Battery cell

Abstract

The invention belongs to the technical field of batteries, and discloses a battery cell, the battery cell comprises a shell, a cover plate assembly and a pole group, the cover plate assembly covers an opening of the shell, the pole group comprises a pole group body, the pole group body is arranged in the shell, the length direction of the pole group body is a first direction, the thickness direction of the pole group body is a second direction, and along the first direction, the thickness direction of the pole group body is a second direction. The middle part of each pole group body is provided with a structure reinforcing part, one side of each pole group body in the second direction is a connecting side, the number of the pole group bodies is two, and the connecting sides of the two pole group bodies are oppositely arranged and are spliced and connected, so that the capacity of the pole group can be improved, and the structural strength of the pole group can also be improved.

Description

Technical Field

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

[0002] In the prior art, in order to increase the capacity of the electrode group, the length of the electrode group is usually extended, that is, the size of the electrode group is increased in the length direction of the electrode group.

[0003] Because of the long electrode assembly, this structure reduces the structural strength of the electrode assembly, making it prone to bending and deformation during the manufacturing process.

[0004] Therefore, there is an urgent need to develop a battery cell to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide a battery cell that can improve both the capacity and structural strength of the electrode assembly.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] A battery cell, comprising:

[0008] case;

[0009] A cover assembly that covers the opening in the housing;

[0010] The pole assembly includes a pole assembly body, which is disposed inside a housing. The length direction of the pole assembly body is a first direction, and the thickness direction of the pole assembly body is a second direction. Along the first direction, a structural reinforcement part is provided in the middle of the pole assembly body. One side of the pole assembly body in the second direction is a connecting side. There are two pole assembly bodies, and the connecting sides of the two pole assembly bodies are arranged facing each other and spliced ​​together.

[0011] Optionally, the other side of the electrode assembly body in the second direction is the reinforcing side. The width direction of the electrode assembly body is the third direction. The structural reinforcing part includes a first protrusion and a second protrusion. The first protrusion protrudes from the reinforcing side. The first protrusion protrudes from both sides of the electrode assembly body in the third direction. The electrode assembly body has a second protrusion protruding from both sides in the third direction. One surface of the second protrusion in the second direction is flush with the surface of the connecting side, and the other surface is flush with the surface of the first protrusion away from the electrode assembly body. The other side of the second protrusion in the second direction is connected to the first protrusion. The dimensions of the first protrusion and the second protrusion in the first direction are equal.

[0012] Optionally, the cover plate assembly is located on one side of the housing in the first direction, and the side of the cover plate assembly facing the housing is provided with a limiting groove structure. The end of the pole body facing the cover plate assembly is provided with a third protrusion, and the third protrusions of the two pole bodies are insulatedly embedded in the limiting groove structure.

[0013] Optionally, the reinforcing side may also have a fourth protrusion.

[0014] Optionally, the fourth protrusion of each of the two pole groups is insulated and embedded in the limiting groove structure at the end opposite to the first protrusion.

[0015] Optionally, the surface of the reinforcing side is flush with the surface of the third protrusion facing the reinforcing side, and along the first direction, one end of the fourth protrusion is connected to the first protrusion and the other end is connected to the third protrusion.

[0016] Optionally, along the second direction, the distance between the connecting side and the side of the fourth protrusion away from the reinforcing side is B, and the distance between the connecting side and the reinforcing side along the second direction is W2, where 7mm≤B-W2≤32mm;

[0017] And / or, the dimension of the fourth protrusion in the third direction is L2, and the dimension of the pole body in the third direction is A1, 0.21≤L2 / A1≤0.64.

[0018] Optionally, there are two cover assemblies and two openings, and they correspond one-to-one. The two cover assemblies are located on both sides of the housing in the first direction.

[0019] Optionally, the pole assembly body has a first electrode tab and a second electrode tab at both ends in the first direction, the first electrode tab and the second electrode tab have opposite polarities, the first electrode tabs of the two pole assembly bodies have the same orientation in the first direction and are electrically connected to a cover plate assembly, and the second electrode tabs of the two pole assembly bodies have the same orientation in the first direction and are electrically connected to another cover plate assembly.

[0020] Optionally, the dimensions of the first protrusion and the second protrusion in the first direction are both L1. Along the first direction, the distance between the two third protrusions of the pole body on opposite sides in the first direction is E, where 0.29≤L1 / E≤0.74.

[0021] The beneficial effects of this invention are:

[0022] First, the electrode assembly of the battery cell includes two connected electrode assembly bodies, which increases the volume of the electrode assembly and thus increases its capacity, which is beneficial to meeting the high-rate fast charging requirements of the battery cell.

[0023] Secondly, in the thickness direction of the pole body, the connecting sides of the two pole bodies are arranged facing each other and spliced ​​together, thereby increasing the thickness of the pole group, which is beneficial to improving the structural strength of the pole group. Especially when the pole group is long, this structure can significantly reduce the probability of the pole group bending deformation.

[0024] Furthermore, a structural reinforcement is provided along the length of the pole assembly body, thereby improving the structural strength of the pole assembly body and consequently the structural strength of the pole assembly. Especially when the pole assembly body is long, the probability of bending deformation in the middle of the pole assembly body along its length is high. This structure, by providing a structural reinforcement in the middle of the pole assembly body along its length, significantly reduces the probability of bending deformation in the middle of a longer pole assembly body, and thus significantly reduces the probability of bending deformation in the middle of the pole assembly along its length. Attached Figure Description

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

[0026] Figure 2 This is a schematic diagram of the first structure of the pole assembly provided by the present invention;

[0027] Figure 3 This is a first structural schematic diagram of the pole assembly body provided by the present invention;

[0028] Figure 4 This is a schematic diagram of the second structure of the pole assembly body provided by the present invention;

[0029] Figure 5 This is a first structural schematic diagram of the cover plate assembly provided by the present invention;

[0030] Figure 6 yes Figure 1 Enlarged partial cross-sectional view along the NN direction (shell not shown);

[0031] Figure 7 yes Figure 1 Enlarged partial sectional view along the MM direction (shell not shown);

[0032] Figure 8 This is a schematic diagram of the second structure of the cover plate assembly provided by the present invention;

[0033] Figure 9 This is an exploded structural diagram of the cover plate assembly provided by the present invention;

[0034] Figure 10 This is a schematic diagram of the structure of the housing provided by the present invention;

[0035] Figure 11 This is a schematic diagram of the second structure of the pole group provided by the present invention;

[0036] Figure 12 This is a schematic diagram of the third structure of the pole assembly provided by the present invention;

[0037] Figure 13 This is a schematic diagram of the fourth structure of the pole group provided by the present invention.

[0038] In the picture:

[0039] D1, First Direction; D2, Second Direction; D3, Third Direction;

[0040] 100. Housing; 110. Groove; 200. Cover plate assembly; 210. Limiting groove structure; 211. First limiting groove; 212. Second limiting groove; 220. Cover plate; 221. First protrusion; 222. Second protrusion; 230. First insulating component; 240. First conductive plate; 250. Second insulating component; 260. Second conductive plate; 270. Electrode post; 300. Electrode assembly body; 310. Structural reinforcement; 311. First protrusion; 312. Second protrusion; 321. Connecting side; 3211. First conductive layer; 3212. Second conductive layer; 322. Reinforcing side; 330. Third protrusion; 340. Fourth protrusion; 350. First electrode tab. Detailed Implementation

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] This embodiment provides a battery cell that can improve both the capacity and structural strength of the electrode assembly.

[0046] Specifically, such as Figures 1 to 3 As shown, the battery cell includes a housing 100, a cover plate assembly 200, and an electrode assembly. The cover plate assembly 200 covers the opening of the housing 100. The electrode assembly includes an electrode assembly body 300, which is disposed inside the housing 100. The length direction of the electrode assembly body 300 is a first direction D1, and the thickness direction of the electrode assembly body 300 is a second direction D2. Along the first direction D1, a structural reinforcement part 310 is provided in the middle of the electrode assembly body 300. One side of the electrode assembly body 300 in the second direction D2 is a connecting side 321. There are two electrode assembly bodies 300, and the connecting sides 321 of the two electrode assembly bodies 300 are arranged facing each other and spliced ​​together.

[0047] Based on the above design, the electrode assembly of the battery cell includes two connected electrode assembly bodies 300, which increases the volume of the electrode assembly and thus improves its capacity, which is beneficial to meeting the high-rate fast charging requirements of the battery cell.

[0048] Secondly, in the thickness direction of the pole body 300, the connecting sides 321 of the two pole bodies 300 are arranged facing each other and spliced ​​together, thereby increasing the thickness of the pole group, which is beneficial to improving the structural strength of the pole group. Especially when the pole group is long, this structure can significantly reduce the probability of the pole group bending deformation.

[0049] Furthermore, along the length of the pole assembly body 300, a structural reinforcement portion 310 is provided, which improves the structural strength of the pole assembly body 300 and thus enhances the structural strength of the pole assembly. Especially when the pole assembly body 300 is long, the probability of bending deformation in the middle of the pole assembly body 300 along its length is high. This structure, by providing a structural reinforcement portion 310 in the middle of the pole assembly body 300 along its length, significantly reduces the probability of bending deformation in the middle of a longer pole assembly body 300, thereby significantly reducing the probability of bending deformation in the middle of the pole assembly along its length.

[0050] Finally, the electrode assembly is formed by joining two electrode assembly bodies 300 along the thickness direction, thereby increasing the thickness of the electrode assembly. In actual production, the thickness of the electrode assembly body 300 can be appropriately reduced as needed to reduce the manufacturing difficulty of the electrode assembly body 300. Since the electrode assembly is formed by joining two electrode assembly bodies 300 along the thickness direction, the structural strength of the electrode assembly will not be significantly reduced. It is evident that this structural design makes the manufacturing dimensions of the electrode assembly body 300 more flexible; when it is necessary to reduce manufacturing difficulty, the thickness of the electrode post 270 body can be appropriately reduced.

[0051] Furthermore, such as Figures 1 to 4 As shown, the other side of the pole assembly body 300 in the second direction D2 is the reinforcing side 322. That is, the sides of the two pole assembly bodies 300 facing each other are the connecting sides 321, and the sides of the two pole assembly bodies 300 away from each other are the reinforcing sides 322. The width direction of the pole assembly body 300 is the third direction D3. The structural reinforcing part 310 includes a first protrusion 311 and a second protrusion 312. The first protrusion 311 protrudes from the reinforcing side 322, and the two sides of the first protrusion 311 protrude from the two sides of the pole assembly body 300 in the third direction D3, respectively. The electrode assembly body 300 has second protrusions 312 on both sides in the third direction D3. One surface of the second protrusion 312 in the second direction D2 is flush with the surface of the connecting side 321, and the other surface is flush with the surface of the first protrusion 311 facing away from the electrode assembly body 300. The other side of the second protrusion 312 in the second direction D2 is connected to the first protrusion 311. The dimensions of the first protrusion 311 and the second protrusion 312 in the first direction D1 are equal. This achieves a widening and thickening of the middle part of the electrode assembly body 300 in the length direction to form a structural reinforcement part 310. This structure not only improves the structural strength of the middle part of the electrode assembly body 300 in the length direction, but also increases the volume of the electrode assembly body 300, thereby increasing the volume of the electrode assembly and achieving the effect of increasing the electrode assembly capacity, which is beneficial to meeting the high-rate fast charging requirements of the battery cell.

[0052] Optionally, the connection side 321 is provided with a first conductive layer 3211 and a second conductive layer 3212. The first conductive layer 3211 and the second conductive layer 3212 have opposite polarities and are spaced apart. The first conductive layer 3211 and the second conductive layer 3212 are non-conductive regions. The first conductive layers 3211 of the two electrode assembly bodies 300 are in contact with each other, and the second conductive layers 3212 of the two electrode assembly bodies 300 are in contact with each other, thereby achieving a conductive connection between the two electrode assembly bodies 300. This structure eliminates the need for conductive elements such as conductive busbars between the two electrode assembly bodies 300. The conductive connection between the two electrode assembly bodies 300 can be achieved through the first conductive layer 3211 and the second conductive layer 3212. This not only reduces the internal space occupied by the electrode assembly in the housing 100, but also helps to reduce the weight of the electrode assembly, thereby achieving the effect of improving the energy density of the battery cell.

[0053] In this embodiment, the first conductive layer 3211 is a negative conductive layer, and the second conductive layer 3212 is a positive conductive layer. Of course, in other embodiments, the first conductive layer 3211 can also be a positive conductive layer, and the second conductive layer 3212 can be a negative conductive layer.

[0054] In this embodiment, the electrode assembly body 300 includes a positive electrode, a separator, and a negative electrode. The positive electrode, separator, and electrode are stacked sequentially along a third direction D3. The negative electrode on the non-conductive region side protrudes from the positive electrode along the direction from the reinforcing side 322 to the connecting side 321 and is connected to the first conductive layer 3211. The positive electrode on the other side of the non-conductive region protrudes from the negative electrode along the direction from the reinforcing side 322 to the connecting side 321 and is connected to the second conductive layer 3212. This achieves a conductive connection between the two electrode assembly bodies 300.

[0055] Optionally, such as Figures 1 to 5 As shown, the cover plate assembly 200 is located on one side of the housing 100 in the first direction D1. The cover plate assembly 200 has a limiting groove structure 210 on the side facing the housing 100. The pole group body 300 has a third protrusion 330 protruding from one end facing the cover plate assembly 200. Both third protrusions 330 of the pole group bodies 300 are insulated and embedded within the limiting groove structure 210. This achieves the effect of limiting the two pole group bodies 300 by the cover plate assembly 200, reducing the probability of relative displacement between the two pole group bodies 300 and improving the structural stability of the pole group. Secondly, it also reduces the probability of the pole group moving within the housing 100, improving the safety of the battery cell. Thirdly, the third protrusion 330 increases the volume of the pole group body 300, thereby increasing the volume of the pole group, which is beneficial for increasing the capacity of the pole group and thus meeting the high-rate fast charging requirements of the battery cell.

[0056] Furthermore, there are two cover plate assemblies 200 and two corresponding openings, with the two cover plate assemblies 200 located on opposite sides of the housing 100 in the first direction D1. That is, the electrode assembly body 300 has a third protrusion 330 at both ends in the first direction D1, and these two third protrusions 330 correspond to the two cover plate assemblies 200 respectively. The electrode assembly has a total of four third protrusions 330, with two third protrusions 330 located at one end of the electrode assembly in the first direction D1, and the other two third protrusions 330 located at the other end of the electrode assembly in the first direction D1. In the first direction D1, the two third protrusions 330 located at the same end of the electrode assembly are respectively located on the two electrode assembly bodies 300, and these two third protrusions 330 are insulated and embedded in the limiting groove structure 210 of the same cover plate assembly 200. On the one hand, this structure increases the number of third protrusions 330, thereby expanding the electrode assembly volume and achieving the effect of increasing the electrode assembly capacity. On the other hand, the two cover plate assemblies 200 cooperate with each other in the first direction D1 to limit the two pole body 300, which can reduce the probability of relative displacement of the two pole body 300 and the probability of pole movement within the housing 100, thereby improving the stability of the pole structure and also improving the safety of the battery cell.

[0057] Furthermore, the electrode assembly body 300 is provided with a first tab 350 and a second tab (not shown in the figure) at both ends in the first direction D1. The first tabs 350 and the second tabs have opposite polarities. The first tabs 350 of the two electrode assembly bodies 300 have the same orientation in the first direction D1 and are electrically connected to one cover plate assembly 200. The second tabs of the two electrode assembly bodies 300 have the same orientation in the first direction D1 and are electrically connected to another cover plate assembly 200. That is to say, the electrode assembly is provided with two first tabs 350 and two second tabs. It can be seen that this structure increases the number of tabs on the electrode assembly, thereby expanding the flow rate between the electrode assembly and the cover plate assembly 200, which is beneficial to meeting the high-rate fast charging requirements of the battery cell. In addition, when the battery cell is charging and discharging, the heat at the tabs is relatively concentrated. Compared with the electrode assembly only having two tabs with opposite polarities, the structure provided in this embodiment increases the number of first tabs 350 and second tabs, which can distribute the heat to four tabs, not only improving the heat dissipation efficiency of the tabs, but also reducing the risk of thermal runaway of the battery cell.

[0058] In this embodiment, the first electrode 350 is the positive electrode, and the second electrode is the negative electrode. Of course, in other embodiments, the first electrode 350 can also be the negative electrode, and the second electrode can be the positive electrode.

[0059] Optionally, on the same electrode assembly body 300, a first tab 350 and a third protrusion 330 located on the same side as the first tab 350 are spaced apart along the second direction D2, and both the first tab 350 and the third protrusion 330 extend along the third direction D3. This structure not only allows the first tab 350 and the third protrusion 330 to avoid each other, but also maximizes the size of the first tab 350 and the third protrusion 330 in the third direction D3. Increasing the size of the first tab 350 is beneficial to improving its heat dissipation and overcurrent capacity to meet the high-rate fast charging requirements of the battery cell. Increasing the size of the third protrusion 330 is beneficial to increasing the volume of the electrode assembly, thereby increasing the capacity of the electrode assembly to meet the high-rate fast charging requirements of the battery cell.

[0060] Furthermore, in the second direction D2, the first tab 350 is located between the third protrusion 330 and the connecting side 321. That is, in the first direction D1, the two first tabs 350 on the same side of the electrode group are both located between the two third protrusions 330 on that side. This allows the third protrusions 330 to protect the first tabs 350, reducing the probability of the first tabs 350 being bumped or knocked during the manufacturing process.

[0061] Optionally, on the same electrode assembly body 300, a second electrode tab and a third protrusion 330 located on the same side as the second electrode tab are spaced apart along a second direction D2, and both the second electrode tab and the third protrusion 330 extend along a third direction D3. This structure not only allows the second electrode tab and the third protrusion 330 to avoid each other, but also maximizes the size of the second electrode tab and the third protrusion 330 in the third direction D3. Increasing the size of the second electrode tab is beneficial to improving its heat dissipation and overcurrent capacity to meet the high-rate fast charging requirements of the battery cell. Increasing the size of the third protrusion 330 is beneficial to increasing the electrode assembly volume, thereby increasing the electrode assembly capacity to meet the high-rate fast charging requirements of the battery cell.

[0062] Furthermore, in the second direction D2, the second tab is located between the third protrusion 330 and the connecting side 321. That is, in the first direction D1, the two second tabs on the same side of the electrode assembly are both located between the two third protrusions 330 on that side. This allows the third protrusions 330 to protect the second tabs, reducing the probability of the second tabs being bumped or knocked during the manufacturing process.

[0063] Optionally, the reinforcing side 322 is further provided with a fourth protrusion 340 to improve the structural strength of the pole group body 300 at the non-central position in the first direction D1, and at the same time increase the volume of the pole group body 300, thereby increasing the volume of the pole group and achieving the effect of increasing the capacity of the pole group.

[0064] Furthermore, the surface of the reinforcing side 322 is flush with the surface of the third protrusion 330 facing the reinforcing side 322. Along the first direction D1, one end of the fourth protrusion 340 is connected to the first protrusion 311, and the other end is connected to the third protrusion 330. This allows the first protrusion 311 and the third protrusion 330 to be connected through the fourth protrusion 340, forming a mutually supporting effect. In addition, this structure creates a rib structure on the reinforcing side 322 for the fourth protrusion 340, which helps to further improve the structural strength of the electrode assembly body 300, achieving the effect of improving the structural strength of the electrode assembly. On the other hand, this structure increases the size of the fourth protrusion 340 in the first direction D1, thereby increasing the volume of the electrode assembly body 300 and the electrode assembly, which helps to increase the capacity of the electrode assembly to meet the high-rate fast charging requirements of the battery cell.

[0065] Optionally, the fourth protrusion 340 is located in the middle of the pole body 300 in the third direction D3, thereby improving the uniformity of the structural strength of the pole body 300 in the third direction D3.

[0066] Optionally, the fourth protrusion 340 of the two pole group bodies 300 is insulated and embedded in the limiting groove structure 210 at the end opposite to the first protrusion 311, so as to improve the limiting effect of the cover plate assembly 200 on the two pole group bodies 300 and further reduce the probability of relative displacement of the two pole group bodies 300.

[0067] Furthermore, the surface of the fourth protrusion 340 facing away from the first protrusion 311 is flush with the surface of the third protrusion 330 facing away from the pole assembly body 300, thereby increasing the volume of the fourth protrusion 340. This not only increases the volume of the pole assembly body 300 and the pole assembly, thereby increasing the pole assembly capacity, but also improves the limiting effect of the limiting groove structure 210 on the fourth protrusion 340.

[0068] Optionally, the two side surfaces of the third protrusion 330 on the third direction D3 are flush with the two side surfaces of the pole body 300 on the third direction D3, so as to increase the volume of the third protrusion 330. This not only increases the volume of the pole body 300 and the pole group, thereby increasing the pole group capacity, but also improves the limiting effect of the limiting groove structure 210 on the third protrusion 330.

[0069] Optionally, two fourth protrusions 340 are provided on the reinforcing side 322 of the same pole group body 300. The two fourth protrusions 340 are respectively located on both sides of the first protrusion 311 of the pole group body 300 in the first direction D1. The two fourth protrusions 340 of the pole group body 300 correspond one-to-one with the two cover plate assemblies 200. That is, each fourth protrusion 340 of the pole group body 300 is insulated and embedded in the limiting groove structure 210 of the corresponding cover plate assembly 200 on the side away from the first protrusion 311.

[0070] In this embodiment, the two pole group bodies 300 have the same structure, and the pole group bodies 300 are symmetrically arranged about their middle parts in the first direction D1 and about their middle parts in the third direction D3. This makes the pole group form a symmetrical structure, which helps to reduce the production and assembly difficulty of the pole group.

[0071] Optionally, such as Figures 1 to 7 As shown, the limiting groove structure 210 includes two first limiting grooves 211 and two second limiting grooves 212. The two first limiting grooves 211 are spaced apart along the second direction D2 on the cover plate assembly 200. The two second limiting grooves 212 are located on opposite sides of the two first limiting grooves 211, and each second limiting groove 212 is connected to a corresponding first limiting groove 211. In the first direction D1, two third protrusions 330 located on the same side of the electrode group are insulatedly embedded in the two first limiting grooves 211 of the cover plate assembly 200 on that side. In the first direction D1, portions of two fourth protrusions 340 located on the same side of the electrode group are insulatedly embedded in the two second limiting grooves 212 of the cover plate assembly 200 on that side.

[0072] Optionally, such as Figures 1 to 9 As shown, the cover plate assembly 200 includes a cover plate 220, which covers the opening of the housing 100. Two first protrusions 221 protrude from the side of the cover plate 220 opposite to the housing 100, and the two first protrusions 221 are spaced apart along a second direction D2. Each first protrusion 221 has a first limiting groove 211 on the side facing the housing 100. Second protrusions 222 protrude from the sides of the two first protrusions 221 opposite to each other, and each second protrusion has a second limiting groove 212 on the side facing the housing 100.

[0073] Furthermore, the cover plate assembly 200 also includes a first insulating member 230 and a first conductive plate 240. The first insulating member 230 is disposed on the side of the cover plate 220 away from the housing 100 and located between two first protrusions 221. The first conductive plate 240 is connected to the side of the first insulating member 230 away from the cover plate 220. Along the direction from the housing 100 to the cover plate 220, the first protrusions 221 protrude from the first insulating member 230 and the first conductive plate 240, so that the first protrusions 221 can protect the first insulating member 230 and the first conductive plate 240, reducing the probability of the first insulating member 230 and the first conductive plate 240 being bumped during the manufacturing process.

[0074] Furthermore, the side of the first conductive plate 240 facing away from the first insulating member 230 is used to weld and fix it to the plate (not shown in the figure). Along the direction from the housing 100 to the cover plate 220, the first protrusion 221 is configured to protrude from the plate, so that the first protrusion 221 can protect the plate and reduce the probability of the plate being bumped during the manufacturing process.

[0075] Optionally, the cover assembly 200 further includes a second insulating member 250, a second conductive plate 260, and a pole post 270. The second insulating member 250 covers the side of the cover plate 220 facing the housing 100, and the second conductive plate 260 is connected to the side of the second insulating member 250 away from the cover plate 220. In the first direction D1, the second conductive plate 260 of the cover assembly 200, located on the same side as the first pole tab 350, is welded to the first pole tab 350. In the first direction D1, the second conductive plate 260 of the cover assembly 200, located on the same side as the second pole tab, is welded to the second pole tab. One end of the pole post 270 is connected to the second conductive plate 260, and the other end passes through the second insulating member 250, the cover plate 220, and the first insulating member 230, and is connected to the first conductive plate 240.

[0076] Optionally, such as Figures 1 to 10 As shown, the inner wall of the housing 100 is provided with grooves 110. The number of grooves 110 is equal to the number of fourth protrusions 340 and corresponds one-to-one. Each fourth protrusion 340 is insulatedly embedded in a corresponding groove 110, thereby achieving the limiting effect of the housing 100 on the pole body 300, preventing relative displacement of the two pole bodies 300, and improving the stability of the pole structure. In addition, the bottoms of the grooves 110 on both sides of the housing 100 in the second direction D2 can cooperate with each other to limit the two pole bodies 300 in the second direction D2, preventing the two pole bodies 300 from separating from each other in the second direction D2.

[0077] Optionally, such as Figures 1 to 11As shown, along the second direction D2, the distance between the connecting side 321 and the side of the fourth protrusion 340 opposite to the reinforcing side 322 is B, and the distance between the connecting side 321 and the reinforcing side 322 along the second direction D2 is W2, where 7mm ≤ B - W2 ≤ 32mm. For example, B - W2 can be 7mm, 8mm, 15mm, 30mm, or 32mm, etc. If B - W2 < 7mm, then with W2 unchanged, B is too small, that is, the size of the fourth protrusion 340 protruding from the reinforcing side 322 is too small. This will reduce the increase in the size of the electrode assembly body 300 and the electrode assembly volume, thereby reducing the increase in the electrode assembly capacity, which is not conducive to meeting the high-rate fast charging requirements of the battery cell. If B-W2 > 32mm, then with W2 remaining constant, an excessively large B will increase the manufacturing difficulty of the electrode assembly body 300, thereby reducing its production yield. It will also reduce the structural strength of the fourth protrusion 340, thus weakening the limiting effect of the groove 110 on the fourth protrusion 340 in the housing 100. Furthermore, it will increase the groove depth of the groove 110, further increasing the manufacturing difficulty and reducing the production yield of the housing 100. Therefore, when 7mm ≤ B-W2 ≤ 32mm, the electrode assembly can achieve a certain capacity increase to meet the high-rate fast charging requirements of the battery cell, while also reducing the manufacturing difficulty of the electrode assembly body 300 and the housing 100, thus ensuring the production and assembly yield of both.

[0078] Optionally, 24mm≤B≤60mm, for example, B can be 24mm, 35mm or 60mm, etc.

[0079] Optionally, along the first direction D1, the third protrusion 330 protrudes from the electrode assembly body 300 by a dimension H, where 18mm ≤ H ≤ 40mm. For example, H can be 18mm, 35mm, or 40mm, etc. This ensures that the third protrusion 330 has a suitable dimension in the first direction D1, guaranteeing sufficient increase in the volume and capacity of the electrode assembly, while also ensuring reliable structural strength. This makes the limiting effect of the first limiting groove 211 of the cover plate assembly 200 on the third protrusion 330 more reliable.

[0080] Optionally, the distance between the connecting side 321 and the third protrusion 330 in the second direction D2 is W1, 0.4≤W1 / W2≤0.6. For example, W1 / W2 can be 0.4, 0.55 or 0.6, etc., to ensure that the third protrusion 330 has a suitable size in the second direction D2, to ensure that the volume and capacity of the pole group have a sufficient increase, and to ensure that the third protrusion 330 has reliable structural strength, so that the limiting effect of the first limiting groove 211 of the cover plate assembly 200 on the third protrusion 330 is more reliable.

[0081] Optionally, in the first direction D1, the two third protrusions 330 located on the same side of the pole group have slopes facing each other, and the angle between the slope and the surface of the pole group on that side is N, 100°≤N≤130°. For example, N can be 100°, 122° or 130°, etc., so as to reduce the molding difficulty of the third protrusion 330 and thus reduce the production difficulty of the pole group body 300.

[0082] Optionally, such as Figures 1 to 12 As shown, the dimensions of the first protrusion 311 and the second protrusion 312 in the first direction D1 are both L1. Along the first direction D1, the distance between the two opposite sides of the two third protrusions 330 of the electrode assembly body 300 in the first direction D1 is E, where 0.29 ≤ L1 / E ≤ 0.74. For example, L1 / E can be 0.29, 0.33, 0.45, 0.5, 0.68, 0.7, or 0.74, etc. If L1 / E < 0.29, then with E remaining constant, L1 is too small, which will make the dimensions of the first protrusion 311 and the second protrusion 312 in the first direction D1 too small, thereby reducing the increase in the volume of the electrode assembly body 300 and the electrode assembly, and thus reducing the increase in the capacity of the electrode assembly, which is not conducive to meeting the high-rate fast charging requirements of the battery cell. If L1 / E > 0.74, then with E remaining constant, an excessively large L1 will increase the manufacturing difficulty of the electrode assembly body 300, thereby reducing its production yield. Simultaneously, the housing 100 conforms to the shape of the electrode assembly, and at positions corresponding to the first protrusion 311 and the second protrusion 312, the housing 100 bulges away from the electrode assembly. If L1 is too large, the size of this bulge will increase, further increasing the manufacturing difficulty and reducing the production yield of the housing 100. Therefore, when 0.29 ≤ L1 / E ≤ 0.74, the electrode assembly can achieve a certain capacity increase to meet the high-rate fast charging requirements of the battery cell, while also reducing the manufacturing difficulty of the electrode assembly body 300 and the housing 100, thus ensuring the production and assembly yields of both.

[0083] Optionally, such as Figures 1 to 13As shown, the fourth protrusion 340 has a dimension of L2 in the third direction D3, and the electrode assembly body 300 has a dimension of A1 in the third direction D3, where 0.21 ≤ L2 / A1 ≤ 0.64. For example, L2 / A1 can be 0.21, 0.25, 0.33, 0.48, 0.5, 0.6, or 0.64, etc. If L2 / A1 < 0.21, then with A1 unchanged, L2 is too small, which will make the dimension of the fourth protrusion 340 in the third direction D3 too small, thereby reducing the increase in the volume of the electrode assembly body 300 and the electrode assembly, and thus reducing the increase in the electrode assembly capacity, which is not conducive to meeting the high-rate fast charging requirements of the battery cell. If L2 / A1 > 0.64, then with A1 remaining constant, an excessively large L2 will increase the size of the second limiting groove 212 in the third direction D3, thereby increasing the manufacturing difficulty of the cover plate 220, reducing its production yield, and simultaneously decreasing the assembly yield of the cover plate 220 and the housing 100. Therefore, when 0.21 ≤ L2 / A1 ≤ 0.64, the electrode assembly can achieve a certain capacity increase to meet the high-rate fast charging requirements of the battery cell, while also reducing the manufacturing difficulty of the cover plate 220, thus ensuring the production yield of the cover plate 220 and the assembly yield of the cover plate 220 and the housing 100.

[0084] Optionally, the first protrusion 311 has a dimension of A2 on the third direction D3, where 16mm ≤ A2-A1 ≤ 70mm. For example, A2-A1 can be 16mm, 55mm, or 70mm, etc.

[0085] Optionally, the dimensions of both the first tab 350 and the second tab on the third-direction D3 are L3, where 4mm ≤ A1-L3 ≤ 12mm. For example, A1-L3 can be 4mm, 10mm, or 12mm, etc. This ensures that the first tab 350 and the second tab have sufficient dimensions on the third-direction D3 to guarantee high heat dissipation and current carrying capacity. Simultaneously, it prevents the first tab 350 and the second tab from extending beyond the electrode assembly body 300 on the third-direction D3, reducing the probability of damage to the first tab 350 and the second tab during the manufacturing process.

[0086] In this embodiment, the shell 100 and cover plate 220 are manufactured using metal stamping and stretching processes, the electrode assembly body 300 is manufactured using lamination and die-cutting processes, and the first electrode tab 350 and its corresponding second conductive plate 260, the second electrode tab and its corresponding second conductive plate 260, the electrode post 270 and the second conductive plate 260, and the electrode post 270 and the first conductive plate 240 are connected using ultrasonic welding. The aforementioned metal stamping, stretching, lamination, die-cutting, and ultrasonic welding processes are all common production processes in the art, which are beneficial for achieving mass automated production.

[0087] 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 shell 100 and the cover plate 220 are all made of aluminum, the insulating film wrapped around the outer surface of the electrode group is polypropylene (PP) film, the first insulating element 230 is made of polyphenylene sulfide (PPS) material, and the second insulating element 250 is made of PP material.

[0088]

[0089] In Example 1, H is 18mm, N is 100°, B-W2 is 8mm, W1 / W2 is 0.4, L1 / E is 0.33, A2-A1 is 16mm, L2 / A1 is 0.25, A1-L3 is 4mm, B is 24mm, and the cell yield is >98%. No abnormalities were found, such as low pole group structural strength or poor pole group body 300 assembly. The pole group, the first tab 350, and the second tab were all undamaged and undeformed. The overcurrent capacity and heat dissipation capacity of the first tab 350 and the second tab, as well as the pole group capacity, all meet the requirements for high-rate fast charging of the cell.

[0090] In Example 2, H is 22mm, N is 110°, B-W2 is 11mm, W1 / W2 is 0.44, L1 / E is 0.42, A2-A1 is 28mm, L2 / A1 is 0.33, A1-L3 is 6mm, and B is 32mm. The cell yield is >98%. No abnormalities were found, such as low pole group structural strength or poor pole group body 300 assembly. The pole group, first tab 350, and second tab are all undamaged and undeformed. The overcurrent capacity and heat dissipation capacity of the first tab 350 and second tab, as well as the pole group capacity, all meet the requirements for high-rate fast charging of the cell.

[0091] In Example 3, H is 26mm, N is 116°, B-W2 is 14mm, W1 / W2 is 0.48, L1 / E is 0.5, A2-A1 is 42mm, L2 / A1 is 0.4, A1-L3 is 8mm, B is 40mm, and the cell yield is >98%. No abnormalities were found, such as low pole group structural strength or poor pole group body 300 assembly. The pole group, the first tab 350, and the second tab were all undamaged and undeformed. The overcurrent capacity and heat dissipation capacity of the first tab 350 and the second tab, as well as the pole group capacity, all meet the requirements for high-rate fast charging of the cell.

[0092] In Example 4, H is 30mm, N is 120°, B-W2 is 18mm, W1 / W2 is 0.52, L1 / E is 0.6, A2-A1 is 50mm, L2 / A1 is 0.47, A1-L3 is 9mm, and B is 46mm. The cell yield is >98%. No abnormalities were found, such as low pole group structural strength or poor pole group body assembly (300). The pole group, first tab 350, and second tab were all undamaged and undeformed. The overcurrent capacity and heat dissipation capacity of the first tab 350 and second tab, as well as the pole group capacity, all meet the requirements for high-rate fast charging of the cell.

[0093] In Example 5, H is 35mm, N is 125°, B-W2 is 22mm, W1 / W2 is 0.56, L1 / E is 0.65, A2-A1 is 60mm, L2 / A1 is 0.52, A1-L3 is 10.5mm, B is 54mm, and the cell yield is >98%. No abnormalities were found, such as low pole group structural strength or poor assembly of the pole group body 300. The pole group, the first tab 350, and the second tab were all undamaged and undeformed. The overcurrent capacity and heat dissipation capacity of the first tab 350 and the second tab, as well as the pole group capacity, all meet the requirements for high-rate fast charging of the cell.

[0094] In Example 6, H is 40mm, N is 130°, B-W2 is 30mm, W1 / W2 is 0.6, L1 / E is 0.7, A2-A1 is 70mm, L2 / A1 is 0.6, A1-L3 is 12mm, B is 60mm, and the cell yield is >98%. No abnormalities were found, such as low pole group structural strength or poor pole group body 300 assembly. The pole group, the first tab 350, and the second tab were all undamaged and undeformed. The overcurrent capacity and heat dissipation capacity of the first tab 350 and the second tab, as well as the pole group capacity, all meet the requirements for high-rate fast charging of the cell.

[0095] In Comparative Example 1, H is 26mm, N is 116°, B-W2 is 6mm, W1 / W2 is 0.48, L1 / E is 0.5, A2-A1 is 42mm, L2 / A1 is 0.4, A1-L3 is 8mm, B is 40mm, and the cell yield is <98%. The increase in electrode capacity is small and cannot meet the high-rate fast charging requirements of the cells.

[0096] In Comparative Example 2, H is 26mm, N is 116°, B-W2 is 33mm, W1 / W2 is 0.48, L1 / E is 0.5, A2-A1 is 42mm, L2 / A1 is 0.4, A1-L3 is 8mm, B is 40mm, and the cell yield is <98%. The electrode assembly body 300 has a low production yield, the groove 110 of the housing 100 has a poor limiting effect on the fourth protrusion 340, and the housing 100 is difficult to produce and has a low production yield.

[0097] In Comparative Example 3, H is 26mm, N is 116°, B-W2 is 14mm, W1 / W2 is 0.48, L1 / E is 0.28, A2-A1 is 42mm, L2 / A1 is 0.4, A1-L3 is 8mm, and B is 40mm. The cell yield is less than 98%. The increase in electrode capacity is small and cannot meet the high-rate fast charging requirements of the cells.

[0098] In Comparative Example 4, H is 26mm, N is 116°, B-W2 is 14mm, W1 / W2 is 0.48, L1 / E is 0.75, A2-A1 is 42mm, L2 / A1 is 0.4, A1-L3 is 8mm, B is 40mm, and the cell yield is <98%. The electrode assembly body 300 and the casing 100 are difficult to produce and have low yield.

[0099] In Comparative Example 5, H is 26mm, N is 116°, B-W2 is 14mm, W1 / W2 is 0.48, L1 / E is 0.5, A2-A1 is 42mm, L2 / A1 is 0.2, A1-L3 is 8mm, and B is 40mm. The cell yield is less than 98%. The increase in electrode capacity is small and cannot meet the high-rate fast charging requirements of the cells.

[0100] In Comparative Example 6, H is 26mm, N is 116°, B-W2 is 14mm, W1 / W2 is 0.48, L1 / E is 0.5, A2-A1 is 42mm, L2 / A1 is 0.65, A1-L3 is 8mm, B is 40mm, and the cell yield is <98%. The cover plate 220 is difficult to produce and has a low yield. The assembly yield of the cover plate 220 and the shell 100 is also low.

[0101] In summary, when 18mm≤H≤40mm, 7mm≤B-W2≤32mm, 0.4≤W1 / W2≤0.6, 0.29≤L1 / E≤0.74, 16mm≤A2-A1≤70mm, 100°≤N≤130°, 0.21≤L2 / A1≤0.64, 4mm≤A1-L3≤12mm, and 24mm≤B≤60mm, the electrode assembly volume can be increased, thereby increasing the electrode assembly capacity to meet the high-rate fast charging requirements of the battery cell. It can also improve the structural strength of the electrode assembly and reduce the probability of bending deformation problems.

[0102] 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 battery cell, characterized in that, include: Casing (100); A cover assembly (200) is provided to cover the opening of the housing (100); The pole assembly includes a pole assembly body (300) disposed within the housing (100). The length direction of the pole assembly body (300) is a first direction (D1), and the thickness direction of the pole assembly body (300) is a second direction (D2). Along the first direction (D1), a structural reinforcement part (310) is provided in the middle of the pole assembly body (300). One side of the pole assembly body (300) in the second direction (D2) is a connecting side (321). There are two pole assembly bodies (300), and the connecting sides (321) of the two pole assembly bodies (300) are arranged facing each other and spliced ​​together.

2. The battery cell according to claim 1, characterized in that, The pole assembly body (300) has a reinforcing side (322) on the other side in the second direction (D2). The width direction of the pole assembly body (300) is a third direction (D3). The structural reinforcing part (310) includes a first protrusion (311) and a second protrusion (312). The first protrusion (311) protrudes from the reinforcing side (322). The first protrusion (311) protrudes from both sides of the pole assembly body (300) in the third direction (D3). The pole assembly body (300) in the third direction (D3)... The second protrusion (312) is provided on both sides. One side surface of the second protrusion (312) in the second direction (D2) is flush with the surface of the connecting side (321), and the other side surface is flush with the side surface of the first protrusion (311) away from the pole body (300). The other side of the second protrusion (312) in the second direction (D2) is connected to the first protrusion (311). The size of the first protrusion (311) in the first direction (D1) and the size of the second protrusion (312) in the first direction (D1) are equal.

3. The battery cell according to claim 2, characterized in that, The cover plate assembly (200) is located on one side of the housing (100) in the first direction (D1). The cover plate assembly (200) is provided with a limiting groove structure (210) on the side facing the housing (100). The pole group body (300) is provided with a third protrusion (330) at one end facing the cover plate assembly (200). The third protrusions (330) of both pole group bodies (300) are insulated and embedded in the limiting groove structure (210).

4. The battery cell according to claim 3, characterized in that, The reinforcing side (322) is also provided with a fourth protrusion (340).

5. The battery cell according to claim 4, characterized in that, The fourth protrusion (340) of each of the two pole body bodies (300) is insulated and embedded in the limiting groove structure (210) at the end opposite to the first protrusion (311).

6. The battery cell according to claim 4, characterized in that, The surface of the reinforcing side (322) is flush with the surface of the third protrusion (330) facing the reinforcing side (322). Along the first direction (D1), one end of the fourth protrusion (340) is connected to the first protrusion (311), and the other end is connected to the third protrusion (330).

7. The battery cell according to claim 4, characterized in that, Along the second direction (D2), the distance between the connecting side (321) and the side of the fourth protrusion (340) away from the reinforcing side (322) is B, and along the second direction (D2), the distance between the connecting side (321) and the reinforcing side (322) is W2, 7mm≤B-W2≤32mm; And / or, the fourth protrusion (340) has a dimension of L2 in the third direction (D3), and the pole body (300) has a dimension of A1 in the third direction (D3), 0.21≤L2 / A1≤0.

64.

8. The battery cell according to claim 3, characterized in that, The number of the cover plate assembly (200) and the number of the opening are both two and correspond one-to-one. The two cover plate assemblies (200) are respectively located on both sides of the housing (100) in the first direction (D1).

9. The battery cell according to claim 8, characterized in that, The electrode assembly body (300) is provided with a first electrode tab (350) and a second electrode tab at both ends in the first direction (D1). The polarity of the first electrode tab (350) and the second electrode tab are opposite. The first electrode tabs (350) of the two electrode assembly bodies (300) are oriented in the same direction (D1) and are electrically connected to one of the cover plate assemblies (200). The second electrode tabs of the two electrode assembly bodies (300) are oriented in the same direction (D1) and are electrically connected to the other cover plate assembly (200).

10. The battery cell according to claim 8, characterized in that, The dimensions of the first protrusion (311) and the second protrusion (312) in the first direction (D1) are both L1. Along the first direction (D1), the distance between the two third protrusions (330) of the pole body (300) on opposite sides in the first direction (D1) is E, 0.29≤L1 / E≤0.74.

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