Battery cell for a high-voltage battery and method for manufacturing a battery cell

Abstract

The invention relates to a battery cell (10) for a high-voltage battery, in particular for a high-voltage battery of an electrically powered vehicle, with a cell housing (12) comprising at least one electrical terminal (20) which is arranged in an opening (14) of the cell housing (12), wherein the electrical terminal (20) is arranged to tightly close the opening (14) by means of plastic deformation. An electrically insulating seal (30) is arranged between the electrical terminal (20) and the cell housing (12). The invention further relates to a method for manufacturing a battery cell (10).

Description

[0001] The invention relates to a battery cell for a high-voltage battery, in particular for a high-voltage battery of an electrically powered vehicle, and to a method for manufacturing a battery cell.

[0002] Battery cell casings require at least one terminal for an electrical connection. These terminals must be mechanically robust, gas-tight, chemically stable, and dimensioned according to the chemical composition used in order to minimize conduction and contact resistances.

[0003] Conventional solutions that involve riveting the connection pole have the disadvantage of requiring a large number of components, increased installation space, and limiting the conductor cross-section due to the rivet.

[0004] The pole connection is typically achieved by crimping a rivet combined with a sealing element, for example, a sealing element made of a fluorocarbon rubber compound (FKM) and metallic contact elements. This sandwich-like assembly, crimped with the rivet, creates a gas-tight pole connection. This type of pole connection is used, for example, in prismatic cells and larger diameter cylindrical cells, such as those in the 46800 format.

[0005] Cylindrical cells in the formats 21700, 18650, and in a few cases 46800, are typically sealed by crimping. In this process, the cell cup and the cell lid are pressed together in an electrically insulating and gas-tight manner. However, this solution is relatively space-consuming.

[0006] One object of the invention is to create a battery cell for a high-voltage battery, in particular for a high-voltage battery of an electrically operated vehicle, with an improved terminal.

[0007] Another task is to specify a method for manufacturing such a battery cell with an improved terminal.

[0008] The aforementioned tasks are solved using the characteristics of independent claims.

[0009] Favorable embodiments and advantages of the invention will become apparent from the further claims, the description and the drawing.

[0010] According to one aspect of the invention, a battery cell for a high-voltage battery, in particular for a high-voltage battery of an electrically powered vehicle, is proposed, comprising a cell housing comprising at least one electrical terminal which is arranged in an opening of the cell housing, wherein the electrical terminal is arranged to tightly close the opening by means of plastic deformation. An electrically insulating seal is arranged between the electrical terminal and the cell housing.

[0011] In the proposed battery cell, the terminal is tightly connected to the cell housing or cell cover (as part of the cell housing) by plastic deformation, a so-called crimp connection, via an electrically insulating seal. Crimping is a joining process in which two components are joined together by plastic deformation, for example by flanging, crushing, crimping, or folding. A crimp connection is only partially reversible and can only be renewed with suitable tools during repairs.

[0012] The cell housing can advantageously have geometric adjustments in the area of ​​the opening, i.e. the breakthrough of the connection pole, such as partial bulges, thickenings and beads for reinforcement and better sealing effect.

[0013] This allows a battery cell to be manufactured with a small number of parts.

[0014] The production of the battery cell can be done cost-effectively and quickly.

[0015] This allows for a direct connection of the terminal to a battery cell pack with a low contact resistance.

[0016] The terminal pole can be dimensioned differently.

[0017] Different conductor cross-sections can be implemented in the proposed battery cell.

[0018] A cell connector can be advantageously integrated into the connection pole.

[0019] A terminal like the one in the proposed battery cell can conveniently be used in cylindrical and prismatic cells.

[0020] According to an advantageous embodiment of the battery cell, the electrical terminal can have a flange part and an adjoining wall, wherein the flange part can be arranged in an interior space of the cell housing at the opening. The wall can be arranged to extend through the opening into an exterior space of the cell housing.

[0021] Alternatively, the flange section can be arranged at the opening in the outer space of the cell housing, with the wall extending through the opening into the interior of the cell housing. In particular, the wall can be designed to contact an electrode stack inside the cell housing. This has the advantage that the electrode stack can be electrically connected to the terminal in a convenient manner, for example, by welding.

[0022] The terminal can be manufactured using various processes. A forming process, using a sheet metal blank as the starting material, is particularly suitable. Both the flange and the wall can be produced through a forming and stamping process. Partial reinforcements, such as in the flange area, can be achieved by means of a fold.

[0023] According to an advantageous embodiment of the battery cell, the electrically insulating seal can have a shoulder and an adjoining wall, the shoulder being arranged between the flange portion of the electrical terminal and the cell housing. The wall of the electrically insulating seal can be positioned between the wall of the electrical terminal and the cell housing. The seal, which may be made of plastic, for example, can advantageously have geometric adaptations to the required geometry of the cell housing, such as partial bulges, thickenings, or beads.

[0024] According to an advantageous embodiment of the battery cell, the electrical terminal and / or the seal and / or the cell housing can have beads and / or partial bulges, particularly around the opening. In particular, the beads and / or bulges can be arranged in the area of ​​the flange part of the electrical terminal.

[0025] The wall, flange, and all other surfaces of the terminal can be geometrically adapted to specific requirements and can vary within the component. The terminal, seal, and cell housing can feature geometric modifications such as partial bulges, thickenings, and beads. This allows for undercuts, which ensure improved interlocking of the components and a reliable seal between the electrical terminal and the cell housing.

[0026] According to an advantageous embodiment of the battery cell, the electrically insulating seal can be made of a plastic. In particular, the electrically insulating seal can be manufactured using a machining or non-machining process, especially an injection molding process. Advantageously, various non-conductive materials can be used for the plastic seal. Manufacturing processes can be advantageously selected specifically depending on the material.

[0027] According to an advantageous embodiment of the battery cell, the cell housing and / or the electrical terminal and / or the electrically insulating seal, particularly in the area of ​​contact points, can exhibit a complete or partial modification of the surface structure. In particular, this complete or partial modification of the surface structure can be achieved through chemical roughening and / or laser roughening. The surface structure can advantageously be modified to achieve a good sealing effect.

[0028] According to an advantageous embodiment of the battery cell, the cell housing and / or the electrical terminal and / or the electrically insulating seal, particularly in the area of ​​contact points with each other, can have a complete or partial surface coating. A surface coating can also favorably influence the sealing effect of the materials involved.

[0029] According to an advantageous embodiment of the battery cell, the electrical terminal pole, in particular the wall of the electrical terminal pole, can be designed as an integrated cell connector for electrical contact with an electrical terminal pole or a cell housing of an adjacent battery cell.

[0030] By selectively varying the wall height of the terminal, an integrated cell connector can be implemented. This allows for subsequent connection of the finished battery cells to each other without the use of additional components and simultaneously minimizes contact resistances that can arise from welding, soldering, or clamping connections.

[0031] Alternatively or additionally, the electrical terminal can be shaped to fit a surface of the cell housing and can have a cross-section that is particularly round, semi-circular, oval, or polygonal. Various terminal shapes can be implemented for cylindrical and prismatic battery cells, depending on the application requirements.

[0032] According to a further aspect of the invention, a method for manufacturing a battery cell, in particular a high-voltage battery of an electrically powered vehicle, is proposed, comprising at least providing a cell housing of the battery cell with an opening; providing an electrical terminal; providing an electrically insulating seal; inserting the electrical terminal into the opening of the cell housing, wherein the electrically insulating seal is arranged between the cell housing and the electrical terminal; and closing the opening of the cell housing with the electrical terminal by means of a plastic forming process of the electrical terminal.

[0033] According to the proposed method, the terminal of the battery cell is tightly connected to the cell housing or cell cover (as part of the cell housing) by plastic deformation, a so-called crimp connection, via an electrically insulating seal. Crimping is a joining process in which two components are joined together by plastic deformation, for example by flanging, crushing, crimping, or folding. A crimp connection is only partially reversible and can only be renewed with suitable tools during repairs.

[0034] The cell housing can advantageously have geometric adjustments in the area of ​​the opening, i.e. the breakthrough of the connection pole, such as partial bulges, thickenings and beads for reinforcement and better sealing.

[0035] This allows a battery cell to be manufactured with a small number of parts.

[0036] The production of the battery cell can be done cost-effectively and quickly.

[0037] This allows for a direct connection of the terminal to a battery cell pack with a low contact resistance.

[0038] The terminal pole can be dimensioned differently.

[0039] Different conductor cross-sections can be implemented in the proposed battery cell.

[0040] A cell connector can be advantageously integrated into the connection pole.

[0041] A terminal like the one in the proposed battery cell can conveniently be used in cylindrical and prismatic cells.

[0042] According to an advantageous embodiment of the method, the electrical terminal pole can have a flange portion and an adjoining wall, wherein the flange portion can be arranged in an interior space of the cell housing at the opening. The electrically insulating seal can have a shoulder and an adjoining wall, wherein the shoulder can be arranged between the flange portion of the electrical terminal pole and the cell housing in the interior of the cell housing. The wall of the electrically insulating seal can be arranged between the wall of the electrical terminal pole and the cell housing. The wall of the electrical terminal pole can be guided through the opening into an exterior space of the cell housing and plastically deformed.

[0043] The wall, flange, and all other surfaces of the terminal pole can be geometrically adapted in their dimensions according to requirements and can vary within the component. The terminal pole can exhibit geometric modifications such as partial bulges, thickenings, and beads.

[0044] The terminal can be manufactured using various processes. A forming process, using a sheet metal blank as the starting material, is particularly suitable. Both the flange and the wall can be produced through a forming and stamping process. Partial reinforcements, such as in the flange area, can be achieved by means of a fold.

[0045] The seal, for example made of plastic, can advantageously have geometric adaptations to the required geometry of the cell housing, such as partial bulges, thickenings or beads.

[0046] In particular, the electrically insulating seal can be manufactured using a machining or non-machining process, especially an injection molding process. Various non-conductive materials can advantageously be used for the plastic seal. Manufacturing processes can be advantageously selected specifically depending on the material.

[0047] Further advantages will become apparent from the following description of the drawings. The drawings illustrate an embodiment of the invention. The drawings, the description, and the claims contain numerous features in combination. A person skilled in the art will expediently consider the features individually and combine them into meaningful further combinations.

[0048] This shows: Fig. 1 a sectional view through a part of a battery cell for a high-voltage battery, in particular for a high-voltage battery of an electrically operated vehicle, according to an embodiment of the invention, before a plastic forming process of a terminal pole; Fig. 2 the sectional view of the battery cell according to Fig. 1 after the plastic forming process of the connecting pole; Fig. 3 an enlarged cross-sectional view of a battery cell according to a further embodiment of the invention after the plastic forming process of the terminal pole with beads and bulges in the terminal pole, seal and cell housing; Fig. 4 a sectional view of a battery cell according to a further embodiment of the invention with a terminal pole designed as a cell connector, after the plastic forming process of the terminal pole; Fig. 5 Cross-sectional views of two battery cells which are electrically connected by means of a terminal pole of one battery cell designed as a cell connector; Fig. 6 a top view of a battery cell designed as a cylindrical cell according to an embodiment of the invention; Fig. 7 a top view of a battery cell designed as a cylindrical cell according to a further embodiment of the invention; Fig. 8 a top view of a battery cell designed as a cylindrical cell according to a further embodiment of the invention; Fig. 9 A top view of two battery cells designed as cylindrical cells, which are electrically connected by means of a terminal pole of a battery cell designed as a cell connector, according to an embodiment of the invention; and Fig. 10 a top view of two battery cells designed as prismatic cells, which are electrically connected by means of a terminal pole of a battery cell designed as a cell connector, according to a further embodiment of the invention.

[0049] In the figures, identical or similar components are numbered with the same reference symbols. The figures merely show examples and are not to be understood as limiting.

[0050] Fig. Figure 1 shows a cross-sectional view through a part of a battery cell 10 for a high-voltage battery, in particular for a high-voltage battery of an electrically operated vehicle, according to an embodiment of the invention, before a plastic forming process of a terminal pole 20.

[0051] The battery cell 10, of which only a portion of a cell housing 12 or cell cover is shown, comprises an electrical terminal 20, which is arranged in an opening 14 of the cell housing 12. An electrically insulating seal 30 is arranged between the electrical terminal 20 and the cell housing 12.

[0052] The electrical terminal 20 has a flange part 22 and an adjoining wall 24. The flange part 22 is arranged in an interior space 16 of the cell housing 12 at the opening 14. The wall 24 extends through the opening 14 into an exterior space 18 of the cell housing 12.

[0053] In an alternative embodiment not shown, the flange part 22 can be arranged in the outer space 18 of the cell housing 12 at the opening 14, with the wall 24 extending through the opening 14 into the interior 16 of the cell housing 12. In particular, the wall 24 can be configured to contact an electrode stack in the interior 16 of the cell housing 12. This has the advantage that the electrode stack can be electrically connected to the terminal 20 in a convenient manner, for example by welding.

[0054] The electrically insulating seal 30 has a shoulder 32 and an adjoining wall 34. The shoulder 32 is located between the flange part 22 of the electrical terminal 20 and the cell housing 12 in the interior 16 of the cell housing 12. The wall 34 of the electrically insulating seal 30 is located between the wall 24 of the electrical terminal 20 and the cell housing 12.

[0055] The electrically insulating seal 30 is made of a plastic and can be manufactured in particular by means of a machining or non-machining process, especially an injection molding process.

[0056] The electrically insulating seal 30 can be slid onto the electrical terminal 20 in the cell housing 12 in the form of a sleeve before the terminal 20 is mounted. Alternatively, the electrically insulating seal 30 can also be inserted directly into the opening 14 of the cell housing 12 as a sleeve, and the terminal 20 can then be mounted.

[0057] Terminal 20 and seal 30 can also form an integral component. Seal 30 can also be applied to terminal 20 as an insulating coating in certain areas.

[0058] The electrical connection pole 20 can be arranged in the opening 14 in a tightly closing manner by means of a plastic forming process.

[0059] In Fig. Figure 2 shows the cross-sectional view of battery cell 10. Fig. 1 shown after the plastic forming process of the connecting pole 20.

[0060] The wall 24 of the terminal 20 has been crimped radially outwards in the opening 14. The wall 34 of the seal 30 is also crimped radially outwards. Terminal 20 and seal 30 form a tight press fit. This seals the opening 14 of the cell housing 12 tightly with the terminal 20.

[0061] The cell housing 12 and / or the electrical terminal 20 and / or the electrically insulating seal 30, particularly in the area of ​​contact points between them, may, as required, exhibit a complete or partial change in surface structure. In particular, the surface may be roughened completely or partially by chemical or laser treatment.

[0062] Alternatively or additionally, the cell housing 12 and / or the electrical terminal pole 20 and / or the electrically insulating seal 30, especially in the area of ​​contact points with each other, can have a complete or partial surface coating.

[0063] Surface treatment or coating can modify the surfaces to provide a favorable sealing effect.

[0064] According to the proposed method, to manufacture the battery cell 10, the cell housing 12 of the battery cell 10 with the opening 14 is first provided. Furthermore, the electrical terminal 20 and the electrically insulating seal 30 are provided.

[0065] The electrical terminal 20 is then inserted into the opening 14 of the cell housing 12, with the electrically insulating seal 30 being arranged between the cell housing 12 and the electrical terminal 20.

[0066] Subsequently, the opening 14 of the cell housing 12 can be tightly closed with the electrical connection pole 20 by means of a plastic forming process of the electrical connection pole 20.

[0067] As described above, the electrical terminal 20 has a flange part 22 and an adjoining wall 24. For the forming process of the terminal 20, the flange part 22 is positioned at the opening 14 in the interior 16 of the cell housing 12. The electrically insulating seal 30 also has a shoulder 32 and an adjoining wall 34. The shoulder 32 is positioned between the flange part 22 of the electrical terminal 20 and the cell housing 12 in the interior 16 of the cell housing 12. The wall 34 of the electrically insulating seal 30 is positioned between the wall 24 of the electrical terminal 20 and the cell housing 12. Subsequently, the wall 24 of the electrical terminal 20 is guided through the opening 14 into an outer space 18 of the cell housing 12 and plastically deformed.

[0068] Fig. Figure 3 shows an enlarged sectional view of a battery cell 10 according to a further embodiment of the invention after the plastic forming process of the terminal pole 20 with beads 25, 35, 13 and bulges 27, 37 in terminal pole 20, seal 30 and cell housing 12.

[0069] The cell housing 12 has grooves 13 on both sides in the flange area of ​​the electrical connection pole 20, into which material from the seal 30 can flow as a bulge 37 during the forming process of the connection pole 20.

[0070] The terminal 20 has a bead 25 on its side facing the outside 18, which is created by the forming process and in turn results in a bulge 27. The flange part 22 also has a bulge 27, through which, during the forming process, the material from the seal 30 is displaced into the beads 13 of the cell housing 12, thereby creating beads 35 and corresponding bulges 37 in the seal 30.

[0071] In this way, the electrical terminal 20, the seal 30, and the cell housing 12 are conveniently interlocked. This ensures a reliable seal between the cell housing 12 and the terminal 20.

[0072] Fig. Figure 4 shows a sectional view of a battery cell 10 according to a further embodiment of the invention with a terminal pole 20 designed as a cell connector 26, after the plastic forming process of the terminal pole 20.

[0073] In this embodiment, the electrical terminal 20, in particular the wall 24 of the electrical terminal 20, is designed as an integrated cell connector 26 for electrical contact with an electrical terminal 20 or a cell housing 12 of an adjacent battery cell 10. The wall 24 is longer on one side than on the other, so that the longer part of the wall 24 remains parallel to the surface 15 of the cell housing 12 and can thus be electrically connected to an adjacent battery cell 10.

[0074] In Fig. Figure 5 shows sectional views of two battery cells 10, which are electrically connected by means of a terminal pole 20 of a battery cell 20 designed as a cell connector 26.

[0075] The connecting pole 20, designed as a cell connector 26, is led to the adjacent cell housing 12 and firmly connected to this cell housing 12, for example by welding. In this way, the battery cells 10 can be electrically connected in series.

[0076] An electrically parallel connection can also be realized in this way by connecting the cell connector 26 to a terminal 20 of an adjacent battery cell 10.

[0077] The electrical terminal 20 can have different geometric designs. For example, the electrical terminal 20 can be suitably shaped parallel to the surface 15 of the cell housing 12 and may have a round, semicircular, oval, or polygonal cross-section.

[0078] Fig. Figure 6 shows a top view of a battery cell 10 designed as a cylindrical cell according to an embodiment of the invention with a semi-circular terminal 20, while in Fig. Figure 7 shows a top view of a battery cell 10 designed as a cylindrical cell with a round terminal 20.

[0079] In the top view, the crimped wall 24 of the connection pole 20 is visible, while inside the connection pole 20 the bottom of the flange part 22 is visible.

[0080] Fig. Figure 8 further shows a top view of a battery cell 10 designed as a cylindrical cell with a hexagonal cross-section.

[0081] In Fig. Figure 9 shows a top view of two battery cells 10 designed as cylindrical cells, which are electrically connected by means of a terminal pole 20 designed as a cell connector 26 of a battery cell 10.

[0082] The terminal poles 20, designed as cell connectors 26, are each terminated with a curvature in order to maintain a uniform distance to the terminal pole 20 of the adjacent battery cell 10 when contacting the cell housing 12 of the adjacent battery cell 10.

[0083] The joining connection 28 at the connection of the cell connector 26 to the cell housing 12 of the adjacent battery cell 10 is shown as a dashed line. The joining connection 28 can be produced, for example, by welding, such as laser welding, friction welding, or ultrasonic welding. Advantageously, a connection using screws, rivets, soldering, or forming processes, such as folding or crimping, is also possible.

[0084] Fig.Figure 10 shows a top view of two battery cells 10 designed as prismatic cells, which are electrically connected by means of a terminal pole 20 of a battery cell 10 designed as a cell connector 26.

[0085] In this embodiment, the terminal poles 20 have an oval cross-section, with each terminal pole 20 extending into a rectangular cell connector 26 on one side. The cell connector 26 can thus be connected to the prismatic cell housing 12 of the adjacent battery cell 10 via a joining connection 28, which extends almost the entire length of the cell connector 26. Reference symbol list 10 battery cells 12 cell casings 13 groove 14 Opening 15 surface 16 Interior 18 Outdoor area 20 electrical connection pole 22 flange 24 wall 25 groove 26 cell connectors 27 Bulging 28 Joining connection 30 electrically insulating seals Paragraph 32 34 wall 35 groove 37 Bulging

Images