Battery cell

Abstract

The invention belongs to the technical field of batteries, and discloses a battery monomer which comprises a battery shell, a battery cover plate and a pole group, the battery shell is provided with a containing cavity and an opening which are communicated, the opening is located in the side, facing a first direction, of the battery shell, the battery cover plate comprises a plate body, and the plate body covers the opening; the plate body comprises a plate body part and a first protruding part which is connected with the plate body part and protrudes towards a first direction, a capacity increasing groove is formed in the side, deviating from the first direction, of the first protruding part, the pole group comprises a pole group body structure and a first protruding structure which is connected to the side, facing the first direction, of the pole group body structure, and the pole group body structure is arranged in the containing cavity; all side walls, parallel to the first direction, of the pole group body structure are attached to the inner wall of the containing cavity, the first protruding structures are located in the capacity increasing grooves, the groove bottoms of the capacity increasing grooves and at least one group of oppositely-arranged inner walls of the capacity increasing grooves are all attached to the first protruding structures, the probability of deformation and damage of the plate bodies of the single batteries is low, the pole group capacity is large, and the capacity of the single batteries is high. And the moving probability of the pole group is low.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more particularly to a single battery cell. Background Technology

[0002] A battery cell typically includes an electrode assembly, a housing, and a cover. The electrode assembly is housed inside the housing, and the cover is placed over the opening in the housing to provide a sealed space for the electrode assembly.

[0003] In the existing technology, the cover plate is a flat structure and the cover plate is relatively thin, which results in low structural strength. During transportation and assembly processes, the cover plate is easily deformed and damaged, which reduces the assembly yield of the cover plate and the shell and is not conducive to improving the safety and production yield of the battery cell.

[0004] On the other hand, the existing technology prevents the electrode assembly from moving inside the housing by having the inner wall of the housing fit against the side wall of the electrode assembly in the circumferential direction to limit the electrode assembly. However, there is no limiting structure between the electrode assembly and the cover plate. In other words, the cover plate cannot limit the electrode assembly. When the internal pressure of the housing is high, the electrode assembly is prone to moving inside the housing, which reduces the safety of the battery cell.

[0005] Therefore, there is an urgent need to propose a new type of battery cell to solve the above-mentioned technical problems. Summary of the Invention

[0006] The purpose of this invention is to provide a battery cell with a low probability of deformation and damage to the plate, a large electrode capacity, and a low probability of electrode misalignment.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] Battery cells, including:

[0009] The battery casing has a communicating receiving cavity and an opening, with the opening located on the side of the battery casing facing the first direction;

[0010] A battery cover plate includes a plate body covering an opening. The plate body includes a plate body portion and a first protrusion portion connected to the plate body portion. The first protrusion portion protrudes in a first direction, and a capacity-enhancing groove is provided on the side of the first protrusion portion away from the first direction.

[0011] The electrode assembly includes an electrode assembly body structure and a first protruding structure. The electrode assembly body structure is disposed within a receiving cavity. All sidewalls of the electrode assembly body structure parallel to the first direction are fitted with the inner wall of the receiving cavity. The first protruding structure is connected to the side of the electrode assembly body structure facing the first direction. The first protruding structure is located within a capacity-enhancing groove. The bottom of the capacity-enhancing groove and at least one set of opposing inner walls of the capacity-enhancing groove are fitted with the first protruding structure.

[0012] Optionally, the battery cover also includes a first terminal assembly, which is disposed through the plate body, and a first protrusion protrudes from the first terminal assembly in a first direction.

[0013] Optionally, the plate also includes an inclined portion, which is connected to the side of the first protrusion away from the first electrode assembly. The inclined portion is inclined from the side facing the first protrusion to the side away from the first protrusion, in a direction away from the first direction. The battery cover also includes a second electrode assembly, which is inserted through the inclined portion. The first protrusion protrudes from the second electrode assembly along the first direction.

[0014] Optionally, the electrode assembly further includes a second protruding structure. The side of the second protruding structure opposite to the first direction is connected to the electrode assembly body structure. The first protruding structure protrudes from the side of the second protruding structure facing the first direction. The second protruding structure is provided with an inclined wall, which is parallel to the inclined portion and is positioned directly opposite the inclined portion.

[0015] Optionally, the electrode assembly further includes a first electrode tab and a second electrode tab, wherein the first electrode tab is connected to the side of the second protruding structure facing the first direction, the first electrode tab is connected to the first electrode post assembly, the second electrode tab is connected to the inclined wall, and the second electrode tab is connected to the second electrode post assembly.

[0016] Optionally, the number of the first protrusion, the inclined portion, the first protruding structure, the second electrode tab, and the inclined wall are all two and correspond one-to-one. In the width direction of the electrode group, the two second electrode tabs are located on both sides of the first electrode tab, and the first electrode tab is positioned directly opposite the first electrode post assembly.

[0017] Optionally, there are two second pole post assemblies, with each of the two second pole post assemblies corresponding to one of the two second pole tabs. In the width direction of the pole group, the two second pole tabs, the two inclined walls, the two second pole post assemblies, the two first protruding structures, the two first protrusions, and the two inclined portions are all symmetrically arranged about the first pole post assemblies.

[0018] Optionally, the side of the inclined wall facing the first direction is the connecting part, which is connected to the first protruding structure. Along the direction in which the two inclined walls point to each other, the distance between the connecting parts of the two inclined walls is A, and the distance between the sides of the two first protruding structures facing each other is B, where 29mm≤AB≤91mm.

[0019] Optionally, the side of the inclined wall facing the first direction is a connecting part, which is connected to the first protruding structure. Along the direction in which the two inclined walls point to each other, the distance between the connecting parts of the two inclined walls is A, and the width of the pole group is L1, where 0.26≤A / L1≤0.51.

[0020] Optionally, the size of the second electrode lug is W1 along the direction parallel to the inclined wall, and the size of the inclined wall is W2, where 0.51≤W1 / W2≤8.7.

[0021] The beneficial effects of this invention are:

[0022] The plate includes a plate portion and a first protrusion connected to the plate portion. The first protrusion protrudes in a first direction and forms a reinforcing structure on the plate, thereby improving the structural strength of the plate and reducing the probability of deformation and damage to the plate during transportation and assembly processes, which is beneficial to improving the safety and production yield of the battery cells.

[0023] On the other hand, the first protrusion is provided with a capacity-enhancing groove on the side away from the first direction. The electrode assembly includes an electrode assembly body structure located in the receiving cavity and a first protrusion structure located in the capacity-enhancing groove. The first protrusion structure is connected to the side of the electrode assembly body structure facing the first direction. This structure not only makes full use of the internal space of the capacity-enhancing groove, but also expands the volume of the electrode assembly and increases the capacity of the electrode assembly, which is beneficial to improving the energy density of the battery cell.

[0024] On the other hand, all sidewalls of the electrode assembly body structure parallel to the first direction are fitted with the inner wall of the receiving cavity, and the bottom of the capacity expansion groove and at least one set of opposing inner walls of the capacity expansion groove are fitted with the first protruding structure. This enables the battery case and plate to limit the electrode assembly, thereby reducing the probability of electrode assembly movement and improving the safety of the battery cell. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of a battery cell provided by the present invention;

[0026] Figure 2 This is a schematic diagram of the battery casing provided by the present invention;

[0027] Figure 3 This is a cross-sectional structural diagram of the battery cover plate provided by the present invention;

[0028] Figure 4 This is a schematic cross-sectional view of the battery cell provided by the present invention;

[0029] Figure 5 This is a schematic diagram of the first structure of the pole assembly provided by the present invention;

[0030] Figure 6 This is a schematic diagram of the second structure of the pole group provided by the present invention;

[0031] Figure 7 This is a partially enlarged structural diagram of the pole group provided by the present invention;

[0032] Figure 8 This is a schematic diagram of the third structure of the pole assembly provided by the present invention.

[0033] In the picture:

[0034] D1, First direction; 1, Battery casing; 11, Opening; 2, Battery cover; 211, Plate part; 212, First protrusion; 2121, Capacity expansion groove; 2121a, First inner wall; 2121b, Second inner wall; 2121c, Groove bottom; 213, Inclined part; 241, Support part; 22, First terminal assembly; 221, First plastic part; 222, First riveting block; 223, First base; 224, First column; 23, Second terminal assembly; 231, Second plastic part; 232. Second riveting block; 233. Second base; 234. Second column; 241. Third plastic part; 242. Fourth plastic part; 31. Electrode assembly body structure; 32. First protruding structure; 321. First fitting wall; 322. Second fitting wall; 323. Third fitting wall; 33. Second protruding structure; 331. Inclined wall; 3311. Connecting part; 332. Recessed structure; 341. First electrode ear; 342. Second electrode ear; 343. Third electrode ear; 4. Third electrode column assembly. Detailed Implementation

[0035] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0036] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0037] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0038] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0039] This embodiment provides a battery cell with a low probability of deformation or damage to the plate, a large electrode capacity, and a low probability of electrode misalignment.

[0040] Specifically, such as Figures 1 to 5 As shown, the battery cell includes a battery casing 1, a battery cover plate 2, and an electrode assembly. The battery casing 1 has a communicating receiving cavity and an opening 11. The opening 11 is located on the side of the battery casing 1 facing the first direction D1. The battery cover plate 2 includes a plate body that covers the opening 11. The plate body includes a plate body portion 211 and a first protrusion 212 connected to the plate body portion 211. The first protrusion 212 protrudes towards the first direction D1, and a capacity-enhancing groove 2121 is provided on the side of the first protrusion 212 facing away from the first direction D1. The electrode assembly includes an electrode assembly body structure 31 and a first protruding structure 32. The electrode assembly body structure 31 is disposed in the receiving cavity. All sidewalls of the electrode assembly body structure 31 parallel to the first direction D1 are in contact with the inner wall of the receiving cavity. The first protruding structure 32 is connected to the side of the electrode assembly body structure 31 facing the first direction D1. The first protruding structure 32 is located in the capacity expansion groove 2121. The bottom 2121c of the capacity expansion groove 2121 and at least one set of opposing inner walls of the capacity expansion groove 2121 are in contact with the first protruding structure 32.

[0041] Based on the above design, the plate includes a plate portion 211 and a first protrusion 212 connected to the plate portion 211. The first protrusion 212 protrudes in the first direction D1 and forms a reinforcing structure on the plate, thereby improving the structural strength of the plate and reducing the probability of deformation and damage to the plate during transportation and assembly processes, which is beneficial to improving the safety and production yield of the battery cells.

[0042] On the other hand, the first protrusion 212 has a capacity-enhancing groove 2121 on the side away from the first direction D1. The electrode assembly includes an electrode assembly body structure 31 located in the receiving cavity and a first protrusion structure 32 located in the capacity-enhancing groove 2121. The first protrusion structure 32 is connected to the side of the electrode assembly body structure 31 facing the first direction D1. This structure not only makes full use of the internal space of the capacity-enhancing groove 2121, but also expands the volume of the electrode assembly and increases the capacity of the electrode assembly, which is beneficial to improving the energy density of the battery cell.

[0043] On the other hand, all the sidewalls of the electrode assembly body structure 31 parallel to the first direction D1 are in contact with the inner wall of the receiving cavity, and the bottom 2121c of the capacity expansion groove 2121 and at least one set of oppositely arranged inner walls of the capacity expansion groove 2121 are in contact with the first protruding structure 32. This enables the battery case 1 and the plate to limit the electrode assembly, thereby reducing the probability of electrode assembly movement and improving the safety of the battery cell.

[0044] In this embodiment, the capacity-enhancing groove 2121 includes two sets of opposing inner walls. Both sets of opposing inner walls and the bottom 2121c of the capacity-enhancing groove 2121 are in contact with the first protruding structure 32. This not only increases the limiting area of ​​the first protruding structure 32 but also increases the limiting direction of the first protruding structure 32, thereby improving the limiting effect on the electrode assembly. Of course, in other embodiments, the capacity-enhancing groove 2121 may also include two sets of opposing inner walls, with one set of these inner walls and the bottom 2121c of the capacity-enhancing groove 2121 in contact with the first protruding structure 32 to achieve the limiting effect on the first protruding structure 32. In another embodiment, the capacity-enhancing groove 2121 may include three or more sets of opposing inner walls, in which case all three or more sets of opposing inner walls may be in contact with the first protruding structure 32 to achieve the limiting effect on the first protruding structure 32.

[0045] Furthermore, the battery cover 2 also includes a first terminal assembly 22, which is disposed through the plate body portion 211. A first protrusion 212 protrudes from the first terminal assembly 22 along a first direction D1, so that the first protrusion 212 protects the first terminal assembly 22 and prevents the first terminal assembly 22 from being bumped during the manufacturing process, which is beneficial to improving the safety of the battery cell and the product yield.

[0046] Optionally, the plate also includes an inclined portion 213, which is connected to the side of the first protrusion 212 away from the first terminal assembly 22. The inclined portion 213 is inclined from the side facing the first protrusion 212 to the side away from the first protrusion 212, and is inclined in a direction away from the first direction D1. The battery cover plate 2 also includes a second terminal assembly 23, which is inserted through the inclined portion 213. The first protrusion 212 protrudes from the second terminal assembly 23 along the first direction D1, so that the first protrusion 212 protects the second terminal assembly 23 and prevents the second terminal assembly 23 from being bumped during the manufacturing process, which is beneficial to improving the safety of the battery cell and the product yield.

[0047] Furthermore, the electrode assembly also includes a second protruding structure 33. The side of the second protruding structure 33 facing away from the first direction D1 is connected to the electrode assembly body structure 31. The first protruding structure 32 protrudes from the side of the second protruding structure 33 facing the first direction D1. That is, the first protruding structure 32 is connected to the side of the electrode assembly body structure 31 facing the first direction D1 through the second protruding structure 33. The second protruding structure 33 is provided with an inclined wall 331, which is parallel to the inclined portion 213 and is positioned directly opposite the inclined portion 213. The arrangement of the second protruding structure 33 further increases the volume of the electrode assembly, which has the effect of further improving the capacity of the electrode assembly. Moreover, the design of the inclined wall 331 being parallel to the inclined portion 213 and directly opposite the inclined portion 213 makes full use of the space on the side of the inclined portion 213 facing away from the first direction D1. This not only improves the internal space utilization of the battery cell, but also maximizes the volume of the second protruding structure 33, which is conducive to further improving the energy density of the battery cell.

[0048] Furthermore, such as Figure 3 , such as 4 and Figure 7 As shown, the expansion groove 2121 includes a set of opposing first inner walls 2121a and second inner walls 2121b. Along the direction towards the bottom 2121c of the expansion groove 2121, the first inner walls 2121a and second inner walls 2121b are inclined in a direction that brings them closer together. The first protruding structure 32 includes a first fitting wall 321, a second fitting wall 322, and a third fitting wall 323. The first fitting wall 321 and the second fitting wall 322 are opposite to each other, and the first fitting wall 321 is connected to the second fitting wall 322 through the third fitting wall 323. The first fitting wall 321 is fitted to the first inner wall 2121a, the second fitting wall 322 is fitted to the second inner wall 2121b, and the third fitting wall 323 is fitted to the bottom 2121c of the expansion groove 2121. Compared to the first inner wall 2121a and the second inner wall 2121b being perpendicular to the bottom 2121c of the capacity expansion groove 2121, the technical solution provided in this embodiment not only expands the limiting area of ​​the capacity expansion groove 2121 on the first protruding structure 32, but also increases the limiting direction of the first protruding structure 32, which is beneficial to improving the limiting effect of the plate on the electrode assembly.

[0049] Furthermore, the first inner wall 2121a is flush with the surface of the inclined portion 213 on the side opposite to the first direction D1. This structural design helps reduce the production difficulty of the plate, especially when the plate is prepared by stamping, which can significantly reduce the stamping difficulty, thereby improving production efficiency and reducing production costs. On the other hand, since the inclined portion 213 is parallel to the inclined wall 331 and the first inner wall 2121a is attached to the first bonding wall 321, the first bonding wall 321 is parallel to the inclined wall 331. This structure helps reduce the production difficulty of the electrode assembly, especially when the first protruding structure 32 and the inclined wall 331 are prepared on the electrode assembly by die-cutting, which can significantly reduce the die-cutting difficulty, thereby improving production efficiency and reducing production costs.

[0050] Optionally, the electrode assembly further includes a first tab 341 and a second tab 342. The first tab 341 is connected to the side of the second protruding structure 33 facing the first direction D1. The first tab 341 is connected to the first pole post assembly 22. The second tab 342 is connected to the inclined wall 331 and the second pole post assembly 23, so that the electrode assembly is electrically connected to the first pole post assembly 22 through the first tab 341 and to the second pole post assembly 23 through the second tab 342.

[0051] Furthermore, the number of the first protrusion 212, the inclined portion 213, the first protruding structure 32, the second electrode ear 342, and the inclined wall 331 are all two and correspond one-to-one, in the width direction of the electrode group ( Figure 4 and Figure 6 In the Z1 direction, two second tabs 342 are located on either side of the first tab 341, with the first tab 341 facing the first pole post assembly 22. Since the inclined portion 213 is connected to the side of the first protrusion 212 away from the first pole post assembly 22, the inclined portion 213 and the first pole post assembly 22 are separated by the first protrusion 212. Furthermore, since the inclined wall 331 is directly opposite the inclined portion 213, and the first tab 341 is directly opposite the first pole post assembly 22, and the first protruding structure 32 is located within the expansion groove 2121, the inclined wall 331 and the first tab 341 are separated by the first protruding structure 32. Therefore, the second tabs 342 located on the inclined wall 331 are separated from the first tab 341 by... The first protruding structure 32 separates the first electrode 341 from the second electrode 341. In this embodiment, the two second electrodes 342 are located on opposite sides of the first electrode 341, so that the first electrode 341 and the two second electrodes 342 are separated from each other and distributed in different areas of the electrode group facing the first direction D1. Therefore, the heat generated by the electrode group during charging and discharging can be dispersed to the first electrode 341 and the two second electrodes 342, that is, the heat can be dispersed to different areas of the electrode group facing the first direction D1, which is beneficial to improving the heat dissipation efficiency of the electrode group and thus improving the safety of the battery cell.

[0052] On the other hand, since the two second tabs 342 are located on opposite sides of the first tab 341, and the two first protruding structures 32 correspond one-to-one with the two second tabs 342, the two first protruding structures 32 are located on opposite sides of the first tab 341. Thus, a recessed structure 332 is formed in the area where the second protruding structure 33 connects with the first tab 341. That is, a recessed structure 332 is formed between the two first protruding structures 32. The recessed structure 332 is conducive to the electrolyte in the cavity wetting the second protruding structure 33 and the electrode body structure 31 in a direction away from the first direction D1, which improves the wetting effect of the electrolyte on the electrode assembly. In addition, the recessed structure 332 also provides additional flow space for the electrolyte, which is conducive to improving the uniformity of electrolyte distribution in the cavity and achieving the effect of improving the performance of the electrode assembly.

[0053] Furthermore, there are two second electrode post assemblies 23, each corresponding to one of the two second electrode tabs 342. In the width direction of the electrode assembly, the two second electrode tabs 342, the two inclined walls 331, the two second electrode post assemblies 23, the two first protruding structures 32, the two first protrusions 212, and the two inclined portions 213 are all symmetrically arranged about the first electrode post assembly 22. This forms a symmetrical structure for both the electrode assembly and the battery cover 2. This symmetrical structural design not only reduces production difficulty but also assembly and positioning difficulties, thereby improving production efficiency and reducing production costs. In addition, this symmetrical structure ensures that the electrode assembly experiences more uniform force in the directions in which the two inclined walls 331 point towards each other, reducing the risk of uneven force distribution causing the electrode assembly to shift.

[0054] Optionally, the first tab 341, the second tab 342, the first terminal assembly 22, and the second terminal assembly 23 have the same polarity. The electrode group also includes a third tab 343, which is connected to the side of the electrode group body structure 31 opposite to the first direction D1. The battery cell also includes a third terminal assembly 4, which is located on the side of the battery casing 1 opposite to the first direction D1. The third terminal assembly 4 is connected to the third tab 343, and has the same polarity as the third tab 343, but opposite to the polarity of the first terminal assembly 22. This structural design allows the battery cell to have three terminal assemblies with the same polarity, which can effectively increase the current carrying capacity of the battery cell and help meet the fast charging requirements of the battery cell.

[0055] In this embodiment, the electrode assembly body structure 31 includes an electrode assembly body and a first insulating film. The first insulating film wraps around the outer periphery of the electrode assembly body to achieve insulation between the electrode assembly body and the battery casing 1. The first protruding structure 32 includes a second protrusion and a second insulating film. The second insulating film wraps around the outer periphery of the second protrusion to achieve insulation between the second protrusion and the battery casing 1 and the plate. The second protruding structure 33 includes a third protrusion and a third insulating film. The third insulating film wraps around the outer periphery of the third protrusion to achieve insulation between the third protrusion and the plate. The first tab 341 and the two second tabs 342 are all connected to the third protrusion.

[0056] Optionally, such as Figure 3 As shown, the first pole post assembly 22 includes a first plastic part 221, a first riveting block 222, and a first pole post. The first plastic part 221 and the first riveting block 222 are both located on the side of the plate portion 211 facing the first direction D1. The first plastic part 221 has a first groove on the side away from the plate portion 211. The first riveting block 222 is embedded in the first groove. The first pole post includes a first base 223 and a first post 224. The first base 223 is located on the side of the plate portion 211 away from the first direction D1. One end of the first pole post is connected to the first base 223, and the other end passes through the plate portion 211, the first plastic part 221, and the first riveting block 222, and is riveted and fixed to the first riveting block 222. The first protrusion 212 protrudes from the first riveting block 222 in the first direction D1 to reduce the probability of the first riveting block 222 being bumped during the manufacturing process.

[0057] The second pole post assembly 23 includes a second plastic part 231, a second rivet block 232, and a second pole post. The second plastic part 231 and the second rivet block 232 are both located on the side of the inclined portion 213 facing the first direction D1. The side of the second plastic part 231 away from the inclined portion 213 is provided with a second groove, and the second rivet block 232 is embedded in the second groove. The second pole post includes a second base 233 and a second column 234. The second base 233 is located on the side of the inclined portion 213 away from the first direction D1. One end of the second column 234 is connected to the second base 233, and the other end passes through the inclined portion 213, the second plastic part 231, and the second rivet block 232, and is riveted and fixed to the second rivet block 232. The first protrusion 212 protrudes from the second rivet block 232 in the first direction D1 to reduce the probability of the second rivet block 232 being bumped during the manufacturing process.

[0058] Furthermore, the side of the first rivet block 222 facing away from the plate body portion 211 is parallel to the plate body portion 211, so as to further reduce the probability of the first rivet block 222 being bumped during the manufacturing process. The side of the second rivet block 232 facing away from the inclined portion 213 is parallel to the inclined portion 213, so as to further reduce the probability of the second rivet block 232 being bumped during the manufacturing process.

[0059] Optionally, each inclined portion 213 is provided with a support portion 241 on the side opposite to the first protrusion 212. The support portion 241 is parallel to the plate portion 211. The shape of the battery case 1 located at the opening 11 is adapted to the shape of the plate so that the plate can cover the opening 11 of the battery case 1.

[0060] Furthermore, one of the two support portions 241 protrudes from the second pole post assembly 23 on the inclined portion 213 connected to the support portion 241 in a direction opposite to the other. Specifically, with Figure 3 For example, in Figure 3 The support portion 241 located on the left side protrudes to the left from the second pole post assembly 23 located on the left side, so that the support portion 241 on the left side protects the second pole post assembly 23 on the left side, reducing the probability of the second pole post assembly 23 on the left side being bumped during the manufacturing process; see continue. Figure 3 ,exist Figure 3 The support portion 241 located on the right side protrudes from the second pole post assembly 23 located on the right side in a rightward direction, so that the support portion 241 on the right side protects the second pole post assembly 23 on the right side and reduces the probability of the second pole post assembly 23 on the right side being bumped during the manufacturing process.

[0061] Optionally, such as Figure 5 and Figure 6As shown, the side of the inclined wall 331 facing the first direction D1 is the connecting part 3311, which is connected to the first protruding structure 32. Along the direction in which the two inclined walls 331 point towards each other, the distance between the connecting parts 3311 of the two inclined walls 331 is A, and the distance between the sides of the two first protruding structures 32 facing each other is B. 29mm≤AB≤91mm. For example, AB can be 29mm, 30mm, 50mm, 65mm, 90mm or 91mm, etc., with 30mm≤AB≤90mm being preferred. If AB < 29mm, then A is too small and B is too large. This will result in the first protruding structure 32 being too small in the direction in which the two inclined walls 331 point to each other, making the structural strength of the first protruding structure 32 low. Consequently, the first protruding structure 32 is prone to deformation and damage. Furthermore, after the first protruding structure 32 is deformed or damaged, it cannot fit tightly with the bottom 2121c and / or inner wall of the capacity-enhancing groove 2121, thereby reducing the limiting effect of the plate on the electrode group, increasing the risk of the electrode group moving around, and ultimately reducing the product yield of the battery cell. If AB > 91mm, then A is too large and B is too small. When the overall dimensions (length, width and thickness) of the electrode group are the same, the size of the inclined wall 331 is too small in the direction in which the two inclined walls 331 point to each other. Consequently, in the direction parallel to the inclined wall 331, the size of the inclined wall 331 (i.e. W2) and the size of the second tab 342 (i.e. W1) will be reduced accordingly, thereby reducing the current carrying capacity of the second tab 342, making the battery cell unable to meet the fast charging requirements.

[0062] Optionally, the side of the inclined wall 331 facing the first direction D1 is a connecting part 3311, which is connected to the first protruding structure 32. Along the direction in which the two inclined walls 331 point to each other, the distance between the connecting parts 3311 of the two inclined walls 331 is A, and the width of the pole group is L1, that is, the size of the pole group in the Z1 direction is L1, 0.26≤A / L1≤0.51. For example, A / L1 can be 0.26, 0.28, 0.3, 0.4, 0.5 or 0.51, etc., among which 0.28≤A / L1≤0.5 is preferred. If A / L1 < 0.26, then A is too small. In this case, the side of the second protruding structure 33 facing the first direction D1 is relatively narrow, which reduces the structural strength of the area of ​​the second protruding part facing the first direction D1. This makes the area of ​​the second protruding part facing the first direction D1 prone to deformation and damage. In addition, the size of the first tab 341 in the direction in which the two inclined walls 331 point to each other will be reduced, thereby reducing the current carrying capacity of the first tab 341, making the battery cell unable to meet the fast charging requirements. If A / L1 > 0.51, then A is too large. With the overall dimensions (length, width, and thickness) of the electrode assembly being the same, the size of the inclined wall 331 is too small in the direction in which the two inclined walls 331 point towards each other. Consequently, in the direction parallel to the inclined wall 331, the size of the inclined wall 331 (i.e., W2) and the size of the second tab 342 (i.e., W1) will both decrease accordingly, thus reducing the current carrying capacity of the second tab 342, making the battery cell unable to meet the fast charging requirements. Furthermore, for the battery cover 2, along the direction parallel to the inclined portion 213, the inclined... The size of the inclined portion 213 decreases as W2 decreases. If W2 is too small (i.e., A is too large), the size of the inclined portion 213 along the direction parallel to its surface will be too small. Since the inclined portion 213 is connected to the first protrusion 212, the size of the first protrusion 212 protruding from the first pole post assembly 22 and the second pole post assembly 23 along the first direction D1 will be reduced, thereby reducing the protective effect of the first protrusion 212 on the first pole post assembly 22 and the second pole post assembly 23 and increasing the risk of the first pole post assembly 22 and the second pole post assembly 23 being bumped during the manufacturing process.

[0063] Optionally, the size of the second tab 342 is W1 along the direction parallel to the inclined wall 331, and the size of the inclined wall 331 is W2, where 0.51 ≤ W1 / W2 ≤ 8.7. For example, W1 / W2 can be 0.51, 0.55, 2.6, 4.5, 6.8, 8.5, or 8.7, with 0.55 ≤ W1 / W2 ≤ 8.5 being preferred. If W1 / W2 < 0.51, the size of the second tab 342 along the direction parallel to the inclined wall 331 is too small, which not only reduces the current carrying capacity of the second tab 342, making the battery cell unable to meet the fast charging requirements, but also reduces the heat dissipation capacity of the second tab 342, increasing the risk of excessively high temperature during charging and discharging of the electrode assembly. If W1 / W2 > 8.7, the size of the second electrode tab 342 along the direction parallel to the inclined wall 331 is too large. When several electrode sheets are stacked to form an electrode group, the second sub-electrodes on several electrode sheets are stacked to form the second electrode tab 342. When the size of the second electrode tab 342 along the direction parallel to the inclined wall 331 is too large, the size error of the stacked second sub-electrodes is large, which increases the risk of wrinkles, deformation and tearing of the second electrode tab 342.

[0064] Optionally, the first protruding structure 32 protrudes from the second protruding structure 33 along the first direction D1 by a dimension H1, where 13mm ≤ H1 ≤ 18mm. For example, H1 can be 13mm, 15mm, or 18mm, etc. If H1 < 13mm, the volume of the first protruding structure 32 will be reduced, thereby reducing the volume of the electrode group, which is not conducive to improving the electrode group capacity. If H1 > 18mm, the first protruding structure 32 protrudes too much from the second protruding structure 33, which will reduce the structural strength of the first protruding structure 32 and increase the risk of deformation and damage to the first protruding structure 32.

[0065] Optionally, the distance between the inclined wall 331 and the first protruding structure 32 on the same side of the first tab 341 in the direction perpendicular to the inclined wall 331 is H2, where 4mm ≤ H2 ≤ 6mm. For example, H2 can be 4mm, 5mm, or 6mm, etc. If H2 < 4mm, the side of the first protruding structure 32 facing the first direction D1 is relatively narrow, which will reduce the structural strength of the first protruding structure 32 facing the first direction D1 and increase the risk of deformation and damage to the first protruding structure 32. If H2 > 6mm, the size of the first protruding structure 32 protruding from the second protruding structure 33 in the first direction D1 is too large, which will also reduce the structural strength of the first protruding structure 32 facing the first direction D1 and increase the risk of deformation and damage to the first protruding structure 32.

[0066] Optionally, along the direction away from the first direction D1, the included angle between the two inclined walls 331 is N, 70°≤N≤110°. For example, N can be 70°, 80°, or 110°, etc. If N<70°, the side of the second protruding structure 33 facing the first direction D1 will tend to be sharp, reducing the volume of the second protruding structure 33, thereby reducing the electrode assembly capacity, and also reducing the structural strength of the side of the second protruding structure 33 facing the first direction D1, increasing the risk of deformation and damage to the second protruding structure 33. If N>110°, the included angle between the two inclined portions 213 of the plate will be too large, which will reduce the protective effect of the first protrusion 212 on the first electrode assembly 22 and the second electrode assembly 23, thereby increasing the risk of the first electrode assembly 22 and the second electrode assembly 23 being bumped during the manufacturing process.

[0067] Optionally, such as Figure 8 As shown, the thickness of both the pole group and the pole group body structure 31 is T, where 15mm ≤ T ≤ 115mm. For example, T can be 15mm, 50mm, or 115mm, etc. It should be noted that in this embodiment, the first direction D1 is the length direction of the pole group, and the direction in which the two inclined walls 331 point to each other is the width direction of the pole group. The thickness direction, length direction, and width direction are perpendicular to each other.

[0068] Table 1 below provides six sets of embodiments and six sets of comparative examples. In the six sets of embodiments and six sets of comparative examples, the battery casing 1 is made of ternary aluminum with a thickness of 0.35 mm. The first insulating film, the second insulating film and the third insulating film are all polypropylene (PP) films. The first plastic part 221 and the second plastic part 231 are both polyphenylene sulfide (PPS) materials. The third plastic part 241 sandwiched between the first base 223 and the plate part 211 is all made of PP materials. The fourth plastic part 242 sandwiched between the second base 233 and the inclined part 213 is all made of PP materials.

[0069]

[0070] In Example 1, AB is 30mm, W1 is 20mm, W1 / W2 is 0.55, A / L1 is 0.28, H1 is 13mm, H2 is 4mm, N is 70°, T is 15mm, and the cell yield is >98%. No electrode group movement problem was found. The electrode group was not damaged when it was installed into the receiving cavity. The overcurrent capacity of the first tab 341 and the two second tabs 342 meet the requirements of the battery cell.

[0071] In Example 2, AB is 46mm, W1 is 36mm, W1 / W2 is 0.62, A / L1 is 0.32, H1 is 14mm, H2 is 4.5mm, N is 78°, T is 40mm, and the cell yield is >98%. No electrode group movement problem was found. The electrode group was not damaged when it was put into the receiving cavity. The overcurrent capacity of the first tab 341 and the two second tabs 342 meet the requirements of the battery cell.

[0072] In Example 3, AB is 58mm, W1 is 48mm, W1 / W2 is 0.68, A / L1 is 0.36, H1 is 15mm, H2 is 5mm, N is 84°, T is 64mm, and the cell yield is >98%. No electrode group movement problem was found. The electrode group was not damaged when it was installed into the receiving cavity. The overcurrent capacity of the first tab 341 and the two second tabs 342 meet the requirements of the battery cell.

[0073] In Example 4, AB is 72mm, W1 is 65mm, W1 / W2 is 0.73, A / L1 is 0.42, H1 is 16.5mm, H2 is 5mm, N is 90°, T is 85mm, and the cell yield is >98%. No electrode group movement problem was found. The electrode group was not damaged when it was put into the receiving cavity. The overcurrent capacity of the first tab 341 and the two second tabs 342 meet the requirements of the battery cell.

[0074] In Example 5, AB is 84mm, W1 is 72mm, W1 / W2 is 0.77, A / L1 is 0.46, H1 is 17mm, H2 is 6mm, N is 100°, T is 105mm, and the cell yield is >98%. No electrode group movement problem was found. The electrode group was not damaged when it was installed into the receiving cavity. The overcurrent capacity of the first tab 341 and the two second tabs 342 meet the requirements of the battery cell.

[0075] In Example 6, AB is 90mm, W1 is 80mm, W1 / W2 is 0.85, A / L1 is 0.5, H1 is 18mm, H2 is 6mm, N is 110°, T is 115mm, and the cell yield is >98%. No electrode group movement problem was found. The electrode group was not damaged when it was installed into the receiving cavity. The overcurrent capacity of the first tab 341 and the two second tabs 342 meet the requirements of the battery cell.

[0076] In Comparative Example 1, AB is 28mm, W1 is 48mm, W1 / W2 is 0.55, A / L1 is 0.36, H1 is 15mm, H2 is 4.5mm, N is 84°, T is 40mm, and the cell yield is <98%. The first protruding structure 32 has low structural strength, is easily deformed and damaged, and cannot be tightly fitted with the bottom 2121c and / or inner wall of the capacity expansion tank 2121, increasing the risk of cross-flow problems in the electrode group.

[0077] In Comparative Example 2, AB is 92mm, W1 is 48mm, W1 / W2 is 0.85, A / L1 is 0.36, H1 is 15mm, H2 is 4.5mm, N is 84°, T is 40mm, and the cell yield is <98%. In the direction parallel to the inclined wall 331, the size of the inclined wall 331 (i.e., W2) and the size of the second tab 342 (i.e., W1) are smaller, the overcurrent capacity of the second tab 342 is low, and the battery cell cannot meet the fast charging requirements.

[0078] In Comparative Example 3, AB is 58mm, W1 is 48mm, W1 / W2 is 0.5, A / L1 is 0.36, H1 is 15mm, H2 is 4.5mm, N is 84°, T is 40mm, and the cell yield is <98%. The second tab 342 is too small in size along the direction parallel to the inclined wall 331, the overcurrent capacity of the second tab 342 is low, the battery cell cannot meet the fast charging requirements, and the heat dissipation capacity of the second tab 342 is poor, which increases the risk of high temperature during charging and discharging of the electrode group.

[0079] In Comparative Example 4, AB is 58mm, W1 is 48mm, W1 / W2 is 0.88, A / L1 is 0.36, H1 is 15mm, H2 is 4.5mm, N is 84°, T is 40mm, and the yield rate of the electrode cell is <98%. The second electrode tab 342 is too large in the direction parallel to the inclined wall 331, and the second electrode tab 342 is more likely to have problems such as wrinkles, deformation and tearing.

[0080] In Comparative Example 5, AB is 58mm, W1 is 48mm, W1 / W2 is 0.68, A / L1 is 0.25, H1 is 15mm, H2 is 4.5mm, N is 84°, T is 40mm, and the yield rate of the battery cell is <98%. The second protruding structure 33 is narrow on the side facing the first direction D1, and the side of the second protrusion facing the first direction D1 is prone to deformation and damage. Furthermore, the first tab 341 is small in size in the direction in which the two inclined walls 331 point to each other, and the first tab 341 has low current carrying capacity, so the battery cell cannot meet the fast charging requirements.

[0081] In Comparative Example 6, AB is 58mm, W1 is 48mm, W1 / W2 is 0.68, A / L1 is 0.52, H1 is 15mm, H2 is 4.5mm, N is 84°, T is 40mm, and the cell yield is <98%. Both W1 and W2 are small, the second tab 342 has low overcurrent capacity and cannot meet the fast charging requirements of the battery cell; the first protrusion 212 has poor protection effect on the first terminal assembly 22 and the second terminal assembly 23, and the first terminal assembly 22 and the second terminal assembly 23 are easily bumped.

[0082] In summary, when the above parameters satisfy 29mm≤AB≤91mm, 0.26≤A / L1≤0.51, 0.51≤W1 / W2≤8.7, 70°≤N≤110°, 13mm≤H1≤18mm, and 15mm≤T≤115mm, the probability of electrode group movement can be reduced, the probability of plate deformation and damage can be reduced, the probability of the first electrode assembly 22 and the second electrode assembly 23 being bumped during the manufacturing process can be reduced, and the fast charging requirements of battery cells can be met, resulting in a battery cell yield rate of >98%.

[0083] In this embodiment, both the plate and the battery casing 1 are made of aluminum and are manufactured using stamping and die-cutting processes. The electrode assembly is manufactured using a lamination process. An injection molding process can be used to form a first plastic part 221 on the plate portion 211 and a second plastic part 231 on the inclined portion 213. The aforementioned stamping, die-cutting, injection molding, and lamination processes are all common production processes in the field, which are conducive to achieving mass automated production.

[0084] This embodiment also provides a battery module, which includes a first connecting piece, a second connecting piece, and at least two of the above-mentioned battery cells. For example, the number of battery cells can be two, three, or more. The first connecting piece and the second connecting piece are both made of metal materials with conductive properties, such as copper or aluminum sheets. The first terminal assembly 22 of each pair of battery cells is welded and fixed to the same first connecting piece, and the second terminal assembly 23 of each pair of battery cells is welded and fixed to the same second connecting piece, so as to realize the conductive connection (series or parallel connection) of the two battery cells.

[0085] Furthermore, the first connecting piece is welded to the side of the first riveting block 222 opposite to the plate body portion 211, and the first protrusion 212 protrudes from the first connecting piece along the first direction D1. The second connecting piece is welded to the side of the second riveting block 232 opposite to the inclined portion 213, and the first protrusion 212 protrudes from the second connecting piece along the first direction D1. This allows the first protrusion 212 to protect the first and second connecting pieces, reducing the probability of the first and second connecting pieces being bumped during the manufacturing process. In addition, compared to a flat cover plate, this structure saves assembly space for the battery module while maintaining the same length, width, and thickness of the battery cell. This is beneficial for increasing the battery module assembly rate, thereby improving the energy density and performance of the battery module and reducing its cost.

[0086] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A single battery cell, characterized in that, include: Battery housing (1), the battery housing (1) is provided with a communicating receiving cavity and an opening (11), the opening (11) being located on the side of the battery housing (1) facing the first direction (D1); Battery cover (2), the battery cover (2) includes a plate body, the plate body is disposed at the opening (11), the plate body includes a plate body part (211) and a first protrusion (212) connected to the plate body part (211), the first protrusion (212) protrudes toward the first direction (D1), and the first protrusion (212) has a capacity-enhancing groove (2121) on the side away from the first direction (D1); The electrode assembly includes an electrode assembly body structure (31) and a first protruding structure (32). The electrode assembly body structure (31) is disposed in the receiving cavity. All sidewalls of the electrode assembly body structure (31) parallel to the first direction (D1) are in contact with the inner wall of the receiving cavity. The first protruding structure (32) is connected to the side of the electrode assembly body structure (31) facing the first direction (D1). The first protruding structure (32) is located in the expansion groove (2121). The bottom (2121c) of the expansion groove (2121) and at least one set of opposing inner walls of the expansion groove (2121) are in contact with the first protruding structure (32).

2. The battery cell according to claim 1, characterized in that, The battery cover (2) further includes a first terminal assembly (22), which is disposed through the plate body portion (211), and the first protrusion (212) protrudes from the first terminal assembly (22) along the first direction (D1).

3. The battery cell according to claim 2, characterized in that, The plate also includes an inclined portion (213), which is connected to the side of the first protrusion (212) away from the first pole post assembly (22). The inclined portion (213) is inclined from the side facing the first protrusion (212) to the side away from the first protrusion (212), and is inclined in a direction away from the first direction (D1). The battery cover (2) also includes a second pole post assembly (23), which is inserted through the inclined portion (213). The first protrusion (212) protrudes from the second pole post assembly (23) along the first direction (D1).

4. The battery cell according to claim 3, characterized in that, The electrode assembly further includes a second protruding structure (33), which is connected to the electrode assembly body structure (31) on the side away from the first direction (D1). The first protruding structure (32) protrudes from the side of the second protruding structure (33) facing the first direction (D1). The second protruding structure (33) is provided with an inclined wall (331), which is parallel to the inclined portion (213) and is positioned directly opposite the inclined portion (213).

5. The battery cell according to claim 4, characterized in that, The electrode assembly further includes a first electrode tab (341) and a second electrode tab (342). The first electrode tab (341) is connected to the side of the second protruding structure (33) facing the first direction (D1). The first electrode tab (341) is connected to the first pole post assembly (22). The second electrode tab (342) is connected to the inclined wall (331). The second electrode tab (342) is connected to the second pole post assembly (23).

6. The battery cell according to claim 5, characterized in that, The number of the first protrusion (212), the inclined portion (213), the first protruding structure (32), the second electrode tab (342), and the inclined wall (331) are all two and correspond one-to-one. In the width direction of the electrode group, the two second electrode tabs (342) are located on both sides of the first electrode tab (341), and the first electrode tab (341) is positioned directly opposite the first electrode post assembly (22).

7. The battery cell according to claim 6, characterized in that, There are two second pole post assemblies (23), and the two second pole post assemblies (23) correspond one-to-one with the two second pole tabs (342). In the width direction of the pole group, the two second pole tabs (342), the two inclined walls (331), the two second pole post assemblies (23), the two first protruding structures (32), the two first protrusions (212), and the two inclined portions (213) are all symmetrically arranged about the first pole post assembly (22).

8. The battery cell according to claim 7, characterized in that, The side of the inclined wall (331) facing the first direction (D1) is a connecting part (3311), which is connected to the first protruding structure (32). Along the direction in which the two inclined walls (331) point to each other, the distance between the connecting parts (3311) of the two inclined walls (331) is A, and the distance between the sides of the two first protruding structures (32) facing each other is B, 29mm≤AB≤91mm.

9. The battery cell according to claim 7, characterized in that, The side of the inclined wall (331) facing the first direction (D1) is a connecting part (3311), which is connected to the first protruding structure (32). Along the direction in which the two inclined walls (331) point to each other, the distance between the connecting parts (3311) of the two inclined walls (331) is A, and the width of the pole group is L1, 0.26≤A / L1≤0.

51.

10. The battery cell according to any one of claims 5-9, characterized in that, Along the direction parallel to the inclined wall (331), the size of the second electrode (342) is W1, and the size of the inclined wall (331) is W2, 0.51≤W1 / W2≤8.7.

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