first type of housing would be the cell housing. A second type of housing would be the module housing. Several cell housings can be integrated in a module housing.

If there are several cell housings, the individual conversion volumes can be found inside the cell housing.

The thickness of the individual side walls, parts and webs of the housing cannot only be designed for the mechanical, static and dynamic requirements. The thickness can be matched to the cooling function. The thickness of the side of the housing that is intended to store and/or dissipate heat is designed so that the heat can be conducted from the active surfaces of the individual cells into the part of the housing. It is advantageous if the thickest side is the one that also serves as a cooling surface. If the cooling surface is equated with the support surface or support plate, in other words, if the cooling surface is also the support surface, then the thickness can be optimized both with regard to mechanical stability and with regard to sufficient cooling capacity. The requirement, whether for cooling performance or for stability, which requires the greater thickness, determines the overall thickness of the page.

The secondary cells can be supported by a carrier plate. The base plate of the accumulator housing can be used as a carrier plate. The module housing has a plate that can also be used as a support plate. Likewise, the cell housing may also have a plate that is used for support.

The carrier plate can also be a cooling plate. The traction accumulator has a thermal exchange surface, which is offered by the carrier plate.

If at least one of the housings is made by an extrusion process, it is particularly advantageous, especially from a production point of view, if an extruded profile is chosen to create the housing, which offers four sides around a cavity and, thanks to its four sides, already two sides of the one to be enclosed body, e.g. B. the secondary cells (in the case of the cell housing) or the cell housing (in the case of the module housing), determine. The housing can B. be matched to the long side and the high side of a secondary cell. The housing can B. be matched to the long side and the high side of a single cell housing, which resemble in particular the long sides and high sides of the secondary cells.

The part of the housing that is formed by the extruded profile can be designed as a one-piece housing that is hollow in its central part. The housing sides, which form a closed shell in turn, are designed to be continuous. These parts of the housing are in one piece. At least four sides of the housing are made at once by one and the same extrusion process.

Advantageously, the thicknesses of the individual sides of the extruded profile are designed in such a way that the mass of a single side of the extruded profile can take on another function, e.g. B. heat, store and possibly dissipate or z. B. can stabilize the individual cells.

Advantageous refinements and developments are set out below, which, viewed individually, both individually and in combination, can also reveal inventive aspects.

For electrical conduction, at least two pole lugs are placed in the area of ​​the high sides directly on the active surfaces or on the active elements of the cell. A suitable method of making an electrical connection is by a welding process. Such an arrangement contributes to better uniform thermal distribution.

Advantageously, only a first cover plate and a second cover plate, which close the cavity for accommodating the cells, possibly in cell housings, need to be added to a housing enclosure in which a significant part of the housing is made from a hollow body extruded profile. In such a cover plate, which can also be referred to as a plate in a shortened manner, further elements and functions can be incorporated, e.g. B. a burst weakening or an indicator element.

By forming the housing using an extruded profile and, if necessary, additional plates, a battery pack can be produced in just a few production steps. If the extruded profile is produced, it can be produced as a so-called endless profile, which is initially present in one piece, coherently, in the form of a hollow rail. A piece can be cut to length from this elongated hollow rail, e.g. B. be sawn, which corresponds to a dimension of the housing to be created, z. B. the width of the cell housing or the module housing.

It must be emphasized that each individual secondary cell has its own housing. In this case, several secondary cells can be combined in their own (common) housing. The secondary cell or the individual cell is part of a group of individual cells that are bordered together. The secondary cells are encased in their own casing. The housing seals against the single or multiple secondary cells. The secondary cells are in direct contact with the inside of the housing. Although the housings take up the installation space of the module volume and thus (superficially) reduce the active volume, the housings create numerous advantages: mechanical stability, plane parallelism, favorable thermals, etc.. As a result, it means that the housings can increase the use of the module volume. In a first embodiment, the cooling part of the case may be provided below the secondary cells and the supporting, reinforcing part of the case may be provided above the secondary cells. In another embodiment, the deepest part of the housing can provide both the "cooling" function and the "mechanical stability" function. The part of the housing that is located at the top can be referred to as the spanning part of the housing.

An electric current can be discharged in the central area, ie in each case in the area of ​​the high sides transversely to the reaction area of ​​the active areas, via the pole lugs and via electrical lines arranged below. The electrical lines are arranged transversely to the active surface.

The space in the module volume immediately adjacent to the pole lugs, of which one pole lug is a positive pole and one pole lug is a negative pole, can each be used for a cooling channel (feed cooling channel and discharge cooling channel). The heat-producing active surfaces are cooled in their lateral areas using cooling channels.

At least two pole lugs are arranged laterally on the respective active areas. The two pole lugs are each located on a high side. The two pole lugs are on opposite high sides of the active area. Fastening via spot welds is a suitable fastening technique.

The housing can be designed to be very space-saving. The housings can be designed so tightly that the housings only expand the active area outwards by approx. 2% in one section. The active area has a height. 2% of this length of height corresponds to the thickness of the case.

In order to keep the temperature distributed as evenly as possible over the active surfaces, e.g. e.g. despite fast charging using a very high charging current (e.g. 3 to 4 times the maximum load current), cooling measures can be taken. The shape of the traction accumulators or the individual cells offers the possibility of inserting cooling plates between two individual cells. If sufficient cooling is required, a cooling plate can be used after each individual cell. Such cooling plates can be implemented as sandwich cooling plates. The sandwich function of the cooling plate results from an internal cooling channel design. Sandwich cooling plates can e.g. B. be formed from a double-walled sheet metal. Another option is to take two plastic half-shells that are glued or welded. This creates a cavity between the layers of the cooling plate, through which the cooling medium can flow. Liquid cooling media, such as e.g. B. a glycol-water mixture or a refrigerant. The cooling capacity can be further increased if the liquid cooling medium is circulated, e.g. B. via a liquid pump for the glycol mixture. The cooling plate can advantageously remove thermal energy both from a secondary cell arranged on a first side of the cooling plate and from a secondary cell arranged on another side of the cooling plate. The cold plate is conveniently designed to transport heat from different cell housings.

The heat dissipation or the heat output of the sandwich cooling plate can be increased if more than two cooling channels are arranged in the sandwich cooling plate. The cooling channels are advantageously arranged in a central area of ​​the sandwich cooling plate. The sandwich cooling plate has two or more cooling channels running longitudinally, especially in a middle area, seen over the high side of the cooling plate. In this embodiment, the cooling channels extend parallel to the long side, which is known from the shape of the basic form.

It has been shown that it is advantageous if between ten (10) and forty (40) secondary cells are combined with their respective active surfaces in order to form a battery pack in a module housing or in a cell housing. The number of cells, such as B. 20 cells is clamped by the housing such as the cell housing or the module housing. Compression takes place on the individual cells.

A housing is designed to be as space-efficient as possible. Faces of cells and housings may touch when cells are tightly packed. A cell or a cell stack and a housing preferably rest against one another. There can be a multi-sided surface contact. The surface contact is maintained when operating a traction accumulator. A possible swelling of cells, e.g. B. by thermal expansion is thus largely prevented.

The cells are equipped with at least two pole lugs. Pole lugs are electrically conductive connections that are used, among other things, to conduct electricity into or out of a cell. The elasticity of the pole lugs reduces possible mechanical loads on the cells.

The respective secondary cells of a string are connected to one another in series. At least one string with secondary cells connected in series is located in a module housing.

The support plate can be that part of the module housing or the cell housing that is intended to be installed at the lowest point in the vehicle.

The module housing, just like the cell housing, can be realized with individual tension elements so that the secondary cells arranged inside the module housing or inside the cell housing are compressed by the module housing or the cell housing. Also by the double wall, ie the wall of the module housing and the wall of an individual cell, an overall compression can be produced using the modulus of elasticity of the material of the housing and the modulus of elasticity of the material of the module housing. The swelling or expansion in the course of charge/discharge cycles or the expansion in the course of aging or the expansion in the course of the storage of water, which is generated by all the stacked secondary cells as a whole, can be caused by tension systems or Tie rods and / or by e-modules of enclosures such. B. housing walls are intercepted.

In a particularly advantageous development, especially in the event that high energy losses, z. B. in fast charging, are to be brought out of the active volume, the support plate can be equipped with cooling structures. A possible cooling structure is created by lines for a coolant incorporated into the plate. Lines through which a coolant such as water with or without additives such as (poly)glycol can flow run longitudinally in the carrier plate. The backing plate is hollow in some places. A coolant flows through the hollow areas. The coolant can then be cooled down again by a heat exchanger after it has flowed through the carrier plate. As its name suggests, the carrier plate can also serve as a mechanical support structure for the pack of individual cells. The carrier plate takes on several functions. It keeps the individual cells in position. It also supports the overall structure of the module with a reinforcement underneath, i.e. the underside. The backing plate provides stiffening of the traction accumulator in the twisting chassis of a motor vehicle. The carrier plate promotes the cooling of the traction accumulator. Depending on the design, one or the other aspect or one or the other function can predominate or come to the fore.

In a favorable development, the housing is profiled on its outer surfaces. Such profiles on one side are z. B. fins such as cooling fins or mountain and valley arrangements.

The proposed form of a traction accumulator is characterized by high active volumes. The traction accumulator presented also offers a favorable energy density-per-weight ratio. In addition to efficient utilization of installation space, the proposed traction accumulator has a favorable temperature profile over a cross-sectional area during charging and discharging processes. The heat development associated with high electrical currents can thus be reliably managed. This aspect also leads to an increase in the service life of the traction accumulators. It is also possible, if necessary, waste heat z. B. via a vehicle heat exchanger for secondary use and thus to further increase the energy efficiency of the electric drive.

It may be emphasized that in a particularly advantageous embodiment the housing of the one or more secondary cells is in contact with the secondary cell(s). That is, the housing can definitely be at the potential of one electrode. The case is not separated from the electrode of the secondary cell. The housing envelops the secondary cell(s) in a touching manner. Cooling takes place via contact heat dissipation.

The section through the secondary cell, which leads to the derivation or visibility of the basic form, covers an area of ​​which at least 80% of the total area can be used as an active area. By optimizing the balance between the long side and the high side, an active area can be created that covers at least 92% of the total area of ​​the basic shape.

In a further aspect, the active volume can also be optimized in the case of the single encapsulated secondary cell design. The active volume is the individual active area of ​​each individual secondary cell of the traction accumulator multiplied by the width of the internal components of the secondary cell. The dimensions of the traction accumulator can be optimized in such a way that at least 60% of the module volume can be used as an active volume. If the relationship between the long side, high side and width is further optimized, module volumes of more than 62%, in some configurations even more than 65%, of the total module volume (ie 60% to more than 65% of the module volume) can be created.

A traction battery, in particular for a motor vehicle such as a passenger car, comprises stacked, prismatic electrochemical secondary cells, in particular with at least one lithium-ion electrode and preferably with a non-aqueous electrolyte. In a section, the secondary cells have a rectangular, elongated basic shape. The basic shape has a length running at least along a long side that is three times as long as the height of the basic shape running along a high side. The basic form continues in width to a conversion volume with active elements layered parallel to each other. The volume is part of a module volume of the traction accumulator. A cut surface resulting from the cut is at least 80% active surface, ideally more than 92% active surface. It is also possible for an active volume resulting from the active area times the width to take up at least 60% of the module volume, ideally even more than 62% of the module volume.

The housings advantageously create a closed surround for a battery pack. Such a housing can be produced by an extruded profile in the configuration that it has at least one of four sides as the thickest side. The thicknesses of the extrusion vary from side to side. The thicknesses are between 0.5 mm and 5 mm. The side that is to take on a cooling function has e.g. B. a thickness of 2 mm, while the other three sides each have a thickness of 1 mm. It is also possible that the cooling side of the extruded profile has a thickness of 4 mm to 5 mm, while the other sides remain at thicknesses below 2 mm.

A middle area of ​​an active surface of a secondary cell can be cooled particularly well via pole lugs. A first pole lug is preferably arranged on a first high side of the secondary cell. A second pole lug can be arranged on a second high side of the secondary cell. There is preferably only a single pole lug on a high side, with each secondary cell in particular being equipped with two pole lugs.

The pole lug is connected to the active surface with as little resistance as possible, preferably with an electrically conductive contact surface. That is, a contact resistance should be less than 0.1 ohms per square centimeter. Good electrical conductivity, in particular of the pole lug, is usually synonymous with good thermal conductivity, as is the case with most metallic materials. The pole lug can have a line cross-section. A pole lug that is arranged in a central area of ​​a high side is particularly advantageous. That is, a first distance between the pole lug and a first long side and a second distance between the pole lug and a second long side of the secondary cell should be approximately the same. In other words, the pole tab provides a heat dissipation path. It is used in particular for temperature stabilization, ie also as protection against overheating, in the inner volume area of ​​the secondary cell. One can also speak of a homogenized temperature distribution, in particular along a high side, especially since heat dissipation via a pole lug is just as effective as heat dissipation via a cell wall, which usually has an electrically insulating layer opposite an active surface. One advantage of a homogenized temperature distribution is, among other things, that thermal expansion of the secondary cell is made more uniform.

According to a further aspect of equalization, a pole lug arranged centrally—relative to a height of the secondary cell—offers the advantage that a constant electric current can be provided through a prismatic cell because the electrochemical processes of the cell take place symmetrically between the pole lugs.

The first line cross-section of the pole lug should be smaller than or equal to a second line cross-section that is present at a connection, such as a stranded wire, of the pole lug to a contact. The contact provides an electrical connection point out of a housing, namely a cell housing or a module housing. The contact aids in heat dissipation across an electrical power distribution network.

Areas of the housing can be designed in the form of conductor plates, although it can preferably be created as an extruded profile or with a component produced by an extrusion process. Individual sides or areas can be formed by deflector plates that promote the dissipation of thermal energy. In a further embodiment, it is also possible to join the extruded profile with a conductor plate to form an overall housing. The collector plate forms one layer of the multi-layer housing.

The box-shaped extruded profile can be closed at its end by plates. These plates are to be used in the extruded profile. For example, the configuration is possible that the panels rest against the ends of the extruded profile from the inside. Burst weakening can be incorporated into such a plate. This works e.g. B. by milling a fracture slot in the face of one of the plates. The part of the housing, which is made as an extruded profile, projects beyond the inserted plate on all four sides. Two such plates are inlaid on opposite sides. The panels look at each other as mirror images. At least one of the plates has a burst weakening, e.g. B. a double Y profile. The housing can bulge outwards at the point of weakened bursting. The bursting area or the bursting weakening results from a perforation or thinning along a cut that fans out at both ends in two directions that differ by 60°. The ends of the cut, thinning, or perforation diverge in a V-shape.

Several secondary cells are combined to form a sub-stack. In a particularly material-saving variant or embodiment, one of the secondary cells rests with an active surface on one of the sides of the extruded profile. This at least one secondary cell determines the electrical potential of the extruded profile. Only the remaining active areas are isolated, e.g. B. layered over inserted foils, opposite the first active surface and opposite the surface of the extruded profile. However, because insulating insert foils contribute only slightly to the increase in weight, an all-round insulated secondary cell that is part of a sub-stack in which all secondary cells are each wrapped in an insulated manner creates an easier-to-handle module. If material is to be saved, the insulation on at least one side between the cell housing and the active volume can be dispensed with. If a safer module is to be created, all secondary cells are individually encased in insulation.

Channels can be incorporated in the housing. It is possible by extrusion with the aid of suitable mandrels to form channels which have an oval flow cross section, with a narrow side of the flow channel cross section preferably being arranged along a thickness of a wall of the housing. Flow channels are also advantageous in order to generate sufficient load-bearing stability with less material compared to a solid wall. Beneficial for passive heat dissipation through a wall, e.g. B. a coolant flow is interrupted, are channels whose long side of the flow channel cross section is aligned along a thickness of the housing wall. A plurality of channels may be juxtaposed and spaced apart by thermally conductive wall material.

Regardless of the cross-section of one of the sides of the extruded profile, the housing has different mean thicknesses. Each side has a medium thickness. The mean thickness is the maximum thickness of the housing on the corresponding side. Deviating from this thickness, the side wall can have points and areas that are even thinner, e.g. B. have channels. For example, a carrier plate of a housing can have a smaller thickness than a side wall, in particular a side wall on which contacts are arranged. The thicknesses of the individual surface areas of the housing can be designed in such a way that the housing provides the same heat capacity in the area of ​​each wall. In a further embodiment, the thickness of a wall can be designed in such a way that the temperature is distributed as evenly as possible over all parts of the housing. According to another aspect, a respective wall thickness is scalable according to a directional amount of heat to be dissipated.

The secondary cells are arranged in the housing such that one extruded side of a four-sided profile is parallel to the active surface of one of the secondary cells. A side adjacent to this extends at a 90° angle to the side parallel to the active surface. The extruded profile acts like a tunnel or collar. Such housings can also be referred to as extruded profile housings. Through an extruded profile, which has a self-contained elongation in a profile cross-section, z. B. unilaterally entered amounts of heat can be distributed extensively within a few minutes. The extruded profile forms a heat sink because there is no connection area between the walls and therefore no heat flow resistance. Secondary cells, which are to be arranged inside the extruded profile, are protected from temperature differences that can affect the housing. The extruded profile can have additional cooling fins. According to another aspect, secondary cells in a housing that has an extruded profile can be heated particularly uniformly by a heating element, in particular by a heating element attached to one side of the housing.

An extruded profile housing can be produced from rod material. The housing, pressed into a selected shape, can be cut to a desired length. This considerably shortens the production time of a production process in comparison with a housing that is screwed together. Extruded profiles for housing can be provided in any length, almost endlessly. The walls each have a constant, predetermined thickness. In particular, the thickness ratios of different walls, z. B. depending on the number of secondary cells to be recorded, precisely adaptable to the area of ​​the required profile cross-section. A first sidewall thickness may e.g. B. be more than one and a half times, in particular more than twice, a second side wall thickness. Two side walls can each have a thickness that differs by less than 50% and in particular more than 5%. With that, among other things an optimization of a required stability at a desired maximum weight possible. The two open ends of the profile are as required or after the introduction of the secondary cells, z. B. in each case by a cover with, preferably exactly, a contact that can be covered. With the help of extruded profiles, housings with tight manufacturing tolerances, i.e. with consistent quality, can be produced.

Secondary cells of a traction accumulator can be combined particularly advantageously in a module housing. A module housing for a traction accumulator includes in particular a housing torso. According to a geometric aspect, a housing torso can also be referred to as a housing shell body. The housing torso has a plurality of sides, preferably at least four sides, each of which can also be referred to as a side wall. A housing torso is a metal body, in particular a one-piece body. If four sides of the housing torso are formed as an extrusion unit, so the housing torso is particularly stable. A housing torso is z. B. as a seamless composite of two opposite pairs of side walls. A side wall can serve as a support plate. A side wall of a housing torso can be the bottom or top of the module housing. The module housing is designed to accommodate at least one secondary cell or at least one secondary cell pack or at least one cell housing in a module housing interior and preferably to hold it on a holder. The holder can be formed by an additional side wall, such as a fifth side wall and/or a sixth side wall. The holder can be used, among other things, to determine a size of the interior, e.g. B. by a clamping device to set or limit. The holder can be in one piece, ie in one piece, and thus part of the housing. There is no need for an additional attachment of a housing attachment. The module housing can include at least one partition, in particular for separating secondary cell packs. The partition wall is preferably a cooling partition wall in which cooling channels are arranged. If there is at least one cooling channel in at least one side wall, heat from the interior of the module housing can be extracted particularly effectively, e.g. B. by a cooling fluid discharge. A cooling channel extends, in particular in a thickest side wall, as far as possible at right angles to the wall thickness of the side wall. Cooling with cooling channels that are supplied with cooling fluid in parallel via a respective cooling connection works particularly reliably if a channel should become blocked.

Additional electronics can be arranged in a module housing. It is particularly advantageous if the module housing includes a contactor in a modular design, so to speak a contactor module. A contactor module downstream of the secondary cells ensures interchangeability of the traction accumulator, among other things. A control board of the contactor module includes at least one logic electronic circuit. A control logic Programming of the contactor module can provide an electronic identification of the traction accumulator or also query an electronic identification of the vehicle for which the traction accumulator is intended, for example by way of a comparison. Operational safety is also improved if the contactor module has a short-circuit fuse, such as at least one safety fuse, so that overheating of the traction battery, in particular due to an electrical short circuit external to the housing or a short-circuit current drawn, can be prevented. A contactor module may include a memory unit and a processor unit. If the module housing is equipped with sensors for secondary cells, in particular individual cells such as temperature sensors or capacitance sensors, operating data determined by sensors, in particular for each individual secondary cell, can be saved as condition monitoring data and read out via the contactor module. A module housing is therefore also advantageous whose contactor module can be connected to vehicle electronics via an electronic diagnostic socket on the module housing.

A secondary cell that is enclosed in a cell housing can be protected particularly well from external influences such as frost. On the other hand, in the event of a cell failure, a secondary cell enclosed or encapsulated in a cell housing can hardly or not at all affect an operational adjacent secondary cell. A cell case or cell case for a traction accumulator comprises a cell case torso. A cell housing torso is a metal body, in particular a one-piece body. Viewed from a geometric point of view, a cell case torso can also be referred to as a cell case shell body. The cell housing torso has a plurality of sides, preferably at least four sides, each of which can also be referred to as a cell housing side wall. A cell housing side wall can be designed as a carrier plate. A side wall of a cell housing torso can be the floor or ceiling of the cell housing. When four sides of the cell case torso are formed as one extrusion unit, the cell case is particularly strong. Extruded case torsos are labor-efficient to manufacture in large quantities with constant dimensions.

The cell housing or cell housing can be equipped to accommodate at least one secondary cell or at least one secondary cell pack, depending on the size of the secondary cells, in a cell housing interior. A cell housing or a group of cell housings can be installed in a module housing. A cell housing, together with the secondary cell(s) enclosed therein, is a replaceable unit. This means that the secondary cells, e.g. B. for replacing a faulty secondary cell in a housing module, particularly safe.

A cell housing has at least two contacts, each of which is available for one pole. The contacts are preferably plug-compatible with one another, so that opposite, unequal poles of two cell housings can be connected to one another. This allows particularly compact series circuits to be created using a cell housing arrangement, e.g. B. to provide a desired operating voltage. In such a contact arrangement, it is particularly advantageous for the lowest possible overall weight if adjacent side walls of cell housings have different thicknesses, because the stability of a thinner side wall is ensured by mutual support on a thicker side wall. Cohesion of two or more cell housings can be increased even further if the cell housings have at least one tongue/groove formation on adjacent side walls that can be plugged into one another. Heat transfer between the cell housings is thus further improved, so that all combined secondary cells can be heated as evenly as possible.

A cell housing is preferably equipped with at least one electronic diagnostic socket, which can also be referred to as a cell diagnostic socket. At least one sensor and/or measuring probe, which is arranged in a cell housing interior on a secondary cell, can be connected to an electronic monitoring unit, such as a contactor module, via a cell diagnostic socket.

At least one cooling channel can extend through at least one side wall of a cell housing. In one embodiment, the cooling channel does not extend into the cell housing interior. The cooling channel is preferably parallel to at least one secondary cell. A cooling channel can be used to flow coolant along a secondary cell. A cell housing cooling duct can be connected to a module housing cooling duct. A cooling channel of a cell housing can be designed like a cooling channel of a module housing. An additional cell housing heater, preferably integrated in a cell housing side wall, can be operated as required via a low-temperature monitor of a contactor module, e.g. B. to protect external secondary cells with low heating current consumption in a cell housing array.

It is particularly advantageous for dissipating heat from an interior of a housing if the housing has a cuboid flat shape. For example, there may be a broadside to highside ratio greater than three to one. Depending on the arrangement of the contacts, particularly in the case of pole lugs on the high sides, a ratio of a broad side to a long side of less than one to three can prove to be advantageous.

The housing of a single cell can be made of a metal. Metals that come into question for this purpose are, for. B. aluminum or stainless steel or brass. The housings can be made of aluminum or stainless steel. Due to the shape of the housing, it is possible to manufacture the metal housing as an extruded profile. Such an extruded profile can be cut to length or width of the active surfaces.

The housing does not have to be kept constant over its circumference, but rather the module housing and/or the cell housing can be designed with different thicknesses. For example, the support plate can be thicker than the cover. In the same way, the housing for the respective secondary cell can be designed with different thicknesses. This saves even more weight.

Character brief description

The present invention can be better understood by reference to the accompanying drawings, in which<ul id="ul0006" list-style="none" compact="compact"><li><figref idref="f0001">figure 1</figref> shows a side view of a single cell in a cell housing with a (visible) contact,</li><li><figref idref="f0002">figure 2</figref> a single cell from a 90° transverse perspective (compared with<figref idref="f0001">figure 1</figref>) with a cell housing, represented by schematic outlines, shows</li><li><figref idref="f0002">figure 3</figref> a section A - A through the single cell<figref idref="f0001">figure 1</figref> shows,</li><li><figref idref="f0003">figure 4</figref> shows the outer outline of a single cell with its cell housing,</li><li><figref idref="f0004">figure 5</figref> shows a stack of mutually oppositely oriented individual cells to form a module,</li><li><figref idref="f0005">figure 6</figref> shows a first embodiment of a module,</li><li><figref idref="f0006">figure 7</figref> shows a second variant of a module,</li><li><figref idref="f0007">figure 8</figref> the module off<figref idref="f0006">figure 7</figref> shows from a perspective from above,</li><li><figref idref="f0008">figure 9</figref> the module after<figref idref="f0006">figure 7</figref> shows in a partially open view,</li><li><figref idref="f0009">figure 10</figref> shows a further embodiment of a single cell in the module housing,</li><li><figref idref="f0010">figure 11</figref> shows a cooling plate in a module housing,</li><li><figref idref="f0011">figure 12</figref> shows an embodiment of a stack made up of individual cells, such as those in<figref idref="f0009">figure 10</figref> shown, can put together,</li><li><figref idref="f0012">figure 13</figref> shows a housing of a module in a further variant from above,</li><li><figref idref="f0013">figure 14</figref> shows a module housing in a further variant in an isometric representation,</li><li><figref idref="f0014">figure 15</figref> shows a partially opened module, e.g. B. from inside the housing<figref idref="f0012">figure 13</figref> can come from</li><li><figref idref="f0015">figure 16</figref> shows a single cell housing with a "bursting disc" or a bursting gap,</li><li><figref idref="f0016">figure 17</figref> shows a traction accumulator with module housing of a further embodiment with a liquid-cooled carrier plate,</li><li><figref idref="f0017">figure 18</figref> an inner part of the traction accumulator<figref idref="f0016">figure 17</figref> shows,</li><li><figref idref="f0018">figure 19</figref> an excerpt from the illustration<figref idref="f0017">figure 18</figref> shows,</li><li><figref idref="f0019">figure 20</figref> shows a traction accumulator with a module housing of a further embodiment, namely with liquid cooling, and</li><li><figref idref="f0020">figure 21</figref> the traction accumulator<figref idref="f0019">figure 20</figref> with the extruded profile part of the module housing removed.</li></ul>

character description

<figref idref="f0001">figure 1</figref> shows a first embodiment of a single cell 53 with its cell housing 31 to which the first contact 47 is attached. Individual cells such as the individual cell 53 can be stacked on top of each other to form a traction battery such as the traction battery 1^II after<figref idref="f0008">figure 9</figref> form. Each individual cell 53 has a width 11 which is determined by the width of the cell housing 31. The shape of the individual cell 53 and thus the shape of the cell housing 31 is, if from the in<figref idref="f0001">figure 1</figref> illustrated lateral view is looked at the cell housing 31, elongated and upright. If the single cell 53 along the in<figref idref="f0001">figure 1</figref> cut line A - A shown, the result is in<figref idref="f0002">figure 3</figref> illustrated sectional drawing of the cell housing 31. The width 11 is narrower than the length 15 of the high side 9.

<figref idref="f0002">figure 2</figref> shows the cell housing 31 from a front view of the individual cell 53. In this view, the basic shape 5 of the individual cell 53, due to the dimensions of the cell housing 31, can be seen clearly. The basic shape 5 is a beam-like, elongated, rectangular shape. The long side 7 is longer than the high side 9. The contacts 47, 49 sit laterally, on the edge of the cell housing 31. The contacts 47, 49 delimit the high sides 9 at each end of the cell housing 31. This means that the prismatic cell shape of the single cell 53 has two contacts 47, 49, one contact 47, 49 each on its high side 9. The prismatic cell shape of the single cell 53 has two high sides 9. The contacts 47, 49 are placed off-centre the length 15 of the high side 9.

As I said, the cell case 31 is after<figref idref="f0002">figure 2</figref> about the middle of its latitude 11 (cf.<figref idref="f0001">figure 1</figref>) cut (section line AA), a (simplified schematic) view results<figref idref="f0002">figure 3</figref>. The cell housing 31 encloses the active surface 19 in a rectangular manner due to its basic shape 5 . The cell housing 31 represents the boundary and delimits the outer or the outside 51 . The active surface 19 is delimited by the cell housing 31 with respect to the outside 51 . The active surface 19 has a length 13 that is a multiple of the height 15 . The length 13 of the long side 7 is extended to the outside 51 by the contacts 47, 49. The contacts 47, 49 are located on the high sides 9. The housing 31 of the cells has different thicknesses 69, 69^I on.

In<figref idref="f0003">figure 4</figref> the cell housing 31 of the individual cell 53 with its contacts 47, 49 is shown as a narrow, elongated, rectangular box enclosing the active area. A part of the conversion volume 21 is made available by each individual cell 53 . If the active surface 19 (see<figref idref="f0002">figure 3</figref>) in width 11 (cf.<figref idref="f0001">figure 1</figref>) extended, the result is the (total) conversion volume 21. Due to the plane-parallel arrangement of the electrodes and the electrolyte over the entire active surface 19, the inner volume of the cell housing 31 is almost completely filled with the conversion volume 21 of the individual cell 53. As a result, active volumes of at least 60% (based on the total volume of traction accumulator 1 (cf.<figref idref="f0004">figure 5</figref>)) produce. With a ratio of more than 3 between long side 7 and high side 9 (see<figref idref="f0002">Figures 2 and 3</figref>) even active volumes of more than 62%, ideally even more than 65%, can be created.

<figref idref="f0004">figure 5</figref> shows a module housing 33 with the two collector current conductors 55, 57. The collector current conductors 55, 57 of the traction battery 1 are located on the first and on the last individual cell of the individual cells 53, 53^I, 53". The individual cell housings 31, 31^I, 31^II are with their surfaces, formed from long side and high side (cf.<figref idref="f0002">figure 3</figref>), stacked on top of each other to form the traction accumulator 1. The individual cells 53, 53^I, 53^II rest on the carrier plate 45. Downstream of the collector current conductor 57 are the secondary cells 3, 3^I, 3^II, 3^III piled up, one abutting the other, present.

<figref idref="f0005">figure 6</figref> shows a sectional view through a further embodiment of a traction accumulator 1^I. The traction accumulator 1^I can be identified using its mounting rails, such as the mounting rail 59 and the mounting rail 59^I, on a vehicle chassis, e.g. B. in the sub-floor area. The term underfloor area designates the area for a floor assembly of a motor vehicle (not shown). A module housing side wall 61 has the uninterrupted or continuous mounting rail 59 in one piece. The pairs of parallel mounting rails 59, 59^I form a structural reinforcement of the traction accumulator 1 in the manner of T-beams^I, e.g. B. to support bracing elements for individual cells, such as tension elements or pressure elements that are present inside a module housing 33 . According to a further aspect, the mounting rail 59 is designed in the manner of cooling ribs. In the installed state of the module housing 33, heat is dissipated from the module housing 33 to the underbody of a vehicle or the vehicle chassis (not shown). The mounting rail 59, 59^I can also be referred to as a (first) heat dissipation bridge of the module housing 33 . The module housing 33 is composed of plate-like elements. The module housing 33 has a module housing base 63 to which the module housing side wall 61 is connected. The module housing 33 is bounded by the module housing cover 65 at the top. The active surface 19 is laterally closed off by its pole lugs 25, 27. It can also be said that the pole lugs 25 , 27 are assigned to the side of the active surface 19 or that the pole lugs 25 , 27 are present on the side areas of the active surface 19 . The active surface 19 can provide a potential difference between the pole lugs 25, 27. The pole lugs 25, 27 are located in the middle area 17, 17^I the active surface 19. The first pole lug 25 merges into the first contact 47. The second pole lug 27 merges into the second contact 49 . Laterally on the active surfaces 19 of the individual cells 53, 53^I, 53^II (p.<figref idref="f0004">figure 5</figref>) the individual contacts 47, 49 connect. A surface-covering connection of the pole lug 25, 29 to the respectively associated contact 47, 49 forms a current conduction cross-section. In this way, a conduction resistance, in particular for electricity and heat, is kept as low as possible. The mounting rail 59 is located on the module housing side wall 61 in an upper area 62 of the module housing side wall 61. The upper area 62 is located closer to the module housing cover 65 than to the module housing floor 63. The mounting rail 59 can, for. B. be formed as a branch or as a fold of the module housing side wall 61. In another aspect, the mounting rail 59 is located closer to the contacts 47,49 than the exchange surface 71. This allows heat to be better conducted away from the contacts 47,49. In the same dimension as the long side 7' extends, the exchange surface 71 extends in its longest extent. The exchange surface 71 and the module housing floor 63 are in the traction accumulator 1^I identical. The high side 9^I stands vertically on the long side 7^I. The arrangement perpendicular to one another relates to an installed state. As an alternative, one can also speak of a right-angled position to one another, as a result of which a particularly space-saving pack is made possible.

In the module housing 33 there are convection channels 77, 77^I, in which the flow of a coolant, such as air, is promoted by heating. Convection channels 77, 77^I support a dissipation of heat, in particular from the contacts 47, 49. A first convection channel 77 is arranged between an inner side 73 of the first module housing side wall 61 and the active surface 19. A second convection channel 77' is in front of an inner side 73^I a second module housing side wall 61^I present. Equilateral heat dissipation creates a temperature gradient at or between the central areas 17, 17^I at least mitigated or flattened. Temperature peaks that are unfavorable for an operating state are avoided.

Spacers 93.93^I, which are located between the active surface 19 and the module housing side walls 61, 61^I are arranged, enable uniform positioning of individual cells in the module housing 33. In addition, spacers 93, 93^I as second heat conduction bridges 93, 93^I be formed and in particular have a high thermal conductivity coefficient. This enables heat to be dissipated, in particular from the central areas 17, 17^I the active surface 19 of a respective individual cell 53 (cf.<figref idref="f0004">figure 5</figref>), further improved. In further advantageous embodiments, spacers can be designed as electrical or also thermal contacts. It is also possible to design one or more spacers each as a flow baffle, in particular as part of a channel, such as a convection channel 77, 77' or a cooling channel, or as part of a cooling channel chamber.

If additional cooling by a convection channel 77, 77' is not required, in a further embodiment a space or chamber provided for the convection channel 77, 77' in the module housing 33 can be filled with a swelling polymer foam. If a filler such as polymer foam is placed between the module housing side walls 61, 61^I and the active surface 19 is present, amplitudes of low-frequency vibrations in the acoustic (frequency) range, in particular below a few kHz (e.g. 5 kHz), are well damped. A possible mechanical load on the active surface 19 due to vehicle vibrations in special driving situations is further reduced.

In<figref idref="f0006">figure 7</figref> is a traction accumulator 1^II seen in 3D. Just like the traction accumulator 1^I (after<figref idref="f0005">figure 6</figref>) is limited at the top by the module housing cover 65, the traction accumulator 1^II from module housing side wall 61^I, module housing floor 63^I, module housing cover 65^I and module housing rear wall 67, 67' assembled. The mounting rail 59 runs along the outside edge^II. On the opposite side to the side with the first mounting rail 59^II is the second mounting rail 59^III arranged. On a top of the traction accumulator 1^II , ie in the area of ​​the module housing cover 65^I, there are convection outflow openings 79, 79^I, such as a first convection exhaust port 79 and a second convection exhaust port 79^I. The housing from module housing side wall 61^l, module housing floor 63^I and module housing cover 65^I is profiled to offer recesses, indentations and openings. Convection inflow openings, such as a first convection inflow opening 75, are located as passages or inlets for air in the module housing floor 63^I. In the embodiment of<figref idref="f0006">figure 7</figref> is a convection inflow opening 75 in the middle between two convection outflow openings 79, 79^I in an area of ​​the module housing base 63^I arranged. The flow through the traction accumulator 1^II with coolant, such as air, thus takes place bidirectionally through a branched convection channel inside the traction accumulator 1^II (therefore in<figref idref="f0006">figure 7</figref> not visible) each in opposite directions. As a result, heat is dissipated particularly efficiently.

Contact points 81, 81^I for an external connection, as in<figref idref="f0006">figure 7</figref> shown, each in a recess of the module housing cover 65^I accessible for a current draw. The contact points 81, 81^I are each covered by an adjustable cover 83, 83^I, in the<figref idref="f0006">figure 7</figref> is shown for a better overview in a partially open state, protected against accidental or unintentional contact. Attachment of the traction accumulator 1^II finds over mounting rails 59^II, 59^III instead, which have a tube-like appearance. In other words, the mounting rails are like little square plates. The mounting rails 59^ll, 59^III are in a repetitive manner on the side like the page 61^I appropriate. The first mounting rail 59^II and the second mounting rail 59^III enable precise feeding of the external contact points 81, 81^I to the electrical connection points on a vehicle (not shown). An opposing arrangement of the first contact point 81 and the second contact point 81^I on the traction accumulator 1^II, especially in the area of ​​the module housing rear wall 67, 67^I, facilitates installation in the vehicle. The mounting rails 59^ll, 59^III form an opposite pole to the contact points 81, 81 with the same polarity^I. In other words, there is an electrical connection via the module housing.

As in<figref idref="f0007">figure 8</figref> seen by the top view, the (from<figref idref="f0006">figure 7</figref> known) individual parts of the module housing side wall 61^l, module housing floor 63^I, module housing cover 65^I and module housing rear wall 67, 67' a module volume 23. The module volume 23 comprises an (almost) cuboid, rectangular, elongated, longer than wider, wider than higher space, which is defined by the basic shape 5 (see<figref idref="f0002">figure 3</figref>) is determined. Between the two module housing rear walls 67, 67' of the traction accumulator 1^II are the convection outflow openings 79, 79^I placed, to which the convection channel 77' transfers the heat from the interior of the traction accumulator 1^II unsubscribes

In<figref idref="f0008">figure 9</figref> becomes the traction accumulator 1^II after<figref idref="f0006">figure 7</figref> shown in a half-open variant, whereby the arrangement of the individual cells 53, 53^l, 53^ll you can see. The single cells 53,53^I, 53^II each have, among other things, a module housing cover connection surface 85, 85^I, 85^II on, which are each flat or planar. A heat conduction connection of the lid connection surfaces 85, 85^l, 85^ll with the module housing cover 65^I (please refer<figref idref="f0007">figure 8</figref>) is trainable. Particularly favorable for dissipating thermal output from the individual cells 53, 53^I, 53^ll it is when between the module housing cover 65^I and the module housing cover connection surfaces 85, 85^l, 85^ll nor a leveling compound (not shown), such as a thermally conductive adhesive or a graphite paste, is present, which has a high thermal conductivity coefficient, z. B. in the size of the thermal conductivity coefficient of a metallic conductor, preferably of more than 1 W / (m * K) (one watt per meter Kelvin). A thickness of the balancing mass is preferably less than 1 mm. The balancing mass can, for. B. on the module housing cover 65^I (please refer<figref idref="f0007">figure 8</figref>) or the module housing base 63^I (please refer<figref idref="f0008">figure 9</figref>) can be sprayed on, poured out, rolled on or glued on. With the help of a contact pressure, a distance between the module housing cover 65^I and the module housing cover connection surfaces 85, 85^l, 85^ll collapsible. In other words, the module housing base is also 63^I in a corresponding manner with the individual cells 53.53^l, 53^ll thermally conductive connectable. The module housing cover 65^I (please refer<figref idref="f0007">figure 8</figref>) and the module housing base 63^I can have a sheet thickness of 1 mm to 3 mm, preferably 2 mm. The respective metal sheets or plates protrude beyond the individual cells, such as the individual cells 53,53^l, 53^II, sideways. This ensures a flat, full-surface connection and, in particular, good heat dissipation from the individual cells 53, 53^I, 53^II allows. The balancing mass can also be referred to as a heat conduction bridge. In this way, all individual cells of the traction accumulator 1^II, like the individual cells 53, 53′, 53″, cool particularly well passively. Thus, as cooling variants, floor cooling, cover cooling and a combination of both—depending on the performance requirement—can be designed. The individual cells 53,53^l, 53^ll are layered next to each other along the module housing side wall 61^l, one next to the other on the module housing floor 63^I arranged. The existing individual cells, such as the individual cells 53, 53^l, 53^ll, form (essentially) the module volume 23.

So that the individual cells 53, 53^l, 53^ll The individual cells 53, 53^I, 53^II have been joined together under mechanical stress. The mechanical tension should not decrease after joining. Due to the nature of lithium-ion cells that increase in thickness over the course of their operating time, the increase in volume can even be used positively to maintain the contact surfaces. One way of making good electrical contact is to prestress the individual parts of the housing, such as the side wall 61^I or the module housing floor 63^I to weld together. The parts forming a frame, e.g. B. the side wall 61^I and the rear panel of the module housing 67^I, can be clamped in a mold and then welded together. The frame is slightly (1% to 2% less than a regular total length of the stacked single cells 53,53^l, 53^II) smaller than for the stacked single cells 53,53^l, 53^ll would be required if they were not introduced into the module volume 23 under tension.

This in<figref idref="f0008">figure 9</figref> shown, partially opened module of the traction accumulator 1^II is without module housing cover 65^I shown (cf.<figref idref="f0007">figure 8</figref>). The side parts, such as the module housing rear wall 67' and the module housing side wall 61^I, are made in one piece to form a circumferential sleeve by extrusion from a metal. Only module housing cover 65^I and module housing floor 63^I are separately removable and represent further parts of the module housing 33^I represent.

In the<figref idref="f0009 f0010 f0011 f0012 f0013 f0014">Figures 10 to 15</figref> becomes a variant of a traction accumulator 101, 101^I, 101^II shown, which is based on a rectangular basic shape 105 next to the active surfaces 119 in the module housing 133, 133^I, 133^II Has cooling channels 135, 137.

As in<figref idref="f0009">figure 10</figref> can be seen, the individual cell 153 is enclosed by the module housing 133 . A cooling channel 135 , 137 is arranged in the module housing 133 on both sides of the active surface 119 , which has a rectangular basic shape 105 . A first cooling channel 135 includes a cooling channel wall 138 fitted into a cooling channel chamber 191 of the module housing 133 . The first cooling duct 135 is located next to a mounting rail 159 and is thus largely protected against possible twisting of the module housing 133 . Further cooling channels branch off from the first cooling channel 135, such as the cooling channel 141 (see FIG<figref idref="f0010">figure 11</figref>), which is oriented transversely to the cooling channel 135 in a cooling plate 139 (see<figref idref="f0010">figure 11</figref>) extend. Like the first cooling channel 135, a second cooling channel 137 is in a second cooling channel chamber 191^I, which is in the area of ​​a second mounting rail 159^I located, arranged. The cooling channel wall 138^I goes into a cooling plate 139 (see<figref idref="f0010">figure 11</figref>) over. Positioning of the active surface 119 in the module housing 133 is possible, among other things, by means of spacers 193, 193^I fixed laterally. Each spacer 193, 193^l is located between a cooling channel chamber 191, 191^I and a convection channel 177, 177^I. A first convection channel 177 is associated with a first pole lug 125 . A second pole lug 127 protrudes into a second convection channel 177^I in. Each convection channel 177, 177^I provides installation space for contacts, such as a first contact 147 or a second contact 149, which may also be referred to as electrical jumpers. The spacers 193, 193^I can be designed in exemplary embodiments, among other things, as components of a tension element or as guides for tension elements. A tension element serves to enclose a plurality of individual cells, such as the individual cell 153, and in particular to press them together to form a compact unit. An even connection of the active surface 119 to the module housing base 163 results in a first dissipation branch for heat output. The cooling channels 135, 137 form a second dissipation branch for heat output, the cooling output of which can be switched on, in particular as required, in connection with a closed cooling circuit. In advantageous embodiments, another heat dissipation branch z. B. also be formed by at least one heat conduction bridge. To monitor a temperature at a specific point on the active area 119 (e.g. at the edge area, adjacent to the cooling channels 135, 137), a temperature sensor 198, 198 is used^I. The temperature sensors 198, 198^I, the z. B. are designed as analog sensors such as a resistor or a bimetallic contact, are each in the module housing 133, in particular in the cooling channel chambers 191, 1⁹₁^I, arranged. The cooling ducts 135, 137 are supplied with coolant as needed by a temperature sensor-controlled pump of a cooling or heat exchanger system (not shown).

In order to enable charging controls such as load balancing, cell voltage monitoring can also be carried out in the module housing 133<figref idref="f0009">figure 10</figref> be installed. A cell voltage monitor can record the voltages of each individual cell, but also the voltage of a group of cells and, if necessary, monitor a critical or a functional working area. If the nominal voltage of a single cell is e.g. B. 3.7 volts, a functional range can be located above 3.7 volts. If the individual cell voltage drops below 3.7 volts, a critical voltage can be assumed. If several cells are combined into a group, a sub-stack, in order to be monitored together, the individual voltage must be multiplied by the number of cells connected together. I.e., e.g. B. with three cells, the nominal voltage is 11.1 volts. The group cell voltage monitor would thus monitor for a limit of 11.1 volts.

In<figref idref="f0010">figure 11</figref> a sandwich cooling plate 139 is shown (open in the middle, ie only one sheet or only one side) which can also be arranged in the module housing 133 . The partially parallel cooling channels 141, 141^I, 141^II, 141^III carry the cooling medium 143. The cooling plate 139 also has an elongated, almost identical basic shape 105 in comparison with the basic shape 105 of the individual cell 153 (see<figref idref="f0009">figure 10</figref>). The single cell 153 is placed in the housing of the cell 131 (see<figref idref="f0011">figure 12</figref>) clamped. As proceeding by height comparison between<figref idref="f0010">figure 11</figref> and<figref idref="f0009">figure 10</figref> As can be seen, a first height 140 of the sandwich panel 139 may preferably be slightly, e.g. B. by a value between 1 mm and 10 mm, deviate from a length of a high side 115 of the single cell 153. Advantageously, at least one sandwich panel foot 142 is present, which at certain points has a spacer that is similar, particularly in terms of its dimensions, to the spacer 193 (cf.<figref idref="f0009">10</figref>), between the sandwich cooling plate 139 and a module housing 133. A loss of cooling power to the module housing 133 is thus kept as low as possible. A possible formation of condensed water on the module housing 133 can be suppressed. In different embodiments, the sandwich plate 139 can be made of a metal, such as stainless steel or copper, or of a plastic with a suitably high thermal conductivity. A thickness of the sandwich cooling plate 139 in a normal direction standing on the largest surface of the plate or the basic form 105 for the module housing 133 is approximately 1.3 mm. In several test series for cooling a traction battery 101, 101^I, 101^II thicknesses between 0.5 mm and 5 mm have proven to be particularly practical. A circumferential sealing lip 195 of the sandwich cooling plate 139 in an edge area of ​​the basic shape 105 encloses all parallel cooling channels 141, 141^I, 141^II, 141^III and in particular the first cooling channel 135 and the second cooling channel 137 at least in a cross-sectional area. If the surface pressure is sufficient, the sealing lip 195 can also be omitted. The first cooling channel 135 and the second cooling channel 137 and respective end regions of the sandwich panel 139 are connected. The sandwich panel 139 has a lower second height 140 in the end regions^I on than the first level 140. The sealing lip can be used as z. B. be formed by a particularly swellable under the action of coolant sealing cord or a sealing rubber ring. A connection of the sandwich cooling plate 139 to an individual cell, such as the individual cell 153 according to FIG.<figref idref="f0009">figure 10</figref>, or their housing can be formed. With a uniform surface compression over an individual cell connection surface 187 of the sandwich cooling plate 139 of an alternating stack arrangement of sandwich cooling plates, such as the sandwich cooling plate 139, and individual cells, such as the individual cell 153, by tension elements, sufficient tightness can already be achieved - even without a sealing lip 195 - be achieved. The sealing lip 195 serves, among other things, to compensate for production-related surface roughness.

When the individual cells 153 and the cooling plates 139 are assembled, the cooling channel 135 must be sealed. The cooling channel 135 is a continuously tight cooling channel 135. Adhesive bonding and (plastic) welding come into consideration as possibilities for sealing. in the in<figref idref="f0010">figure 11</figref> shown embodiment, the individual pieces of the cooling channel 135 are glued. Alternatively, of course, the use of elastomer seal(s) such as e.g. B. O-rings into consideration.

In<figref idref="f0010">figure 11</figref> is also shown that the first cooling channel 135 and the second cooling channel 137, preferably also the parallel cooling channels 141, 141^I, 141^II, 141^III, have a height or depth that corresponds to at least part of the thickness of the sandwich cooling plate 139 . The cooling ducts 135, 137, both of which can also be referred to as supply cooling ducts, are used to supply or discharge coolant 143 to or from the cooling ducts 141, 141^l, 141^II, 141^III. The cooling channels 141, 141^I, 141^II, 141^III can also be referred to as plate cooling ducts, which in particular open into the supply cooling ducts 135, 137. The cooling channels 141, 141^I, 141^II, 141^III are present in the sandwich cooling plate 139 as fanned out flow connection(s). A flow occurs, for example, through the basic form 105 in a direction from a first side wall 161 to a second side wall 161^I leads. The first cooling channel 135 and the second cooling channel 137 have a channel height 144 and a channel width 144^I on. The channel height 144 is a multiple of the channel width 144^I. The channel height 144 is smaller than a high side 115 of a single cell 153 (see Fig.<figref idref="f0009">10</figref>). The space in the module housing 133 is thus used optimally, so that the largest possible basic form 105 can be present in the module housing 133 in addition to the required electrical connections (not shown). Flow through the sandwich cooling plate 139 is as uniform as possible by directing the flow at cooling channel fins, such as cooling channel fins 194, 194^I, 194^II, generated. The cooling channel fins 194, 194^I, 194^II delimit cooling channels, such as cooling channels 141, 141^I, 141^II, 141^III. The cooling medium 143, which can also be referred to as coolant or cooling fluid, thus flows evenly through various areas of the base area 105. The cooling channels, the cooling channels 141, 141^I, 141^II, 141^III are narrower or less wide than a channel width 144^I and in particular less high than a channel height 144 of the first cooling channel 135 or second cooling channel 137. The cooling channels 141, 141^I, 141^II, 141^III have a first cooling channel width 196 in the vicinity of the supply channels 135, 137, which is smaller than a second cooling channel width 197, which extends in the remaining area of ​​the basic shape 105. In other words, a longer compensation section 199 and, as a result, a shorter cooling channel 141 also forms a greater flow resistance than a shorter compensation section 199 due to its greater length^I. There is a longer cooling channel 141^III before, the compensation section is 199^I shorter (see also the cooling channel 141^I). A flow velocity profile that can be applied over a supply channel height 144 can thus be kept constant in the supply channels 135, 137. A quasi-laminar flow through the cooling channels 135, 137, 141, 141^I, 141^II, 141^III is made possible, which means that cooling requires less pump power. In particular, the cooling channels of different sandwich cooling plates are like the cooling channels 141, 141^I, 141^II, 141^III in a stack arrangement according to<figref idref="f0011">figure 12</figref>, which has a plurality of sandwich cooling plates, such as the sandwich cooling plate 139, are arranged parallel to each other.

The cell housings 131, 131^I, 131^II offer, as in<figref idref="f0011">figure 12</figref> can be seen, the contact surfaces for the attachment of the individual cells 153. The individual cells, like those in<figref idref="f0011">figure 12</figref> shown single cell 153 of the traction accumulator 101 are arranged on a carrier plate 145 . Depending on the orientation of the traction accumulator 101, either the cover plate 146 or the support plate 145 form a mechanical support element of the traction accumulator 101. The support plate 145 and the cover plate 146 belong to the module housing 133. In the module housing 133 are between the support plate 145 and the cover plate 146 all Cell housings, such as cell housings 131, 131^I, 131^II, flush with sandwich panels, such as sandwich panels 139, 139^I, 139^II, arranged side by side. The sandwich panel 139 forms part of the cell case 131. In other words, each cell case comprises 131, 131^I, 131^II exactly one sandwich panel 139, 139^I, 139^II. The individual cell arrangement extends in the module housing 133 from a first collector current conductor 155 via a first secondary cell 103, a second secondary cell 103^I, via a total of 20 additional secondary cells to a second collector current conductor 157. A traction accumulator with a larger or smaller number of secondary cells can also be structured in the same way as that from<figref idref="f0009">figure 10</figref> known traction accumulator 101 are constructed. Outside 151 on the module housing 133 are the cooling channel connections 136, 136^I, which are present as a quick connector for the first cooling channel 135, are arranged. The quick connectors 136, 136^I are equipped with an unlocking element. When the traction accumulator 101 is connected to a closed cooling circuit, the unlocking element (not shown) makes it possible to open a respective associated quick connector counterpart with a retaining valve. A coolant-cooled accumulator 101 can thus be replaced particularly quickly by a second accumulator, in particular one of identical construction. This second can be put into operation immediately as an energy source.

<figref idref="f0012">figure 13</figref> shows a module housing 133^I a traction accumulator 101^I from above, ie in a view of a module housing cover 165. The module housing cover 165 has a plurality of recesses, in particular for a first convection outflow opening 179 and a first contact point 181. From the module housing 133^I the individual cells (not visible) are enclosed by the pairs of tension elements 134, 134^I as well as 134^II, 134^III are pressed together. Tension elements 134, 134^I, 134^II, 134^III are via housing connectors 132, 132^I, 132^II, 132^III flexibly to the module housing 133^I connected. To a housing connector 132, 132^I, 132^II, 132^III includes a flexible hard rubber sleeve. This allows installations inside the module housing 133^I from the module housing 133^I uncouple. There is a decoupling of vibrations, tensions or torsions that affect the module housing 133^I, e.g. B. via the mounting rails 159, 159^I, can have an effect. Each mounting rail 159, 159<i>^l</i> extends a little along each side of the housing 133^I. The mounting rail 159, 159^l is part of a larger overall track. The mounting rail159, 159^I has a length that depends on the main vibration behavior of the traction accumulator 101^I is matched. The mounting rails 159, 159^I are along a length of housing 133^I not completely continuous, they are interrupted and composed of individual pieces.

As already to<figref idref="f0012">figure 13</figref> addressed, there are case connectors 132, 132^l, 132^ll, 132^III. Thanks to the housing connectors 132, 132^I, 132^II, 132^III can be charged from the outside on the traction accumulator 101^I decouple impacting vibrations better. In addition, the combination of tension elements 134, 134^I, 134^II, 134^III and the housing connectors 132, 132 designed as bushings^I, 132^II, 132^III re-tightening or releasing the tension elements 134, 134^I, 134^II, 134^III from outside the module housing 133^I.

Another embodiment of a module housing 133^II for a traction accumulator 101^II is in isometric representation in<figref idref="f0013">figure 14</figref> shown. The module housing rear walls 167, 167^I of the module housing 133^II have passages for a first cooling channel 135 and for a second cooling channel 137 . In other words, the two cooling channels 135, 137 are parallel through the module housing 133^II laid through. A first contact point 181 is located between the cooling channels 135, 137 in a triangular configuration in the manner of an isosceles triangle or trapezium. Thus, a maximum distance for the installation of the respective connectors (not shown) in a motor vehicle is made possible. Cooling medium cannot reach contact point 181.

As in<figref idref="f0014">figure 15</figref> can be seen who is in<figref idref="f0012">figure 13</figref> shown module housing 133^I in open form, the contacts 147, 149 are aligned adjacent to each other. The contacts 147, 149 can be realized by spot welds 129. Unlike in<figref idref="f0012">figure 13</figref> have been included for the sake of clarity<figref idref="f0014">figure 15</figref> the train elements hidden. Between two single cells, such as single cells 153, 153^I, a sandwich plate, such as the sandwich plate 139, is fitted in each case. The sandwich panel 139 is connected to both the first cooling channel 135 and the second cooling channel 137 . The sandwich plate 139 can also be referred to as a cooling plate or a flow or cross-flow connection. A refrigerant (not shown) enables the cooling plate 139 to cool the traction accumulator 101^I to provide. The cooling capacity is assigned to the individual cells 153, 153^I provided evenly. The cooling plate 139 works as a cold spreader. A first single cell 153 and a second single cell 153^I are connected to one another in terms of heat flow via the cooling plate 139 . By lining up cooling plates, such as cooling plate 139, and individual cells 153, 153^I an operating temperature of the traction accumulator 101 can be measured over an entire module volume 123^I stabilize. On the single cells, like single cells 153, 153^I, is at high sides 109, 109^I a shield spring, such as shield spring 130, is attached. The shielding springs 130 offer additional protection both thermally and mechanically, in particular in terms of vibration, for the cooling channel walls 138, 138^I. High outside temperatures or deformations can affect the cooling channels 138, 138 to a lesser extent via the module housing side walls 161 (compared to a traction accumulator without a shielding spring).^I affect, so that cooling of the individual cells 153, 153^I can work particularly efficiently and reliably.

In<figref idref="f0015">figure 16</figref> becomes a single cell housing 131^III with a surface equipped with a rupture gap 76 is shown. The rupture gap 76 is located in a special area of ​​the housing 131^III, the rupture zone 150. The rupture zone 150 is adjacent to, directly adjacent to, one of the contacts, the first contact 147^I of the housing. In its main direction of extension, the bursting joint leads from the carrier plate 145^I of the single cell housing 131^III away. In<figref idref="f0015">figure 16</figref> it can be seen that the single cell housing 131^III has sides of different thicknesses, the carrier plate 145^I is the thickest plate of the single cell case 131^III.

<figref idref="f0016">figure 17</figref> shows a further embodiment of a traction accumulator 201. The module housing 233 of the traction accumulator 201 can be seen from the outside. How based on<figref idref="f0017">figure 18</figref> can be seen are the essential parts, the individual cells with their cell housings 231, 231', 231", 231^III inside the module housing 233 (see<figref idref="f0016">figure 17</figref>) arranged. The module housing 233 is made from an extruded profile. The module housing 233 forms the individual cell housings 231, 231 through its individual sides such as the module housing cover 265^I, 231^II, 231^III fully enclosing housing. Further sides of the module housing 233 are a first module housing side wall 261 and a second module housing wall 261^I. Another side of the module housing 233 is formed by the module housing base 263 .

On the module housing side walls 261, 261^I are short mounting rails 259, 259', 259", 259" that only extend a few centimeters^III arranged, which are spaced from each other. The mounting rails 259, 259', 259", 259^III are all in alignment. They are attached to the module housing side wall 261 at the same height, spaced apart from one another.

The module housing base 263 is also a supporting plate with coolant lines 292, 292^I. The coolant lines 292, 292^I run parallel in the same direction. The coolant lines 292, 292^I extend from one side to another side of the module housing 233. The module housing base 263 assumes the function of a support plate 245. Between the support plate 245 and the other parts of the module housing, such as. B. the module housing side walls 261, 261^I or like e.g. B. the cell housings 231, 231^I, 231^II, 231^III (please refer<figref idref="f0017">figure 18</figref>) a film 290 is interposed, which is a thermally conductive film and at the same time an insulating film. The thickest side is the module housing base 263. In an alternative variant, not shown here, a paste-like layer, e.g. B. an elastomeric, slightly adhesive thermally conductive layer can be interposed during assembly.

As said,<figref idref="f0017">figure 18</figref> shows large parts of the "inner workings" of the traction accumulator 201, which can be seen from the outside in<figref idref="f0016">figure 17</figref> is shown. In<figref idref="f0017">figure 18</figref> it can be seen that the cell housings 231, 231^I, 231^II, 231^III are layered next to each other and lined up contacting over their three sides.

As can be seen from a synopsis of the<figref idref="f0016">figures 17</figref> and<figref idref="f0017">18</figref> results, there are two cells in a cell housing 231, 231^I, 231", 231^III on an equal potential 288, 288^I, 288^II merged. That is, the two cells 253, 253^I have the potential 288. The two cells 253^II, 253^III have the potential 288^I.

Below the cell housings 231, 231^I, 231^II, 231^III a single cell case plate 289 is disposed as part of the cell case. With a sufficient linear arrangement of the cell housings 231, 231^I, 231^II, 231^III the single housing plate 289 can be omitted. If it is manufactured with greater tolerances, then the individual housing plate 289 serves as a contacting plate for heat transfer. Below the cell housings 231, 231', 231", 231^III is the foil 290 as an intermediate element between the carrier plate 245 and the heat-carrying parts of the heat from the cell housing 231, 231^I, 231^II, 231^III arranged. The carrier plate 245 has at least one coolant line 292^II. With the coolant, all individual cell housings 231, 231^I, 231^II, 231^III to be underflowed. This means that heat can escape from all cell housings 231, 231^I, 231^II, 231^III be deployed.

Electrical are the cell housings 231, 231', 231", 231^III connected in series. As already mentioned, from a synopsis of the<figref idref="f0018">figures 19</figref> and<figref idref="f0017">18</figref> it can be seen that two individual cells 253, 253^I, 253^II, 253^III to a cell housing 231, 231^I are put together. This results in the potentials of the cell housing 231, 231^I. The first single cell, which is similar to the single cell 253, and the last single cell, which is similar to the single cell 253^III is, are through-connected to the outside via bus conductors 255, 257. Through spacers 293, 293^I a surface pressure stress is applied to the cell casings 231, 231^I, 231^II, 231^III upset. The spacers 293, 239^I are filling elements between the module housing side walls 261, 261^I and the cell case 231, 231^I, 231^II, 231^III. As a result, the cell housing 231, 231^I, 231^II, 231^III under tension (in a mechanical sense).

The cutout marked X in<figref idref="f0017">figure 18</figref> is marked is even bigger in<figref idref="f0018">figure 19</figref> shown. As a result (in particular based on the hatching), the potential equalization of individual cells 253, 253^I, 253^II, 253^III recognizable (same hatching expresses a potential). The active surfaces or the active surfaces 19, 119 (cf<figref idref="f0005">figure 6</figref> and<figref idref="f0009">figure 10</figref>) are so insulating on the respective cell housing 231, 231^I, 231^II, 231^III led to contact taking place via one side. This makes the potential 288, 288^I, 288^II determined (see<figref idref="f0018">figure 19</figref>). Roughness and unevenness on the side of the cell housing 231, 231 that makes contact with the carrier plate 245^I, 231^II, 231^III are balanced by the single housing plate 289. There is a heat-conducting foil 290 to dissipate the heat. The heat-conducting foil 290 conducts the heat out of the individual cells 253, 253^I, 253^II, 253^III onto the support plate 245. The heat is dissipated via the coolant in the coolant line 292.

Individual features from the described embodiments and variants as well as the exemplary embodiments shown in the figures can be combined with one another individually and in groups of features to form further exemplary embodiments, which can result in additional aspects and advantages according to the invention.

A useful further development is e.g. B. therein, a single cooling channel, such as one of the cooling channels 141, 141^I, 141^II, 141^III after<figref idref="f0010">figure 11</figref>, preferably in an area that runs parallel to a further cooling channel, successively equipped with different cross-sectional sizes. The different size can B. as a gradually increasing cooling channel width in the area of ​​a first cooling channel width 196 and/or in the area of ​​a second cooling channel width 197. In particular, the compensation sections 199, 199^I be conical or funnel-shaped. A gradual increase (or decrease) in the width of the cooling channel 196, 197 preferably takes place along an incline of the cooling channel in comparison with the course of a module housing base. According to a further aspect, in an advantageous further development, the cross-sectional sizes of the cooling channels can be proportional to a spatial temperature distribution (without coolant supply) on individual cells, such as the individual cell 153 in<figref idref="f0011">figure 12</figref>, be chosen. The temperature distribution is caused by heat generation and heat flow in charging or discharging processes, e.g. B. in a load operation of a traction battery 101, 101^I, 101^II. A larger cooling channel cross section offers a larger capacity for coolant in a first area, in which the operational heat output causes a higher temperature, than in a second area with a lower temperature, in which a comparatively smaller cooling channel cross section is sufficient. The coolant preferably has a heat capacity that is greater than or equal to a heat capacity of water. In a module housing 133 (see<figref idref="f0009">figure 10</figref>) or in a traction accumulator 101^I, 101^II an even more even temperature can be set. Heat generation or heat flow in the traction accumulators 101, 101^I, 101^II can be calculated using known numerical methods, which results in, among other things, the most favorable possible gradient or cooling channel cross section.

About the channel geometry of the cooling channels 141, 141^I, 141^II, 141^III the running behavior or the flow time of the cooling medium can also be influenced. This enables equal distribution between the individual channels 141, 141^I, 141^II, 141^III be ensured. The cooling channels 141, 141^I, 141^II, 141^III have different lengths from each other. They have mutually different cooling channel widths 196, 197. The lengths and the cooling channel widths 196, 197 are matched to one another, resulting in an equal distribution.

<figref idref="f0019">figure 20</figref> shows a module housing 333. The module housing 333 is part of the traction accumulator 301 and represents its outer shell. The module housing 333 is designed in one piece along four sides. The base or the module housing base 363, the cover or the module housing cover 365 and the rails 359 of the module housing 333 are manufactured as one part from a metallic extruded profile. The base 363 is only half as thick as the cover 365 of the module housing 333. The lid 365 spans the in<figref idref="f0020">figure 21</figref> seen cell housing 331, 331^I, 331^II, 331^III. The cover 365 creates the mechanical stability for common motor vehicle tests such as a test by driving over a vibrating track.

<figref idref="f0020">figure 21</figref> shows the inner workings of the module housing 333<figref idref="f0019">figure 20</figref>. The cell housings 331, 331', 331^II, 331^III are all arranged parallel to each other, side by side, so to speak, more precisely stacked on similar sides. The plates of the module housing 333 span the cell housings 331, 331^I, 331^II, 331^III a. Contacts 347, 347^I, 347^II, 347^III are on the same level. Contacts 347, 347^I, 347^II, 347^III lie next to each other. Tension member 334 secures the panels of the housing. The tension element 334 is hollow and can also be used as a cooling channel, in particular for a cooling liquid.

It is understandable that the developments shown in the individual exemplary embodiments can also be combined in a further embodiment, e.g. B. a module housing with a liquid-cooled support plate and with liquid-cooled lines that lead into the traction accumulator and thus to the cell housings.

Reference List

<ul id="ul0007" list-style="none" compact="compact"><li>1, 1^I, 1^II, 101, 101^I, 101", 201, 301 traction accumulator</li><li>3, 3^I, 3^II, 3^III, 103, 103^I first, second, third, fourth secondary cell</li><li>5, 105 basic shape</li><li>7, 7' first, second long side</li><li>9, 9^I, 109, 109^I first, second high side</li><li>11 Broad</li><li>13 Length, especially a long side</li><li>15, 115 length, especially a high side</li><li>17, 17^I middle area, especially a high side</li><li>19, 119 active area or active area</li><li>21 conversion volume</li><li>23, 123 module volume</li><li>25, 125 first pole lug, in particular pole lug of the positive pole</li><li>27, 127 second pole lug, in particular pole lug of the negative pole</li><li>129 spot weld</li><li>130 shield spring</li><li>31, 31^I, 31^II, 131, 131^I, 131^II, 131^III, 231, 231^I, 231^II, 231^III, 331, 331^I, 331^II, 331^III cell housing</li><li>132, 132^I, 132^II, 132^III housing connector</li><li>33, 33^I, 133, 133^I, 133", 233, 333 module housing</li><li>134, 134^I, 134^II, 134^III, 334 traction element</li><li>135 first cooling channel</li><li>136, 136^I Cooling channel connection, in particular quick connector</li><li>137 second cooling channel</li><li>138, 138^I cooling channel wall</li><li>139, 139^I, 139^II Sandwich plate or cooling plate</li><li>140, 140^I Panel height, especially sandwich panel height</li><li>141, 141^I, 141^II, 141^III Cooling channel, especially in a sandwich panel</li><li>142 Panel base, in particular sandwich panel base</li><li>143 Cooling medium such as a refrigerant or a glycol-water mixture</li><li>144 supply channel height</li><li>144^I supply channel width</li><li>45, 145, 145^I, 245 carrier plate</li><li>146 Cover plate, in particular with the function of a carrier plate</li><li>47, 147, 147', 347, 347^I, 347^II, 347^III first contact</li><li>49, 149 second contact</li><li>150 burst area</li><li>51, 151 outside</li><li>53, 53^I, 53^II, 153, 153^I, 253, 253^I, 253", 253^III single cell</li><li>55, 155, 255 first collector conductor</li><li>57, 157, 257 second collector conductor</li><li>59, 59^I, 59^II, 59^III, 159, 159^I, 159^II, 159^III, 259, 259^I, 259^II, 259^III, 359 mounting rail</li><li>61, 161, 261 module housing side wall, in particular first side wall</li><li>61^I, 161', 261' module housing side wall, in particular second side wall</li><li>62 upper area</li><li>63, 63^I, 163, 263, 363 module housing base</li><li>65, 65^I, 165, 265, 365 module housing cover</li><li>67, 67^I, 167, 167^I module housing rear panel</li><li>69, 69^I thickness</li><li>71 exchange surface</li><li>73, 73^I inside</li><li>75 Convection inflow opening, in particular the area of ​​the module housing base</li><li>76 Bursting joint, in particular (double) Y-shaped</li><li>77, 77^I, 177, 177^I convection channel</li><li>79, 179 first convection exhaust port</li><li>79^I second convection outflow opening</li><li>81, 181 first point of contact</li><li>81^I second point of contact</li><li>83 first cover</li><li>83^I second cover</li><li>85, 85^I, 85^II Connection surface, in particular for a module housing cover</li><li>187 single cell pad</li><li>288, 288^I, 288^II potential</li><li>289 single cell housing plate</li><li>290 Foil, in particular thermally conductive and/or insulating foil</li><li>191, 191^I cooling channel chamber</li><li>292, 292', 292" coolant line</li><li>93, 93^I, 193, 193^I, 293, 293^Ispacers</li><li>194, 194^I, 194^II cooling channel fin</li><li>195 sealing lip</li><li>196 first cooling channel width</li><li>197 second cooling channel width</li><li>198, 198^I temperature sensor</li><li>199, 199^I compensation section</li><li>AA section AA, in particular section plane</li><li>X cut X</li></ul>