Cover plate assembly for a battery cell

Abstract

The invention relates to a cover plate assembly for a battery cell, comprising: a metal base plate (2); at least one terminal (3, 4) arranged in a through-hole (20) of the base plate (2); a sealing element (5, 5') fastening the terminal on the base plate (2) and sealing, wherein the sealing element (5, 5') is arranged in the through-hole (20) and is configured for sealing a first connection area (6) between the terminal (3, 4) and the sealing element (5) and a second connection area (7) between the base plate (2) and the sealing element (5, 5'), and for providing a connection between the terminal (3, 4) and the base plate (2).

Description

Technical Field

[0001] The present invention relates to a cover assembly for a battery cell, particularly a prismatic cell, and a battery cell having such a cover assembly. Background Technology

[0002] Battery cells, such as prismatic battery cells, are used in rechargeable lithium-ion batteries, sodium-ion batteries, or supercapacitors. Each battery cell includes a casing, typically made of aluminum, and a cover assembly disposed on and enclosing the casing. Therefore, the cover assembly's task is to seal and enclose the battery casing to protect the environment from the battery chemistry and vice versa. Furthermore, the cover assembly should enable electrode connections inside the battery cell and electrical contacts outside the cell. Current systems use potting materials for sealing, for example. However, these potting materials can age, shrink, and create leakage paths during their lifespan. Ambient oxygen is particularly critical, as it can diffuse into the battery and potentially significantly shorten the electrolyte's lifespan. Summary of the Invention

[0003] The object of the present invention is to provide an improved cover assembly and a battery cell having such a cover assembly, while ensuring complete sealing, in a manner that is easy to manufacture and has low manufacturing costs.

[0004] The solution of the present invention to achieve the above-mentioned objective is a cover plate assembly having the features of claim 1, and a battery cell having the features of claim 16.

[0005] The dependent claims illustrate preferred improvements of the invention.

[0006] The cover plate assembly of the present invention, having the features of claim 1, has the advantage of significantly improving the sealing in the electrode post region through the through-hole in the cover plate assembly. The cover plate assembly of the present invention has a particularly simple and low-cost structure. It reliably seals the gap at the electrode post outlet under all operating conditions, especially at extremely cold and hot temperatures; therefore, according to the present invention, leakage through the gap at the electrode post outlet can be prevented.

[0007] This invention achieves this by including a cover assembly for a battery cell comprising a metal substrate and at least one terminal (electrode post) disposed in a through-hole in the substrate. The terminal is configured to provide electrical contact between the outer side and the inner side of the battery cell. Furthermore, the cover assembly includes a sealing element that secures and seals the terminal to the substrate. Thus, the sealing element has the dual function of sealing and securing the terminal. The sealing element is disposed in the through-hole of the substrate and configured to seal a first leakage path between the terminal and the sealing element, and a second leakage path between the substrate and the sealing element, providing connection and fixation between the terminal and the substrate.

[0008] Preferably, the sealing element is integrally molded. This allows for simple and low-cost manufacturing of the sealing element. Particularly preferably, the sealing element is a component manufactured by injection molding, which is injection molded onto the terminal and the substrate.

[0009] Particularly preferably, the sealing element is configured such that it has an outer region, a middle region disposed in a through-hole, and an inner region, wherein the outer and inner regions extend parallel to the substrate and surround at least a portion of the substrate. This allows the sealing element to be securely fixed to the substrate. In the installed state, the outer region is outside the battery cell, and the inner region is inside the battery cell.

[0010] More preferably, the terminal surface that the sealed element abuts against and seals, and / or the substrate surface that the sealed element abuts against and seals, is designed as a surface-treated surface. This surface-treated surface allows for a reliable connection between the sealing element and the terminal and / or substrate. Preferably, the terminal and substrate are processed with the same surface treatment on the surfaces abutting the sealed element.

[0011] More preferably, the surface treated surface is conductive. Specifically, this conductivity is provided at the cathode. Thus, the cathode can be conductively connected to the metal substrate to provide corrosion protection for the cathode.

[0012] Surface treatment of terminals and / or substrates on the surfaces in contact with sealing elements is preferably carried out by plasma activation and / or application of a primer and / or application of a tackifier and / or mechanical surface treatment, such as roughening and / or pickling and / or etching.

[0013] More preferably, the sealing element is an injection-molded component. Specifically, this allows for a simple form-fit between the sealing element and the terminal and / or substrate.

[0014] More preferably, the cover assembly includes at least one first terminal, and according to a specific embodiment of the battery cell energy storage device, it also includes a second terminal. According to the numbering scheme used herein, the first terminal is the cathode of the battery cell, and the second terminal is the anode of the battery cell.

[0015] According to a particularly preferred embodiment of the invention, when the sealing element is arranged at the cathode, the sealing element is an elastomer, particularly a conductive elastomer. The elastomer can be manufactured, for example, by injection molding in a vulcanizing mold in which a substrate serving as an insert and one or more terminals are embedded. When the cover assembly includes two terminals, different materials can be used for the sealing elements on the first and second terminals. In particular, an electrically insulating elastomer is used for the anode, and a conductive elastomer for the cathode. The elastomer can be: FFKM, FKM, NR, IR, IIR, CR, ECO, EPDM, EPM, NBR, HNBR, PU, ​​ACM, AEM, VMW, FVMQ, thermoplastic elastomers, and mixtures thereof; preferably, EPDM (ethylene propylene diene monomer rubber) or FKM (fluorinated elastomer rubber).

[0016] According to an alternative embodiment of the invention, the sealing element is a plastic, particularly a thermoplastic. To ensure the thermoplastic on the cathode is conductive, additives can be added to guarantee its conductivity. The sealing element, made of thermoplastic material, is preferably also injection molded onto the terminal and / or substrate in an injection mold. The thermoplastic is preferably PPS (polyphenylene sulfide) or PP (polypropylene). More preferably, a thermosetting material and potting compound are used.

[0017] Preferably, when thermoplastic is used as a sealing element, a flexible elastomer layer is additionally provided between the thermoplastic and the terminal and / or between the thermoplastic and the substrate. If conductivity between the terminal and the substrate is desired, the flexible elastomer layer can also be made conductive, for example, by means of additives.

[0018] The terminals are preferably made entirely of aluminum, or of an aluminum-copper composite material, or of copper-plated aluminum, or of stainless steel. More preferably, the substrate is made of aluminum or stainless steel. More preferably, the terminals have a quadrilateral, particularly rectangular, basic shape. Preferably, the terminals have an annular edge region facing inward toward the cover assembly. This annular edge region forms a shoulder at the terminal, against which the sealing element can additionally abut. This increases the contact area between the terminal and the sealing element, thereby achieving a more reliable seal and more reliably securing the terminal to the substrate.

[0019] Quadrilateral terminals are preferably designed without sharp corners. The corners of quadrilateral terminals are preferably rounded.

[0020] Preferably, the cover plate assembly includes an insulating plate made of non-conductive plastic that is snapped onto the substrate, or includes an insulating plate made of non-conductive plastic that is attached to the substrate during injection molding.

[0021] The present invention also relates to a battery cell comprising the cover assembly of the present invention. Attached Figure Description

[0022] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In the drawings: Figure 1 This is a schematic cross-sectional view of a cover plate assembly according to a first embodiment of the present invention. Figure 2 for Figure 1 A schematic, partially enlarged cross-sectional view of the first terminal of the cover plate assembly. Figure 3 for Figure 1 A schematic, partially enlarged cross-sectional view of the second terminal of the cover plate assembly. Figure 4 A schematic diagram of a battery cell having the cover plate assembly of the present invention, and Figure 5 This is a schematic diagram of a battery cell with a cover assembly according to a second embodiment of the present invention. Detailed Implementation

[0023] The following is for reference. Figures 1 to 4 The cover plate assembly 1 according to a first preferred embodiment of the present invention will be described in detail.

[0024] like Figure 1 As shown, the cover plate assembly 1 includes a metal substrate 2. Two through holes 20 are formed in the metal substrate 2.

[0025] The cover plate assembly 1 also includes a first terminal (cathode) 3 and a second terminal (anode) 4. The first terminal 3 and the second terminal 4 are each arranged in a through hole 20 in the substrate 2.

[0026] The first terminal 3, which forms the cathode, is made entirely of aluminum. The second terminal 4, which forms the anode, is made of a first part 4a of aluminum and a second part 4b of copper.

[0027] The first and second terminals have the same geometric shape and are rectangular (see...). Figure 4 ).

[0028] The cover assembly 1 also includes a first sealing element 5, which secures the first terminal 3 to the substrate 2. The first sealing element 5 is made of a conductive material. The first sealing element 5 includes an outer region 50, a middle region 51, and an inner region 52. The outer region 50 faces outward from the cover assembly. The inner region 52 is disposed on the inner side of the cover assembly 1.

[0029] like Figure 1 As shown, the sealing element is C-shaped in cross-section, having two arms formed by an outer region 50 and an inner region 52, respectively, and an intermediate region 51 connecting the outer region 50 and the inner region 52.

[0030] from Figure 1 It can also be seen that the first terminal 3 has a main region and an annular edge region 30, which is arranged inside the cover plate assembly 1 and completely surrounds the main region of the first terminal 3. The corners of the quadrilateral first terminal are rounded. This ensures a reliable connection between the sealing element 5 and the first terminal 3.

[0031] The surfaces of the terminal 3, which is abutted and sealed by the sealing element 5, and the substrate 2 are respectively designed as surface-treated surfaces. These surface-treated surfaces are conductive and can be manufactured, for example, by plasma activation, application of a primer or tackifier, or mechanical surface treatments such as roughening, pickling, or etching. Through the surface-treated surfaces in the area in contact with the sealing element 5, an airtight and dielectrically sealed connection can be formed with the first terminal 3 and the substrate 2 throughout the service life of the cover assembly 1.

[0032] The sealing element 5 can be injection molded onto the first terminal 3 and the substrate 2 through an injection molding process, and the terminal and the substrate can be embedded in the injection mold, for example, as inserts.

[0033] The sealing element 5 can be made of a conductive elastomer, such as EPDM or FKM. The sealing element 5 is designed to be conductive at the first terminal 3 of the cathode forming the cover assembly 1 to provide corrosion protection for the first terminal 3. Alternatively, a conductive thermoplastic can be used as the material for the sealing element 5.

[0034] The C-shaped design of the sealing element 5 in cross-section creates a relatively long first connection region 6, which provides a medium seal between the sealing element 5 and the first terminal 3. Similarly, a relatively long second connection region 7 is formed between the sealing element 5 and the substrate 2.

[0035] In particular, by performing a combined surface treatment on the first connection area 6 between the sealing element 5 and the first terminal 3 and the second connection area 7 between the sealing element 5 and the substrate 2, it is possible to ensure that a medium-sealed connection is formed throughout the entire service life, so that leakage does not occur from the inside to the outside or from the outside to the inside via the first connection area 6 and the second connection area 7.

[0036] In addition to sealing the first terminal 3 or the substrate 2, the sealing element 5 is also used as a fixing device to fix the first terminal 3 in the through hole 20 of the substrate 2. In particular, by means of the structural design of the first terminal 3 having an annular edge region 30, and the step on the substrate 2 that is at least partially located on the annular edge region 30, a reliable form fit fixing of the first terminal 3 can be achieved.

[0037] The substrate 2 is also provided with a filling port 8 and a bursting zone 9.

[0038] Furthermore, an insulating plate 10 is provided on the inner side of the substrate 2, which can be snapped onto the substrate 2 before or after the injection molding process of the sealing element 5. The insulating plate 10 has an annular edge 10a in the area of ​​the through hole 20, which ensures the correct positioning of the injected sealing element 5 during the injection molding process.

[0039] At the second terminal 4, the sealing element is indicated by reference numeral 5'. The geometry of the second sealing element 5' is the same as that of the first sealing element 5, because the geometry of the second terminal 4 is also the same as that of the first terminal 3. However, the second sealing element 5' is made of a non-conductive material. Therefore, the material of the second sealing element 5' is electrically insulating.

[0040] Alternatively, the same electrically insulating plastic can be used on the first and second terminals 3, 4, and conductive material can be sprayed onto the material on the first terminal (cathode) to coat the cathode with 2K material.

[0041] Figure 1 It is also shown that the two sealing elements 5, 5' are designed such that the inner region 52 partially encircles the edge regions 30, 40 of the two terminals 3, 4. This allows for better fixation of the terminals 3, 4 to the sealing elements 5, 5', and consequently, better fixation to the substrate 2.

[0042] If thermoplastic is used as the material for sealing elements 5 and 5', then PPS or PP is preferred.

[0043] Further preferably, it should be noted that when thermoplastic is used as the material of the sealing element, a flexible elastomer layer may also be provided on the two contact areas of the sealing element 5, namely the contact area with the terminals 3 and 4 and the contact area with the substrate 2.

[0044] The contact area on the anode is preferably pretreated in the same manner as the contact area on the cathode.

[0045] Figure 4The assembled battery cell 100 is shown, with the cover assembly 1 fixed to the prismatic battery housing 101. The battery housing 101 is preferably made of the same material as the metal substrate 2, particularly aluminum. This allows for a simple connection between the cover assembly 1 and the battery housing 101, for example, through a welding process.

[0046] Figure 5 An alternative design for the battery cell 100 is shown, wherein two battery cell covers 1a and 1b are provided, respectively arranged on opposite narrow sides of the battery cell 100, and covering the battery housing 101. A first terminal 3 is arranged on the first battery cell cover 1a, and a second terminal 4 is arranged on the second battery cell cover 1b. The second battery cell cover 1b also has a filling opening 8. A bursting zone 9 is provided on the long narrow side of the battery housing 101 (see reference). Figure 5 ). Figure 5 The sealing element in this embodiment is designed in the same way as in the first embodiment.

Claims

1. A cover assembly for a battery cell, comprising: -Metal base plate (2), - At least one terminal (3, 4), said terminal being disposed in a through hole (20) of said substrate (2), - Sealing element (5, 5'), which secures the terminal to the substrate (2) and seals it. -The sealing element (5, 5') is disposed in the through hole (20) and configured to seal the first connection area (6) between the terminal (3, 4) and the sealing element (5) and the second connection area (7) between the substrate (2) and the sealing element (5, 5'), and to provide a connection between the terminal (3, 4) and the substrate (2).

2. The cover assembly according to claim 1, wherein the sealing element (5, 5') is integrally formed.

3. The cover plate assembly according to claim 2, wherein the sealing element (5, 5') has an outer region (50), a middle region (51) disposed in the through hole (20) and an inner region (52), wherein the outer region and the inner region extend substantially parallel to the substrate (2) and surround a portion of the substrate (2).

4. The cover plate assembly according to any one of the preceding claims, wherein the surfaces of the terminals (3, 4) abutted and sealed by the sealing elements (5, 5'), and / or the surfaces of the substrate (2) abutted and sealed by the sealing elements (5, 5'), are designed as surface-treated surfaces.

5. The cover plate assembly according to claim 4, wherein the surface treated surface is conductive.

6. The cover plate assembly according to claim 4 or 5, wherein the surface treated surface is a plasma-activated surface, or a surface treated with a primer, or a surface coated with a tackifier, or a surface with mechanical surface treatment.

7. The cover plate assembly according to any one of the preceding claims, the cover plate assembly comprising a first terminal (3) and a second terminal (4).

8. The cover assembly according to any one of the preceding claims, wherein the sealing element (5, 5') is an injection-molded part.

9. The cover assembly according to any one of the preceding claims, wherein the sealing element (5, 5') is made of an elastomeric material, particularly EPDM or FKM.

10. The cover assembly according to any one of claims 1 to 8, wherein the sealing element (5, 5') is plastic, particularly thermoplastic, especially PPS or PP.

11. The cover plate assembly according to claim 10, wherein an elastomeric layer is arranged between the sealing element (5, 5') and the terminal (3, 4) and / or between the sealing element (5, 5') and the substrate (2).

12. The cover assembly according to any one of claims 7 to 11, wherein the sealing element on the first terminal (3) is made of a conductive material and the sealing element (5') on the second terminal (4) is made of a non-conductive material.

13. The cover plate assembly according to any one of the preceding claims, wherein the terminals (3, 4) are rectangular, and in particular have annular edges.

14. The cover plate assembly according to any one of claims 7 to 13, wherein the first terminal (3) is made of aluminum or copper or stainless steel, the second terminal (4) is made of aluminum-copper composite material or copper, or copper-plated aluminum, or stainless steel, and the substrate is made of aluminum or stainless steel.

15. The cover plate assembly according to any one of the preceding claims, comprising: - An insulating plate (10) made of non-conductive plastic, which is snapped onto the substrate (2), or - An insulating plate (10) made of non-conductive plastic is attached to the substrate (2) during injection molding.

16. A battery cell comprising a cover assembly (1) according to any one of the preceding claims.

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