roof assembly

Abstract

The invention relates to a top cover assembly (1) of a battery cell, comprising a metal base plate (2), a first terminal (3) arranged in a through opening (20) of the base plate (2), a sealing element (5) fixing and sealing the first terminal (3) on the base plate (2), wherein the sealing element (5) is arranged in the through opening (20) and is configured to seal a first connection area (6) between the first terminal (3) and the sealing element (5) and a second connection area (7) between the base plate (2) and the sealing element (5) and to provide a connection between the first terminal (3) and the base plate (2), wherein the first connection area (6) has an untreated surface (11) on the first terminal (3), wherein the second connection area (7) has a treated surface (12) on the base plate (2), and the sealing element (5) is configured to exert a pressure F perpendicular to the untreated surface (11) of the first terminal (3) to fluidically seal the first connection area (6).

Description

Technical Field

[0001] The present invention relates to a top cover assembly and a battery cell having such a top cover assembly. Background Technology

[0002] Battery cells, such as prismatic cells, are used in rechargeable lithium-ion batteries, sodium-ion batteries, or supercapacitors. Here, a battery cell includes a housing, typically made of aluminum, and a top cover assembly disposed on and enclosing the housing. Therefore, the top cover assembly has the task of sealing and enclosing the battery housing to protect the environment from the cell's chemistry. The top cover assembly should also prevent interfering substances such as oxygen or water from entering the cell from the outside. Furthermore, the top cover assembly should enable connection of electrodes inside the battery cell as well as electrical contact with the outside of the battery cell. For efficient cooling, it is advantageous to cool the battery cell by immersion cooling, in which the battery cell is completely immersed in a liquid cooling medium. However, this places high demands on the sealing elements, which seal the terminals (electrodes) in the substrate. In particular, material compatibility issues arise between the electrolyte disposed inside the battery cell and the external liquid cooling medium. Summary of the Invention

[0003] The objective of this invention is to provide an improved top cover assembly with simple and low-cost manufacturability, particularly suitable for immersion cooling using a liquid cooling medium. Furthermore, the objective of this invention is to provide a battery cell having such a top cover assembly.

[0004] This task is solved by a top cover assembly having the features of claim 1 and a battery cell having the features of claim 13.

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

[0006] The top cover assembly according to claim 1 has the advantages of simple and low-cost construction, and is particularly suitable for immersion cooling. A sealing element, which is fixed to a substrate at a terminal and seals the inner side of a battery cell relative to the outer side in the installed state, is particularly suitable for different liquids inside, especially the electrolyte, and different liquids outside, especially the immersion liquid. In other words, the sealing element preferably has sufficient material resistance on the outer side of the battery cell relative to both the electrolyte and the immersion liquid with respect to the battery cell life. According to the invention, this is achieved by the following: the top cover assembly has a metallic substrate and a first terminal arranged in a through-opening in the substrate. The sealing element is configured to fix and seal the first terminal to the substrate. Thus, the sealing element is arranged in the through-opening and configured to seal a first connection area between the first terminal and the sealing element and a second connection area between the substrate and the sealing element, and to provide a connection between the first terminal and the substrate. The first connection area has an untreated surface on the first terminal. The second connection area has a treated surface on the substrate. The treated surface is manufactured by surface treatment methods, such as as a plasma-activated surface, a surface treated with a primer, a surface coated with an adhesion promoter, or a mechanically treated surface, for example, by roughening. The sealing element is configured to apply a pressure F perpendicular to the untreated surface of the first terminal to fluidly seal the first connection area between the sealing element and the first terminal, i.e., to seal against liquids and gases. The untreated and treated surfaces are opposite each other on the sealing element. The sealing element is fixedly fastened to the treated surface, and the unevenness and / or increased roughness compared to the untreated surface generated by the treated surface creates a pressure F perpendicular to the untreated surface on the first terminal.

[0007] Therefore, according to the present invention, only surface treatment needs to be performed on the substrate, and the first terminal can be used without surface treatment. This simplifies the construction of the top cover assembly and reduces costs. The pressure F generated in the top cover assembly's mounted state still provides sufficient sealing capability of the sealing element at the first terminal.

[0008] Preferably, the substrate has a fully treated surface in the second connection area with the sealing element. In other words, the sealing element is fixed to the substrate only at the treated surface of the substrate.

[0009] Preferably, the first terminal has a completely untreated surface in the first connection area. In other words, the first terminal, in the first connection area pointing toward the sealing element, has a surface free of unevenness, roughness, or coatings. The surface on the first terminal is preferably a smooth metallic surface.

[0010] Particularly preferably, the sealing element is an elastomer. The advantage of using an elastomer as a sealing element is that it allows for the generation of exceptionally high pressure in the direction of the first connection area on the first terminal in a simple manner. Furthermore, elastomers have the advantage of being easily injection molded onto a substrate.

[0011] Preferably, the first terminal is configured as a cathode, and the sealing element is made of a conductive material. This provides corrosion protection for the cathode because the electrical connection between the cathode and the metal substrate is formed by the sealing element.

[0012] Preferably, the sealing element undergoes a volume-increasing process after mounting on the substrate and attaching the first terminal. This volume increase of the sealing element increases the pressure F applied to the first terminal. The volume increase can be achieved, for example, through targeted swelling of the sealing element. Therefore, the sealing element is preferably made of a swellable material and exposed to the swelling process after mounting to increase the pressure F applied to the first terminal. This results in a significant improvement in the sealing quality at the first connection area in a particularly cost-effective manner.

[0013] Preferably, the top cover assembly can be used for immersion-cooled battery cells. Here, the sealing element contacts the electrolyte of the battery cell on the inside and the immersion liquid for cooling the battery cell on the outside. Preferably, the sealing element is a one-piece component having a first portion region and a second portion region, the first portion region being made of a first component and the second portion region being made of a second component. Here, the two components are made of two different materials. The first portion region is exposed only to the inside of the top cover assembly, and the second portion region is exposed only to the outside of the top cover assembly. Therefore, the first portion region is in contact only with the electrolyte on the inside of the top cover assembly. The second portion region is in contact only with the immersion liquid, such as heat transfer oil or the like, on the outside of the top cover assembly. Thus, a top cover assembly suitable for immersion cooling can be provided in a simple and low-cost manner.

[0014] Preferably, the boundary line between the first and second portions of the sealing element is arranged such that the boundary line lies within a through opening in the substrate. The through opening is preferably cylindrical, such that the boundary line abuts against the cylindrical wall region of the through opening.

[0015] Particularly preferably, the first component of the first portion region is selected such that the first component is resistant to the electrolyte of the battery cell. The second component is preferably selected such that the second component is resistant to the heat transfer fluid.

[0016] Preferably, the first component is made of a first elastomer, and the second component is made of a second elastomer different from the first elastomer. The first component is preferably EPDM (ethylene propylene diene monomer rubber), and the second component is preferably NBR (nitrile butadiene rubber).

[0017] Preferably, a single adhesion-promoting coating is disposed on the substrate, on a surface oriented toward the sealing element. This adhesion-promoting coating improves the seal between the sealing element and the substrate. Here, a single adhesion-promoting coating is sufficient, providing improved adhesion of the first component in a first partial region and also providing improved adhesion of the second component in a second partial region. The adhesion-promoting coating is preferably disposed entirely within the through-hole and on the outer and inner sides of the substrate.

[0018] Preferably, the first terminal is configured as a cathode, and the first component and / or the second component are conductive. This prevents corrosion at the first terminal.

[0019] Preferably, the first and second components are applied to the metal substrate and the first terminal via an injection molding process. These two different components can be injection molded in one mold through two sequentially performed injection molding processes. Alternatively, two injection molds can also be used.

[0020] Preferably, the top cover assembly includes a first terminal and a second terminal. The sealing element at the first terminal is made of a conductive material.

[0021] The sealing element forming the anode on the second terminal is made of a non-conductive material.

[0022] The first and / or second terminals are preferably rectangular and, in particular, have a surrounding edge. The surrounding edge is preferably oriented toward the inside of the battery cell.

[0023] 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. The substrate is also preferably made of aluminum.

[0024] Preferably, the sealing element includes an outer region, a central region disposed in the through opening, and an inner region. The outer and inner regions are substantially parallel to the substrate structure and extend such that they surround at least a portion of the substrate. Thus, the inner region is made of a first component, and the outer region is made of a second component.

[0025] Furthermore, the present invention relates to a battery cell comprising a top cover assembly according to the present invention. Attached Figure Description

[0026] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In the drawings: Figure 1This is a schematic cross-sectional view of the top cover assembly according to a first embodiment of the present invention; Figure 2 yes Figure 1 A schematic enlarged partial cross-sectional view of the first terminal of the top cover assembly; Figure 3 yes Figure 1 Enlarged partial cross-sectional view of the second terminal of the top cover assembly; Figure 4 It has Figure 1 A schematic diagram of a battery cell in the top cover assembly according to the present invention; and Figure 5 This is a schematic diagram of a battery cell having a top cover assembly according to a second embodiment of the present invention. Detailed Implementation

[0027] The following reference Figures 1 to 4 The top cover assembly 1 according to a first preferred embodiment of the present invention is described in detail.

[0028] like Figure 1 As shown, the top cover assembly 1 includes a metal substrate 2. Two through openings 20 are formed in the metal substrate 2.

[0029] The top cover assembly 1 also includes a first terminal (cathode) 3 and a second terminal (anode) 4. A corresponding terminal is arranged in a through opening 20 in the through opening in the substrate 2.

[0030] The first terminal 3, which forms the cathode, is made entirely of aluminum. The second terminal 4, which forms the anode, consists of a first part 4a and a second part 4b, the first part being made of aluminum and the second part being made of copper.

[0031] The first and second terminals are geometrically identical and have a rectangular shape (see...). Figure 4 ).

[0032] The top 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 is oriented towards the outside of the top cover assembly. The inner region 52 is disposed on the inside of the top cover assembly 1.

[0033] As from Figure 1 and Figure 2 As can be seen, the sealing element is C-shaped in cross-section through two legs formed by the outer region 50 and the inner region 52, and the middle region 51 connecting the outer region 50 and the inner region 52.

[0034] First terminal 3, as further in Figure 1As shown, the top cover assembly 1 has a main region and a surrounding edge region 30, which is arranged inside the top cover assembly 1 and extends completely around the main region of the first terminal 3. The corners of the quadrilateral of the first terminal are rounded here. This ensures a reliable connection between the sealing element 5 and the first terminal 3.

[0035] The first sealing element 5 can be injection molded onto the first terminal 3 and the substrate 2 through an injection molding process, for example, it can be placed in the injection mold as an insert. In the same manner, the second sealing element 5 is injection molded onto the second terminal 4 and the substrate 2 at the second terminal 4.

[0036] The sealing elements 5 and 5' on the first terminal 3 and the second terminal 4 are geometrically identical. The sealing elements 5 and 5' are arranged in the through opening 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 provide connection and reliable fixation between the terminal and the substrate.

[0037] The sealing element 5 on the first terminal 3 is conductive and includes a first portion region 5a and a second portion region 5b. The sealing element 5 is a single-piece component. The first portion region 5a is made of a first component, and the second portion region 5b is made of a second component, wherein the two components are made of different materials. The first portion region 5a is oriented only towards the inside of the top cover assembly and is exposed inwards, while the second portion region 5b is oriented only towards the outside of the top cover assembly and is exposed outwards.

[0038] In other words, the first region 5a is in contact only with the electrolyte 14 on the inner side of the top cover assembly, and the second region 5b is in contact only with the immersion cooling fluid 15 on the outer side of the top cover assembly.

[0039] The dividing line 13 between the first region 5a and the second region 5b is arranged in the region of the through opening 20. The dividing line 13 is preferably parallel to the substrate 2. Particularly preferably, the dividing line 13 is arranged in the middle of the through opening 20 in the through direction.

[0040] Since the first sealing element 5 is made of a conductive material, corrosion protection can be achieved for the first terminal 3, which is configured as a cathode. Here, it is sufficient for either the first portion 5a or the second portion 5b to be conductive. Therefore, an electrical connection is provided from the first terminal 3 to the substrate 2 via the conductive first sealing element 5.

[0041] By setting the dividing line 13 within the through opening 20, it is ensured that the first portion region 5a is connected only to the electrolyte, and the second portion region 5b is connected only to the immersion cooling fluid 15. The material of the first portion region 5a is selected such that it is resistant to the electrolyte 14. The material of the second portion region 5b is selected such that it is resistant to the immersion cooling fluid 15.

[0042] An elastomer is preferably used as the material for the first and second regions 5a and 5b. EPDM is preferably used for the first region 5a, and NBR is preferably used for the second region 5b.

[0043] At the first connection region 6, the first terminal 3 has an untreated surface 11. Specifically, as from... Figure 2 As can be seen, the sealing element 5 is completely attached to the untreated surface 11 of the first terminal 3.

[0044] At the second connection region 7, a treated surface 12 is formed on the substrate. The connecting element 5 is fully attached to the treated surface 12 here.

[0045] In other words, the sealing element 5 is fully attached to the untreated surface at the first terminal 3, and the sealing element 5 is attached to the fully treated surface 12 at the substrate 2.

[0046] Through these measures, the sealing element 5 is configured to apply a pressure F perpendicular to the untreated surface 11 of the first terminal 3. Thus, the sealing element 5 presses against the untreated surface 11 of the first terminal 3 with pressure F, thereby fluid-tightly sealing the first connection region 6.

[0047] A fluid-sealed connection is formed between the sealing element 5 and the substrate 2 at the treated surface 12 of the substrate 2. The treated surface 12 on the second connection region 7 can be treated by various chemical and / or mechanical methods, or can have a coating. The coating is preferably an adhesion-promoting coating or a primer. Mechanical surface treatments are, for example, roughening, and chemical surface treatments are, for example, etching processes. Various combinations of surface treatment measures are possible, particularly improving the roughness of the treated surface 12.

[0048] Especially from Figure 2 and 3 As can be seen, no surface treatment is provided on the first connection area 6, so that the sealing element 5 is in complete contact with the untreated surface 11 on the first terminal. On the second connection area 7, the contact surface between the sealing element 5 and the substrate 2 is entirely formed by the treated surface 12, so that the sealing element 5 is always in contact with the treated surface 12.

[0049] The elastomer material is preferably selected such that after the top cover assembly is installed, a process for increasing the volume of the sealing element can be performed, thereby increasing the pressure F from the sealing element 5 to the first terminal 3.

[0050] In the same manner, on the second terminal 4, the first connection region 6 and the second connection region 7 are constructed as on the first terminal 3.

[0051] Therefore, the first terminal 3 and the second terminal 4 can be simply placed into an injection mold, for example, as untreated components. Surface treatment is only required on the substrate in the area of ​​the through opening 20.

[0052] At the second terminal 4, the first portion 5'a and the second portion 5'b of the second sealing element 5' are not necessarily made of a conductive material, but rather of a non-conductive material. Here, the first portion 5'a is resistant to the electrolyte 14, and the second portion 5'b is resistant to the immersion cooling fluid 15.

[0053] The top cover assembly can be manufactured, preferably in a single injection mold, through multiple injection molding processes. Here, the substrate 2, the first terminal 3, and the second terminal 4 are configured as inserts. Since four different materials are used for the four portion regions of the first and second sealing elements 5, 5', four separate injection molding processes are required in a common injection mold. If only one of the two portion regions 5'a and 5'b of the first sealing element 5 is conductive, the other portion of these two portion regions can be selected as the same material as the anode at the second terminal 4. Thus, only three injection molding processes are required, because a corresponding portion region at the first and second terminals 3, 4 can be injection molded in one process.

[0054] Due to the C-shaped structure of the sealing elements 5 and 5' in cross-section, a relatively long first connection region 6 is obtained, which provides a medium seal between the sealing element 5 and the first terminal 3. Similarly, a relatively long second connection region 7 is obtained between the sealing elements 5 and 5' and the substrate 2.

[0055] In addition to sealing relative to terminals 3, 4 or substrate 2, sealing elements 5 and 5' also serve as fixing devices for securing terminals 3 and 4 in the through opening 20 of substrate 2. Specifically, by constructing surrounding edge regions 30 and 40 and stepped portions 22 on substrate 2 for the first and second terminals 3 and 4, reliable form-locking fixing of terminals 3 and 4 can be achieved, with the stepped portions at least partially located above the surrounding edge regions 30 and 40.

[0056] The substrate 2 also includes a filling port 8 and a crack area 9.

[0057] 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 elements 5, 5'. The insulating plate 10 here has a surrounding edge 10a in the area of ​​the through opening 20, which ensures proper positioning during the injection molding process of the sealing elements 5, 5'.

[0058] For example, further from Figure 1 As can be seen, the two sealing elements 5 and 5' are constructed such that the inner region 52 partially surrounds the edge regions 30 and 40 of the two terminals 3 and 4. This achieves better fixation of the terminals 3 and 4 on the substrate 2.

[0059] Figure 4 The assembled battery cell 100 is shown, wherein the top cover assembly 1 is 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. Thus, the connection between the top cover assembly 1 and the battery housing 101 can be achieved in a simple manner, for example, by a welding process.

[0060] Therefore, a top cover assembly 1 for a battery cell with immersion cooling can be provided, wherein the sealing elements 5, 5' are made of two-component materials that are optimized for resistance to the electrolyte 14 and the immersion cooling fluid 15, respectively. This achieves improved material resistance relative to the electrolyte and the immersion cooling fluid. Preferably, the sealing elements 5, 5' are injection molded in one mold, preferably in multiple molds. Adhesion on the components to which the sealing elements 5, 5' are attached promotes the coatings 11, 12 to improve the sealing of the connection areas 6, 7. This additional effect is further enhanced by the arrangement of the dividing line 13 in the area of ​​the through opening 20.

[0061] Figure 5 An alternative configuration of the battery cell 100 is shown, wherein two cell top covers 1a and 1b are provided, respectively arranged on the narrow sides of the battery cell 100 opposite to each other, and covering the battery casing 101. Here, a first terminal 3 is arranged on the first cell top cover 1a, and a second terminal 4 is arranged on the second cell top cover 1b. The second cell top cover 1b also additionally has a filling opening 8. A rupture region 9 is provided in the battery casing 101 on the long narrow side (see [reference]). Figure 5 On. The sealing element is on. Figure 5 It is constructed in the same manner as the first embodiment.

Claims

1. A top cover assembly (1) for a single battery cell, the top cover assembly comprising: Metal substrate (2). The first terminal (3) is arranged in the through opening (20) of the substrate (2). A sealing element (5) is used to fix and seal the first terminal (3) on the substrate (2). The sealing element (5) is arranged in the through opening (20) and configured to seal a first connection region (6) between the first terminal (3) and the sealing element (5) and a second connection region (7) between the substrate (2) and the sealing element (5), and to provide a connection between the first terminal (3) and the substrate (2). The first connection area (6) has an untreated surface (11) on the first terminal (3). The second connection region (7) has a processed surface (12) on the substrate (2), and The sealing element (5) is configured to apply pressure F perpendicular to the untreated surface (11) of the first terminal (3) to fluid seal the first connection area (6).

2. The top cover assembly according to claim 1, wherein, The substrate (2) has a fully treated surface (12) on the second connection area (7), and the sealing element (5) is fixed on the fully treated surface.

3. The top cover assembly according to any one of the preceding claims, wherein, The first terminal (3) has a completely untreated surface (11) on the first connection area (6), and the sealing element (5) seals the completely untreated surface.

4. The top cover assembly according to any one of the preceding claims, wherein, The sealing element (5) is an elastomer.

5. The top cover assembly according to any one of the preceding claims, wherein, The first terminal (3) is constructed as a cathode, and the sealing element (5) on the first terminal is made of a conductive material.

6. The top cover assembly according to any one of the preceding claims, wherein, After installation, the sealing element (5) undergoes a process to increase its volume in order to increase the pressure F on the first terminal (3).

7. The top cover assembly according to any one of the preceding claims, wherein, The sealing element (5) is a one-piece component having a first part region (5a) and a second part region (5b), the first part region being made of a first material and the second part region being made of a second material, wherein the first material is different from the second material, and the first part region (5a) is exposed only to the inside of the top cover assembly and the second part region (5b) is exposed only to the outside of the top cover assembly.

8. The top cover assembly (1) according to claim 7, wherein, The dividing line (13) between the first part region (5a) and the second part region (5b) is located in the through opening (20).

9. The top cover assembly (1) according to any one of claims 7 or 8, wherein, The first material of the first part region (5a) is resistant to the electrolyte (14), and the second material of the second part region (5b) is resistant to the heat transfer fluid (15).

10. The top cover assembly (1) according to any one of claims 7 to 9, wherein, The first region (5a) is made of a first elastomer, and the second region (5b) is made of a second elastomer different from the first elastomer.

11. The top cover assembly (1) according to any one of the preceding claims, the top cover assembly comprising a first terminal (3) and a second terminal (4), wherein, A second sealing element (5') made of non-conductive material is arranged on the second terminal (4).

12. The top cover assembly (1) according to claim 11, wherein, The first terminal (3) and the second terminal (4) are respectively constructed as rectangles, and in particular have surrounding edge regions (30, 40).

13. A battery cell, said battery cell comprising a top cover assembly (1) according to any one of the preceding claims.

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