WO2014060579A1

WO2014060579A1 - Rechargeable battery cell, and battery module

Info

Publication number: WO2014060579A1
Application number: PCT/EP2013/071839
Authority: WO
Inventors: Dietmar Niederl; András LUKÀCS; Harald Stütz; Volker Hennige; Thomas TRAUSSNIG
Original assignee: Avl List Gmbh
Priority date: 2012-10-18
Filing date: 2013-10-18
Publication date: 2014-04-24
Also published as: AT513558A1; AT513558B1; DE112013003981A5

Abstract

The invention relates to a rechargeable battery cell (100, 100') with a housing in which a first and a second electrode (41, 42) are arranged. The housing has at least one first and at least one second housing part (10, 20), and the first and the second housing parts (10, 20) are each made of plastic.

Description

Rechargeable battery cell and battery module

The invention relates to a rechargeable battery cell having a housing, in which a first and a second electrode are arranged, wherein the housing has at least a first and at least a second housing part and the first and the second housing part are each made of plastic, and a battery module.

Rechargeable batteries, so-called accumulators are found in all areas of technology. In the automotive industry, such accumulators are used for alternative drive systems, with high demands on performance, reliability and maintenance of the accumulators used in this area. In particular, the size and weight of such high capacity accumulators are a significant factor in their efficiency in automotive applications.

Battery cells of the type mentioned can be removed, for example, WO 2012/025505 AI, DE 10 2010 013 028 AI or DE 10 2010 041 285 AI.

It is therefore an object of the invention to provide a rechargeable battery cell, which has a low weight with high security against voltage flashovers in high voltage systems and is also inexpensive to manufacture. At the same time, for the optimal operation of the battery cell, a uniform distribution of an electrolyte inside the cell and in particular at the electrodes is essential.

This object is achieved by a battery cell of the type mentioned above in that the second housing part has a flow device for an electrolyte liquid. The electrolyte liquid, which serves for reactant transport within the battery cell, is supplied from the outside. On the one hand it supplies the active material of the electrodes with the reactant, on the other hand it simultaneously serves to cool the battery cell according to the invention by dissipating the heat generated during the reaction. Therefore, no separate cooling circuit is needed. In this way, a particularly slim design of the battery cell according to the invention is achieved.

In order to obtain a uniform distribution of the electrolyte liquid within the battery cell, in a preferred embodiment of the invention, the flow device has at least one inlet opening and at least one outlet opening for the electrolyte liquid, wherein the inlet opening and the outlet opening communicate with one another via at least one flow channel. Conveniently, the inlet opening and the outlet opening are each designed as openings penetrating the entire battery cell. The longitudinal axes of the openings are arranged substantially normal to the longitudinal axis of the battery cell. These openings are connected to the at least one flow channel as described above. It is particularly preferred that a plurality of flow channels is provided, wherein the flow channels are preferably arranged parallel to each other in order to obtain a uniform flow.

The uniform flow of the electrolyte liquid within the battery cell is further improved in that the flow channels communicate with the at least one inlet opening via a first liquid reservoir, the flow cross section of the first liquid reservoir having a multiple of the flow cross section of the flow channels. In one variant of the invention, the flow channels are favorably connected to the at least one outlet opening via a second liquid reservoir, the flow cross section of the second liquid reservoir also having a multiple of the flow cross section of the flow channels here.

Battery cells can be connected to a battery module either serially or in parallel. In a variant of the invention, the flow device of the battery cell according to the invention has two inlet openings and two outlet openings for the electrolyte liquid, which can be connected in series or in parallel with the inlet openings and outlet openings of at least one second battery cell, depending on the desired arrangement.

The housing of the battery cell according to the invention has at least a first and at least one second housing part, which are each made of plastic. The plastic is arbitrary, but advantageously chosen so that it withstands ionic liquids - a suitable plastic would be e.g. Polyamide, others are possible. This low weight and ease of manufacture allows, and it takes place in a simple way insulation against adjacent battery cells.

In a variant of the invention, the second housing part has a receiving recess for an active material of the battery cell, while the first housing part is designed as a cover plate element for the receiving recess. With active material here for the storage of the energy of the battery cell necessary material is referred to - in the present case, therefore, the first and second electrode.

In a further variant of the invention, the second housing part has a bottom plate element and a frame element arranged on the bottom plate element, while the first housing part is designed as a cover plate element. Frame member and bottom plate member of the second housing part may be made in one piece or separately, wherein they are connected to each other in the second case by corresponding known connection methods. Frame member and bottom plate member then form the above-described receiving recess for the active material. The cover plate member is arranged on the side opposite the bottom plate member side of the frame member. As described above, the lid plate member functions as a lid for the receiving recess.

It is particularly preferred that the plastic fiber-reinforced, in particular made with glass fiber offset, in order to achieve an improved rigidity of the housing, without substantially increasing the low weight achieved by the use of plastic. At the same time, the use of plastic has the advantage already mentioned above that the insulation required for the housings made of metal, which are usually used, is not required for voltage flashovers, for example to adjacent battery cells.

A cost-effective production of the battery cell according to the invention in particular in large quantities is given if the first and the second housing part are made by injection molding or thermoforming, and the two housing parts are preferably connected by gluing, plastic laser welding or friction welding.

In order to merge the battery cell according to the invention with at least one adjacent battery cell in a simple manner to form a battery module, in a preferred embodiment of the invention, the housing at least one positioning, wherein the at least one positioning device is arranged in a region of the battery cell, which in arrangement of the Battery cell facing in a battery module of an adjacent battery cell. Conveniently, the housing has a plurality of positioning devices, which are preferably arranged on opposite sides of the housing. According to a variant of the invention, the at least one positioning device is designed as a positioning pin or as a positioning pin.

For example, it is provided that a positioning pin is arranged on the housing, for example on the first housing part, while a correspondingly dimensioned positioning pin receptacle is provided on the second housing part. If now two battery cells are plugged together, then the positioning pin of the first battery cell is arranged in the positioning pin receptacle of the second battery cell. If, in particular, two such positioning devices are provided on each housing part, then the two battery cells are fixed relative to one another in their position. It is particularly preferred in this case that the position devices are manufactured in one piece with the housing or the respective housing parts. A particularly slim and simple construction of the battery cell is achieved if the flow device and the second housing part are made in one piece, in particular made of plastic.

Conveniently, in a further embodiment of the invention, the flow device is embodied at the bottom of the receiving recess described above or on the base plate element described above. In a variant of the invention, in this case flow device and bottom plate element of the second housing part are manufactured in one piece.

The structure according to the invention is particularly suitable for use in lithium-air batteries. Here, the first electrode is made, for example, of a porous material, such as e.g. Graphite wetted by the electrolyte fluid. As the second electrode, for example, metallic lithium is used.

The object is further achieved by a battery module having at least two battery cells according to the invention. Battery cells can be connected to a battery module either serially or in parallel. In a variant of the invention already described, the flow device of the battery cell according to the invention has two inlet openings and two outlet openings for the electrolyte liquid, which can be connected in series or in parallel with the inlet openings and outlet openings of at least one second battery cell, depending on the desired arrangement.

In this case, it is particularly preferably provided that an inlet opening for the electrolyte liquid of the first battery cell is in fluid-tight connection with an inlet opening of at least one second adjacent battery cell and an outlet opening of the first battery cell with an outlet opening of at least one adjacent second battery cell. Thus, by arranging two or more battery cells in succession through the inlet openings arranged in this way, an inlet pipe and through the thus arranged outlet openings a collecting tube for the electrolyte liquid within the battery module is formed, which allows a uniform inflow or withdrawal of the electrolyte liquid. The battery cells are in this case connected in parallel with regard to the electrolyte flow.

In order to prevent the escape of electrolyte fluid from the battery module, in a preferred embodiment of the invention in the region of the inlet openings and in the region of the outlet openings provided sealing grooves for receiving sealant, in particular soft-material seals.

The battery module according to the invention is particularly suitable for use in drive systems of motor vehicles due to its low weight, its slim design and high reliability. The invention is explained in more detail below with reference to a non-limiting exemplary embodiment with associated figures. Herein shows

1 is an exploded view of the battery cell according to the invention,

FIG. 2 shows the second housing part of the battery cell from FIG. 1,

3 shows the second housing part from FIG. 2 with the active material,

Figs. 4a, 4b. a partial cross-sectional view of the battery cell of FIG. 1,

Fig. 5 is an exploded view of another embodiment of

Battery cell

Fig. 6 shows two battery cells in serial circuit, and

7 shows a battery module according to the invention.

In Fig. 1 shows an exploded view of the construction of the battery cell 100 according to the invention. It has a first housing part 10, which is designed as a cover plate element, that is essentially flat. The first housing part has a cell pole 13, for example made of copper, and is provided on the inside of the battery cell 100 facing inside with a consisting of sponge-like material compression element 30 (Figs 4a, 4b), which in the assembled state of the battery cell 100, the active material 40 of Battery cell 100, in the present example, a graphite electrode as a first electrode 41 and metallic lithium as a second electrode 42 (see FIGS. 4a and 4b), pressed against the flow device described below in the second housing part 20. This compression element 30 also serves to compensate for differences in expansion of the active material 40 during the charging or discharging phases.

Furthermore, a second housing part 20 is provided. The second housing part 20 has a receiving recess for the active material 40 of the battery cell 100, wherein this receiving recess is formed in the illustrated embodiment, characterized in that the second housing part 20 has a bottom plate member 21 and a frame member 22. Frame member 22 and bottom plate member 21 may be made in one piece or - as shown in this example - separately. In the assembled state, the bottom plate element 21 is then arranged on one side of the frame element 22 and the first housing part 10 as a cover plate element on the other side of the frame element 22nd

The housing parts 10, 21, 22 are made of plastic, wherein the plastic is preferably fiber-reinforced, in particular offset with glass fiber, is executed. Thus, the housing can be made easily and resistant, and it can er- rehearsed and cost-effective manufacturing processes such as injection molding or thermoforming are used.

To connect the first housing part 10 and the second housing part 20 (or of the bottom plate element 21 and the frame element 22), proven methods such as gluing, plastic laser welding or friction welding can be used.

The second housing part 20 has a flow device for electrolyte liquid with two inlet openings 23 and two outlet openings 24 which communicate with each other via flow channels 25 extending parallel to one another (not visible in FIG. 1). According to FIG. 2, the flow device is embodied in one piece with the bottom plate element 21 or is located at the bottom of the receiving recess for the active material 40 formed by the frame element 22 and bottom plate element 21. The supply of the electrolyte liquid to the flow channels 25 takes place via a first liquid reservoir 26 due to its much larger flow cross-section with respect to the flow cross-section of the flow channels 25, a uniform flow through the flow channels 25 and thus a uniform wetting of the disposed in the immediate vicinity of the flow channels 25 active material 40 (see, for example, Fig. 3) guaranteed. At the same time, the resulting heat of reaction can be dissipated, so that no additional cooling system is to be provided.

For discharging the electrolyte liquid, a second liquid reservoir 26 'is provided, through which the flow channels 25 communicate with the outlet opening or the outlet openings 24. The flow cross section of the second liquid reservoir 26 'also has a multiple of the flow cross section of the flow channels 25.

The Fig. 3 shows the second housing part 20, on the flow device of which the active material 40 is arranged. The active material 40 is in this case encompassed by a frame, not shown, which is in electrically conductive connection with the active material 40 and has the cell pole 13, which serves for current collection.

In order to facilitate the arrangement of the battery cells 100, 100 'relative to each other during assembly of a battery module 200 (FIGS. 6 and 7) comprising a plurality of battery cells 100, 100', positioning devices 51, 52 (FIGS and 6) are provided, which are formed in the illustrated embodiment as positioning pins 51, 51 'and positioning pins 52, 52'. By means of these positioning devices 51, 51 ', 52, 52', adjacent battery cells 100, 100 'are fixed in a rotationally fixed manner relative to each other. Accordingly, the positioning devices 51, 51 ', 52, 52' are in regions of the battery cell 100 arranged, which face in arrangement of the battery cell 100 in a battery module 200 of an adjacent battery cell 100 '.

In Figs. 4a and 4b, the battery cell 100 according to the invention is shown schematically in cross section, FIG. 4a an upper area and FIG. 4b shows a lower area. Via the inlet opening 23, electrolyte liquid (arrow A) is fed into the battery cell 100, for. B. pumped (Fig. 4a). The inlet opening 23 extends through the entire battery cell 100 (the longitudinal axis of the openings, which runs substantially horizontally in the illustration according to FIG. 4a), is normal to the longitudinal axis of the battery cell 100, which runs vertically as shown - for reasons of clarity, these are Axes in the figures not shown) - Electrolyte thus penetrates from the left side (left as shown in Fig. 4a) along arrow A in the battery cell 100 and partially flows into the first liquid reservoir 26, partially enters the electrolyte fluid but also through the Battery cell 100 through and along the arrow A 'on the right again - so that in a battery module 200 (see Figures 6 and 7) and adjacent battery cells 100' are supplied with electrolyte liquid, or form the inlet openings 23, 23 'of adjacent battery cells 100, 100 'continuous inlet pipes.

The electrolyte liquid flows via the first liquid reservoir 26 into the flow channels 25 and thereby wets the active material 40 of the battery cell 100. The active material 40 consists of a first electrode 41, which is designed as a porous graphite electrode, and a second electrode 42 made of metallic lithium. Between flow channels 25 and first electrode 41 here is a net-like structure as a current collector (see, for example, Fig. 5) is arranged, whose net-like design does not hinder the reactant supply of the electrodes 41, 42.

In the case of a lithium-air secondary battery, the oxygen present in the porous electrode 41 reacts with lithium ions of the lithium electrode 42 in the electrolyte liquid, and oxygen is supplied as a reactant via the electrolyte liquid. In this case, the two electrodes 41, 42 are separated from one another by a commercially available separator (see, for example, FIG. 5), for example made of polymer material or ceramic.

At the same time, the circulating electrolyte liquid also serves to cool the battery cell 100 by dissipating heat of reaction from the battery cell 100. Due to the pumping pressure and, depending on the installation direction of the battery cell 100 and also the force of gravity, the electrolyte liquid flows via a second liquid reservoir 26 'to the outlet opening 24 and leaves the battery cell 100 in the direction of the arrow B (FIG. 4b). Again, the outlet opening 24 extends through the entire battery cell 100 - the effluent electrolyte fluid mixes that is to say with the electrolyte liquid flowing in from adjacent battery cells 100 'along the arrow B'.

In the Fig. FIG. 5 shows a further embodiment of the battery cell 100 in the variant as a metal-air accumulator in an exploded view. Again, the second housing part 20 has a bottom plate member 21 and a frame member 22. The bottom plate member 21 is made of plastic and has a plurality of parallel flow channels 25.

Between the flow channels 25 and the first electrode 41, a first current collector 41 a is arranged, which is made for example of aluminum and has a first cell pole 13. This first current collector 41 a is in conductive contact with the first electrode 41, a porous carbon, in particular graphite plate, which acts as a positive electrode of the battery cell 100. For the electrical separation of the first electrode 41 from the second electrode 42, in the present case a negative electrode made of metallic lithium, a separator 43 is arranged between the two electrodes 41, 42. In addition to lithium, alternative metal-air combinations can be used. The second electrode 42 also has a current collector 42a arranged in the region of the frame element 22 with a second cell pole 14.

Finally, a compression element 30 is provided which is arranged between the second electrode 42 and the first housing part 10 designed as a cover plate element and serves to compensate for changes in thickness during operation of the battery cell 100.

In the Fig. 6, two battery cells 100, 100 'are shown, which in the present example are arranged in series with one another to form a battery module 200 (see FIG. 7). It can be seen here how the positioning device, in the present case positioning pins 51, 51 'and corresponding positioning pin receptacles 52, 52', serve to precisely align the two battery cells 100, 100 'to one another. The inlet openings 23, 23 'and the outlet openings 24, 24' are in this case arranged in liquid-tight connection to each other, wherein a sealing element 27, in this case O-rings, in the corresponding inlet or. Outlet opening 23, 24 surrounding grooves are inserted, this tightness guaranteed. Due to the number of two inlet and outlet openings 23, 23 ', 24, 24' for the electrolyte liquid, only one of the two battery cells 100, 100 'has to be turned over in order to realize a series-connected cell stack with the battery cells 100, 100' according to the invention ,

In this way, according to FIG. 7 a plurality of battery cells 100, 100 ', a battery module 200 according to the invention, which is used for example as a drive unit for a motor vehicle. By the arrangement of the battery cells 100, 100 ' and their inlet and outlet ports 23, 23 ', 24, 24' to each other are continuous inlet and manifolds for the supply and removal of the electrolyte fluid and thus for cooling - in an emergency, by interrupting the electrolyte supply and the cell reaction can be stopped.

It is understood that the invention is not limited to the described embodiment. In particular, the shape and the number of housing parts can vary. Likewise, the arrangement of the flow channels can be designed differently. Also, the electrolyte does not necessarily have to be a liquid, as well as a gaseous electrolyte may be used depending on the cell type.

Claims

PATENT APPLICATIONS

A rechargeable battery cell (100, 100 ') having a housing in which a first and a second electrode (41, 42) are arranged, wherein the housing has at least a first and at least a second housing part (10, 20) and the first and the second housing part (10, 20) are each made of plastic, characterized in that the second housing part (20) has a flow device for an electrolyte liquid.

2. Rechargeable battery cell (100, 100 ') according to claim 1, characterized in that the flow device has at least one inlet opening (23, 23') and at least one outlet opening (24, 24 ') for the electrolyte liquid, wherein the inlet opening (23, 23 ') and the outlet opening (24, 24') via at least one flow channel (25) communicate with each other.

3. Rechargeable battery cell (100, 100 ') according to claim 2, characterized in that the inlet opening (23, 23') and the outlet opening (24, 24 ') in each case as the entire battery cell (100, 100') penetrating openings are executed ,

4. Rechargeable battery cell (100, 100 ') according to claim 2 or 3, characterized in that a plurality of flow channels (25) is provided, wherein the flow channels (25) are preferably arranged parallel to each other.

5. Rechargeable battery cell (100, 100 ') according to one of claims 2 to

4, characterized in that the flow channels (25) via a first liquid reservoir (26) with the at least one inlet port (23, 23 ') are in communication, wherein the flow cross section of the first liquid reservoir (26) a multiple of the flow cross section of the flow channels (25 ) having.

6. Rechargeable battery cell (100, 100 ') according to one of claims 2 to

5, characterized in that the flow channels (25) via a second liquid reservoir (26 ') with the at least one outlet opening (24, 24') are in communication, wherein the flow cross-section of the second liquid reservoir (26 ') is a multiple of the flow cross-section of the flow channels (25).

7. Rechargeable battery cell (100, 100 ') according to one of claims 2 to

6, characterized in that the flow device via two Inlet openings (23, 23 ') and two outlet openings (24, 24') for the electrolyte liquid has.

8. Rechargeable battery cell (100, 100 ') according to one of claims 1 to

7, characterized in that the second housing part (20) has a receiving recess for active material (40) of the battery cell (100, 100 '), while the first housing part (10) is designed as a cover plate member for the receiving recess.

9. Rechargeable battery cell (100, 100 ') according to one of claims 1 to

8, characterized in that the second housing part (20) has a bottom plate element (21) and a frame element (22) arranged on the bottom plate element (21), while the first housing part (10) is designed as a cover plate element.

10. Rechargeable battery cell (100, 100 ') according to one of claims 1 to

9, characterized in that the plastic fiber-reinforced, in particular offset with glass fiber, is executed.

11. Rechargeable battery cell (100, 100 ') according to one of claims 1 to

10, characterized in that the first and the second housing part (10, 20) are produced by means of injection molding or thermoforming,

12. Rechargeable battery cell (100, 100 ') according to one of claims 1 to

11, characterized in that the two housing parts (10, 20) are connected by means of gluing, plastic laser welding or friction welding.

13. Rechargeable battery cell (100, 100 ') according to one of claims 1 to

12, characterized in that the housing in each case at least one positioning device (51, 51 ', 52, 52'), wherein the at least one positioning device (51, 51 ', 52, 52') in a region of the battery cell (100, 100 ') is arranged, which in the arrangement of the battery cell (100, 100') in a battery module (200) of an adjacent battery cell (100, 100 ') faces

14. Rechargeable battery cell (100, 100 ') according to claim 13, characterized in that the housing has a plurality of positioning means (51, 51', 52, 52 '), which are preferably arranged on opposite sides of the housing.

15. Rechargeable battery cell (100, 100 ') according to claim 13 or 14, characterized in that the at least one positioning device (51, 51', 52, 52 ') is designed as a positioning or positioning pin.

16. Rechargeable battery cell (100, 100 ') according to one of claims 1 to 7, characterized in that the flow device and the second housing part (20) are made in one piece.

17. Rechargeable battery cell (100, 100 ^λ ) according to any one of claims 9 to

16, characterized in that the flow device and a bottom plate element (21) of the second housing part (20) are made in one piece.

18. Rechargeable battery cell (100, 100 ') according to one of claims 1 to

17, characterized in that the battery cell (100, 100 ') is a lithium-air battery.

19. Battery module (200), characterized in that it comprises at least two battery cells (100, 100 ') according to one of claims 1 to 18.

20. Battery module (200) according to claim 19, characterized in that an inlet opening (23) for the electrolyte liquid of the first battery cell (100) with an inlet opening (23 ') at least a second adjacent battery cell (100') and an outlet opening (24). the first battery cell (100) is in fluid-tight connection with an outlet opening (24 ') of at least one adjacent second battery cell (100').

21. Battery module (200) according to claim 19 or 20, characterized in that in the region of the inlet opening (23, 23 ') and in the region of the outlet opening (24, 24') sealing grooves for receiving sealing means (27), in particular of soft material -Seals, are provided.

22. Use of a battery module (200) according to any one of claims 19 to 21 in a drive system for motor vehicles.

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