Battery monomer

Abstract

The invention belongs to the technical field of batteries, and discloses a battery monomer which comprises a pole group and a shell, the length direction of the pole group is a first direction, one of the width direction and the thickness direction of the pole group is a second direction, and the pole group comprises a first pole group body and two second pole group bodies, the two second pole group bodies are located on the two sides of the first pole group body in the first direction respectively and connected with the first pole group body in a spliced mode, the shell is provided with a containing cavity and two openings, the two openings are located on the two sides of the containing cavity in the first direction respectively and communicated with the containing cavity, and the first pole group body and the two second pole group bodies are all located in the containing cavity. The shell comprises a first side wall, the first side wall is located on one side of the containing cavity in the second direction, the first side wall is provided with an assembling hole communicated with the containing cavity, and the orthographic projection of the first pole group body on the first side wall in the second direction is located in the assembling hole, so that the capacity and the structural strength of the pole group are improved, the pole group shell entering difficulty is reduced, and the pole group shell entering efficiency is improved.

Description

Technical Field

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

[0002] In the prior art, in order to increase the capacity of the electrode assembly, the length of the electrode assembly is usually extended. However, extending the length of the electrode assembly will reduce the structural strength of the electrode assembly, and thus the electrode assembly is prone to bending and deformation before and during the installation process.

[0003] Furthermore, existing battery casings typically have openings at one end along their length. When inserting the electrode assembly into the casing, it is gradually inserted through these openings along the length of both the electrode assembly and the casing. Extending the length of the electrode assembly also increases the length of the battery casing, which not only increases the difficulty of inserting the electrode assembly but also reduces its efficiency. Therefore, there is an urgent need to propose a new battery cell design to address these technical problems. Summary of the Invention

[0004] The purpose of this invention is to provide a battery cell that can improve the capacity and structural strength of the electrode assembly, reduce the assembly difficulty of the electrode assembly and the casing, and improve the assembly efficiency of the electrode assembly and the casing.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] A single battery cell, comprising:

[0007] The pole group has a length direction as the first direction and a width direction or a thickness direction as the second direction. The pole group includes a first pole group body and two second pole group bodies. The two second pole group bodies are located on both sides of the first pole group body in the first direction and are connected to the first pole group body.

[0008] The housing has a cavity and two openings, which are located on both sides of the cavity in a first direction and are connected to the cavity. The first pole body and two second pole bodies are located inside the cavity. The housing includes a first sidewall located on one side of the cavity in a second direction. The first sidewall has an assembly hole that is connected to the cavity. The orthographic projection of the first pole body on the first sidewall along the second direction is located inside the assembly hole.

[0009] Optionally, the first sidewall is provided with two structural reinforcements, which are located on both sides of the assembly hole in the first direction.

[0010] Optionally, the structural reinforcement includes a protrusion that protrudes from the side of the first sidewall away from the cavity. The protrusion extends along a first direction, with one end extending to the edge of the assembly hole and the other end extending to the opening.

[0011] Optionally, a protruding edge is provided on the side of the first sidewall away from the cavity. The protruding edge is located at the edge of the assembly hole. The protruding edge extends circumferentially along the assembly hole and is connected end to end. The protruding edge encloses and forms an expansion space. The expansion space is connected to the cavity through the assembly hole. A first expansion part is provided on the side of the first pole body facing the first sidewall. The first expansion part passes through the assembly hole and is located in the expansion space.

[0012] Optionally, the dimension of the first sidewall in the first direction is W1, and the distance between the two opposite sides of the convex edge in the first direction is W2, where 0.29≤W2 / W1≤0.64.

[0013] Optionally, there are two first sidewalls, which are located on opposite sides of the cavity in the second direction.

[0014] Optionally, along the second direction, the distance between the opposite sides of the protrusions of the two first sidewalls is B, and the distance between the opposite sides of the two first sidewalls is L1, where 3mm≤B-L1≤17mm.

[0015] And / or, the other of the width direction and thickness direction of the electrode group is a third direction, the dimension of the protrusion in the third direction is L2, the dimension of the first sidewall in the third direction is A, 0.21≤L2 / A≤0.69.

[0016] Optionally, a through groove is provided on the side of the protrusion facing the cavity, and the through groove extends along the first direction;

[0017] The second pole body has a second capacity-enhancing part protruding on the side facing the first sidewall. The two second pole bodies correspond one-to-one with the two structural reinforcement parts. The second capacity-enhancing part of each second pole body is slidably connected to the through groove of the corresponding structural reinforcement part.

[0018] Optionally, the battery cell also includes two cover plate assemblies, each of which corresponds to one of the two openings. Each cover plate assembly includes a first cover plate, and the first cover plate of each cover plate assembly covers one of the corresponding openings. The first cover plate has a first protrusion and a second protrusion on the side facing the housing, and the first protrusion covers the side of the protrusion away from the assembly hole.

[0019] The other of the width direction and the thickness direction of the electrode group is the third direction. The housing also includes a second sidewall, which is connected to the first sidewall on the third direction. Both ends of the second sidewall are provided with notches in the first direction. The two notches correspond one-to-one with the first cover plates of the two cover plate assemblies. The second protrusion of each first cover plate is respectively embedded in the corresponding notch.

[0020] Optionally, the battery cell also includes a separator and an explosion-proof valve. The separator has an exhaust channel, and the housing also includes a second sidewall. The second sidewall has a flat plate structure and an explosion-proof hole. The separator is sandwiched between the electrode group and the side of the second sidewall facing the cavity. The cavity is connected to the explosion-proof hole through the exhaust channel, and the explosion-proof valve is sealed at the explosion-proof hole.

[0021] The beneficial effects of this invention are:

[0022] First, the electrode assembly is formed by joining a first electrode assembly body and two second electrode assembly bodies along the length of the electrode assembly. This increases the length and volume of the electrode assembly, thereby increasing its capacity. Furthermore, compared to extending the length of a single electrode assembly, this structure helps to reduce the length of the first and second electrode assembly bodies, thus improving their structural strength. This enhances the overall structural strength of the electrode assembly and reduces the likelihood of bending deformation during manufacturing.

[0023] Secondly, when assembling the electrode assembly into the housing, the first electrode assembly body can be inserted into the cavity through the assembly hole, so that the two second electrode assembly bodies correspond one-to-one with the two openings. Each second electrode assembly body is inserted into the cavity through its corresponding opening, and both second electrode assembly bodies are spliced ​​and connected to the first electrode assembly body. This completes the electrode assembly installation process. Compared with the existing technology, this structure can significantly reduce the difficulty of electrode assembly installation and improve the efficiency of electrode assembly installation. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of a battery cell provided by the present invention;

[0025] Figure 2 This is a schematic diagram of the pole assembly provided by the present invention;

[0026] Figure 3 This is an exploded structural diagram of the shell provided by the present invention;

[0027] Figure 4 This is a schematic diagram of the structure of the housing provided by the present invention;

[0028] Figure 5 This is a schematic diagram of the structure of the second pole group body provided by the present invention;

[0029] Figure 6 This is a schematic diagram of the structure of the first pole group body provided by the present invention;

[0030] Figure 7 This is a first structural schematic diagram of the cover plate assembly provided by the present invention;

[0031] Figure 8 This is a schematic diagram of the second structure of the cover plate assembly provided by the present invention;

[0032] Figure 9 This is an exploded structural diagram of the cover plate assembly provided by the present invention;

[0033] Figure 10 This is a schematic diagram of the first cross-sectional structure of the shell provided by the present invention;

[0034] Figure 11 This is a schematic diagram of the second cross-sectional structure of the housing provided by the present invention.

[0035] In the picture:

[0036] D1, First Direction; D2, Second Direction; D3, Third Direction;

[0037] 110. First electrode assembly body; 111. First capacity expansion section; 112. Slot; 113. First conductive layer; 114. Second conductive layer; 120. Second electrode assembly body; 121. Second capacity expansion section; 122. Third capacity expansion section; 123. Third conductive layer; 124. Fourth conductive layer; 130. Electrode tab; 200. Housing; 210. Cavity; 220. Opening; 230. First sidewall; 231. Assembly hole; 232. Protrusion; 2321. Through slot ; 233, convex edge; 240, expansion space; 250, second sidewall; 251, notch; 252, explosion-proof hole; 260, second cover plate; 300, cover plate assembly; 310, first cover plate; 311, first protrusion; 312, second protrusion; 313, third protrusion; 314, groove; 320, first insulating component; 330, first conductive plate; 340, second insulating component; 350, second conductive plate; 360, pole; 400, explosion-proof valve. Detailed Implementation

[0038] 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.

[0039] 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.

[0040] 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 being 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 being 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.

[0041] 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.

[0042] This embodiment provides a battery cell that can improve the capacity and structural strength of the electrode assembly, reduce the assembly difficulty of the electrode assembly and the casing, and improve the assembly efficiency of the electrode assembly and the casing.

[0043] Specifically, such as Figures 1 to 4 As shown, the battery cell includes an electrode assembly and a housing 200. The length direction of the electrode assembly is a first direction D1, and either the width direction or the thickness direction of the electrode assembly is a second direction D2. The electrode assembly includes a first electrode assembly body 110 and two second electrode assembly bodies 120. The two second electrode assembly bodies 120 are located on both sides of the first electrode assembly body 110 in the first direction D1 and are both connected to the first electrode assembly body 110. The housing 200 has a cavity 210 and two openings 220. The two openings 220 respectively... Located on both sides of the cavity 210 in the first direction D1 and connected to the cavity 210, the first pole body 110 and the two second pole bodies 120 are both located inside the cavity 210. The housing 200 includes a first sidewall 230, which is located on one side of the cavity 210 in the second direction D2. The first sidewall 230 is provided with an assembly hole 231, which is connected to the cavity 210. The orthographic projection of the first pole body 110 along the second direction D2 on the first sidewall 230 is located inside the assembly hole 231.

[0044] In this embodiment, the thickness direction of the electrode group is the second direction D2, and the width direction of the electrode group is the third direction D3. Of course, in other embodiments, the thickness direction of the electrode group can be the third direction D3, and the width direction of the electrode group can be the second direction D2.

[0045] Based on the above design, the electrode assembly is formed by splicing a first electrode assembly body 110 and two second electrode assembly bodies 120 along the length of the electrode assembly. This increases the length and volume of the electrode assembly, thereby increasing its capacity. Furthermore, compared to extending the length of a single electrode assembly, this structure helps to reduce the length of the first electrode assembly body 110 and the second electrode assembly body 120, thus improving the structural strength of both bodies and enhancing the overall structural strength of the electrode assembly. This reduces the likelihood of bending deformation during the manufacturing process.

[0046] Secondly, when assembling the electrode assembly into the housing 200, the first electrode assembly body 110 can be inserted into the cavity 210 through the assembly hole 231, so that the two second electrode assembly bodies 120 correspond one-to-one with the two openings 220. Each second electrode assembly body 120 is inserted into the cavity 210 through its corresponding opening 220, and both second electrode assembly bodies 120 are spliced ​​and connected with the first electrode assembly body 110. This completes the electrode assembly housing process. Compared with the prior art, this structure can significantly reduce the difficulty of electrode assembly housing and improve the efficiency of electrode assembly housing.

[0047] Optionally, the first sidewall 230 has an assembly hole 231, which weakens the structural strength of the first sidewall 230. In order to improve the structural strength of the first sidewall 230, in this embodiment, the first sidewall 230 is provided with two structural reinforcements, which are located on both sides of the assembly hole 231 in the first direction D1, so as to improve the structural strength of the first sidewall 230.

[0048] Furthermore, the structural reinforcement includes a protrusion 232, which protrudes from the side of the first sidewall 230 opposite to the cavity 210. The protrusion 232 extends along the first direction D1, with one end extending to the edge of the assembly hole 231 and the other end extending to the opening 220. In other words, the assembly hole 231 has protrusions 232 on both sides in the first direction D1. This structure is relatively simple, which can improve the structural strength of the first sidewall 230 and reduce the manufacturing difficulty of the first sidewall 230, thus improving the production efficiency of the housing 200.

[0049] Furthermore, a protruding edge 233 is provided on the side of the first sidewall 230 facing away from the cavity 210. The protruding edge 233 is located at the edge of the assembly hole 231 and extends circumferentially along the assembly hole 231, connecting end to end. The protruding edge 233 encloses and forms a capacity-enhancing space 240, which communicates with the cavity 210 through the assembly hole 231. A first capacity-enhancing part 111 protrudes from the side of the first electrode assembly body 110 facing the first sidewall 230. The first capacity-enhancing part 111 passes through the assembly hole 231 and is located within the capacity-enhancing space 240. This structure increases the size of the first electrode assembly body 110 in the second direction D2, thereby increasing the volume of the electrode assembly and improving its capacity, which is beneficial for meeting the high-rate fast charging requirements of individual battery cells. On the other hand, when the pole group is long, the middle part of the pole group in the length direction is a structurally weak area, and the probability of bending deformation in this area is relatively high. In this embodiment, the two second pole group bodies 120 are respectively connected to the two sides of the first pole group body 110 along the length direction of the pole group. That is, the first pole group body 110 is the structurally weak area in the length direction of the pole group. Increasing the size of the first pole group body 110 in the second direction D2 can improve the structural strength of the first pole group body 110, that is, improve the structural strength of the structurally weak area of ​​the pole group, and provide a guarantee for the structural consistency of the pole group.

[0050] Furthermore, the first capacity-enhancing part 111 is insulatedly embedded within the capacity-enhancing space 240. On the one hand, this maximizes the volume of the first capacity-enhancing part 111, thereby increasing the volume of the electrode assembly and improving its capacity. On the other hand, the protruding edge 233 along the first direction D1 and the third direction D3 can limit the first capacity-enhancing part 111, and thus the first sidewall 230 also limits the first electrode assembly body 110. This not only improves the stability of the connection between the first electrode assembly body 110 and the second electrode assembly body 120, but also reduces the probability of the electrode assembly shifting or displacing within the cavity 210.

[0051] Optionally, the housing 200 also includes a second cover plate 260, which covers the side of the protruding edge 233 opposite to the first sidewall 230 to block the assembly hole 231.

[0052] Furthermore, the protrusion 232 is connected to the protruding edge 233 on the side opposite to the opening 220, so that the protrusion 232 provides support for the protruding edge 233, improves the structural strength of the protruding edge 233, reduces the risk of deformation of the protruding edge 233, and thus provides a guarantee for the stability and reliability of the connection between the protruding edge 233 and the second cover plate 260.

[0053] Optionally, a through groove 2321 is provided on the side of the protrusion 232 facing the cavity 210. The through groove 2321 extends along the first direction D1, that is, the opening of the through groove 2321 faces the cavity 210, and one end of the through groove 2321 communicates with the opening 220, and the other end communicates with the assembly hole 231. A second capacity-enhancing part 121 protrudes from the side of the second pole body 120 facing the first sidewall 230. The two second pole body 120 correspond one-to-one with the two structural reinforcements. The second capacity-enhancing part 121 of each second pole body 120 is slidably connected to the through groove 2321 of the corresponding structural reinforcement. A protrusion 232 is provided on the side of the first sidewall 230 away from the cavity 210, and a through groove 2321 is provided on the side of the protrusion 232 facing the cavity 210. This structure can be manufactured by common production processes in the art, such as stamping. It can be seen that this structure reduces the production difficulty of the first sidewall 230, thereby helping to improve the production yield and production efficiency of the first sidewall 230. Secondly, the provision of the second capacity-enhancing section 121 increases the volume of the second electrode assembly body 120, thereby increasing the electrode assembly volume and thus improving the electrode assembly capacity, which is beneficial for meeting the high-rate fast charging requirements of individual battery cells. Thirdly, the provision of the second capacity-enhancing section 121 forms a first rib structure on the second electrode assembly body 120, which improves the structural strength of the second electrode assembly body 120, thereby increasing the structural strength of the electrode assembly. Finally, when the second electrode assembly body 120 is installed into the cavity 210, the second expansion part 121 slides into the through groove 2321. The through groove 2321 guides the second electrode assembly body 120. After the second electrode assembly body 120 is installed, the inner wall of the through groove 2321 limits the second expansion part 121 along the third direction D3, thereby limiting the second electrode assembly body 120. This not only improves the stability of the connection between the second electrode assembly body 120 and the first electrode assembly body 110, but also reduces the probability of the electrode assembly moving and shifting within the cavity 210.

[0054] Optionally, there are two first sidewalls 230, located on opposite sides of the cavity 210 along the second direction D2. When the first electrode assembly body 110 is installed into the cavity 210, the assembly hole 231 on one of the two first sidewalls 230 can be selected for installation, depending on the actual situation. This structure improves the flexibility of assembling the first electrode assembly body 110 with the housing 200, reduces the difficulty of inserting the first electrode assembly body 110 into the housing, and increases the efficiency of inserting the first electrode assembly body 110 into the housing. Furthermore, the assembly holes 231 of the two first sidewalls 230 are arranged opposite each other along the second direction D2. In actual production, the assembly holes 231 can be manufactured using common processes in the art, such as stamping. Therefore, this structural design helps reduce the production difficulty of the first sidewalls 230.

[0055] Furthermore, the first electrode assembly body 110 is provided with two first capacity-enhancing portions 111, which are located on both sides of the first electrode assembly body 110 in the second direction D2. Each first capacity-enhancing portion 111 corresponds to one of the two first sidewalls 230, and each first capacity-enhancing portion 111 is insulated and embedded within a corresponding capacity-enhancing space 240. On one hand, this structure further increases the size of the first electrode assembly body 110 in the second direction D2, which not only further expands the volume of the first electrode assembly body 110 and the electrode assembly, increasing the electrode assembly capacity, but also further improves the structural strength of the first electrode assembly body 110. On the other hand, both first sidewalls 230 provide a limiting effect for the first electrode assembly body 110, further improving the stability of the connection between the first electrode assembly body 110 and the second electrode assembly body 120, and further reducing the probability of the electrode assembly shifting or displacing within the cavity 210. On the other hand, the two first sidewalls 230 limit the first pole group body 110 on both sides along the second direction D2, which improves the uniformity of the force on the first pole group body 110 and can further reduce the probability of the first pole group body 110 and the pole group moving and shifting.

[0056] Optionally, such as Figures 1 to 5 As shown, the second electrode assembly body 120 has second capacity-enhancing portions 121 protruding from both sides in the second direction D2. Each side of the same second electrode assembly body 120 in the second direction D2 corresponds to one of the two first sidewalls 230. In the second direction D2, the second capacity-enhancing portion 121 located on the same side of the second electrode assembly body 120 is slidably connected to a through groove 2321 in one of the corresponding first sidewalls 230. This increases the number of second capacity-enhancing portions 121 on the second electrode assembly body 120, thereby further expanding the volume of the second electrode assembly body 120 and the electrode assembly, and further increasing the capacity of the electrode assembly. This structure forms first rib structures on both sides of the second electrode assembly body 120 along the second direction D2, which helps to further improve the structural strength of the second electrode assembly body 120. When the second electrode assembly body 120 is installed into the cavity 210, the through grooves 2321 of the two first sidewalls 230 can simultaneously guide the second electrode assembly body 120, improving the guiding effect of the housing 200 on the second electrode assembly body 120. After the second pole group body 120 is installed into the cavity 210, both first sidewalls 230 can limit the second pole group body 120 in the second direction D2. This not only improves the limiting effect of the second pole group body 120, but also improves the uniformity of the force on the second pole group body 120, which can reduce the probability of the second pole group body 120 and the pole group moving or shifting.

[0057] Furthermore, the second capacity-enhancing portion 121 extends along the first direction D1, and the side surface of the second capacity-enhancing portion 121 facing away from the outlet 220 is flush with the surface of the second electrode assembly body 120 facing the first electrode assembly body 110. This can increase the size of the second capacity-enhancing portion 121 in the first direction D1, further increase the volume of the second electrode assembly body 120 and the electrode assembly, further increase the capacity of the electrode assembly, and further improve the structural strength of the second electrode assembly body 120. At the same time, it can further improve the guiding and limiting effect of the housing 200 on the second electrode assembly body 120.

[0058] Optionally, such as Figures 1 to 6 As shown, the second electrode assembly body 120 has a third capacity-enhancing part 122 protruding from the side facing the first electrode assembly body 110. The first electrode assembly body 110 has slots 112 on both sides in the first direction D1. Each slot 112 corresponds to one of the two second electrode assembly bodies 120. The third capacity-enhancing part 122 of each second electrode assembly body 120 is inserted into its corresponding slot 112, thereby achieving the splicing connection between the second electrode assembly body 120 and the first electrode assembly body 110. After the third capacity-enhancing part 122 is inserted into the slot 112, the inner wall of the slot 112 can limit the third capacity-enhancing part 122, thereby locking the relative position of the first electrode assembly body 110 and the second electrode assembly body 120 and improving the stability of the electrode assembly structure.

[0059] Furthermore, the third capacity-enhancing portion 122 extends along the second direction D2. Both ends of the third capacity-enhancing portion 122 in the second direction D2 are respectively connected to the second capacity-enhancing portions 121 on both sides of the second electrode assembly body 120 in the second direction D2. Additionally, the two surfaces of the third capacity-enhancing portion 122 in the second direction D2 are flush with the surfaces of the second electrode assembly body 120 on the opposite sides of the second capacity-enhancing portions 121 in the second direction D2. This forms a second rib structure on the second electrode assembly body 120, which helps improve the structural strength of the second electrode assembly body 120. Moreover, the two ends of the third capacity-enhancing portion 122 are respectively connected to the two second capacity-enhancing portions 121, forming a mutually supporting structure between the third capacity-enhancing portion 122 and the second capacity-enhancing portions 121, which helps improve the structural strength of both the second capacity-enhancing portions 121 and the third capacity-enhancing portion 122.

[0060] Furthermore, the slot 112 extends along the second direction D2, and the slot 112 passes through the two opposing sides of the first capacity expansion portions 111 on both sides of the second direction D2. This structure increases the assembly area of ​​the third capacity expansion portion 122 and the slot 112, which is beneficial to improving the stability of the connection between the first pole group body 110 and the second pole group body 120.

[0061] Optionally, the first electrode assembly body 110 has a first conductive layer 113 and a second conductive layer 114 on the side facing the second electrode assembly body 120. The first conductive layer 113 and the second conductive layer 114 have opposite polarities and are respectively disposed on both sides of the slot 112 along the third direction D3. The second electrode assembly body 120 has a third conductive layer 123 and a fourth conductive layer 124 on the side facing the first electrode assembly body 110. The third conductive layer 123 has the same polarity as the first conductive layer 113, and the fourth conductive layer 124 has the same polarity as the second conductive layer 114. The third conductive layer 123 and the fourth conductive layer 124 are respectively disposed on both sides of the third capacity expansion portion 122 along the third direction D3. The third conductive layer 123 is attached to the first conductive layer 113, and the fourth conductive layer 124 is attached to the second conductive layer 114 to achieve conductive connection between the first electrode assembly body 110 and the second electrode assembly body 120. This structural design eliminates the need for conductive components such as conductive connecting pieces between the first electrode assembly body 110 and the second electrode assembly body 120, which helps to reduce the space occupied by the electrode assembly in the cavity 210, thereby improving the space utilization of the casing 200 and increasing the energy density of the battery cell.

[0062] In this embodiment, the first conductive layer 113 and the third conductive layer 123 are both positive conductive layers, and the second conductive layer 114 and the fourth conductive layer 124 are both negative conductive layers. Of course, in other embodiments, the first conductive layer 113 and the third conductive layer 123 can be both negative conductive layers, and the second conductive layer 114 and the fourth conductive layer 124 can be both positive conductive layers.

[0063] Furthermore, the first electrode assembly body 110 includes a first positive electrode, a first separator, and a first negative electrode. The first positive electrode, the first separator, and the first negative electrode are stacked sequentially along the second direction D2. In the third direction D3, the first positive electrode located on one side of the slot 112 protrudes from the first negative electrode along the direction from the first electrode assembly body 110 to the second electrode assembly body 120 and is connected to the first conductive layer 113. In the third direction D3, the first negative electrode located on the other side of the slot 112 protrudes from the first positive electrode along the direction from the first electrode assembly body 110 to the second electrode assembly body 120 and is connected to the second conductive layer 114. The second electrode assembly body 120 includes a second positive electrode, a second separator, and a second negative electrode. The second positive electrode, the second separator, and the second negative electrode are stacked sequentially along the second direction D2. In the third direction D3, the second positive electrode located on one side of the third capacity expansion section 122 protrudes from the second negative electrode along the direction of the second electrode assembly body 120 toward the first electrode assembly body 110 and is connected to the third conductive layer 123. In the third direction D3, the second negative electrode located on the other side of the third capacity expansion section 122 protrudes from the second positive electrode along the direction of the second electrode assembly body 120 toward the first electrode assembly body 110 and is connected to the fourth conductive layer 124, thereby realizing the conductive connection between the first electrode assembly body 110 and the second electrode assembly body 120.

[0064] Optionally, the battery cell also includes a separator (not shown in the figure) and an explosion-proof valve 400. The separator is provided with an exhaust channel. The housing 200 also includes a second side wall 250, which is a flat plate structure. An explosion-proof hole 252 is provided on the second side wall 250. The separator is sandwiched between the electrode group and the side of the second side wall 250 facing the cavity 210. The cavity 210 is connected to the explosion-proof hole 252 through the exhaust channel. The explosion-proof valve 400 is sealed at the explosion-proof hole 252. When the internal pressure of the cavity 210 reaches the burst pressure of the explosion-proof valve 400, the explosion-proof valve 400 bursts. The high-temperature and high-pressure material in the cavity 210 is discharged from the housing 200 through the exhaust channel and the explosion-proof hole 252. During this process, the electrode assembly is at risk of moving along with the flow of the high-temperature and high-pressure material. The partition prevents the moving electrode assembly from blocking the explosion-proof hole 252, thus ensuring the smooth discharge of the high-temperature and high-pressure material from the housing 200 after the explosion-proof valve 400 bursts. In addition, the flat plate structure of the second sidewall 250 helps reduce the assembly difficulty of the partition, housing 200, and electrode assembly, and also avoids wasting space in the cavity 210, thereby improving the space utilization rate of the cavity 210.

[0065] It should be noted that the exhaust passage can be an exhaust hole or an exhaust groove opened on the partition, etc., which will not be listed here.

[0066] Optionally, such as Figures 1 to 8As shown, the battery cell also includes two cover plate assemblies 300, each corresponding to one of the two openings 220. Each cover plate assembly 300 includes a first cover plate 310, with the first cover plate 310 covering a corresponding opening 220. The first cover plate 310 facing the housing 200 has a first protrusion 311 and a second protrusion 312. The first protrusion 311 covers the side of the protrusion 232 facing away from the assembly hole 231. The other of the electrode assembly's width direction and thickness direction is a third direction D3. A second sidewall 250 is connected to the first sidewall 230 on the third direction D3. The second sidewall 250 has notches 251 at both ends in the first direction D1, each notch 251 corresponding to one of the first cover plates 310 of the two cover plate assemblies 300. The second protrusion 312 of each first cover plate 310 is embedded in a corresponding notch 251. This structure enables rapid positioning of the cover plate assembly 300 and the housing 200, and also improves the positioning accuracy of the cover plate assembly 300 and the housing 200. Specifically, when the first cover plate 310 is placed over the opening 220, the first protrusion 311 can be aligned with the protrusion 232, and the second protrusion 312 can be aligned with the notch 251. Thus, the relative positions of the first cover plate 310 and the housing 200 can be quickly found in both the second direction D2 and the third direction D3, achieving rapid positioning of the cover plate assembly 300 and the housing 200. Furthermore, this structure enables positioning of the first cover plate 310 and the housing 200 in both the second direction D2 and the third direction D3, which helps to improve the positioning accuracy of the two.

[0067] Furthermore, there are two second sidewalls 250, which are arranged opposite each other along the third direction D3. The first sidewall 230 is connected to the two second sidewalls 250 on both sides of the third direction D3, thereby forming a cavity 210 by the two first sidewalls 230 and the two second sidewalls 250. The cavity 210 has an opening 220 at both ends in the first direction D1.

[0068] Furthermore, there are two explosion-proof valves 400 and two partitions, with each pair of explosion-proof valves 400, partitions, and second sidewalls 250 corresponding to one another. This simplifies the structure of the housing 200, reduces its manufacturing difficulty, and increases the number of explosion-proof valves 400. When an explosion-proof valve 400 bursts, it improves venting efficiency, which is beneficial to improving the safety of the battery cells.

[0069] Furthermore, the first cover plate 310 has two first protrusions 311 and two second protrusions 312. On the same first cover plate 310, the two first protrusions 311 correspond one-to-one with the two first sidewalls 230, and on the same first cover plate 310, the two second protrusions 312 correspond one-to-one with the two second sidewalls 250.

[0070] Optionally, along the third direction D3, the surface of the second sidewall 250 facing away from the cavity 210 and the surface of the protrusion 233 on the same side as the second sidewall 250 facing away from the expansion space 240 are flush, so as to improve the consistency of the housing 200 structure.

[0071] Optionally, the structural strength of the first sidewall 230 and the structural strength of the second sidewall 250 are both less than the structural strength of the second cover plate 260, and the wall thickness of the first sidewall 230 and the second sidewall 250 are equal. This can improve the consistency of the structural strength of the housing 200, and minimize the weight and cost of the housing 200, thereby increasing the energy density of the battery cell and reducing the production cost.

[0072] Furthermore, the thickness of both the first sidewall 230 and the second sidewall 250 is less than the thickness of the second cover plate 260, so that the structural strength of both the first sidewall 230 and the second sidewall 250 is less than the structural strength of the second cover plate 260. Alternatively, the structural strength of the material of the second cover plate 260 is greater than the structural strength of the materials of the first sidewall 230 and the second sidewall 250.

[0073] Optionally, such as Figures 1 to 9 As shown, the cover plate assembly 300 also includes a first insulating member 320 and a first conductive plate 330. Two third protrusions 313 protrude from the side of the first cover plate 310 opposite to the housing 200. The two third protrusions 313 are spaced apart along a second direction D2 to form a groove 314 between them. The first insulating member 320 is located on the side of the first cover plate 310 opposite to the housing 200 and is situated within the groove 314. The first conductive plate 330 is connected to the side of the first insulating member 320 opposite to the first cover plate 310. Along the direction from the housing 200 to the first cover plate 310, the third protrusions 313 protrude from the first insulating member 320 and the first conductive plate 330, thus protecting the first insulating member 320 and the first conductive plate 330 and reducing the probability of them being bumped during manufacturing.

[0074] Furthermore, the two first protrusions 311 are located on opposite sides of the two third protrusions 313 along the second direction D2.

[0075] Optionally, the side of the first conductive plate 330 facing away from the first insulating member 320 is used to connect with the pad (not shown in the figure). Along the direction of the housing 200 pointing towards the first cover plate 310, the third protrusion 313 protrudes from the pad so that the third protrusion 313 can protect the pad and reduce the probability of the pad being bumped during the manufacturing process.

[0076] Optionally, the cover plate assembly 300 further includes a second insulating member 340, a second conductive plate 350, and a pole post 360. The second insulating member 340 covers the side of the first cover plate 310 facing the housing 200. The second conductive plate 350 is connected to the side of the second insulating member 340 away from the first cover plate 310. One end of the pole post 360 is connected to the second conductive plate 350, and the other end passes through the second insulating member 340, the first cover plate 310, and the first insulating member 320, and is connected to the first conductive plate 330. Thus, the first conductive plate 330 and the second conductive plate 350 are electrically connected through the pole post 360.

[0077] Furthermore, the second electrode group body 120 is provided with a tab 130 on the side opposite to the first electrode group body 110, and the tabs 130 of the two second electrode group bodies 120 have opposite polarities. In the first direction D1, the tabs 130 located on the same side of the electrode group are connected to the corresponding second conductive plate 350 to realize the conductive connection between the electrode group and the cover plate assembly 300.

[0078] Optionally, such as Figures 1 to 10 As shown, the dimension of the first sidewall 230 in the first direction D1 is W1, and the distance between the two opposite sides of the protruding edge 233 in the first direction D1 is W2, where 0.29 ≤ W2 / W1 ≤ 0.64. For example, W2 / W1 can be 0.29, 0.33, 0.45, 0.58, 0.6, or 0.64, etc. If W2 / W1 < 0.29, then with W1 unchanged, W2 is too small, which will reduce the dimension of the first capacity-enhancing part 111 in the first direction D1, thereby reducing the increase in electrode volume and capacity, which is not conducive to meeting the high-rate fast charging requirements of battery cells. If W2 / W1 > 0.64, then with W1 remaining constant, an excessively large W2 will increase the manufacturing difficulty of the housing 200, thereby reducing its production yield and efficiency. Furthermore, an excessively large W2 will not only reduce the structural strength of the protrusion 233 on the third direction D3, but also cause the assembly hole 231 to be too large in the first direction D1, thus reducing the structural strength of the first sidewall 230. Therefore, only when 0.29 ≤ W2 / W1 ≤ 0.64 can a significant capacity increase in the electrode assembly be ensured, sufficient structural strength in the housing 200 be guaranteed, and the manufacturing difficulty of the housing 200 be reduced.

[0079] Optionally, along the second direction D2, the distance between the opposite sides of the protrusions 232 of the two first sidewalls 230 is B, and the distance between the opposite sides of the two first sidewalls 230 is L1, where 3mm≤B-L1≤17mm. For example, B-L1 can be 3mm, 4mm, 10mm, 16mm, or 17mm, etc. If B-L1<3mm, then with L1 unchanged, B is too small, which will make the size of the second capacity-enhancing part 121 too small in the second direction D2, thereby reducing the increase in electrode volume and capacity, which is not conducive to meeting the high-rate fast charging requirements of battery cells. On the other hand, if B is too small, the protrusion 232 will protrude too little from the surface of the first sidewall 230. This will reduce the structural strength of the protrusion 232, increase the risk of deformation due to impacts during manufacturing, and consequently reduce the positioning accuracy and connection stability of the first protrusion 311 and the protrusion 232 of the first cover plate 310, thus reducing the assembly yield of the cover plate assembly 300 and the housing 200. If B-L1>17mm, then with L1 unchanged, if B is too large, the protrusion 232 will protrude too much from the surface of the first sidewall 230, increasing the manufacturing difficulty of the first sidewall 230, and thus reducing the manufacturing yield and efficiency of the housing 200. Furthermore, to improve the stability of the connection between the protruding edge 233 and the protruding portion 232, on the same first sidewall 230, the protrusion of the protruding edge 233 from the first sidewall 230 is larger than that of the protruding portion 232. If the protruding portion 232 protrudes too much from the surface of the first sidewall 230, the protrusion of the protruding edge 233 will also be larger. This will further increase the manufacturing difficulty of the first sidewall 230 and reduce the structural strength of the protruding edge 233, thereby increasing the risk of deformation of the protruding edge 233 and reducing the stability and reliability of the connection between the protruding edge 233 and the second cover plate 260. It can be seen that only when 3mm≤B-L1≤17mm can the electrode group have a large capacity increase, the housing 200 have sufficient structural strength, the manufacturing difficulty of the housing 200 be reduced, and the housing 200, the first cover plate 310, and the second cover plate 260 have a high assembly yield.

[0080] Optionally, in the first direction D1, the distance between the side of the protrusion 232 on the same side of the housing 200 facing the opening 220 and the side of the notch 251 facing the first cover plate 310 is H1, 18mm≤H1≤60mm. For example, H1 can be 18mm, 45mm or 60mm, etc.

[0081] Optionally, in the first direction D1, the protrusion 232 located on the same side of the housing 200 protrudes from the second sidewall 250 toward the opening 220 in the direction from the first pole body 110 toward the second pole body 120, with a size of H2, 0.28≤H2 / H1≤0.5. For example, H2 / H1 can be 0.28, 0.35, or 0.5, etc.

[0082] It should be noted that the dimension W1 of the first sidewall 230 in the first direction D1 refers to the distance between the two protrusions 232 on the same first sidewall 230 that are opposite to each other in the first direction D1.

[0083] Optionally, in the second direction D2, the included angle between the two inner walls opposite to the notch 251 is N, 70°≤N≤100°. For example, N can be 70°, 88° or 100°, etc.

[0084] Optionally, the thickness of the first sidewall 230 is T2, where 0.3mm ≤ T2 ≤ 1mm. For example, T2 can be 0.3mm, 0.58mm, or 1mm, etc.

[0085] Optionally, the thickness of the second cover plate 260 is T1, where 1mm ≤ T1 ≤ 3.5mm. For example, T1 can be 1mm, 2.8mm, or 3.5mm, etc.

[0086] Optionally, such as Figures 1 to 11 As shown, the other of the width direction and thickness direction of the electrode assembly is a third direction D3. The dimension of the protrusion 232 in the third direction D3 is L2, and the dimension of the first sidewall 230 in the third direction D3 is A. 0.21≤L2 / A≤0.69. For example, L2 / A can be 0.21, 0.25, 0.43, 0.5, 0.65, or 0.69, etc. If L2 / A<0.21, then with A unchanged, L2 is too small. This will result in the through slot 2321 and the second capacity-enhancing part 121 being too small in the third direction D3, reducing the increase in electrode assembly volume and capacity, which is not conducive to meeting the high-rate fast charging requirements of battery cells. If L2 / A>0.69, then with A unchanged, L2 is too large. This will increase the manufacturing difficulty of the first sidewall 230, thereby reducing the production yield and efficiency of the casing 200. It can be seen that when 0.21≤L2 / A≤0.69, the electrode assembly can be guaranteed to have a large capacity increase, which can improve the production yield and production efficiency of the housing 200.

[0087] Optionally, on the same first sidewall 230, the distance between the side of the protrusion 232 facing away from the cavity 210 and the side of the first sidewall 230 facing away from the cavity 210 in the second direction D2 is E, 8.5mm≤E≤35mm. For example, E can be 8.5mm, 22mm or 35mm, etc., to ensure that the protrusion 232 has a certain structural strength, reduce the production difficulty of the first sidewall 230, and at the same time ensure that the second capacity-enhancing part 121 has a large size in the second direction D2, so that the electrode group has a sufficient capacity increase.

[0088] In this embodiment, the shell 200 and the first cover plate 310 are manufactured using metal stamping and extrusion molding processes, the first insulating component 320 and the second insulating component 340 are manufactured using injection molding processes, and the electrode tab 130 and the second conductive plate 350, the electrode post 360 and the second conductive plate 350, the electrode group and the first conductive plate 330 are connected using high-frequency welding and laser welding processes. The aforementioned metal stamping, extrusion molding, injection molding, high-frequency welding and laser welding processes are all common production processes in the field, which are conducive to realizing mass automated production.

[0089] 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 200 and the first cover plate 310 are all made of aluminum, the insulating film wrapped around the outer surface of the electrode group is polypropylene (PP) film, the first insulating component 320 is made of polyphenylene sulfide (PPS) material, and the second insulating component 340 is made of PP material.

[0090]

[0091] In Example 1, H1 is 18mm, H2 / H1 is 0.28, B-L1 is 4mm, E is 8.5mm, L2 / A is 0.25, W2 / W1 is 0.33, N is 70°, T1 is 1mm, T2 is 0.3mm, and the yield rate of the battery cells is >98%. No abnormalities were found in the positioning or structural strength of the first cover plate 310, the casing 200, or the electrode assembly. The casing 200, the electrode assembly, the tabs 130, and the first cover plate 310 all showed no deformation or damage.

[0092] In Example 2, H1 is 26mm, H2 / H1 is 0.32, B-L1 is 6mm, E is 14mm, L2 / A is 0.4, W2 / W1 is 0.39, N is 76°, T1 is 1.5mm, T2 is 0.4mm, and the yield rate of the battery cells is >98%. No abnormalities were found in the positioning or structural strength of the first cover plate 310, the casing 200, or the electrode assembly. The casing 200, electrode assembly, electrode tabs 130, and the first cover plate 310 all showed no deformation or damage.

[0093] In Example 3, H1 is 35mm, H2 / H1 is 0.36, B-L1 is 8mm, E is 20mm, L2 / A is 0.48, W2 / W1 is 0.45, N is 80°, T1 is 2mm, T2 is 0.6mm, and the yield rate of the battery cells is >98%. No abnormalities were found in the positioning or structural strength of the first cover plate 310, the casing 200, or the electrode assembly. The casing 200, the electrode assembly, the tabs 130, and the first cover plate 310 all showed no deformation or damage.

[0094] In Example 4, H1 is 42mm, H2 / H1 is 0.4, B-L1 is 10mm, E is 24mm, L2 / A is 0.54, W2 / W1 is 0.51, N is 85°, T1 is 2.5mm, T2 is 0.7mm, and the yield rate of the battery cells is >98%. No abnormalities were found in the positioning or structural strength of the first cover plate 310, the casing 200, or the electrode assembly. The casing 200, the electrode assembly, the tabs 130, and the first cover plate 310 all showed no deformation or damage.

[0095] In Example 5, H1 is 53mm, H2 / H1 is 0.44, B-L1 is 12mm, E is 30mm, L2 / A is 0.6, W2 / W1 is 0.55, N is 92°, T1 is 3mm, T2 is 0.9mm, and the yield rate of the battery cells is >98%. No problems were found with the positioning of the first cover plate 310, the casing 200, or the electrode assembly, or with abnormal structural strength. The casing 200, the electrode assembly, the tabs 130, and the first cover plate 310 all showed no deformation or damage.

[0096] In Example 6, H1 is 60mm, H2 / H1 is 0.5, B-L1 is 16mm, E is 35mm, L2 / A is 0.65, W2 / W1 is 0.6, N is 100°, T1 is 3.5mm, T2 is 1mm, and the yield rate of the battery cells is >98%. No abnormalities were found in the positioning or structural strength of the first cover plate 310, the casing 200, or the electrode assembly. The casing 200, electrode assembly, electrode tabs 130, and the first cover plate 310 all showed no deformation or damage.

[0097] In Comparative Example 1, H1 is 35mm, H2 / H1 is 0.36, B-L1 is 2mm, E is 20mm, L2 / A is 0.48, W2 / W1 is 0.45, N is 80°, T1 is 2mm, T2 is 0.6mm, and the yield rate of individual battery cells is <98%. The capacity improvement of the electrode assembly is small and cannot meet the high-rate fast charging requirements of individual battery cells. The protrusion 232 is deformed, and the positioning accuracy of the first cover plate 310 and the shell 200 is low, resulting in poor connection stability.

[0098] In Comparative Example 2, H1 is 35mm, H2 / H1 is 0.36, B-L1 is 18mm, E is 20mm, L2 / A is 0.48, W2 / W1 is 0.45, N is 80°, T1 is 2mm, T2 is 0.6mm, and the yield of qualified battery cells is <98%; the casing 200 is difficult to produce and has a low yield, the protruding edge 233 is deformed, and the stability and reliability of the connection between the protruding edge 233 and the second cover plate 260 are poor.

[0099] In Comparative Example 3, H1 is 35mm, H2 / H1 is 0.36, B-L1 is 8mm, E is 20mm, L2 / A is 0.2, W2 / W1 is 0.45, N is 80°, T1 is 2mm, T2 is 0.6mm, and the yield rate of the battery cell is <98%; the capacity improvement of the electrode group is small and cannot meet the high-rate fast charging requirements of the battery cell.

[0100] In Comparative Example 4, H1 is 35mm, H2 / H1 is 0.36, B-L1 is 8mm, E is 20mm, L2 / A is 0.7, W2 / W1 is 0.45, N is 80°, T1 is 2mm, T2 is 0.6mm, and the yield of qualified battery cells is <98%; the casing 200 is difficult to produce and has a low yield.

[0101] In Comparative Example 5, H1 is 35mm, H2 / H1 is 0.36, B-L1 is 8mm, E is 20mm, L2 / A is 0.48, W2 / W1 is 0.28, N is 80°, T1 is 2mm, T2 is 0.6mm, and the yield rate of the battery cell is <98%; the capacity improvement of the electrode group is small and cannot meet the high-rate fast charging requirements of the battery cell.

[0102] In Comparative Example 6, H1 is 35mm, H2 / H1 is 0.36, B-L1 is 8mm, E is 20mm, L2 / A is 0.48, W2 / W1 is 0.65, N is 80°, T1 is 2mm, T2 is 0.6mm, and the yield of qualified battery cells is <98%; the casing 200 is difficult to produce and has a low yield, the first sidewall 230 and the protrusion 233 have low structural strength, and the first sidewall 230 and the protrusion 233 are easy to deform.

[0103] It can be seen that when 18mm≤H1≤60mm, 0.28≤H2 / H1≤0.5, 3mm≤B-L1≤17mm, 8.5mm≤E≤35mm, 0.21≤L2 / A≤0.69, 0.29≤W2 / W1≤0.64, 70°≤N≤100°, 1mm≤T1≤3.5mm, and 0.3mm≤T2≤1mm, the structural strength of the electrode assembly and housing 200 can be improved, the probability of bending deformation of the electrode assembly and housing 200 can be reduced, the efficiency of electrode assembly into cavity 210 can be improved, the capacity of the electrode assembly can be increased to meet the high-rate fast charging requirements of battery cells, and the assembly yield of housing 200, electrode assembly, cover plate assembly 300 and second cover plate 260 can be improved.

[0104] 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: The pole group has a length direction as a first direction (D1) and a width direction or a thickness direction as a second direction (D2). The pole group includes a first pole group body (110) and two second pole group bodies (120). The two second pole group bodies (120) are located on both sides of the first pole group body (110) in the first direction (D1) and are spliced ​​and connected to the first pole group body (110). The housing (200) has a cavity (210) and two openings (220). The two openings (220) are located on both sides of the cavity (210) in the first direction (D1) and are connected to the cavity (210). The first pole group body (110) and two second pole group bodies (120) are located in the cavity (210). The housing (200) includes a first sidewall (230). The first sidewall (230) is located on one side of the cavity (210) in the second direction (D2). The first sidewall (230) has an assembly hole (231) that is connected to the cavity (210). The orthographic projection of the first pole group body (110) along the second direction (D2) onto the first sidewall (230) is located within the assembly hole (231).

2. The battery cell according to claim 1, characterized in that, The first sidewall (230) is provided with two structural reinforcements, which are located on both sides of the assembly hole (231) in the first direction (D1).

3. The battery cell according to claim 2, characterized in that, The structural reinforcement includes a protrusion (232) which protrudes from the side of the first sidewall (230) away from the cavity (210). The protrusion (232) extends along the first direction (D1), with one end of the protrusion (232) extending to the edge of the assembly hole (231) and the other end extending to the opening (220).

4. The battery cell according to claim 3, characterized in that, The first sidewall (230) has a protruding edge (233) on the side away from the cavity (210). The protruding edge (233) is located at the edge of the assembly hole (231). The protruding edge (233) extends circumferentially along the assembly hole (231) and is connected end to end. The protruding edge (233) encloses and forms an expansion space (240). The expansion space (240) is connected to the cavity (210) through the assembly hole (231). The first pole body (110) has a first expansion part (111) protruding on the side facing the first sidewall (230). The first expansion part (111) passes through the assembly hole (231) and is located in the expansion space (240).

5. The battery cell according to claim 4, characterized in that, The dimension of the first sidewall (230) in the first direction (D1) is W1, and the distance between the two opposite sides of the protruding edge (233) in the first direction (D1) is W2, 0.29≤W2 / W1≤0.

64.

6. The battery cell according to claim 3, characterized in that, There are two first sidewalls (230), and the two first sidewalls (230) are located on both sides of the cavity (210) in the second direction (D2).

7. The battery cell according to claim 6, characterized in that, Along the second direction (D2), the distance between the opposite sides of the protrusions (232) of the two first sidewalls (230) is B, and along the second direction (D2), the distance between the opposite sides of the two first sidewalls (230) is L1, 3mm≤B-L1≤17mm; And / or, the other of the width direction and the thickness direction of the pole group is a third direction (D3), the size of the protrusion (232) in the third direction (D3) is L2, the size of the first sidewall (230) in the third direction (D3) is A, 0.21≤L2 / A≤0.

69.

8. The battery cell according to any one of claims 3-7, characterized in that, The protrusion (232) has a through groove (2321) on the side facing the cavity (210), and the through groove (2321) extends along the first direction (D1); The second pole body (120) has a second capacity expansion portion (121) protruding on the side facing the first sidewall (230). The two second pole bodies (120) correspond one-to-one with the two structural reinforcement portions. The second capacity expansion portion (121) of each second pole body (120) is slidably connected to the through groove (2321) of the corresponding structural reinforcement portion.

9. The battery cell according to any one of claims 3-7, characterized in that, The battery cell also includes two cover plate assemblies (300), each of which corresponds to one of the two openings (220). Each cover plate assembly (300) includes a first cover plate (310), and the first cover plate (310) of each cover plate assembly (300) covers one of the corresponding openings (220). The first cover plate (310) has a first protrusion (311) and a second protrusion (312) on the side facing the housing (200). The first protrusion (311) covers the side of the protrusion (232) away from the assembly hole (231). The other of the width direction and the thickness direction of the electrode group is a third direction (D3). The housing (200) also includes a second sidewall (250). The second sidewall (250) is connected to one side of the first sidewall (230) in the third direction (D3). The second sidewall (250) has notches (251) at both ends in the first direction (D1). The two notches (251) correspond one-to-one with the first cover plates (310) of the two cover plate assemblies (300). The second protrusion (312) of each first cover plate (310) is respectively embedded in one of the corresponding notches (251).

10. The battery cell according to any one of claims 1-7, characterized in that, The battery cell also includes a separator and an explosion-proof valve (400). The separator is provided with an exhaust channel. The housing (200) also includes a second sidewall (250). The second sidewall (250) is a flat plate structure. An explosion-proof hole (252) is provided on the second sidewall (250). The separator is sandwiched between the electrode group and the side of the second sidewall (250) facing the cavity (210). The cavity (210) is connected to the explosion-proof hole (252) through the exhaust channel. The explosion-proof valve (400) is sealed at the explosion-proof hole (252).

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