Battery cell

Abstract

The invention belongs to the technical field of batteries, and discloses a battery monomer which comprises a pole group and a battery shell, the battery shell is provided with a containing cavity, the pole group is arranged in the containing cavity, the battery shell comprises two first side walls, and the two first side walls are arranged in a mirror image mode relative to the middle of the containing cavity in the first direction. The two sides of the battery shell in the second direction are a first side and a second side respectively, the first side wall comprises a slope part, the slope part points to the second side from the first side, the slope part inclines in the direction away from the containing cavity, the slope part extends from one side of the first side wall to the other side in the third direction, and the containing cavity is at least provided with an opening in the second side in the second direction; the first direction, the second direction and the third direction are perpendicular to each other, and when the pole group is arranged in the battery shell, the battery shell can guide the pole group, so that the pole group is prevented from skewing in the process of being arranged in the accommodating cavity, and the probability that the pole group is knocked by the inner wall of the battery shell can be reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery, in particular to a battery cell. BACKGROUND

[0002] The battery cell generally comprises a battery shell, a pole group and a cover plate, wherein the battery shell is provided with a receiving cavity and an opening communicating with the receiving cavity, the pole group is loaded into the receiving cavity through the opening, and the cover plate is arranged at the opening to form a closed space.

[0003] When the pole group is loaded into the battery shell, the pole group is prone to be skewed, and then the problems of difficulty in loading the pole group into the shell or the pole group being scratched by the inner wall of the battery shell may occur.

[0004] Therefore, it is urgent to provide a battery cell to solve the above technical problems. SUMMARY

[0005] The purpose of the present application is to provide a battery cell, when the pole group is loaded into the battery shell, the battery shell can provide a guiding effect for the pole group, prevent the pole group from being skewed during loading into the receiving cavity, and reduce the probability of the pole group being scratched by the inner wall of the battery shell.

[0006] To achieve this purpose, the present application adopts the following technical solutions:

[0007] The battery cell comprises:

[0008] a pole group;

[0009] a battery shell, the battery shell is provided with a receiving cavity, the pole group is arranged in the receiving cavity, and the battery shell comprises two first side walls, the two first side walls are mirror image arranged about the middle part of the receiving cavity in a first direction, two sides of the battery shell in a second direction are a first side and a second side respectively, the first side wall comprises a slope part, the slope part is inclined in a direction away from the receiving cavity from the direction of the first side to the second side, the slope part extends from one side of the first side wall to the other side along a third direction, and in the second direction, the receiving cavity is provided with an opening at least on the second side, and the first direction, the second direction and the third direction are perpendicular to each other.

[0010] Optionally, the first side wall further comprises two plane parts, and the two plane parts are respectively connected to the two sides of the slope part in the second direction, and the plane part is perpendicular to the first direction.

[0011] Optionally, one of the two plane parts is a first plane part, and the other is a second plane part, the first plane part is connected to one side of the slope part facing the first side, the second plane part is connected to one side of the slope part facing the second side, and the second plane part is provided with a protruding part protruding away from the receiving cavity.

[0012] Optionally, the battery cell further comprises two explosion-proof valves, and the two explosion-proof valves are arranged on the second plane parts of the two first side walls respectively.

[0013] Optionally, the wall thickness of the convex part and the second planar part is T1, the wall thickness of the first planar part is T2, and 0.21mm≤T1-T2≤0.79mm.

[0014] Optionally, the convex part is located on the side of the second planar part away from the slope part, and the convex part extends to the opening of the accommodation cavity on the second side in the second direction.

[0015] Optionally, the two side walls of the pole group in the first direction are both contoured walls, in the first direction, the contoured walls on the same side of the pole group are contoured to the shape of the first side wall, in the second direction, the distance between the side of the slope part facing the first side and the side of the convex part facing the second side is W1, the size of the convex part in the second direction is W2, and 0.31≤W2 / W1≤0.59.

[0016] Optionally, the accommodation cavity is provided with openings on the first side and the second side, the first planar part extends to the opening of the accommodation cavity on the first side in the second direction, and the battery shell further comprises two second side walls, the two second side walls are symmetrically arranged about the middle part of the accommodation cavity in the third direction, and the two sides of the two second side walls in the first direction are connected with the two first side walls, respectively.

[0017] Optionally, the battery monomer further comprises two cover plate assemblies, the two cover plate assemblies are respectively arranged on the opening on the first side and the opening on the second side;

[0018] The end face of the second side wall at both ends in the second direction comprises a first planar section, two inclined sections and two second planar sections, the first planar section and the second planar section are both perpendicular to the second direction, the two second planar sections are respectively located on both sides of the first planar section in the first direction and are respectively connected to the two first side walls, each second planar section is connected to the first planar section through an inclined section, one end of the inclined section connected to the first planar section is a first end, one end of the inclined section connected to the second planar section is a second end, in the direction from the first end to the second end, the inclined section is inclined to the direction of the battery shell pointing to the cover plate assembly corresponding to the inclined section, and the accommodation cavity forms an increased space on the first side and the second side;

[0019] The pole group comprises a pole group body and two first protrusions, the two first protrusions are respectively protruded on both ends of the pole group body in the second direction and are respectively located in the increased space on the first side and the increased space on the second side.

[0020] Optionally, in the first direction, the distance between the sides away from each other of the two first planar parts is A2, and the distance between the second ends of the two inclined sections connected to the same first planar section is L2, and 0.51≤L2 / A2≤0.89.

[0021] The beneficial effects of the present application are as follows:

[0022] When the polar group is loaded into the accommodating cavity through the opening of the battery shell located at the second side, the slope parts of the two first side walls can provide a guiding effect for the polar group, preventing the polar group from being skewed during the loading process into the accommodating cavity, which not only facilitates the polar group to be smoothly loaded into the shell, but also reduces the probability of the polar group being scratched by the inner wall of the battery shell. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a first structural schematic diagram of a battery shell provided by the present application;

[0024] Figure 2 is a second structural schematic diagram of a battery shell provided by the present application;

[0025] Figure 3 is a sectional structural schematic diagram of a battery shell provided by the present application;

[0026] Figure 4 is a sectional structural schematic diagram of a battery monomer provided by the present application;

[0027] Figure 5 is a first structural schematic diagram of a battery monomer provided by the present application;

[0028] Figure 6 is a second structural schematic diagram of a battery monomer provided by the present application;

[0029] Figure 7 is a first enlarged structural schematic diagram of a battery shell provided by the present application;

[0030] Figure 8 is a second enlarged structural schematic diagram of a battery shell provided by the present application;

[0031] Figure 9 is an exploded structural schematic diagram of a cover plate assembly provided by the present application;

[0032] Figure 10 is a structural schematic diagram of a cover plate assembly provided by the present application;

[0033] Figure 11 is a sectional structural schematic diagram of a cover plate assembly provided by the present application;

[0034] Figure 12 is a third structural schematic diagram of a battery shell provided by the present application.

[0035] In the drawings:

[0036] D1, first direction; D2, second direction; D3, third direction;

[0037] 100, battery case; 111, accommodating cavity; 112, opening; 113, volume-increased space; 114, volume-increased cavity; 120, first side wall; 121, slope portion; 122, first planar portion; 123, second planar portion; 124, protruding portion; 131, first side; 132, second side; 140, second side wall; 141, first planar segment; 142, inclined segment; 142a, first end; 142b, second end; 143, second planar segment; 200, explosion-proof valve; 300, cover plate assembly; 310, cover plate body; 311, first plate body; 312, second plate body; 313, support eave; 314, raised portion; 320, first plastic plate; 321, first plastic portion; 322, second plastic portion; 330, second plastic plate; 340, first conductive plate; 341, first conductive portion; 342, second conductive portion; 350, pole structure; 351, second conductive plate; 352, pole; 410, pole group body; 420, first protruding portion; 430, second protruding portion. DETAILED DESCRIPTION

[0038] The application will be further described below in conjunction with the drawings and examples. It should be understood that the specific examples described herein are intended to be illustrative only and are not in any way limiting of the application. In addition, it should be understood that the drawings are not necessarily to scale and that, unless otherwise indicated, the drawings are simplified for the sake of clarity.

[0039] In the description of the present application, unless otherwise clearly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrated; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0040] In the present application, unless otherwise clearly specified and limited, the "upper" or "lower" of the first feature to the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the "upper", "above" and "on" of the first feature to the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The "below", "under" and "under" of the first feature to the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of 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 where the battery case can guide the electrode assembly when it is installed into the battery housing, preventing the electrode assembly from tilting during installation and reducing the chance of the electrode assembly being damaged by the inner wall of the battery housing.

[0043] Specifically, such as Figures 1 to 3 As shown, the battery cell includes an electrode assembly (not shown) and a battery casing 100. The battery casing 100 has a receiving cavity 111, and the electrode assembly is disposed in the receiving cavity 111. The battery casing 100 includes two first sidewalls 120, which are mirror images of the receiving cavity 111 in a first direction D1. The two sides of the battery casing 100 in a second direction D2 are a first side 131 and a second side 132, respectively. The first sidewall 120 includes a sloped portion 121 pointing from the first side 131 to the second side 132. The sloped portion 121 is inclined in a direction away from the receiving cavity 111. The sloped portion 121 extends from one side of the first sidewall 120 to the other side in a third direction D3. In the second direction D2, the receiving cavity 111 has an opening 112 at least in the second side 132. The first direction D1, the second direction D2, and the third direction D3 are perpendicular to each other.

[0044] In this embodiment, the first direction D1 is the width direction of the battery cell, the second direction D2 is the length direction of the battery cell, and the third direction D3 is the thickness direction of the battery cell.

[0045] When the electrode assembly is inserted into the receiving cavity 111 through the opening 112 on the second side 132 of the battery casing 100, the sloped surfaces 121 of the two first sidewalls 120 can provide guidance for the electrode assembly, preventing the electrode assembly from tilting during the insertion into the receiving cavity 111. This not only facilitates the smooth insertion of the electrode assembly into the casing, but also reduces the probability of the electrode assembly being damaged by the inner wall of the battery casing 100.

[0046] On the other hand, since the slope 121 is inclined in the direction away from the receiving cavity 111, the structure increases the volume of the area of ​​the slope 121 corresponding to the receiving cavity 111, thereby increasing the volume of the area of ​​the slope 121 corresponding to the electrode group, which is beneficial to improving the capacity of the electrode group and thus realizing high-rate fast charging of the battery cell.

[0047] In still another aspect, the mirror image arrangement of the two first side walls 120 reduces the difficulty of producing the battery case 100, and is conducive to improving the production efficiency and reducing the production cost.

[0048] Optionally, the first side wall 120 further comprises two planar portions, which are respectively connected to two sides of the slope portion 121 in the second direction D2, and the planar portions are perpendicular to the first direction D1. Compared with the structure that the slope portion 121 extends from the first side 131 to the second side 132, the technical solution provided in the embodiment can avoid that the volume of the battery case 100 at the first side 131 is too small, and provides sufficient space for the pole group at the first side 131, which is conducive to ensuring that the pole group has a large enough volume on the side facing the first side 131.

[0049] Further, one of the two planar portions is a first planar portion 122, and the other is a second planar portion 123. The first planar portion 122 is connected to the side of the slope portion 121 facing the first side 131, and the second planar portion 123 is connected to the side of the slope portion 121 facing the second side 132. The second planar portion 123 is provided with a protruding portion 124 protruding away from the accommodation cavity 111. The design of the protruding portion 124 can improve the structural strength of the first side wall 120, thereby reducing the probability of deformation of the first side wall 120. Secondly, the protruding portion 124 protrudes away from the accommodation cavity 111, so that a capacity-increasing cavity 114 is formed in the accommodation cavity 111 corresponding to the position of the protruding portion 124, thereby the volume of the pole group in the area corresponding to the protruding portion 124 can be enlarged, which is conducive to improving the capacity of the pole group, thereby realizing high-rate fast charging of the battery monomer. Thirdly, since the second planar portion 123 is located at the side of the slope portion 121 facing the second side 132, the volume of the accommodation cavity 111 at the second planar portion 123 is larger than the volume of the accommodation cavity 111 at the first planar portion 122. By arranging the protruding portion 124 on the second planar portion 123, the volume of the capacity-increasing cavity 114 can be enlarged, thereby being conducive to further enlarging the volume of the pole group in the area of the protruding portion 124.

[0050] Further, the protruding portion 124 is located on the side of the second planar portion 123 away from the slope surface portion 121, and extends along the second direction D2 to the opening 112 of the accommodating cavity 111 on the second side 132. Thus, in the direction from the first side 131 to the second side 132, an indirect protruding structure is formed on the first side wall 120 in the direction away from the accommodating cavity 111, specifically, the slope surface portion 121 and the second planar portion 123 form a first-order protruding structure on the first side wall 120, the protruding portion 124 is a second-order protruding structure on the first side wall 120, and the second-order protruding structure protrudes more in the direction away from the accommodating cavity 111 than the first-order protruding structure. This structure design can not only expand the volume of the accommodating cavity 111 on the side of the second side 132, but also ensure the structural strength of the first-order and second-order protruding structures, thereby facilitating the improvement of the overall structural strength of the first side wall 120. On the other hand, when the battery shell 100 is prepared by stamping process, the design that the protruding portion 124 extends to the opening 112 of the accommodating cavity 111 on the second side 132 can reduce the stamping difficulty, thereby facilitating the improvement of production efficiency and the reduction of production cost.

[0051] Optionally, the accommodating cavity 111 is provided with the opening 112 on both the first side 131 and the second side 132, the first planar portion 122 extends along the second direction D2 to the opening 112 of the accommodating cavity 111 on the first side 131, and the battery shell 100 further comprises two second side walls 140, which are symmetrically arranged about the middle part of the accommodating cavity 111 in the third direction D3, and the two second side walls 140 are respectively connected to the two first side walls 120 on both sides in the first direction D1. Thus, the overall structure of the battery shell 100 can be simplified, thereby facilitating the reduction of production difficulty and the reduction of production cost.

[0052] Optionally, as shown in Figure 4 the two side walls of the pole group on both sides in the first direction D1 are contoured walls, and in the first direction D1, the contoured walls on the same side of the pole group are contoured to the shape of the first side wall 120. Specifically, the pole group comprises a pole group body 410 and two second protruding portions 430, the two second protruding portions 430 are respectively protruding on both sides of the pole group body 410 in the first direction D1, and each second protruding portion 430 is located in a corresponding capacity-increasing cavity 114. In the first direction D1, the pole group body 410 and the regions corresponding to the first planar portion 122 and the second planar portion 123 are all planar, the region of the pole group body 410 corresponding to the slope surface portion 121 is a slope surface, and the inclination angle of the slope surface of the pole group body 410 is the same as the inclination angle of the slope surface portion 121. Thus, not only the internal space of the battery shell 100 is fully utilized, but also the volume of the pole group is expanded, thereby the capacity of the pole group can be improved, and the high-rate rapid charging of the battery monomer is facilitated.

[0053] As shown in Figure 3As shown, in the second direction D2, the distance between the side of the slope portion 121 facing the first side 131 and the side of the protruding portion 124 facing the second side 132 is W1, and the size of the protruding portion 124 in the second direction D2 is W2, 0.31≤W2 / W1≤0.59. Exemplarily, W2 / W1 can be 0.31, 0.33, 0.4, 0.5, 0.55, or 0.59, etc., and preferably 0.33≤W2 / W1≤0.55. If W2 / W1<0.31, the size of the capacity-increasing cavity 114 in the second direction D2 is too small, which reduces the volume of the capacity-increasing cavity 114 and the second protruding portion 430, and in turn reduces the improvement range of the cell group capacity, which is not conducive to meeting the high-rate rapid charging requirement of the battery cell. If W2 / W1>0.59, the size of the protruding portion 124 in the second direction D2 is too large, which increases the stamping difficulty of the battery shell 100, not only increases the production cost of the battery shell 100, but also increases the failure rate of the battery shell 100.

[0054] Optionally, as shown in Figure 1 and Figure 2 The battery cell further comprises two explosion-proof valves 200, which are respectively arranged on the second planar portions 123 of the two first side walls 120. When the pressure in the battery shell 100 reaches the burst pressure value of the explosion-proof valve 200, the explosion-proof valve 200 bursts, and the high-temperature and high-pressure gas in the battery shell 100 is discharged out of the battery shell 100 through the explosion-proof valve 200. The technical scheme provided in the embodiment is provided with two explosion-proof valves 200, which increases the exhaust path and is conducive to improving the exhaust efficiency. Moreover, the explosion-proof valve 200 is arranged on the second planar portion 123, and since the second planar portion 123 is located between the slope portion 121 and the protruding portion 124, the second planar portion 123 is located at a relatively central position of the first side wall 120 in the second direction D2. Arranging the explosion-proof valve 200 on the second planar portion 123 is conducive to shortening the exhaust path, and in turn can further improve the exhaust efficiency.

[0055] Further, as shown in Figure 3As shown, the wall thickness of the protruding portion 124 and the second flat portion 123 is T1, the wall thickness of the first flat portion 122 is T2, and 0.21mm≤T1-T2≤0.79mm, that is, the wall thickness of the protruding portion 124 and the second flat portion 123 is equal, and both are greater than the wall thickness of the first flat portion 122. On one hand, the protruding portion 124 is the area of the battery shell 100 with the largest size in the first direction D1, and thus the volume of the pole group in the area corresponding to the protruding portion 124 (i.e., the area of the second protruding portion 430) is the largest. When the first direction D1 is parallel to the vertical direction, the protruding portion 124 located below bears the largest pressure from the pole group. Therefore, increasing the wall thickness of the protruding portion 124 to T1 helps to improve the structural strength of the protruding portion 124, so that it can support a larger pressure from the pole group. On the other hand, when the explosion-proof valve 200 is welded to the second flat portion 123, the second flat portion 123 is prone to deformation due to welding heat. Therefore, increasing the wall thickness of the second flat portion 123 to T1 can improve the structural strength of the second flat portion 123, and thus reduce the probability of deformation of the second flat portion 123 due to welding heat. On the other hand, the first flat portion 122 is the area of the battery shell 100 with the smallest size in the first direction D1, and thus the volume of the pole group in the area corresponding to the first flat portion 122 is the smallest. When the first direction D1 is parallel to the vertical direction, the first flat portion 122 located below bears the smallest pressure from the pole group. Therefore, appropriately reducing the wall thickness of the first flat portion 122 can reduce the material used for the production of the battery shell 100 under the premise of reducing the probability of deformation of the second flat portion 123 and the protruding portion 124, which helps to reduce the weight of the battery shell 100 and reduce the production cost of the battery shell 100. Moreover, the wall thickness of the protruding portion 124 and the second flat portion 123 is equal, which helps to reduce the production difficulty, and thus can improve the production efficiency and reduce the production cost.

[0056] For example, T1-T2 can be 0.21mm, 0.3mm, 0.4mm, 0.55mm, 0.6mm, 0.7mm, or 0.79mm, etc., and preferably 0.3mm≤T1-T2≤0.7mm. If T1-T2<0.21mm, the wall thickness of the first flat portion 122 is close to that of the second flat portion 123, which increases the material used for the production of the first flat portion 122, and increases the weight of the battery shell 100, and reduces the volume of the accommodation cavity 111, which is not conducive to increasing the volume of the pole group and improving the capacity of the pole group. If T1-T2>0.79mm, the difference between the wall thickness of the first flat portion 122 and the second flat portion 123 is too large, which increases the production difficulty of the battery shell 100, especially the forming difficulty of the first side wall 120, which not only increases the production cost, but also increases the failure rate of the battery shell 100.

[0057] Optionally, 0.6mm≤T1≤1.5mm. For example, T1 can be 0.6mm, 1mm or 1.5mm, so as to reduce T1 as much as possible while ensuring that the protrusion 124 and the second flat part 123 have sufficient structural strength, so as to reduce the weight of the battery case 100 and reduce the materials used in the production of the battery case 100.

[0058] Optionally, such as Figures 4 to 8 As shown, the battery cell also includes two cover plate assemblies 300, which are respectively covered at the opening 112 on the first side 131 and the opening 112 on the second side 132. The end faces of the second sidewall 140 at both ends in the second direction D2 include a first planar segment 141, two inclined segments 142, and two second planar segments 143. The first planar segment 141 and the second planar segment 143 are both perpendicular to the second direction D2. The two second planar segments 143 are located on both sides of the first planar segment 141 in the first direction D1 and are respectively connected to the two first sidewalls 120. Each second planar segment 143 is connected to the first planar segment 141 through an inclined segment 142. The end of the inclined segment 142 connected to the first planar segment 141 is the first end 142a, and the end of the inclined segment 142 connected to the second planar segment 143 is the second end 142b. The inclined segment 142 is inclined towards the direction of the cover assembly 300 corresponding to the inclined segment 142 pointing towards the battery case 100. The receiving cavity 111 forms an expansion space 113 on both the first side 131 and the second side 132. The electrode assembly includes an electrode assembly body 410 and two first protrusions 420. The two first protrusions 420 are respectively protruding from both ends of the electrode assembly body 410 in the second direction D2, and are respectively located within the capacity-enhancing space 113 on the first side 131 and the capacity-enhancing space 113 on the second side 132. On the one hand, this structure forms capacity-enhancing spaces 113 on both the first side 131 and the second side 132 of the battery casing 100, thereby enabling the provision of two first protrusions 420 on the electrode assembly body 410, with each first protrusion 420 located within its corresponding capacity-enhancing space 113. This increases the volume of the electrode assembly and thus its capacity, which is beneficial for achieving high-rate fast charging of individual battery cells. On the other hand, the design of the first planar segment 141, the inclined segment 142, and the second planar segment 143 improves the stability of the cover assembly 300 covering the opening 112, and also improves the positioning accuracy of the cover assembly 300 and the battery casing 100.

[0059] It should be noted that the portion of the first sidewall 120 located on the first side 131 is the first flat portion 122, and the portion of the first sidewall 120 located on the second side 132 is the protrusion 124. Therefore, the second flat segment 143 located on the first side 131 is connected to the first flat portion 122 of the first sidewall 120, and the second flat segment 143 located on the second side 132 is connected to the protrusion 124 of the first sidewall 120.

[0060] Furthermore, such as Figure 3 As shown, in the first direction D1, the distance between the opposite sides of the two first planar portions 122 is A2, and the distance between the second ends 142b of the two inclined segments 142 connected to the same first planar segment 141 is L2, where 0.51 ≤ L2 / A2 ≤ 0.89. For example, L2 / A2 can be 0.51, 0.55, 0.6, 0.75, 0.85, or 0.89, with 0.55 ≤ L2 / A2 ≤ 0.85 being preferred. If L2 / A2 < 0.51 while A2 remains constant, the size of the capacity expansion space 113 in the first direction D1 is too small. This reduces the size of the first protrusion 420 in the first direction D1, thereby reducing the volume of the first protrusion 420 and decreasing the increase in electrode capacity, which is detrimental to meeting the high-rate fast charging requirements of individual battery cells. With A2 unchanged, if L2 / A2 > 0.89, the size of the second planar segment 143 in the first direction D1 will be reduced. In particular, the size of the second planar segment 143 located on the first side 131 in the first direction D1 will be too small. This will reduce the mating size between the second planar segment 143 and the cover assembly 300, which is not conducive to the positioning of the cover assembly 300 and the battery case 100, and at the same time reduces the welding yield of the cover assembly 300 and the battery case 100.

[0061] It should be noted that, since the second planar segment 143 located on the first side 131 is connected to the first planar portion 122 of the first sidewall 120, and the second planar segment 143 located on the second side 132 is connected to the protrusion 124 of the first sidewall 120, the size of the second planar segment 143 located on the second side 132 is larger than the size of the second planar segment 143 located on the first side 131 in the first direction D1. On the same second sidewall 140, the distance between the second ends 142b of the two inclined segments 142 located on the second side 132 in the first direction D1 is equal to the distance between the second ends 142b of the two inclined segments 142 located on the first side 131 in the first direction D1. That is, on the same second sidewall 140, the distance between the second ends 142b of the two inclined segments 142 located on the second side 132 in the first direction D1 is L1, and the distance between the second ends 142b of the two inclined segments 142 located on the first side 131 in the first direction D1 is L2, and L1 and L2 are equal.

[0062] Optionally, such asFigure 3 As shown, in the first direction D1, the distance between the side of the protrusion 124 facing away from the receiving cavity 111 and the side of the second flat portion 123 facing away from the receiving cavity 111 is H1, 10mm≤H1≤30mm. For example, H1 can be 10mm, 15mm or 30mm. This ensures that the second protrusion 430 has a certain size in the first direction D1, thereby ensuring the increase in electrode capacity, and also reduces the production difficulty of the battery case 100, thereby ensuring the production yield of the battery case 100.

[0063] Optionally, the distance between the first planar segment 141 and the second planar segment 143 in the second direction D2 is H2, where 10mm≤H2≤45mm. For example, H2 can be 10mm, 30mm or 45mm. This ensures that the first protrusion 420 has a certain size in the second direction D2, thereby ensuring the increase in the capacity of the electrode group, while also reducing the production difficulty of the battery case 100 and ensuring the production yield of the battery case 100.

[0064] Optionally, the included angle between the two inclined segments 142 connected to the same first planar segment 141 is N1, where 75°≤N1≤120°. For example, N1 can be 75°, 100°, or 120°. If N1<75°, the volume of the first protrusion 420 will be reduced, thereby reducing the increase in electrode capacity. If N1>120°, the size of the second planar segment 143 in the first direction D1 will be reduced, thereby reducing the positioning accuracy of the cover assembly 300 and the battery case 100, and also reducing the welding yield of the cover assembly 300 and the battery case 100.

[0065] Optionally, the included angle between the slopes 121 of the two first sidewalls 120 is N2, where 8°≤N2≤20°. For example, N1 can be 8°, 15°, or 20°. If N2<8°, the angle of inclination of the slope 121 is too small, which will reduce the guiding effect of the slope 121 on the electrode assembly when the electrode assembly is inserted into the battery case 100. If N2>20°, it will increase the production difficulty of the battery case 100, which is not conducive to reducing production costs and improving production yield.

[0066] Optionally, the distance between the two protrusions 124 on opposite sides in the first direction D1 is A1, 0.4≤L1 / A1≤0.75. For example, L1 / A1 can be 0.4, 0.6 or 0.75, etc. This ensures that the second protrusion 430 has a certain size in the first direction D1, thereby ensuring the increase in electrode capacity, and also reduces the production difficulty of the battery case 100, thereby ensuring the production yield of the battery case 100.

[0067] Optionally, such as Figure 12As shown, the first side wall 120 has a dimension B in the third direction D3, and 20mm≤B≤120mm, and exemplary, B can be 20mm, 85mm, or 120mm, etc.

[0068] Optionally, as Figures 7 to 11 As shown, the cover plate assembly 300 includes a cover plate body 310, a first plastic plate 320, a second plastic plate 330, a first conductive plate 340, and a pole structure 350, wherein the cover plate body 310 includes a first plate body 311, two second plate bodies 312, and two support eaves 313, the first plate body 311 is covered on the first planar section 141, the two second plate bodies 312 are respectively connected to the two sides of the first plate body 311 in the first direction D1, in the first direction D1, the second plate body 312 on the same side of the first planar section 141 is covered on the inclined section 142, and the two support eaves 313 are respectively connected to the sides of the two second plate bodies 312 away from the first plate body 311, in the first direction D1, the support eave 313 on the same side of the first planar section 141 is covered on the second planar section 143.

[0069] The first plastic plate 320 includes a first plastic part 321 and two second plastic parts 322, wherein the first plastic part 321 covers the side of the first plate body 311 away from the battery case 100, and the two second plastic plates 330 are respectively covered on the sides of the two second plate bodies 312 away from the battery case 100. The first conductive plate 340 includes a first conductive part 341 and two second conductive parts 342, the first conductive part 341 is embedded on the side of the first plastic part 321 away from the first plate body 311, and the two second conductive parts 342 are respectively embedded on the sides of the two second plastic parts 322 away from the battery case 100.

[0070] The side of the first plate body 311 away from the battery case 100 is provided with a raised part 314, the raised part 314 is raised in the direction away from the battery case 100, and the raised part 314 is provided through the first plastic part 321 and the first conductive part 341, in the direction of the cover plate body 310 pointing to the first conductive plate 340, the raised part 314 protrudes from the second plastic part 322 and the second conductive part 342. Thus, the raised part 314 can protect the first plastic plate 320 and the first conductive plate 340, and reduce the probability of the first plastic plate 320 and the first conductive plate 340 being bumped in the process.

[0071] Further, the first plate body 311, the first plastic part 321, and the first conductive part 341 are parallel, in the first direction D1, the second plate body 312, the second plastic part 322, and the second conductive part 342 on the same side of the first plate body 311 are parallel, to further reduce the probability of the second plastic part 322 and the second conductive part 342 being bumped.

[0072] Further, the first conductive part 341 and the second conductive part 342 are away from the side of the first plastic plate 320 for welding the bar piece (not shown in the figure), and in the direction in which the cover plate body 310 points to the first conductive plate 340, the protruding part 314 protrudes from the bar piece on the first conductive part 341 and the bar piece on the second conductive part 342, so that the protruding part 314 can protect the bar piece and reduce the probability of the bar piece being bumped in the process.

[0073] Optionally, in the first direction D1, the support eaves 313 on the same side of the first plate body 311 protrude from the second plastic part 322 and the second conductive part 342, so as to protect the second plastic part 322 and the second conductive part 342 in the first direction D1 and reduce the probability of the second plastic part 322 and the second conductive part 342 being bumped.

[0074] It should be noted that although in the first direction D1, the size of the support eaves 313 of the cover plate assembly 300 on the second side 132 is greater than the size of the support eaves 313 of the cover plate assembly 300 on the first side 131, that is, the size of the support eaves 313 of the cover plate assembly 300 on the first side 131 in the first direction D1 is smaller, but in the cover plate assembly 300 on the first side 131, in the first direction D1, the support eaves 313 on the same side of the first plate body 311 still protrude from the second plastic part 322 and the second conductive part 342, so as to protect the second plastic part 322 and the second conductive part 342.

[0075] The pole structure 350 includes a second conductive plate 351 and a pole 352, wherein the second conductive plate 351 is the same shape as the first conductive plate 340, the second plastic plate 330 is clamped between the cover plate body 310 and the second conductive plate 351, the side of the second conductive plate 351 away from the cover plate body 310 is welded and fixed with the lug (not shown in the figure) of the pole group, and the pole 352 is inserted into the second conductive plate 351, the second plastic plate 330, the second plate body 312, the second plastic part 322, and is riveted and welded with the second conductive part 342, so that the pole group is electrically connected with the first conductive plate 340 through the pole 352.

[0076] In the embodiment, the cover plate body 310 and the battery shell 100 are made of metal stamping process and extrusion process, the first plastic plate 320 and the second plastic plate 330 are made of injection molding process, and the cover plate body 310 and the battery shell 100, the lug and the second conductive plate 351, and the pole 352 and the second conductive part 342 are connected by high-frequency welding process and / or laser welding process. The above-mentioned metal stamping process, extrusion process, injection molding process, high-frequency welding process and laser welding process are all mature processes commonly used in the art, which are conducive to realizing batch automatic production.

[0077] The following Table 1 provides six groups of examples and six groups of comparative examples, the battery shell 100 in the six groups of examples and the six groups of comparative examples is made of aluminum material, the insulating film wrapped on the outer surface of the pole group is a polypropylene (PP) film, the first plastic plate 320 is a polyphenylene sulfide (PPS) material, and the second plastic plate 330 is a PP material.

[0078]

[0079] In Example 1, H1 is 10 mm, H2 is 10 mm, W2 / W1 is 0.33, T1 is 0.6 mm, T1-T2 is 0.3 mm, L1 / A1 is 0.4, L2 / A2 is 0.55, N1 is 75°, N2 is 8°, B is 20 mm, and the battery cell qualified rate is >98%: There is no problem of low positioning accuracy and low structural strength of the cover plate assembly 300 and the battery shell 100. The battery shell 100 protruding part 124, the pole group and the tab are not damaged and deformed. The battery cell assembly is normal.

[0080] In Example 2, H1 is 14 mm, H2 is 18 mm, W2 / W1 is 0.36, T1 is 0.8 mm, T1-T2 is 0.35 mm, L1 / A1 is 0.5, L2 / A2 is 0.6, N1 is 80°, N2 is 10°, B is 38 mm, and the battery cell qualified rate is >98%: There is no problem of low positioning accuracy and low structural strength of the cover plate assembly 300 and the battery shell 100. The battery shell 100 protruding part 124, the pole group and the tab are not damaged and deformed. The battery cell assembly is normal.

[0081] In Example 3, H1 is 18 mm, H2 is 28 mm, W2 / W1 is 0.4, T1 is 1 mm, T1-T2 is 0.4 mm, L1 / A1 is 0.6, L2 / A2 is 0.66, N1 is 90°, N2 is 12°, B is 54 mm, and the battery cell qualified rate is >98%: There is no problem of low positioning accuracy and low structural strength of the cover plate assembly 300 and the battery shell 100. The battery shell 100 protruding part 124, the pole group and the tab are not damaged and deformed. The battery cell assembly is normal.

[0082] In Example 4, H1 is 22 mm, H2 is 35 mm, W2 / W1 is 0.42, T1 is 1.1 mm, T1-T2 is 0.45 mm, L1 / A1 is 0.65, L2 / A2 is 0.7, N1 is 100°, N2 is 15°, B is 72 mm, and the battery cell qualified rate is >98%: There is no problem of low positioning accuracy and low structural strength of the cover plate assembly 300 and the battery shell 100. The battery shell 100 protruding part 124, the pole group and the tab are not damaged and deformed. The battery cell assembly is normal.

[0083] In Example 5, H1 is 26 mm, H2 is 40 mm, W2 / W1 is 0.46, T1 is 1.2 mm, T1-T2 is 0.5 mm, L1 / A1 is 0.7, L2 / A2 is 0.75, N1 is 110°, N2 is 18°, B is 100 mm, and the battery cell pass rate is >98%: the problems of low positioning accuracy and low structural strength of the cover plate assembly 300 and the battery shell 100 do not occur. The battery shell 100 protrusion 124, the pole group, and the tab are not damaged and deformed. The battery cell assembly is normal.

[0084] In Example 6, H1 is 30 mm, H2 is 45 mm, W2 / W1 is 0.55, T1 is 1.5 mm, T1-T2 is 0.7 mm, L1 / A1 is 0.75, L2 / A2 is 0.85, N1 is 120°, N2 is 20°, B is 120 mm, and the battery cell pass rate is >98%: the problems of low positioning accuracy and low structural strength of the cover plate assembly 300 and the battery shell 100 do not occur. The battery shell 100 protrusion 124, the pole group, and the tab are not damaged and deformed. The battery cell assembly is normal.

[0085] In Comparative Example 1, H1 is 18 mm, H2 is 28 mm, W2 / W1 is 0.3, T1 is 1 mm, T1-T2 is 0.4 mm, L1 / A1 is 0.6, L2 / A2 is 0.66, N1 is 90°, N2 is 12°, B is 54 mm, and the battery cell pass rate is <98%: the second protrusion 430 has a small volume, the capacity of the pole group is not improved, and the high-rate rapid charging requirement of the battery cell cannot be met.

[0086] In Comparative Example 2, H1 is 18 mm, H2 is 28 mm, W2 / W1 is 0.6, T1 is 1 mm, T1-T2 is 0.4 mm, L1 / A1 is 0.6, L2 / A2 is 0.66, N1 is 90°, N2 is 12°, B is 54 mm, and the battery cell pass rate is <98%: the battery shell 100 is difficult to stamp, the production cost of the battery shell 100 is high, and the production defect rate of the battery shell 100 is high.

[0087] In Comparative Example 3, H1 is 10 mm, H2 is 10 mm, W2 / W1 is 0.33, T1 is 0.6 mm, T1-T2 is 0.2 mm, L1 / A1 is 0.6, L2 / A2 is 0.66, N1 is 90°, N2 is 12°, B is 54 mm, and the battery cell pass rate is <98%: the first flat portion 122 uses a large amount of material, increases the weight of the battery shell 100, and the volume of the accommodating cavity 111 is small.

[0088] In the comparative example 4, H1 is 30 mm, H2 is 45 mm, W2 / W1 is 0.55, T1 is 1.5 mm, T1-T2 is 0.8 mm, L1 / A1 is 0.6, L2 / A2 is 0.66, N1 is 90°, N2 is 12°, B is 54 mm, and the battery cell qualified rate is less than 98%: the battery shell 100 is difficult to produce, the production cost of the battery shell 100 is high, and the production of the battery shell 100 is high.

[0089] In the comparative example 5, H1 is 18 mm, H2 is 28 mm, W2 / W1 is 0.4, T1 is 1 mm, T1-T2 is 0.4 mm, L1 / A1 is 0.6, L2 / A2 is 0.5, N1 is 90°, N2 is 12°, B is 54 mm, and the battery cell qualified rate is less than 98%: the size of the first protruding portion 420 in the first direction D1 is small, the capacity of the pole group is small, and the high rate of the battery cell cannot meet the demand of the high rate of the battery cell.

[0090] In the comparative example 6, H1 is 18 mm, H2 is 28 mm, W2 / W1 is 0.4, T1 is 1 mm, T1-T2 is 0.4 mm, L1 / A1 is 0.6, L2 / A2 is 0.9, N1 is 90°, N2 is 12°, B is 54 mm, and the battery cell qualified rate is less than 98%: the size of the second flat section 143 and the cover plate assembly 300 is small, the positioning accuracy of the cover plate assembly 300 and the battery shell 100 is low, and the welding rate of the cover plate assembly 300 and the battery shell 100 is low.

[0091] In summary, when the above parameters satisfy 10 mm≤H1≤30 mm, 10 mm≤H2≤45 mm, 0.31≤W2 / W1≤0.59, 0.6 mm≤T1≤1.5 mm, 75°≤N1≤120°, 8°≤N2≤20°, 0.21 mm≤T1-T2≤0.79 mm, 0.4≤L1 / A1≤0.75, 0.51≤L2 / A2≤0.89, and 20 mm≤B≤120 mm, the pole group can provide a good guiding effect when the pole group is assembled into the battery shell 100, the structural strength of the battery shell 100 is ensured, the capacity of the pole group is maximized, and the assembly rate of the cover plate assembly 300 and the battery shell 100 is considered.

[0092] Obviously, the above embodiments of the present application are only examples for clear illustration of the present application, and are not a limitation on the embodiments of the present application. Those skilled in the art can make various obvious changes, readjustments and substitutions without departing from the protection scope of the present application. It is unnecessary and impossible to enumerate all the embodiments. Any modification, equivalent substitution and improvement within the spirit and principle of the present application shall be included in the protection scope of the claims of the present application.

Claims

1. A battery cell, characterized by The application relates to a battery cell, comprising: a pole group; a battery shell (100) provided with a containing cavity (111), the pole group being arranged in the containing cavity (111), the battery shell (100) comprising two first side walls (120) which are mirror arranged about the middle of the containing cavity (111) in a first direction (D1), the two sides of the battery shell (100) in a second direction (D2) being a first side (131) and a second side (132) respectively, the first side wall (120) comprising a slope surface part (121) which is inclined in a direction away from the containing cavity (111) from the direction of the first side (131) to the second side (132), the slope surface part (121) extending from one side of the first side wall (120) to the other side in a third direction (D3), and in the second direction (D2), the containing cavity (111) is provided with an opening (112) at least on the second side (132), the first direction (D1), the second direction (D2) and the third direction (D3) being perpendicular to each other.

2. The battery cell of claim 1, wherein, The first side wall (120) further comprises two plane parts, the two plane parts being connected to the two sides of the slope surface part (121) in the second direction (D2) respectively, and the plane parts being perpendicular to the first direction (D1).

3. The battery cell of claim 2, wherein, One of the two plane parts is a first plane part (122), and the other is a second plane part (123), the first plane part (122) being connected to one side of the slope surface part (121) towards the first side (131), the second plane part (123) being connected to one side of the slope surface part (121) towards the second side (132), and the second plane part (123) being provided with a convex part (124) which is convex in a direction away from the containing cavity (111).

4. The battery cell of claim 3, wherein, The battery cell further comprises two explosion-proof valves (200) arranged on the second plane part (123) of the two first side walls (120) respectively.

5. The battery cell of claim 4, wherein, The wall thicknesses of the convex part (124) and the second plane part (123) are both T1, and the wall thickness of the first plane part (122) is T2, 0.21mm<=T1-T2<=0.79mm.

6. The battery cell of any one of claims 3-5, wherein, The convex part (124) is located on the side of the second plane part (123) away from the slope surface part (121), and the convex part (124) extends to the opening (112) of the containing cavity (111) on the second side (132) in the second direction (D2).

7. The battery cell of claim 6, wherein, The two side walls of the pole group on the first direction (D1) are both profiled walls, on the first direction (D1), the profiled walls on the same side of the pole group profile the shape of the first side wall (120), on the second direction (D2), the distance between the side of the slope part (121) facing the first side (131) and the side of the convex part (124) facing the second side (132) is W1, the size of the convex part (124) on the second direction (D2) is W2, 0.31≤W2 / W1≤0.

59.

8. The battery cell of claim 6, wherein, The accommodating cavity (111) is provided with the opening (112) on the first side (131) and the second side (132), the first plane part (122) extends to the opening (112) of the accommodating cavity (111) on the first side (131) along the second direction (D2), and the battery shell (100) further comprises two second side walls (140), the two second side walls (140) are symmetrically arranged about the middle part of the accommodating cavity (111) on the third direction (D3), and the two second side walls (140) are connected with the two first side walls (120) on the two sides in the first direction (D1).

9. The battery cell of claim 8, wherein, The battery monomer further comprises two cover plate assemblies (300), and the two cover plate assemblies (300) are respectively arranged at the opening (112) of the first side (131) and the opening (112) of the second side (132); The end face of the second side wall (140) at both ends in the second direction (D2) comprises a first plane segment (141), two inclined plane segments (142) and two second plane segments (143), the first plane segment (141) and the second plane segment (143) are both perpendicular to the second direction (D2), the two second plane segments (143) are respectively located on the two sides of the first plane segment (141) in the first direction (D1) and are respectively connected with the two first side walls (120), each second plane segment (143) is connected with the first plane segment (141) through an inclined plane segment (142), one end of the inclined plane segment (142) connected with the first plane segment (141) is a first end (142a), one end of the inclined plane segment (142) connected with the second plane segment (143) is a second end (142b), the direction from the first end (142a) to the second end (142b) is inclined to the direction of the cover plate assembly (300) corresponding to the inclined plane segment (142) and pointing to the battery shell (100), and the accommodating cavity (111) forms an increased space (113) on the first side (131) and the second side (132). The pole group comprises a pole group body (410) and two first protrusions (420), and the two first protrusions (420) are respectively protruded at two ends of the pole group body (410) in the second direction (D2) and are respectively located in the capacity-increasing space (113) of the first side (131) and the capacity-increasing space (113) of the second side (132).

10. The battery cell of claim 9, wherein, In the first direction (D1), the distance between the sides of the two first plane sections (122) away from each other is A2, and the distance between the second ends (142b) of the two inclined surface sections (142) connected to the same first plane section (141) is L2, 0.51≤L2 / A2≤0.89.

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