Cover assembly for a battery cell

Abstract

This invention relates to a cover assembly for a battery cell, comprising: a metal substrate (2); a first terminal (3) designed as a cathode, disposed in a through-hole (20) of the substrate (2); and a sealing element (5) that fastens and seals the first terminal (3) to the substrate (2), wherein the sealing element (5) is made of a conductive material, the sealing element (5) is disposed in the through-hole (20) and configured to seal a first connection region (6) between the terminal (3, 4) and the sealing element (5) and a second connection region (7) between the substrate (2) and the sealing element (5), and in the A connection is provided between the first terminal (3) and the substrate (2), and a surface-treated first facet (13) and an untreated second facet (14) are provided on the first contact surface (31) of the first terminal (3) facing the sealing element (5), and / or a surface-treated first facet (11) and an untreated second facet (12) are provided on the second contact surface (21) of the through hole (20) of the substrate facing the sealing element (5), thereby forming a force-locking connection between the substrate (2) and the sealing element (5) and between the first terminal (3) and the sealing element (5).

Description

Technical Field

[0001] This invention relates to a cover assembly for a battery cell, wherein the cover assembly provides a pressure-activated region to ensure conductivity between the terminal (cathode) and a metal substrate. The invention also relates to a battery cell, particularly a prismatic 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 housing, typically made of aluminum, and a cover assembly disposed on and enclosing the housing. Therefore, the cover assembly's function is to seal and enclose the battery housing to protect the environment from the battery's chemical system. The cover assembly also needs to prevent interfering substances (such as oxygen or water) from seeping into the battery cell from the outside. Furthermore, the cover assembly should enable electrode connections inside the battery cell as well as electrical contact with the outside of the battery cell. Battery cells may experience extremely high or low temperatures during operation. Consequently, the electrical connection between the terminal used as the cathode and the metal substrate may be interrupted. This electrical connection between the terminal and the metal substrate is particularly important for corrosion protection of the cathode. Summary of the Invention

[0003] The object of this invention is to provide an improved cover plate assembly that provides a reliable electrical connection between the cathode and the metal substrate of the cover plate assembly in all operating states, while being easy to manufacture and having a low manufacturing cost. Another object of this invention is to provide a battery cell having such a cover plate assembly.

[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 11.

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

[0006] The advantage of the cover assembly of claim 1 of the present invention is that it ensures reliable electrical contact between the cathode and the metal substrate throughout all temperature ranges that may occur during battery use. That is, when the temperature changes, the cover assembly may warp or twist, potentially causing the electrical connection required for cathode corrosion protection between the cathode and the metal substrate to loosen or temporarily lose electrical contact. According to the present invention, this problem is now solved by arranging a first terminal designed as a cathode in a through-hole of the substrate. A sealing element is arranged between the substrate and the first terminal, which secures and seals the first terminal to the substrate. The sealing element is made of a conductive material, thereby providing an electrical connection between the first terminal and the substrate. The sealing element arranged in the through-hole is configured to seal a first connection area between the terminal and the sealing element and a second connection area between the substrate and the sealing element, thus achieving fixation and electrical connection between the first terminal and the substrate. Furthermore, a first contact surface facing the sealing element is provided on the substrate, and a second contact surface facing the sealing element is provided on the terminal. The first contact surface and / or the second contact surface each have a surface-treated first facet and an untreated second facet, thereby forming force-locking connections between the substrate and the sealing element and / or between the first terminal and the sealing element. These force-locking connections on the contact area of ​​the sealing element provide pressure-activated zones, ensuring reliable electrical contact between the sealing element and the first terminal and the substrate even if the cover assembly warps or similar conditions during operation. Because the surface-treated surfaces are not entirely formed on the contact surfaces of the substrate and / or the first terminal, the substrate and the first terminal can at least partially conform to the warping or similar deformation of the cover assembly in these contact areas and maintain electrical contact. This prevents cathode corrosion throughout the entire service life of the cover assembly.

[0007] Preferably, the surface-treated first facet comprises a plurality of discrete surface regions. These discrete surface regions may be, for example, circular, quadrilateral, or other geometrically shaped surfaces. Preferably, all discrete surface regions lie in the same plane, and more preferably, are uniformly distributed along the entire circumference on the contact surfaces in the through-hole and / or on the contact surfaces of the first terminal. Alternatively, an untreated second facet may also be provided as a plurality of discrete surface regions.

[0008] More preferably, for example, if the first terminal is designed to be cylindrical, then the surface-treated first facet includes one or more rectangular or arc-shaped surface areas. In this case, the remaining surface areas on the first terminal and / or the through-hole of the substrate constitute the untreated second facet. It should be noted that the arrangement of the surface-treated and untreated facets can be exactly opposite.

[0009] Particularly preferably, the surface-treated first facet extends completely around the circumference of the first terminal and / or the circumference of the through-hole in the substrate. Therefore, the surface-treated first facet can be designed as a strip along the entire circumference.

[0010] More preferably, the area of ​​the first surface-treated facet is the same as the area of ​​the untreated second surfacet.

[0011] The surface-treated facets are configured to maintain conductivity, thereby enabling electrical contact between the first terminal and the substrate through the surface-treated first facets.

[0012] The first surface-treated facet is manufactured 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. Of course, the conductivity of the surface-treated first facet must be maintained during this process.

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

[0014] More preferably, the sealing element is made of a conductive elastomeric material, particularly EPDM or FKM. Alternatively, the sealing element is a conductive thermoplastic, particularly PPS or PP.

[0015] More preferably, the cover assembly includes first and second terminals. A sealing element on the first terminal is made of a conductive material. A sealing element on the second terminal, which forms the anode, is made of a non-conductive material.

[0016] The first and / or second terminals are preferably rectangular, and in particular have annular edges. The annular edges preferably face inward toward the inside of the battery cell.

[0017] The first terminal, used as the cathode, is preferably made of aluminum. The second terminal, used as the anode, is preferably made of an aluminum-copper composite material. More preferably, the substrate is made of aluminum.

[0018] More preferably, the sealing element is integrally formed and specifically includes an outer region, a middle region disposed in the through-hole, and an inner region. The outer and inner regions are generally parallel to the substrate and extend such that they surround at least a portion of the substrate.

[0019] More preferably, the surface-treated first facet of the first terminal and the surface-treated first facet of the substrate are in the same plane when the assembly is complete. Therefore, in the completed state, the shortest electrical connection between the first terminal and the substrate can be achieved.

[0020] The present invention also relates to a battery cell comprising the cover assembly of the present invention. Attached Figure Description

[0021] 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 Another enlarged cross-sectional view of the first terminal of the cover plate assembly. Figure 4 for Figure 1 A schematic side view of the first terminal of the cover plate assembly. Figure 5 for Figure 1 A schematic partial cross-sectional view of the substrate of the cover plate assembly. Figure 6 For having Figure 1 A schematic diagram of the battery cell of the cover plate assembly of the present invention, and Figure 7 This is a schematic diagram of a battery cell with a cover assembly according to a second embodiment of the present invention. Detailed Implementation

[0022] The following is for reference. Figures 1 to 6 The cover plate assembly 1 according to a first preferred embodiment of the present invention will be described in detail.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] The first and second terminals have the same geometric shape and are rectangular (see...). Figure 6 ).

[0027] 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.

[0028] like Figure 1 and Figure 2 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.

[0029] 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.

[0030] The first 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. The second sealing element 5' on the second terminal 4 is injection molded onto the second terminal 4 and the substrate 2 in the same manner.

[0031] The sealing elements 5 and 5' on the first terminal 3 and the second terminal 4 have the same geometry. The sealing elements 5 and 5' are arranged in the through hole 20 and are configured to seal the first connection area 6 between the terminal and the sealing element and the second connection area 7 between the substrate and the sealing element, and to provide connection and reliable fixation between the terminal and the substrate.

[0032] The sealing element 5 on the first terminal 3 is made of a conductive material. This provides corrosion protection for the first terminal 3, which is designed as a cathode, because there is an electrical connection from the first terminal 3 to the substrate 2 via the conductive first sealing element 5.

[0033] To ensure electrical connection between the first terminal 3 on the cathode and the substrate 2 under all operating conditions, a surface-treated first facet and an untreated second facet are formed on the first terminal 3 and on the through-hole 20 in the substrate 2 where the first terminal 3 is disposed.

[0034] Figure 4A side view of the first terminal 3 is shown. Here, the first contact surface 31 of the first terminal 3 facing the sealing element 5 has a surface-treated first facet 11. The surface-treated first facet 11 is a discrete surface with a circular geometry. All surface-treated first facets 11 lie within the same plane E1. The contact surface 31 on the first terminal 3 also has an untreated second facet 12. Figure 4 As shown, the second facet 12 surrounds multiple first facets 11.

[0035] Therefore, the first terminal 3 has a first contact surface 31 on its outer peripheral surface facing the sealing element 5. The substrate 2 has a second contact surface 21 in the through hole 20 facing the sealing element 5. The first contact surface 31 is detailed in [reference needed]. Figure 4 The second contact surface 21 is detailed in [reference needed]. Figure 5 .

[0036] Figure 5 A cross-section of a through-hole 20 with a first terminal 3 is shown. Here, the second contact surface 21 in the through-hole 20 has surface-treated first facets 13, which are also designed as discrete surfaces. The contact surface 21 of the through-hole 20 also has untreated second facets 14. The surface-treated first facets 13 are also located within the same plane E2.

[0037] When installed, the first plane E1 is within the second plane E2, or has only a very small deviation relative to the second plane E2, particularly a maximum deviation of 2 mm. This ensures that the surface-treated first facet 11 on the first terminal 3 and the surface-treated first facet 13 on the substrate 2 are at the same height in the through hole and form a pressure activation zone.

[0038] This ensures that, in the event of warping of the cover assembly 1, the surface-treated first facet 11 on the first terminal 3 remains in contact with the sealing element 5, and the sealing element 5 remains in contact with the surface-treated first facet 13 in the through hole 20.

[0039] The sealing element 5 on the first terminal 3 is made of a conductive material. Conductive elastomers or conductive thermoplastics can be used as the material for the sealing element 5.

[0040] Therefore, reliable electrical contact can be achieved in all operating states from the first terminal 3 to the sealing element 5 via the surface-treated first facet 11, and from the sealing element 5 to the through hole 20 via the surface-treated first facet 13.

[0041] The surface-treated first facets 11 and 13 can be manufactured using different processes. It is important to note that the surface-treated first facets 11 and 13 must always be conductive. For example, the surface-treated first facets 11 and 13 can be manufactured by plasma activation, application of a primer or tackifier, or mechanical surface treatment.

[0042] By intermittently setting the surface-treated first facets 11 and 13 at the first terminal 3 and through hole 20, it can be ensured that when the cover plate assembly is twisted, the sealing element 5 can conform to the twist to a certain extent without losing its sealing properties or losing electrical contact with the first terminal 3 and the substrate 2.

[0043] Therefore, the cover plate assembly of the present invention can always ensure the electrical contact of the first terminal 3, which is designed as a cathode, at both low and high temperatures, thereby preventing corrosion on the first terminal 3.

[0044] The sealing element 5' on the second terminal 4 is made of a non-conductive material. This non-conductive material can be an elastomer or a thermoplastic. The second terminal 4 also has an annular edge region 40.

[0045] Therefore, the cover assembly can be manufactured, for example, by two injection molding processes carried out in one injection mold, wherein in the first step, the sealing element 5 is injection molded at the first terminal 3, and in the second step, the sealing element 5' is injection molded at the second terminal 4 from a different material.

[0046] The sealing element 5 is C-shaped in cross-section, forming a relatively long first connection region 6 that 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.

[0047] 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. Specifically, the first terminal 3 with an annular edge region 30 and the step 22 on the substrate 2 that is at least partially located on the annular edge region 30 can reliably fix the first terminal 3 in a shape fit.

[0048] The substrate 2 is also provided with a filling port 8 and a bursting zone 9.

[0049] 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.

[0050] Figure 1It 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 better secures the terminals 3, 4 to the substrate 2.

[0051] Figure 6 The 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.

[0052] Therefore, to ensure conductivity between the cathode and the substrate 2, a pressure-activated zone can be provided under all operating conditions, especially at different temperatures, so that conductive connection exists even when the thermal expansion coefficients of the components differ. Thus, even in the event of deformation, a certain pressure exists between the components in the areas between the sealing element 5 and the substrate 2, and between the sealing element 5 and the first terminal 3, ensuring conductivity in at least one pressure-activated zone.

[0053] Figure 7 An alternative design for the battery cell 100 is shown, wherein two battery cell covers 1a and 1b are provided, respectively arranged on the narrow side surfaces of the battery cell 100 opposite to each other, 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 surface of the battery housing 101 (see reference). Figure 7 ). Figure 7 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), - The first terminal (3) is designed as the cathode, and the first terminal is arranged in the through hole (20) of the substrate (2), and - A sealing element (5) secures and seals the first terminal (3) to the substrate (2), wherein the sealing element (5) is made of a conductive material. -The sealing element (5) is disposed in the through hole (20) and configured to seal the first connection area (6) between the first terminal (3) and the sealing element (5) and the second connection area (7) between the substrate (2) and the sealing element (5), and to provide a connection between the first terminal (3) and the substrate (2). -A surface-treated first facet (13) and an untreated second facet (14) are provided on the first contact surface (31) of the first terminal (3) facing the sealing element (5), and / or, a surface-treated first facet (11) and an untreated second facet (12) are provided on the second contact surface (21) of the through hole (20) of the substrate facing the sealing element (5), thereby forming a force-locking connection between the substrate (2) and the sealing element (5) and between the first terminal (3) and the sealing element (5).

2. The cover plate assembly of claim 1, wherein the surface-treated first facet (11, 13) comprises a plurality of discrete facet regions.

3. The cover plate assembly according to claim 2, wherein the discrete surface regions are circular or quadrilateral.

4. The cover assembly according to any one of the preceding claims, wherein the surface-treated first facet (11, 13) is completely surrounded by the untreated second facet (12, 14).

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

6. 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).

7. The cover plate assembly according to claim 6, wherein the first terminal (3) and the second terminal (4) are rectangular and, in particular, have annular edge regions (30, 40).

8. The cover assembly according to any one of claims 6 or 7, wherein the sealing element (5') on the second terminal (4) is made of a non-conductive material.

9. The cover plate assembly according to any one of the preceding claims, wherein, with the first terminal (3) installed in the through hole (2), the surface-treated first facet (11) of the first terminal (3) and the surface-treated first facet (13) of the substrate are in the same plane.

10. The cover assembly according to any one of the preceding claims, wherein the sealing element (5, 5') is integrally formed.

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

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