Lateral component for spacing the plates of a stack of plates in an electrochemical battery and process for establishing a nondetachable, fluid- and gas-tight junction with said plates

(42) Date of commencement of the patent: 15. 8.1997 (45) Date of issue: 27. 4.1998

<td>(56) Documents:</td><td>(73) Patent owner:</td>

<td>EP 0479765A2 OE 3408373A1</td><td>ELIN ENERGIEANNEMXJNG SOCIETY HBH A-1141 VIENNA (AT).</td>

<td></td><td>(72) Inventor:</td>

<td></td><td>TCMAZIC GERD DIPL.ING. DR. MÜRZZUSCHLAG, STEIEFMARK (AT).</td>

(54) SIDE COMPONENT FOR THE SPACING POSITIONING OF THE PLATES OF A PLATE STACK OF ONE

ELECTROCHEMICAL BATTERY, AND METHOD FOR PRODUCING AN UNMATCHABLE, FLUID AND GAS-DIRECT CONNECTION TO THESE PLATES

CD

AT 403 634 (57) The invention relates to a side member made of electrically non-conductive material for spacing a stack of plates from successive, thin-walled electrode plates with separator plates arranged therebetween for electrochemical batteries, especially for zinc-bromine batteries, as well as for the fluid and gas-tight connection of the end regions of the electrode plates and separator plates, and a method for producing a non-detachable and fluid and gas-tight connection between the Plattenfepel and the side member.

According to the invention, the side member (3) is plate-shaped with reinforcing ribs (8) and provided with passage openings (7) for connecting a pipe system for conveying the electrolyte. Until the melting temperature has been reached, the area of ​​the end faces (5) and the side of the side component (3) facing the plate fens (4) are radiated by a heating mirror (2) introduced temporarily and at a spacing between the side component (3) and plate stack (1) heated and then, after removal of the heating mirror (2), the side member (3) and the end faces (5) gegensteindgepreßt to Werkstoftekaltung

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AT 403 634 Β

The invention relates to a soap component made of electrically nonconducting material for the distance positioning of a plate stack of successive, thin-walled electrode plates, each with separator plates arranged therebetween for electrochemical batteries, especially for zinc-bromine batteries, and for the fluid-tight and gas-tight connection of the end regions of the electrode plates and separator plates, and a method for producing a non-detachable and fluid and gas-tight connection between the plate stack and the side member.

Zinc-bromine batteries are made up of bipolar electrode plates made of plastic-bonded carbon. The individual electrode plates are separated by flat, made of plastic Separatorplatten. By producing the electrode plates and / or separator plates with reinforced plastic side edges, electrode interspaces, specifically anode and cathode spaces, respectively result between electrode plates and separator plates.

The electrolytes, that is to say anolyte and catholyte, are each guided as separate circuits and are introduced and discharged via transverse distribution tunnels into the anode or cathode compartments. For both electrolyte circuits each own electrolyte reservoir is provided with pump.

Because of the high reactivity of the bromine, special attention must be paid to the chemical resistance of the plastics used. It is also important that the end portions of the electrode plates and Separatorplatten, which form the conclusion of the aforementioned anode and Katodenräume be closed both fluid and gas-tight.

Another problem with bromine-zinc batteries is that in their - resulting from the stacking of a plurality of electrode plates and Separatorplatten - stacking plates stack the tolerances of the plate thicknesses, so that a precise match with the inlet and outlet openings for the connection the electrolyte-promoting circulatory systems, after completion of the final plate positioning, difficult to guarantee.

It is known a method in which the end portions of the electrode plates and Separatorplatten are glued together.

In practice, however, has shown that with this method no tightness can be guaranteed.

Furthermore, it has been proposed to carry out the connection of the end regions by screw fastening a provided with a seal plate-shaped side part, wherein the screws engage directly in the end face area. Even so, it is not possible, mainly due to distortions of the seal, to prevent leakage of the electrolyte.

Furthermore, a method is used, which is to heat a plate-shaped thermoplastic member and the end portions of the electrode plates and Separatorplatten by contact with a heating element and then to press the component to the end faces. The compounds created by this method can only guarantee the fluid and gas density for a very limited period of time.

By extruding sidewalls on the plate stacks consisting of electrode plates and separator plates, the problem of tightness could indeed be improved; However, there is the disadvantage that a warpage of the side edges and thus also the electrode plates and Separatorplatten occurs.

Furthermore, it is disadvantageous that after completion of the extruded side walls in a further operation passage openings for the connection of the electrolyte lines to the anode and cathode chambers must be created. Due to the distortion of the forehead areas during extrusion, it is not always possible to place the passage openings precisely enough so that large material failures occur.

In addition, the inaccuracies of the plate spacing produced during extrusion have the effect of shortening the service life, as well as deviations in the rated output and, in addition, faster power loss of the battery.

The object of the invention is to design a side member and a method for its connection to the plate package, whereby a precise final positioning of the electrode plates and separator plates to each other, as well as fluid and gas tightness of the plate stack is ensured to the outside.

The object is achieved by the invention. This is characterized that the side member is plate-shaped and formed on the side facing away from the plate stack with reinforcing ribs and on the side facing the plate stack with a light surface structuring, and that passage openings are provided for connecting a pipe system lying outside the plate stack to electrolyte distribution channels arranged inside the battery, wherein the side member is preferably made of a thermoplastic material and has a consideration of the respective electrolyte used taking into account chemical resistance.

AT 403 634 Β

With the invention it is possible to extend the life of batteries of the type mentioned enormously. In addition, compliance with the specified nominal data can be guaranteed.

In the context of the invention, a method for producing a non-detachable and fluid-tight and gas-tight connection between the plate stack and the side member is provided, which is characterized that the side member is guided at a distance and parallel to the respective Stinseiten the electrode plates and separator plates of the plate stack and then the area of ​​the end faces and at the same time the plate stack facing side of the side member temporarily exposed to a heating of the surface up to melting temperature and then be pressed against each other to Werkstoftekaltung ,

This is advantageous because it retains most of the crystallinity of the thermoplastic materials.

In one embodiment of the invention, the heating of the plate stack facing side of the side member and the region of the end faces of the electrode plates and Separatorplatten by means of a joining welding process.

The advantage that results from this is the possibility of an uncomplicated adaptation of any existing welding devices for the application of the method according to the invention.

A development of the invention provides the heating of the side of the side component facing the plate stack and of the region of the end sides of the electrode plates and separator plates takes place by means of the mirror welding method, wherein until reaching the melting temperature, the end faces and the plate stack facing side of the side member pressed against a temporarily introduced between the side member and plate stack heating mirror and then, after removal of the heating mirror, the side member and the end faces are pressed against each other to Werkstoftwerkaltung.

This advantageously further increases the quality of the connection between the side component and the stack of plates.

In a special embodiment of the invention, the heating of the side member and the region of the end faces of the electrode plates and separator plates by means of the mirror welding process, wherein, until the melting temperature has been attained, the end faces and the side of the side component facing the plate stack are heated by radiation, and subsequently, by a heating mirror introduced temporarily and in each case at a distance between the side component and the plate stack; after removal of the heating mirror, the side member and the end faces are pressed against each other to the Werkstofferkaitung.

In this way, a particularly high quality of connection between side member and plate stack can be combined with short production times.

In a particular embodiment of the invention recesses for the positioning of the inlet and outlet openings of the positioning device are provided to the electrode spaces in the heating mirror.

This is advantageously prevented that the inlet and outlet ports must be pretreated for further processing of the battery.

Based on embodiments, the invention will be explained in more detail. FIGS. 1 to 6 illustrate the subregions of the invention, each of which is specified in claims 1 to 6.

In Fig. 1 is a plate stack 1 for electrochemical batteries can be seen, which consists of thin-walled electrode plates, each with separator plates arranged therebetween. Parallel and - for the time being - at a distance from the end faces of the plate stack 1 is the side member 3 according to the invention. The side member 3 is plate-shaped; he has on the plate stack 1 side facing a light surface structuring 6, while it is provided on the side facing away from the plate stack 1 with reinforcing ribs 8. To connect a lying outside the plate stack 1 pipe system to the battery inside arranged electrolyte distribution channels through openings 7 are provided. The side member 3 is preferably made of a thermoplastic material. It must have a chemical resistance which takes into account the particular electrolyte used.

FIG. 2a shows, in a highly schematic form, how the heating of the end faces 5 of the electrode plates and separator plates 4 of the plate stack 1 and the side of the side member 3 facing the plate stack 1 are carried out in the basic principle. In the present case, a hot air stream 9 is guided past the surfaces to be heated. After their appropriate melting the air flow 9 is turned off; Thereafter, the said surfaces are pressed against each other until the occurrence of Werkstoftwerkaltung. In Fig. 2b, the components, which are already connected together in a fluid-tight and gastight manner, plate stack 1 and side component 3 can be seen.

Fig. 3 is concerned with the application of the principle of Fügeschweißens on the present inventive method. The heating of the corresponding surfaces of plate stack 1 and side member 3 is carried out in this case advantageously by means of a heating source 10, which temporarily between the corresponding sides of the components to be heated, ie the plate stack 1 side facing

AT 403 634 Β of the side member 3 and the region of the end faces 5 of the electrode plates and Separatorpiatten 4 is introduced. With Α, B and C, the respective production stages are marked in the process according to the invention.

As shown in FIG. 4 can be seen in the production phase A one of a plurality of electrode plates and separator plates 4 existing plate stack 1 at a distance and parallel to the end faces 5 of the plates 4 of the side member 3 according to the invention. Above the gap of side member 3 and plate stack 1 is a heating mirror 2, the heater is not turned on at this time. The manufacturing phase B of FIG. 4 shows the lowered, already on the plate stack 1 concretely: on the end faces 5 of the electrode plates and Separatorpiatten 4 - and the side member 3 adjacent heating mirror. 2 In this phase of production, the Heizspiegei 2 is already turned on. The areas of the front side 5 of the electrode plates and Separatorpiatten 4, as well as the Plattenstapei 1 facing side of the side member 3 are now heated directly from the heating mirror 2. The heating phase only lasts until a sufficient - low - layer of the surface of the side member 3 and the region of the end faces 5 is melted. Then, the heating mirror 2 is pulled up, the heater is turned off and the molten surface layers of side member 3 and end faces 5 pressed against each other. Phase C of the production shows the insoluble at the end faces 5 of the plates 4 as well as fluid and gas tight adherent side member. 3 During the so-called joining time, which is composed of pressing time and cooling time, a compound of the thermoplastic parts was formed in which the majority of crystallinity was retained; this implies a quality guarantee both for the mechanical strength and for the fluid and gas density of the joint created.

The in Fig. 5 schematically represented method corresponds largely: namely in the manufacturing phases A and C, that It. FIG. 5th Again, a Heizspiegei 2 is used, but now the corresponding surfaces are heated by infrared radiation. For this reason, as can be seen in production phase B, the heating mirror 2 is lowered at a distance and parallel to the plate stack 1 and the side panel 3. In this phase of production, the Heizspiegei is already turned on. The areas of the front side 5 of the electrode plates and Separatorpiatten 4, as well as the plate stack 1 facing side of the side member 3 are thus now heated by infrared radiation. After raising the heating mirror 2 and switching off its heating (production phase C), the molten surface layers are pressed against each other until they cool.

Fig. 6 shows an embodiment of a heating mirror 2, in which recesses 11 are provided for the positioning of the inlet and outlet openings of a positioning device 12 to the electrode spaces.

In special designs of heating mirrors and associated mirror-lowering devices, it is of course also possible to carry out the manufacturing process without respective Ausund and switching on the heater because of the short cycle times.