Solid electrolyte battery and method of manufacturing the same

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to a solid electrolyte battery and a method for producing the same.

【0002】

[Conventional technology]

In recent years, many portable electronic devices such as mobile phones, PDAs (Personal Digital Assistants), and camera-integrated VTRs have appeared, and their size and weight have been reduced. As a portable power source for these electronic devices, research and development for improving the energy density of batteries, especially secondary batteries, is being actively promoted.

【0003】

With respect to these secondary batteries, as electronic devices become smaller and lighter, there is a remarkable increase in demand for smaller size, especially thinner size, as well as further improvement in safety. Further, in recent years, there has been a demand for an optimum battery design corresponding to various uses of electronic devices, such as a card-shaped battery and a flexible battery having a high degree of freedom in shape.

【0004】

Among the secondary batteries, so-called non-aqueous electrolyte batteries such as lithium batteries and lithium ion secondary batteries that use a non-aqueous electrolyte as an electrolyte are lead batteries and nickel cadmium that are secondary batteries that use a conventional aqueous electrolyte solution. Expectations are high because a large energy density can be obtained compared to batteries and the like.

【0005】

[Problems to be Solved by the Invention]

By the way, in order to realize a high capacity in the non-aqueous electrolyte battery as described above, it is necessary to construct a multilayer electrode structure in which a large number of negative electrodes and positive electrodes are laminated. Further, in order to realize a non-aqueous electrolyte battery (hereinafter, may be referred to as a deformed battery) having a shape different from the usual cylindrical shape, rectangular shape, flat sheet shape, etc., a load such as bending is applied to the electrodes. It is necessary to have an electrode structure that does not cause an internal short circuit even if the above is given.

【0006】

However, a deformed battery that has both high capacity and prevention of internal short circuit has not yet been realized.

【0007】

For example, as a conventional electrode structure, as shown in FIG. 17, a so-called winding structure (Winding) in which a positive electrode 101 and a negative electrode 102 are laminated via an electrolyte 103 and wound in a spiral shape can be mentioned. The electrode having this winding structure has advantages that it is relatively easy to manufacture and is advantageous for increasing the capacity, but on the other hand, the shape of the battery is limited, so that it is possible to manufacture a deformed battery or the like. It is disadvantageous.

【0008】

Further, as an electrode structure capable of manufacturing a deformed battery and realizing a relatively high capacity, as shown in FIG. 18, a plurality of sheet-shaped positive electrodes 104 and a plurality of sheet-shaped negative electrodes 105 are connected via an electrolyte 106. A stacking structure (Stacking) in which a plurality of elementary batteries 107 are further laminated to form a unit cell 107 can be mentioned. Further, as shown in FIG. 19, it has a zigzag sheet-shaped positive electrode 108 and a zigzag sheet-shaped negative electrode 109, and the sheet-shaped positive electrode 108 and the sheet-shaped positive electrode 109 are folded so as to be orthogonal to each other. Folding structure (Folding) of the structure can be mentioned.

【0009】

However, when a battery having these electrode structures is formed into a curved surface shape, for example, the degree of freedom of sliding between adjacent elementary batteries is low, so that no deviation (slip) occurs between the elementary batteries and an internal short circuit occurs due to stress concentration. May cause.

【0010】

Therefore, the present invention has been proposed in view of such conventional circumstances, and provides a solid electrolyte battery which exhibits high capacity and can be molded into various shapes without causing an internal short circuit, and a method for manufacturing the same. The purpose is.

【0011】

[Means for solving problems]

In order to achieve the above object, in the solid electrolyte battery according to the present invention, the first electrode and the second electrode, one of which is the negative electrode and the other of which is the positive electrode, are alternately laminated via the solid electrolyte. It is a solid electrolyte battery having a battery element formed by stacking a plurality of raw batteries, and the first electrode has a strip-shaped first electrode sheet having a valley fold, a mountain fold, and a valley fold with respect to one main surface. The second electrode is folded in order, and the second electrode is folded in half, and on one main surface side of the first electrode sheet, the inner fold line folded in half and the mountain fold line of the first electrode sheet are formed. One of the second electrode sheets arranged so that the two electrodes are in contact with each other, and the inner bending line folded in half on the other main surface side of the first electrode sheet, and the first one. It is composed of the other second electrode sheet arranged so as to abut one valley fold line of the electrode sheet, and the one second electrode sheet and the other second electrode sheet extend from the longitudinal edge. It has tabs, and the tabs are electrically connected to each other.

【0012】

In the solid electrolyte battery configured as described above, the elementary battery has a composite structure of a folding structure and a laminated structure, and the second electrode sheets are electrically connected to each other by tabs derived from the edges in the longitudinal direction. ing. As a result, a wide facing area is secured between the first electrode and the second electrode, and even when an external force such as imparting a curvature to the solid electrolyte battery is applied, between the elementary batteries. Since the degree of freedom of displacement is increased and the load on the tab is reduced, it is possible to prevent stress concentration from occurring in the battery element.

【0013】

Further, the method for manufacturing a solid electrolyte battery according to the present invention is a base battery in which the first electrode and the second electrode, one of which is a negative electrode and the other is a positive electrode, are alternately laminated via a solid electrolyte. , A method of manufacturing a solid electrolyte battery having a plurality of stacked battery elements, in which a valley fold, a mountain fold, and a valley fold are formed in this order on one main surface of the strip-shaped first electrode sheet. A step, a step of folding one second electrode sheet and the other second electrode sheet in half to form a bending line, and a mountain fold of the first electrode sheet on one main surface side of the first electrode sheet. The wire and the bending wire inside the one second electrode sheet are arranged so as to be in contact with each other, and on the other main surface side of the first electrode sheet, with one valley folding wire of the first electrode sheet. , The step of arranging the bending line inside the other second electrode sheet so as to abut, and the first electrode sheet, the one second electrode sheet and the other second electrode sheet from the thickness direction. A step of crimping to form a base cell, a step of laminating a plurality of the base batteries to manufacture a battery element, and a tab extending from the longitudinal edge of the one second electrode sheet and the other second electrode sheet. It is characterized by having a step of electrically connecting the electrodes to each other.

【0014】

In the method for manufacturing a solid electrolyte battery as described above, the first electrode and the second electrode are folded and laminated to produce a base battery, and a plurality of the base batteries are laminated to manufacture a battery element. Next, the tabs derived from the longitudinal edge are electrically connected to collect current from the second electrode. Therefore, even when an external force such as imparting a curvature is applied, the solid electrolyte is less likely to cause stress concentration in the battery element due to the high degree of freedom of displacement in and / or between the elementary batteries. Can manufacture batteries.

【0015】

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the solid electrolyte battery to which the present invention is applied and a method for manufacturing the same will be described in detail with reference to the drawings.

【0016】

As shown in FIG. 1, the solid electrolyte battery 1 to which the present invention is applied has a band shape, and includes a battery element 3 formed by stacking three elementary batteries 2 and an exterior material 4 accommodating the battery element 3. Consists of. Further, a pair of protective plates 5 are arranged so as to sandwich the battery element 3 from both main surfaces in the stacking direction. Further, as will be described in detail later, a negative electrode tab 6 extends from a substantially central portion of the longitudinal edge of each elementary battery 2, and these negative electrode tabs 6 are grouped together on one main surface side of the battery element 3 to form a negative electrode. It is electrically connected to lead 7. One end of the negative electrode lead 7 is electrically connected to the negative electrode tab 6, and the other end is pulled out from the longitudinal end of the solid electrolyte battery 1 to the outside of the exterior material 4. Further, a positive electrode tab 8 extends from one end in the longitudinal direction of each elementary battery 2, and these positive electrode tabs 8 are collectively electrically connected to the positive electrode lead 9. One end of the positive electrode lead 9 is electrically connected to the positive electrode tab 8, and the other end is an exterior material from the end opposite to the side where the negative electrode lead 7 in the longitudinal direction of the solid electrolyte battery 1 is pulled out. It is pulled out of 4.

【0017】

As shown in FIGS. 1 and 2, the battery element 3 is configured by stacking, for example, three strip-shaped elementary batteries 2.

【0018】

Then, as shown in FIG. 3, the elementary battery 2 has a long shape, and the positive electrode 10 which is bent in three places in a zigzag manner at a predetermined interval, and the first negative electrode 11a and two which are bent in two. A negative electrode 11 composed of a second negative electrode 11b bent in a row and a solid electrolyte film 12 provided so as to sandwich the negative electrode 11 are provided, and the spirally folded positive electrode 10 is formed by the first negative electrode 11a and the second negative electrode 11b. The positive electrode 10, the solid electrolyte film 12, the negative electrode 11, and the solid electrolyte film 12 are sequentially laminated so as to be sandwiched in a staggered manner. Further, the negative electrode tab 6 is derived from the negative electrode 11 at the position where the displacement stress between the positive electrode 10 and the negative electrode 11 is minimized on the normal line with respect to each laminated surface of each battery element 3, and these negative electrode tabs 6 are derived. Are overlapped with each other and electrically connected to collect electricity from the negative electrode 11.

【0019】

Further, the positive electrode 10 faces outward on one main surface of the elementary battery 2, and the negative electrode 11 faces outward on the other main surface, so that the positive electrode 10 and the negative electrode 11 face each other between the adjacent elementary batteries 2. The battery element 3 is configured so as to face each other.

【0020】

The positive electrode 10 has a positive electrode active material layer 14 containing a positive electrode active material formed on both main surfaces of the positive electrode current collector 13, and is folded in a zigzag manner at three bent portions 15. The above-mentioned positive electrode tab 8 is derived from one end of the positive electrode current collector 13 in the longitudinal direction in order to collect current from the positive electrode 10. At the base end portion and the bent portion 15 of the positive electrode tab 8, the positive electrode current collector 13 is covered with the sealing material 16 without forming the positive electrode active material layer 14.

【0021】

As the material constituting the positive electrode 10, any conventionally known positive electrode material used for this type of solid electrolyte battery can be used. In particular, the positive electrode 10 of the solid electrolyte battery to which the present invention is applied is preferably a so-called composite type positive electrode in which the positive electrode active material, the conductive auxiliary agent, and the solid electrolyte are uniformly dispersed in the positive electrode active material layer 14. ..

【0022】

For example, the positive electrode active material is not particularly limited as long as it is a material capable of doping and dedoping alkali metal ions, and for example, a metal oxide or metal sulfurization is used depending on the type of the target battery. Powders of substances and the like can be used.

【0023】

For example, when constructing a lithium battery, TiS is used as the positive electrode active material.₂, MoS₂, NbSe₂, FeS, FeS₂, V₂O₅Lithium-free metal oxides such as, or metal sulfides can be used. In addition, as a positive electrode active material, Li_xMO₂(However, M in the formula represents one or more transition metal elements. In addition, x varies depending on the charge / discharge state of the battery and is usually in the range of 0.05 or more and 1.10 or less.) Or LiNi._pM1_qM2_rMO₂(However, M1 and M2 in the formula represent at least one element selected from the group consisting of Al, Mn, Fe, Co, Ni, Cr, Ti and Zn, or M1 and M2 represent P, B and the like. In addition, p, q, and r may satisfy the condition of p + q + r = 1), and a lithium composite oxide or the like containing the above can be used.

【0024】

The transition metal M constituting the lithium composite oxide is preferably Co, Ni, Mn or the like. Specifically, LiCoO₂, LiNiO₂, LiNi_yCo₁_-yO₂(However, y in the formula is 0 <y <1.) Etc. can be mentioned. In particular, it is preferable to use a lithium cobalt composite oxide or a lithium nickel composite oxide because a high voltage and a high energy density can be obtained and the cycle characteristics are excellent.

【0025】

Of course, it is also possible to use a mixture of a plurality of the above-mentioned materials as the positive electrode active material.

【0026】

As described above, the bent portion 15 of the positive electrode 10 is preferably covered with the insulating sealing material 16 while the positive electrode active material layer 14 is removed. As a result, even when a local force is applied to the bent portion 15 when bending the positive electrode 10, the positive electrode active material does not peel off, and the inside caused by the peeling of the positive electrode active material. The occurrence of a short circuit can be avoided. On the contrary, when the positive electrode active material is adhered to the bent portion 15 of the positive electrode 10, the positive electrode active material of the bent portion 15 is peeled off when the positive electrode 10 is bent, and the peeled positive electrode active material is a solid electrolyte film. Penetration of 12 may cause an internal short circuit.

【0027】

The sealing material 16 is made of an insulating material that can be welded to the positive electrode current collector 13, and for example, an olefin resin such as polyethylene or polypropylene can be used. The sealing material 16 needs to have a sufficient thickness so that the sealing material 16 does not undergo dielectric breakdown due to heat when the sealing material 16 is fixed to the positive electrode current collector 13, for example, about 5 μm to 100 μm. Is preferable. However, since the appropriate value of the thickness of the sealing material 16 changes depending on the specifications of the electrodes and electrolytes used, it shall be set appropriately.

【0028】

Further, in the first negative electrode 11a and the second negative electrode 11b, a negative electrode active material layer 18a and a negative electrode active material layer 18b having a negative electrode active material are formed on both main surfaces of the negative electrode current collector 17a and the negative electrode current collector 17b, respectively. , Folded in two in the longitudinal direction. In the following, for the sake of simplicity, the first negative electrode 11a and the second negative electrode 11b may be collectively referred to as the negative electrode 11.

【0029】

Further, the above-mentioned negative electrode tab 6 is derived from the widthwise end of the negative electrode current collector 17 corresponding to the substantially central portion in the longitudinal direction of the solid electrolyte battery 1 in order to collect the current of the negative electrode 11.

【0030】

As the material constituting the negative electrode 11, any conventionally known negative electrode material used for this type of solid electrolyte battery can be used.

【0031】

As the negative electrode current collector 17, for example, a copper foil can be used. As the negative electrode active material, conventionally known materials such as alkali metals, alloys capable of doping and dedoping alkali metals, and carbon materials capable of doping and dedoping alkali metals can be used. Specific examples thereof include alkali metals such as lithium and sodium, alloys containing them, carbon materials and the like. Specific examples of the carbon material include pyrolytic carbons, cokes, carbon black, glassy carbon, calcined organic polymer, carbon fiber and the like.

【0032】

As the solid electrolyte film 12, a conventionally known solid electrolyte can be used.

【0033】

The material of the exterior material 4 is not particularly limited, but if consideration is given to increasing the capacity, thinning, and miniaturization of the solid electrolyte battery 1, an aluminum laminate film using a heat-sealing material is used. Is preferable.

【0034】

The protective material 5 is provided to prevent distortion, wrinkles, and the like from entering the battery element 3 when the solid electrolyte battery 1 is formed into a curved surface shape. As the protective material 5, it is preferable to use a material that is chemically stable with respect to the electrodes and electrolytes used, and the protective material 5 is made of, for example, PET (polyethylene terephthalate) or the like. The thickness of the protective plate 5 needs to be appropriately set depending on the number of stacked elementary batteries 2 and the shape of the solid electrolyte battery 1, but it is preferably about 200 μm to 500 μm, for example, and thus the volume energy of the solid electrolyte battery 1. The effect of protecting the battery element 3 can be surely obtained without causing a decrease in density.

【0035】

In the solid electrolyte battery 1 as described above, the elementary battery 2 has a composite structure in which the positive electrode 10 and the negative electrode 11 have a folded structure and a laminated structure via the solid electrolyte film 12. Further, three elementary batteries 2 are laminated so that the same electrodes do not face each other between the adjacent elementary batteries 2, that is, the positive electrode 10 and the negative electrode 11 face each other via the solid electrolyte film 12. It constitutes 3. Further, the negative electrode tab 6 for collecting the current of the negative electrode 11 is led out from the side in the width direction of the negative electrode 11 and is overlapped with each other to form an electrical connection inside the elementary battery 2 and between the elementary batteries 2.

【0036】

In this way, by forming the battery element 3 with the structure as described above, a sufficiently wide facing area is secured between the positive electrode 10 and the negative electrode 11, and the inside of the elementary battery 2 and / or between the elementary batteries 2 is provided. The degree of freedom of displacement is increased, and the occurrence of an internal short circuit due to stress concentration is prevented even when an external force such as bending is applied to the solid electrolyte battery 1. Further, since the negative electrode tabs 6 are overlapped with each other and electrically connected to each other, when the solid electrolyte battery 1 is formed into a curved shape as described later, a load is applied to the negative electrode tab 6 and the negative electrode tab 6 is damaged. Is prevented.

【0037】

Therefore, the solid electrolyte battery 1 to which the present invention is applied is difficult to mold not only in a planar shape but also in a conventional manner while achieving a high capacity and suppressing the occurrence of an internal short circuit to maintain excellent reliability. It is possible to take various shapes depending on the usage pattern, such as a curved surface shape and a bendable shape. Moreover, since the solid electrolyte battery 1 to which the present invention is applied uses a so-called solid electrolyte that does not contain a solvent as the electrolyte, there is no concern about liquid leakage even when the shape is deformed as described above, and it is extremely. Shows high safety.

【0038】

The present invention is suitable for application to the curved solid electrolyte battery 1 as shown in FIG. As described above, in the solid electrolyte battery 1, the negative electrode tabs 6 are arranged on the normal line of the battery element 3 in the stacking direction of the battery element 3. Therefore, even when an external force is applied to impart curvature to the solid electrolyte battery 1, the degree of freedom of displacement between the elementary batteries 2 is high, so that stress concentration is prevented from being caused in the battery element 3. .. Therefore, the solid electrolyte battery 1 can realize a curved surface shape without causing an internal short circuit.

【0039】

In order to obtain such a curved solid electrolyte battery 1, as shown in FIG. 4, the elementary batteries 2a, the elementary batteries 2b, and the elementary batteries 2c in which the lengths are lengthened in this order are sequentially laminated as the elementary batteries 2. It is preferable to have the battery element 3 having the configuration. The length of each of these elementary batteries 2 is determined by the amount of delamination between the elementary batteries calculated from the radius of curvature of the curved surface shape of the solid electrolyte battery, the number of elementary batteries stacked, the thickness of the elementary batteries, and the like.

【0040】

By imparting a curvature to the solid electrolyte battery 1 having such a battery element 3 by a method described later, the positions of the ends of the elementary batteries 2 in the band-shaped battery element 3 are matched without being displaced. Effective use of space is planned. On the other hand, when a curvature is given to a solid electrolyte battery having a battery element 3 formed by stacking strip-shaped elementary batteries 2 having the same length, among the solid electrolyte batteries, as shown in FIG. Due to the difference between the circumference and the outer circumference, the end portion of each elementary battery is displaced, and a region where the positive electrode and the negative electrode do not face each other is created.

【0041】

Next, a method for manufacturing the solid electrolyte battery as described above will be described.

【0042】

First, as shown in FIG. 6, the positive electrode active material layer 14 is discontinuously formed on both main surfaces of the positive electrode current collector 13, and the positive electrode 10 is produced. The portion where the positive electrode current collector 13 is exposed without forming the positive electrode active material layer 14 is referred to as a bent portion 15 in a later step. Further, at one end of the positive electrode current collector 13 in the longitudinal direction, a slightly longer region where the positive electrode current collector 13 is exposed is used as the positive electrode tab 8.

【0043】

As a method of forming the positive electrode active material layer 14 discontinuously, a coating material for the positive electrode active material layer is uniformly printed or applied on the positive electrode current collector 13, and after drying, the positive electrode active material layer in a predetermined region is removed. A method of printing a positive electrode active material layer 14 having a predetermined shape on the positive electrode current collector 13 or a coating device provided with an intermittent coating mechanism is used to activate the positive electrode having a predetermined shape on the positive electrode current collector 13. Examples thereof include a method of intermittently applying the material layer 14.

【0044】

Next, as shown in FIG. 7, a sealing material 16 for preventing an internal short circuit is added to the exposed portion of the positive electrode current collector 13 which is the bent portion 15 and the base of the positive electrode tab 8 of the positive electrode 10. Examples of the method for adding the sealing material 16 include heat welding such as a hot air method, an impulse sealing method, a high frequency method and an ultrasonic sealing method, and an adhesive coating method such as a hot melt method.

【0045】

Further, a band-shaped negative electrode current collector 17 having a length approximately half that of the positive electrode 10 is prepared, and a paint for a negative electrode active material layer is printed or applied on both main surfaces of the negative electrode current collector 17. The negative electrode active material layer 18 as shown in FIG. 8 is formed to prepare the negative electrode 11. Prepare another similar negative electrode 11. Of the two prepared negative electrodes 11, one is referred to as the first negative electrode 11a and the other is referred to as the second negative electrode 11b.

【0046】

Next, the solid electrolyte film 12 is attached to both main surfaces of the negative electrode 11. In the following description, an example in which the solid electrolyte film 12 is bonded to both main surfaces of the negative electrode 11 is given, but the present invention is not limited to this, and for example, the solid electrolyte film is previously formed on both main surfaces of the positive electrode 10. You may paste 12 together. Further, when the positive electrode 10 and / or the negative electrode 11 is devised to prevent a short circuit, the solid electrolyte film 12 is unnecessary.

【0047】

Next, as shown in FIG. 9, in each bent portion 15 of the positive electrode 10, the valley fold and valley fold lines and the mountain fold line with respect to the main surface creasing repeat and Ri line in this order. Further, a crease 19 is made with respect to the negative electrode 11 at a position where the negative electrode 11 is substantially bisected in the longitudinal direction. Here, each bent portion 15 is referred to as a bent portion 15a, a bent portion 15b, and a bent portion 15c in this order from the side on which the positive electrode tab 8 is formed.

【0048】

Next, as shown in FIGS. 10 and 11, the first negative electrode 11a folded in half so that the mountain fold line of the positive electrode 10, that is, the bent portion 15b and the crease 19a of the first negative electrode 11a coincide with each other. The inner main surface of the positive electrode 10 and the region from the bent portion 15a to the bent portion 15c of one main surface of the positive electrode 10 are overlapped with each other facing each other. At the same time, a second negative electrode 11b is prepared, and the bent portion 15c of the positive electrode 10 and the crease 19b of the second negative electrode 11b are aligned so that the main surface inside the second negative electrode 11b folded in half and the main surface inside the second negative electrode 11b are formed. The region from the bent portion 15b on the other main surface of the positive electrode 10 to the end on the opposite side of the positive electrode 10 from the positive electrode tab 8 is overlapped with each other facing each other.

【0049】

At this time, the elementary battery 2 is positioned so that the negative electrode tabs 6 overlap each other when stacked.

【0050】

Next, the solid electrolyte film 12 adheres between the positive electrode 10 and the negative electrode 11 by pressing and crimping the positive electrode 10 and the negative electrode 11 which are alternately overlapped as shown in FIG. 11 from above and below, and the positive electrode 10 The elementary battery 2 as shown in FIG. 12 is obtained in which the negative electrode 11 and the negative electrode 11 are alternately laminated via the solid electrolyte film 12.

【0051】

Next, as shown in FIG. 13, the negative electrode tabs 6 and the positive electrode tabs 8 are aligned in the thickness direction, and the positive electrode 10 forming the outermost layer of one of the elementary batteries 2 is adjacent to the elementary batteries 2. Three elementary batteries 2 are laminated in the thickness direction so that the negative electrode 11 forming the outermost layer of the elementary battery 2 faces the negative electrode 11 via the solid electrolyte film 12.

【0052】

At this time, as shown in FIG. 13, it is preferable to prepare the elementary batteries 2a, the elementary batteries 2b, and the elementary batteries 2c whose lengths in the longitudinal direction are lengthened in this order as the elementary batteries 2, and to stack them in sequence.

【0053】

Next, by pressing the stacked elementary batteries 2 from above and below, the elementary batteries 2 are adhered to each other by the solid electrolyte film 12 interposed between the elementary batteries 2, and the battery element 3 as shown in FIG. 14 is obtained. ..

【0054】

Next, protective plates 5 are arranged on both main surfaces of the battery element 3.

【0055】

Next, a reed is connected to each electrode in order to conduct the same electrodes between the elementary batteries 2 of the battery element 3 to each other. That is, a plurality of positive electrode tabs 8 derived from the longitudinal end of each elementary battery 2 are physically and electrically connected to the positive electrode lead 9. Further, a plurality of negative electrode tabs 6 derived from one side in the width direction of each elementary battery 2 are biased onto the protective plate 5 and physically and electrically connected to the negative electrode leads 7. The negative electrode lead 7 projects to the side opposite to the positive electrode lead 9 of the battery element 3.

【0056】

Next, the negative electrode lead 7 and the positive electrode lead 9 are pulled out to the outside, and the battery element 3 is sealed with the exterior material 4, so that the battery precursor 20 as shown in FIG. 15 is produced.

【0057】

Next, the battery precursor 20 is molded into a predetermined shape using, for example, a curved surface molding device 21 as shown in FIG. 16, to produce a curved solid electrolyte battery 1.

【0058】

As shown in FIG. 17 (1), the curved surface forming apparatus 21 is composed of a cylindrical forming guide 22 having an appropriate curvature and a forming guide 22 which is arranged parallel to and directly above the axis of the forming guide 22. It has a fixing member 23 capable of holding the battery precursor 20 between them, and a pair of molding rollers 24 arranged on both sides of the fixing member 23 and capable of rolling on the peripheral surface of the molding guide 22. The molding guide 22 is not limited to the one having a circular cross section as shown in FIG. 17 (1), and any shape can be used.

【0059】

When imparting curvature to the battery precursor 20, first, as shown in FIG. 17 (1), the battery precursor 20 is fixed to the curved surface forming apparatus 21. Specifically, the band-shaped battery precursor 20 is arranged on the peripheral surface of the molding guide 22 so as to be orthogonal to the axis of the molding guide 22, and is sandwiched between the molding guide 22 and the fixing member 23. At this time, the molding guide 22 and the fixing member 23 are positioned so as to sandwich the substantially central portion of the battery precursor 20 in which the negative electrode tab 6 is formed in the longitudinal direction.

【0060】

Next, as shown in FIGS. 17 (2) and 17 (3), the battery precursor 20 is sandwiched between the apex of the peripheral surface of the molding guide 22 and the fixing member 23, and the battery precursor 20 is placed on the peripheral surface of the molding guide 22. Roll the forming roller 24 along. Along with this, when the pressure of the molding roller 24 slightly exceeds the adhesive force of the solid electrolyte film 12, the positive electrode 10 forming between the elementary batteries 2 and the elementary batteries 2 is maintained while maintaining the adhesive force of the solid electrolyte film 12. Delamination (so-called misalignment) occurs between the forming roller 24 and the negative electrode 11 in the moving direction of the forming roller 24. In this way, the molding pressure on the battery element 3 and the delamination gradually impart curvature to the battery precursor 20 from the fulcrum toward both ends of the battery precursor 20.

【0061】

At this time, depending on the thickness of the battery element 3, the degree of delamination is small on the inner peripheral side of the battery element 3, and the degree of delamination is relatively large on the outer peripheral side, that is, a so-called inner and outer peripheral difference is generated. As shown, battery precursors 2 having different lengths are prepared, and these are stacked in order of length to form a battery element 3, and a battery precursor is provided so that the short battery 2 is on the inner peripheral side. It is preferable to mold 20. As a result, the battery elements 3 are aligned so that the ends of the elementary batteries 2 are not displaced due to the difference between the inner and outer circumferences when molding into a curved surface shape. Therefore, a wider facing area between the positive electrode 10 and the negative electrode 11 can be secured.

【0062】

On the other hand, when a battery element formed by stacking elementary batteries of the same length is formed into a curved surface shape, the ends of the elementary batteries are displaced due to the difference between the inner and outer circumferences, and the positive electrode and the negative electrode do not face each other. That is, a region that is not involved in the battery reaction is generated, which may lead to a decrease in capacity per unit volume.

【0063】

Further, by arranging the protective plates 5 on both main surfaces of the battery element 3, the elementary battery 2 on the inner peripheral side is affected by the difference between the inner and outer circumferences when giving curvature to the flat battery precursor 20. It is possible to prevent distortion and wrinkles from occurring.

【0064】

The pressure for molding the battery precursor 20 is not particularly limited, but if the pressure of the molding roller 24 is set excessively high, the battery precursor bends and the positive electrode and / or the negative electrode breaks through the solid electrolyte film. Therefore, it is preferable to appropriately determine the optimum value according to the number of elementary batteries 2 constituting the battery element 3.

【0065】

Finally, as shown in FIG. 16 (4), the battery precursor 20 has a curved surface shape substantially the same as the shape of the peripheral surface of the molding guide 22, and becomes a solid electrolyte battery 1 having a desired shape.

【0066】

According to the above-mentioned manufacturing method of the solid electrolyte battery, not only the planar shape but also the conventional molding is difficult while achieving high capacity and suppressing the occurrence of internal short circuit to maintain excellent reliability. It is possible to easily manufacture the solid electrolyte battery 1 which can take various shapes depending on the usage pattern such as a curved shape and a bendable shape. Moreover, by using a so-called solid electrolyte that does not contain a solvent as the electrolyte, it is possible to manufacture a solid electrolyte battery that exhibits extremely high safety without worrying about liquid leakage even when the shape is deformed as described above.

【0067】

Further, as described above, the positions where the negative electrode tabs 6 are derived are arranged on the normal line with respect to the laminated surface, and the battery precursor 20 is given a curvature with the position where the negative electrode tabs 6 are derived as a fulcrum. It is preferable to go. As a result, even when the delamination between the positive electrode 10 and the negative electrode 11 and the misalignment between the elementary batteries 2 occur, the displacement stress at the position of the negative electrode tab 6 is minimized. Therefore, the load applied to the negative electrode tab 6 due to the difference between the inner and outer circumferences between the elementary batteries 2 is reduced, and the curved solid electrolyte battery 1 can be manufactured without causing damage to the negative electrode tab 6.

【0068】

As described above, the solid electrolyte battery to which the present invention is applied has high capacity and high safety, has few restrictions on the shape, and can correspond to various shapes such as a curved surface shape. Therefore, the solid electrolyte battery to which the present invention is applied reduces restrictions on the shape of the battery housing of the electronic device to be mounted, realizes miniaturization and thinning of the electronic device, and improves the design and function of the electronic device. It is possible to relax the restrictions and contribute to the diversification of variations of electronic devices. Furthermore, the solid electrolyte battery to which the present invention is applied can be used in a worn state, such as by molding it into a wristband shape and wearing it on the wrist, taking advantage of its high safety and excellent flexibility. It will be possible and the range of applications of batteries will be newly expanded.

【0069】

Further, according to the present invention, it is possible to easily manufacture a solid electrolyte battery having various shapes having high capacity and high safety.

【0070】

In the above description, a solid electrolyte battery in which three elementary batteries are stacked to form a battery element is given as an example, but the present invention is not limited to this, and the number of stacked elementary batteries of the battery element is not limited to this. Can be increased or decreased arbitrarily.

【0071】

Further, in the above description, a method of imparting a curvature to the battery precursor 20 after the battery element 3 is housed in the exterior material 4 has been given as an example, but for example, the curvature is imparted to the battery element 3 in advance. , The curved battery element 3 may be housed in the exterior material 4.

【0072】

Further, the solid electrolyte battery to which the present invention is applied may have a structure in which the positive electrode and the negative electrode are interchanged in the above-mentioned solid electrolyte battery 1.

【0073】

Further, the present invention can be applied to both a primary battery and a secondary battery.

【0074】

[Effect of the invention]

As is clear from the above description, in the solid electrolyte battery according to the present invention, the elementary battery has a composite structure of a folding structure and a laminated structure, and the second electrode sheets are tabs derived from the edges in the longitudinal direction. Are electrically connected to each other. As a result, a wide facing area is secured between the first electrode and the second electrode, and even when an external force such as imparting a curvature to the solid electrolyte battery is applied, between the elementary batteries. Since the degree of freedom of displacement is increased and the load on the tab is reduced, it is possible to prevent stress concentration from occurring in the battery element. That is, it is possible to achieve a high capacity and to form various shapes according to the usage pattern. Further, since the solid electrolyte battery according to the present invention uses a solid electrolyte as the electrolyte, there is no risk of liquid leakage even when various shapes and flexibility are required, and the safety is extremely high. Is shown. Therefore, according to the present invention, it is possible to provide a solid electrolyte battery that can be molded into various shapes such as a curved surface shape while ensuring high capacity and excellent reliability.

【0075】

Further, according to the present invention, the first electrode and the second electrode are folded and laminated to produce a base battery, and a plurality of the base batteries are laminated to manufacture a battery element. Next, the tabs derived from the longitudinal edge are electrically connected to collect current from the second electrode. Therefore, even when an external force such as imparting a curvature is applied, the solid electrolyte is less likely to cause stress concentration in the battery element due to the high degree of freedom of displacement in and / or between the elementary batteries. Can manufacture batteries. Therefore, according to the present invention, it is possible to easily manufacture a solid electrolyte battery which has a high capacity and excellent reliability and can take various shapes such as a curved surface shape.

[Simple explanation of drawings]

[Figure 1]

It is sectional drawing which shows one structural example of the solid electrolyte battery to which this invention was applied.

[Figure 2]

It is sectional drawing of the main part of a battery element.

[Fig. 3]

It is sectional drawing of the main part of the elementary battery.

[Fig. 4]

It is sectional drawing which shows the battery element before giving a curvature.

[Fig. 5]

It is sectional drawing which shows the state which gave the curvature to the battery element which is made by stacking elementary batteries of the same length.

[Fig. 6]

It is a perspective view which shows the state which the positive electrode active material layer is formed on the positive electrode current collector.

[Fig. 7]

It is a perspective view which shows the state which the sealing material is loaded on the positive electrode.

[Fig. 8]

It is a perspective view which shows the negative electrode.

[Fig. 9]

It is a perspective view which shows the positive electrode and the negative electrode which made the crease.

[Fig. 10]

It is a perspective view which shows the state in which the positive electrode and the negative electrode shown in FIG. 9 are overlapped.

[Fig. 11]

It is a perspective view which shows the state in which the positive electrode and the negative electrode shown in FIG. 10 are further overlapped.

[Fig. 12]

It is a perspective view which shows the elementary battery formed by pressing the positive electrode and the negative electrode shown in FIG.

[Fig. 13]

It is a perspective view which shows the state which three elementary batteries of different lengths are stacked.

[Fig. 14]

FIG. 3 is a perspective view showing a battery element composed of the three elementary batteries shown in FIG.

[Fig. 15]

It is sectional drawing which shows the battery precursor.

[Fig. 16]

It is sectional drawing which shows the state which gives the curvature to the battery precursor, and shows the solid electrolyte battery of a curved surface shape.

[Fig. 17]

It is sectional drawing of the electrode of the winding type structure which is a conventional electrode structure.

[Fig. 18]

(a) is a perspective view of an electrode having a laminated structure, which is a conventional electrode structure. (b) is an AA cross-sectional view of the electrode shown in (a).

[Fig. 19]

(a) is a perspective view of an electrode having a foldable structure, which is a conventional electrode structure. (b) is a BB cross-sectional view of the electrode shown in (a).

[Explanation of symbols]

1 solid electrolyte battery, 2 element battery, 3 battery element, 4 exterior material, 5 protective plate, 6 negative electrode tab, 7 negative electrode lead, 8 positive electrode tab, 9 positive electrode lead, 10 positive electrode, 11 negative electrode, 12 solid electrolyte film, 13 positive electrode Current collector, 14 positive electrode active material layer, 15 bent part, 16 sealing material, 17 negative electrode current collector, 18 negative electrode active material layer, 19 creases, 20 battery precursor, 21 curved surface forming device, 22 forming guide, 23 fixed Parts, 24 forming rollers