Battery cell

Abstract

The invention belongs to the technical field of batteries, and discloses a battery cell, the battery cell comprises a shell, a pole group and a cover plate assembly, the shell is provided with an accommodating cavity and an opening which are communicated, the pole group is arranged in the accommodating cavity, the cover plate assembly comprises a cover plate, the cover plate covers the opening, the cover plate comprises a first plate body and two second plate bodies, and the first plate body and the second plate body are arranged in the accommodating cavity. A first protruding part and two second protruding parts are arranged on the side, away from the shell, of the first plate body, the two second protruding parts are located on the two opposite sides of the first protruding part respectively and are arranged at intervals with the first protruding part, and the two second plate bodies are connected to the two opposite sides of the first plate body respectively in the direction where the two second protruding parts point to each other. In the direction from the shell to the cover plate, the two second plate bodies incline in the direction close to each other, the two second protruding parts extend in the direction away from each other and are connected to the sides, away from the shell, of the corresponding second plate bodies respectively, and therefore the structural strength of the cover plate can be improved.

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 pole group, a shell and a cover plate, wherein the pole group is arranged in the shell, and the cover plate is arranged at the opening of the shell.

[0003] In the prior art, in order to reduce the weight of the battery cell, the thickness of the cover plate is made as thin as possible, and the existing cover plate is a flat plate structure, which results in low structural strength of the cover plate. In the production process and use process, the cover plate is prone to deformation, thereby reducing the sealing performance between the cover plate and the shell.

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

[0005] The present application aims to provide a battery cell, which can improve the structural strength of the cover plate and reduce the deformation probability of the cover plate.

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

[0007] A battery cell comprises:

[0008] A shell, the shell is provided with a cavity and an opening in communication;

[0009] A pole group, the pole group is arranged in the cavity;

[0010] A cover plate assembly, the cover plate assembly comprises a cover plate, the cover plate is arranged at the opening, the cover plate comprises a first plate body and two second plate bodies, a first protruding part and two second protruding parts are arranged on the side of the first plate body away from the shell, the two second protruding parts are respectively arranged on the opposite sides of the first protruding part and are spaced apart from the first protruding part, along the direction in which the two second protruding parts point to each other, the two second plate bodies are respectively connected to the opposite sides of the first plate body, along the direction in which the two second plate bodies incline to each other along the direction in which the shell points to the cover plate, the two second protruding parts extend along the direction in which they are away from each other and are respectively connected to the side of the corresponding second plate body away from the shell.

[0011] Optionally, the cover plate assembly further comprises a first conductive plate, the first conductive plate comprises a first conductive part and two second conductive parts, the first conductive part is insulatively connected to the side of the first plate body away from the shell, the two second conductive parts correspond to the two second plate bodies one by one, each second conductive part is insulatively connected to the side of the corresponding second plate body away from the shell, the two second conductive parts are connected to the first conductive part, and the first conductive part and the two second conductive parts are used to be connected to the busbar.

[0012] Optionally, the first conductive part is provided with a first avoiding hole and two second avoiding holes, in a direction in which the two second conductive parts point to each other, the two second avoiding holes are respectively located on opposite sides of the first avoiding hole, the two second avoiding holes are spaced apart from the first avoiding hole, and the two second avoiding holes extend to a corresponding one of the second conductive parts in a direction away from each other.

[0013] The first protruding part penetrates the first avoiding hole, and the two second protruding parts correspond to the two second avoiding holes one by one, each second protruding part penetrates a corresponding one of the second avoiding holes, and at least one of the first protruding part and the second protruding part protrudes from the first conductive plate in a direction in which the shell points to the cover plate.

[0014] Optionally, in a direction in which the two second protruding parts point to each other, a distance between one of the two second protruding parts and a side of the first protruding part facing the second protruding part is W1, and a distance between two sides of the two second protruding parts away from each other is L2, and 0.06≤W1 / L2≤0.19.

[0015] Optionally, a side of the pole group facing the cover plate is provided with a tab, and the cover plate assembly further comprises a pole column structure, the pole column structure comprising a second conductive plate and a column body, the second conductive plate being insulatively covered on a side of the first plate body facing the shell and connected with the tab, and the column body penetrating the first plate body, two ends of the column body being connected with the first conductive plate and the second conductive plate respectively.

[0016] Optionally, the column body and the second conductive plate are in a split structure.

[0017] And / or, the number of the column bodies is multiple.

[0018] Optionally, a width direction of the battery cell is a first direction, a direction in which the two second plate bodies point to each other is the first direction, a thickness direction of the battery cell is a second direction, and the first plate body is provided with two through holes;

[0019] The first protruding part comprises a thickness-reduced area and two non-thickness-reduced areas, in the first direction, two ends of the thickness-reduced area are connected with the two non-thickness-reduced areas respectively, in the second direction, a size of the thickness-reduced area is smaller than a size of the non-thickness-reduced area, the through holes are located between the two non-thickness-reduced areas, and the two through holes are respectively located on two sides of the thickness-reduced area in the second direction;

[0020] The battery cell further comprises cooling pipes, the cooling pipes penetrating the pole group insulatively, a cooling medium flows in the cooling pipes, the number of the cooling pipes is two, and the two cooling pipes correspond to the two through holes one by one, each cooling pipe penetrates a corresponding one of the through holes.

[0021] Optionally, in the second direction, the size of the thickness-reduced area is W2, and the size of the non-thickness-reduced area is W3, and 16mm≤W3-W2≤32mm.

[0022] Optionally, the width direction of the battery cell is the first direction, the direction in which the two second plate bodies point to each other is the first direction, the thickness direction of the battery cell is the second direction, the shell comprises two first side walls and two second side walls, the two first side walls are oppositely arranged along the second direction, and the two second side walls are oppositely arranged along the first direction; the first side wall and the second side wall are sequentially connected in a head-to-tail manner to form a cavity, the first side wall comprises a wall body part and two folded parts, along the first direction, the two sides of the wall body part are connected to the two second side walls through the two folded parts respectively, one of the two first side walls is inclined in a direction away from the other, and the two folded parts of the first side wall are inclined in a direction close to each other; the pole group comprises a pole group body, two first capacity increasing parts and two second capacity increasing parts, the two first capacity increasing parts are respectively protruded on the two sides of the pole group body in the first direction, and the two second capacity increasing parts are respectively protruded on the two sides of the pole group body in the second direction.

[0023] Optionally, along the first direction, the size of the wall body part is L1, and the distance between the sides of the two second side walls away from each other is A, and 0.51≤L1 / A≤0.94.

[0024] The beneficial effects of the present application are as follows:

[0025] Firstly, the two second plate bodies are respectively connected to the opposite sides of the first plate body, and along the direction in which the shell points to the cover plate, the two second plate bodies are inclined in a direction close to each other, thereby forming a structure in which the first plate body protrudes from the two second plate bodies in the direction in which the shell points to the cover plate, compared with the flat cover plate, the structure in which the first plate body protrudes from the two second plate bodies can improve the structural strength of the cover plate, and further can reduce the deformation probability of the cover plate.

[0026] Secondly, the side of the first plate body away from the shell is provided with a first protruding part and two second protruding parts, and the two second protruding parts are spaced apart from the first protruding part, thereby forming three independent reinforcing structures on the first plate body, thereby improving the structural strength of the first plate body, and further facilitating the reduction of the deformation probability of the first plate body.

[0027] Thirdly, the two second protruding parts extend in a direction away from each other and are respectively connected to the side of the corresponding second plate body away from the shell, thereby enabling the second protruding part and the second plate body to form a mutual supporting effect, thereby further improving the structural strength of the cover plate and reducing the deformation probability of the cover plate. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a structural schematic diagram of the battery cell provided by the present application;

[0029] Figure 2 is a structural schematic diagram of the shell provided by the present application;

[0030] Figure 3is a first cross-sectional structure schematic view of the battery cell provided by the application;

[0031] Figure 4 is a first structure schematic view of the cover plate assembly provided by the application;

[0032] Figure 5 is an explosion structure schematic view of the cover plate assembly provided by the application;

[0033] Figure 6 is a structure schematic view of the pole group provided by the application;

[0034] Figure 7 is a partial enlarged structure schematic view of the shell provided by the application;

[0035] Figure 8 is a second structure schematic view of the cover plate assembly provided by the application;

[0036] Figure 9 is a second cross-sectional structure schematic view of the battery cell provided by the application;

[0037] Figure 10 is a third structure schematic view of the cover plate assembly provided by the application;

[0038] Figure 11 is Figure 10 a cross-sectional view in the direction of E-E;

[0039] Figure 12 is Figure 10 a structure schematic view in the direction of G.

[0040] in the figure:

[0041] D1, first direction; D2, second direction; D3, third direction;

[0042] 100, shell; 110, cavity; 120, opening; 131, first side wall; 1311, wall part; 1312, folding part; 132, second side wall; 200, pole group; 210, pole lug; 220, pole group body; 230, first capacity-increasing part; 240, second capacity-increasing part; 250, third capacity-increasing part; 260, fourth capacity-increasing part; 270, fifth capacity-increasing part; 280, sub-pole group body; 300, cover plate assembly; 310, cover plate; 311, first plate body; 3111, first protruding part; 3111a, thickness-reduced area; 3111b, non-thickness-reduced area; 3111c, first capacity-increasing groove; 3112, second protruding part; 3112a, second capacity-increasing groove; 3113, through hole; 312, second plate body; 313, protruding eave; 314, capacity-increasing space; 320, first conductive plate; 321, first conductive part; 3211, first avoiding hole; 3212, second avoiding hole; 322, second conductive part; 330, pole column structure; 331, second conductive plate; 3311, third avoiding hole; 3312, avoiding notch; 332, column body; 410, first insulating plate; 420, second insulating plate; 400, cooling pipe. DETAILED DESCRIPTION

[0043] 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, for ease of description, only the parts related to the application are shown in the drawings and not all the structures.

[0044] In the description of the application, unless otherwise explicitly 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 it can be 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 application can be understood according to the specific circumstances.

[0045] In the present application, unless otherwise explicitly 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.

[0046] 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.

[0047] This embodiment provides a battery cell that can improve the structural strength of the cover plate, thereby reducing the probability of cover plate deformation.

[0048] Specifically, such as Figures 1 to 5 As shown, the battery cell includes a housing 100, an electrode assembly 200, and a cover plate assembly 300. The housing 100 has a communicating cavity 110 and an opening 120. The electrode assembly 200 is disposed within the cavity 110. The cover plate assembly 300 includes a cover plate 310, which covers the opening 120. The cover plate 310 includes a first plate 311 and two second plates 312. The first plate 311 has a first protrusion 3111 and two second protrusions 3112 on the side facing away from the housing 100. 112 are located on opposite sides of the first protrusion 3111 and are spaced apart from the first protrusion 3111. Along the direction in which the two second protrusions 3112 point towards each other, the two second plates 312 are respectively connected to opposite sides of the first plate 311. Along the direction from the housing 100 to the cover plate 310, the two second plates 312 are inclined in the direction of approaching each other. The two second protrusions 3112 extend in the direction of opposing each other and are respectively connected to the side of the corresponding second plate 312 away from the housing 100.

[0049] First, two second plates 312 are respectively connected to opposite sides of the first plate 311 and are inclined in the direction from the housing 100 to the cover plate 310. This forms a structure in which the first plate 311 protrudes from the two second plates 312 in the direction from the housing 100 to the cover plate 310. Compared with a flat cover plate 310, the structure of the first plate 311 protruding from the two second plates 312 can improve the structural strength of the cover plate 310 and thus reduce the probability of deformation of the cover plate 310.

[0050] Secondly, the first plate 311 has a first protrusion 3111 and two second protrusions 3112 on the side opposite to the shell 100, and the two second protrusions 3112 are spaced apart from the first protrusion 3111. Thus, three independent reinforcing structures are formed on the first plate 311, which can improve the structural strength of the first plate 311 and thus help reduce the probability of deformation of the first plate 311.

[0051] Furthermore, the two second protrusions 3112 extend in opposite directions and are respectively connected to the side of the corresponding second plate 312 away from the housing 100. This makes the second protrusions 3112 and the second plate 312 mutually support each other, thereby further improving the structural strength of the cover plate 310 and reducing the probability of deformation of the cover plate 310.

[0052] Optionally, the cover plate assembly 300 further includes a first conductive plate 320, which includes a first conductive portion 321 and two second conductive portions 322. The first conductive portion 321 is insulated from the side of the first plate body 311 facing away from the housing 100. The two second conductive portions 322 correspond one-to-one with the two second plates 312, and each second conductive portion 322 is insulated from the side of the corresponding second plate body 312 facing away from the housing 100. Both second conductive portions 322 are connected to the first conductive portion 321. The first conductive portion 321 and the two second conductive portions 322 are both used to connect to the busbar. In the prior art, the cover plate assembly 300 is provided with a riveting block for connecting to the busbar (not shown in the figure). However, the connection area between the riveting block and the busbar is limited, which restricts the flow rate between the cover plate assembly 300 and the busbar. In this embodiment, the first conductive part 321 and two second conductive parts 322 of the first conductive plate 320 are connected to the busbar, which greatly expands the connection area between the cover plate assembly 300 and the busbar, thereby expanding the current-passing area between the cover plate assembly 300 and the busbar, which is beneficial to meeting the high-rate fast charging requirements of the battery cell.

[0053] Furthermore, the first conductive part 321 is provided with a first clearance hole 3211 and two second clearance holes 3212. In the direction in which the two second conductive parts 322 point towards each other, the two second clearance holes 3212 are respectively located on opposite sides of the first clearance hole 3211. The two second clearance holes 3212 are spaced apart from the first clearance hole 3211. The two second clearance holes 3212 extend in opposite directions to a corresponding second conductive part 322. The first conductive plate 320 is approximately U-shaped. The first protrusion 3111 passes through the first clearance hole 3211. The two second protrusions 3112 correspond one-to-one with the two second clearance holes 3212. Each second protrusion 3112 passes through a corresponding second clearance hole 3212. In the direction from the housing 100 to the cover plate 310, both the first protrusion 3111 and the second protrusion 3112 protrude from the first conductive plate 320. This ensures that both the first protrusion 3111 and the second protrusion 3112 protect the first conductive plate 320, reducing the chance of the first conductive plate 320 being bumped or knocked during the manufacturing process.

[0054] In another embodiment, the first protrusion 3111 protrudes from the first conductive plate 320 in a direction of the cover plate 310 along the shell 100. In yet another embodiment, the second protrusion 3112 protrudes from the first conductive plate 320 in a direction of the cover plate 310 along the shell 100.

[0055] Further, the first protrusion 3111 and the second protrusion 3112 are both configured to protrude from the busbar in a direction of the cover plate 310 along the shell 100, so that the first conductive plate 320 protects the busbar and reduces the probability of the busbar being bumped.

[0056] Optionally, as shown in FIG. 1, the pole group 200 is provided with a tab 210 on a side facing the cover plate 310, and the cover plate assembly 300 further includes a pole structure 330, which includes a second conductive plate 331 and a column 332. The second conductive plate 331 is insulated and covers a side of the first plate body 311 facing the shell 100 and is connected to the tab 210. The column 332 is arranged through the first plate body 311, and two ends of the column 332 are connected to the first conductive plate 320 and the second conductive plate 331, respectively. Figures 1 to 6 In the prior art, the pole structure includes a pole body and a base, one side of the base is connected to the pole body, and the other side is connected to the tab 210. However, the cross-sectional area of the base in this structure is limited, which reduces the connectable area of the pole structure 330 and the tab 210, and further limits the overcurrent capacity between the cover plate assembly 300 and the tab 210. In the present embodiment, the second conductive plate 331 insulated and covering the side of the first plate body 311 facing the shell 100 is connected to the tab 210. It can be seen that this structure enlarges the cross-sectional area of the component (i.e., the second conductive plate 331) connected to the tab 210, and further enlarges the connectable area of the pole structure 330 and the tab 210, which is conducive to improving the overcurrent capacity between the cover plate assembly 300 and the tab 210, and further meeting the high-rate fast charging requirements of the battery cell.

[0057] Further, the column 332 and the second conductive plate 331 are in a split structure. In actual production, the column 332 and the second conductive plate 331 can be produced separately, and then connected through welding or other common processes in the field, which not only enables the column 332 and the second conductive plate 331 in the pole structure 330 to be produced separately, but also simplifies the connection process of the column 332 and the second conductive plate 331. It can be seen that this structure is conducive to improving the production efficiency and reducing the production difficulty of the pole structure 330, and further achieving the effects of reducing production cost and improving production yield.

[0058] Optionally, the number of the column 332 is multiple, for example, the number of the column 332 is two, three, four or more, by increasing the number of the column 332 to increase the overcurrent between the first conductive plate 320 and the second conductive plate 331, thereby improving the overcurrent capacity of the cover plate assembly 300.

[0059] Further, the column 332 is a cylindrical or elliptical cylindrical shape, to expand the connection area between the first conductive plate 320 and the second conductive plate 331 and the column 332, thereby facilitating the increase of the overcurrent between the first conductive plate 320 and the column 332 and the overcurrent between the second conductive plate 331 and the column 332.

[0060] It should be noted that the length and width of the cover plate 310 are usually different, if the width of the cover plate 310 is small, the elliptical cylindrical column 332 is suitable, specifically, the short axis of the elliptical cylindrical column 332 is parallel to the width direction of the cover plate 310, and the long axis of the elliptical cylindrical column 332 is parallel to the length direction of the cover plate 310, thereby under the premise that the width of the cover plate 310 is limited, by increasing the size of the column 332 in the length direction of the cover plate 310 to increase the connection area between the column 332 and the first conductive plate 320 and the second conductive plate 331, thereby increasing the overcurrent between the first conductive plate 320 and the column 332 and the overcurrent between the second conductive plate 331 and the column 332. The length direction of the cover plate 310 refers to the width direction of the battery cell, and the width direction of the cover plate 310 refers to the thickness direction of the battery cell.

[0061] Optionally, the width direction of the battery cell is the first direction D1, the direction in which the two second plate bodies 312 point to each other is the first direction D1, the thickness direction of the battery cell is the second direction D2, and the first plate body 311 is provided with two through holes 3113. The first protruding part 3111 includes a thickness-reduced area 3111a and two non-thickness-reduced areas 3111b. In the first direction D1, the two ends of the thickness-reduced area 3111a are connected to the two non-thickness-reduced areas 3111b, respectively. In the second direction D2, the size of the thickness-reduced area 3111a is smaller than that of the non-thickness-reduced area 3111b. The through holes 3113 are located between the two non-thickness-reduced areas 3111b, and the two through holes 3113 are respectively located on the two sides of the thickness-reduced area 3111a in the second direction D2. The battery cell further includes cooling pipes 400, the cooling pipes 400 are insulated and arranged in the pole group 200, a cooling medium (not shown in the figure) flows in the cooling pipes 400, the number of the cooling pipes 400 is two, and the two cooling pipes 400 correspond to the two through holes 3113 one by one, and each cooling pipe 400 is arranged in a corresponding through hole 3113. When the battery cell is charging and discharging, the temperature inside the pole group 200 is obviously higher than the temperature at the edge of the pole group 200. In the prior art, a common cooling method is to paste a cooling plate on the side wall of the shell 100, that is, the cooling plate absorbs the heat of the pole group 200 inside the shell 100 outside the shell 100. However, due to the long distance between the cooling plate and the middle part of the pole group 200, the cooling effect of the structure on the middle part of the pole group 200 is not ideal. At present, most of the reasons for the thermal runaway of the battery cell are also caused by the excessive temperature of the middle part of the pole group 200. In the embodiment, the two cooling pipes 400 are insulated and arranged in the pole group 200 to cool the pole group 200 inside the pole group 200. The distance between the cooling pipe 400 and the pole group 200 is shortened, and the cooling pipe 400 can directly cool the middle part of the pole group 200, which greatly improves the cooling effect of the pole group 200, especially the cooling effect of the middle part of the pole group 200, which is beneficial to reduce the risk of thermal runaway of the battery cell. On the other hand, the through holes 3113 are located between the two non-thickness-reduced areas 3111b, and the two through holes 3113 are respectively located on the two sides of the thickness-reduced area 3111a in the second direction D2. Each cooling pipe 400 is arranged in a corresponding through hole 3113. Without affecting the structural strength of the cover plate 310, the structure can reduce the size of the cover plate assembly 300 in the second direction D2, so that the overall structure of the cover plate assembly 300 is more compact, which is beneficial to improve the volume density of the battery cell.

[0062] Further, the cooling medium flowing in the cooling pipe 400 is cooling water, refrigerant or cooling gas, etc., which is not limited here.

[0063] Optionally, as Figures 1 to 7As shown, the shell 100 includes two first side walls 131 and two second side walls 132, the two first side walls 131 are oppositely arranged along the second direction D2, and the two second side walls 132 are oppositely arranged along the first direction D1, the first side wall 131 and the second side wall 132 are sequentially connected in a head-to-tail manner to form the cavity 110, the first side wall 131 includes a wall body 1311 and two folded portions 1312, along the first direction D1, the two sides of the wall body 1311 are connected to the two second side walls 132 through the two folded portions 1312 respectively, one of the two first side walls 131 is inclined in a direction away from the other, and the two folded portions 1312 of the first side wall 131 are inclined in a direction close to each other. The pole group 200 includes a pole group body 220, two first capacity increasing portions 230 and two second capacity increasing portions 240, the two first capacity increasing portions 230 are respectively protruded on both sides of the pole group body 220 in the first direction D1, and the two second capacity increasing portions 240 are respectively protruded on both sides of the pole group body 220 in the second direction D2. The structure design that the first side wall 131 is provided with the two folded portions 1312 expands the internal space of the shell 100, specifically, the volume of the cavity 110 is increased in both the first direction D1 and the second direction D2, and then the pole group body 220 can be provided with the first capacity increasing portion 230 on both sides in the first direction D1, and the second capacity increasing portion 240 on both sides in the second direction D2. It can be seen that the structure design expands the volume of the pole group 200, and then the capacity of the pole group 200 can be increased, which is beneficial to realize the high rate fast charging demand of the battery cell.

[0064] Optionally, the cover plate 310 further includes a convex eave 313 connected to the side of the cover plate 310 facing the shell 100, the convex eave 313 extends along the circumference of the cover plate 310 and is connected in a head-to-tail manner. The shape of the convex eave 313 is matched with the shape of the opening 120 of the shell 100, so as to facilitate the cover plate 310 to be arranged at the opening 120 of the shell 100 and reduce the assembly difficulty of the cover plate 310 and the shell 100.

[0065] Optionally, as shown, Figures 1 to 9 Since the two second plate bodies 312 are respectively connected to the opposite sides of the first plate body 311 and are inclined in a direction close to each other along the direction of the shell 100 pointing to the cover plate 310, the cover plate 310 forms a capacity increasing space 314 on the side facing the shell 100, the pole group body 220 is provided with a third capacity increasing portion on the side facing the cover plate 310, and the third capacity increasing portion 250 penetrates through the opening 120 of the shell 100 and is located in the capacity increasing space 314. This structure not only makes full use of the space on the side of the cover plate 310 facing the shell 100, but also increases the volume of the pole group 200, thereby improving the space energy density of the battery cell, and increasing the capacity of the pole group 200, which is beneficial to meet the high rate fast charging demand of the battery cell.

[0066] Further, the first protruding part 3111 is provided with a first capacity-increasing groove 3111c on the side facing the pole group 200, each second protruding part 3112 is provided with a second capacity-increasing groove 3112a on the side facing the pole group 200, the second conductive plate 331 is provided with a third avoiding hole 3311 and two avoiding notches 3312, the third avoiding hole 3311 is opposite to the slot of the first capacity-increasing groove 3111c and communicates with the first capacity-increasing groove 3111c, and the two avoiding notches 3312 correspond to the two second capacity-increasing grooves 3112a respectively, each avoiding notch 3312 communicates with a corresponding second capacity-increasing groove 3112a. The third capacity-increasing part 250 is provided with a fourth capacity-increasing part 260 and two fifth capacity-increasing parts 270 on the side facing the cover plate 310, the fourth capacity-increasing part 260 is arranged in the third avoiding hole 3311 and located in the first capacity-increasing groove 3111c, and the two fifth capacity-increasing parts 270, the two second capacity-increasing grooves 3112a and the two avoiding notches 3312 correspond to each other respectively, each fifth capacity-increasing part 270 is arranged in a corresponding avoiding notch 3312 and located in a corresponding second capacity-increasing groove 3112a. Thus, the space of the cover plate 310 is further utilized, and the volume of the pole group 200 is further increased, so as to further improve the energy density of the battery cell and further increase the capacity of the pole group 200.

[0067] Further, the fourth capacity-increasing part 260 is insulatively arranged in the first capacity-increasing groove 3111c, and each fifth capacity-increasing part 270 is insulatively arranged in a corresponding second capacity-increasing groove 3112a. Further, in the first direction D1 and the second direction D2, the inner wall of the first capacity-increasing groove 3111c can support and limit the fourth capacity-increasing part 260, and the inner wall of the second capacity-increasing groove 3112a can support and limit the fifth capacity-increasing part 270, that is, in the first direction D1 and the second direction D2, the cover plate 310 supports and limits the pole group 200, so as to reduce the probability of the pole group 200 moving and shifting in the capacity cavity 110.

[0068] Further, the length direction of the battery cell is a third direction D3, both ends of the shell 100 in the third direction D3 are provided with openings 120, the number of the cover plate assemblies 300 is two, and the two cover plate assemblies 300 correspond to the two openings 120 one by one, that is, one cover plate 310 is provided at each opening 120. Thus, in the third direction D3, the groove bottoms of the first capacity-increasing grooves 3111c of the two cover plates 310 can cooperate with each other to provide limiting support for the pole group 200, and the groove bottoms of the second capacity-increasing grooves 3112a of the two cover plates 310 can cooperate with each other to provide limiting support for the pole group 200. This structural design not only realizes the limiting support effect of the cover plate 310 on the pole group 200 in the third direction D3, but also is conducive to further reducing the probability of problems such as movement and displacement of the pole group 200 in the cavity 110, and the structure also makes the pole group body 220 be provided with a third capacity-increasing portion 250, a fourth capacity-increasing portion 260, and a fifth capacity-increasing portion 270 at both ends thereof in the third direction D3, thereby further increasing the volume of the pole group 200 and further increasing the capacity of the pole group 200.

[0069] Optionally, the cover plate assembly 300 further comprises a first insulating plate 410 and a second insulating plate 420, wherein the first insulating plate 410 is shaped according to the shape of the first conductive plate 320, and the first insulating plate 410 is clamped between the first conductive plate 320 and the cover plate 310 to realize insulation between the first insulating plate 410 and the cover plate 310, and the second insulating plate 420 is shaped according to the shape of the cover plate 310, and the second insulating plate 420 is clamped between the second conductive plate 331 and the cover plate 310 to realize insulation between the second conductive plate 331 and the cover plate 310.

[0070] Optionally, the tab 210 is located on the side of the third capacity-increasing portion 250 away from the pole group body 220, both sides of the fourth capacity-increasing portion 260 are provided with the tab 210 along the second direction D2, and the tab 210 extends along the first direction D1. Thus, the area of the tab 210 can be increased, the welding area of the tab 210 and the second conductive plate 331 is increased, and the current capacity of the tab 210 and the second conductive plate 331 is increased, which is conducive to meeting the high-rate fast charging demand of the battery cell.

[0071] Optionally, the pole group body 220 comprises two sub-pole group bodies 280, which are symmetrically arranged about the middle part of the cavity 110 in the first direction D1 and are connected by splicing, one of the two sub-pole group bodies 280 is provided with a groove on the side facing the other, and the grooves of the two sub-pole group bodies 280 are spliced to form a through hole, the number of the through holes is two, the two through holes correspond to the two cooling pipes 400 one by one, and each cooling pipe 400 is respectively arranged in a corresponding through hole. In actual assembly, the two sub-pole group bodies 280 are arranged on both sides of the cooling pipe 400 in the first direction D1 respectively, and then the two sub-pole group bodies 280 are moved in the direction of approaching each other until the two sub-pole group bodies 280 are connected by splicing to form the pole group body 220. Compared with arranging the pole group body 220 as a whole and arranging the cooling pipe 400 in the pole group body 220, the technical scheme provided in the embodiment can reduce the difficulty of assembling the pole group body 220 and the cooling pipe 400, and can also reduce the probability of damaging the pole group body 220 in the assembly process, which is beneficial to improve the production yield and production efficiency of the battery cell.

[0072] Optionally, as Figures 1 to 11As shown, along the direction in which the two second protrusions 3112 point away from each other, the distance between one of the two second protrusions 3112 and the side of the first protrusion 3111 facing the second protrusion 3112 is W1, and the distance between the two second protrusions 3112 pointing away from each other is L2, 0.06≤W1 / L2≤0.19, and exemplarily, W1 / L2 can be 0.06, 0.075, 0.08, 0.15, 0.165 or 0.19, etc., and preferably 0.075≤W1 / L2≤0.165. If W1 / L2<0.06, the distance between the first protrusion 3111 and the second protrusion 3112 is too small, which will result in too small volume of the area on the first conductive plate 320 between the first avoiding hole 3211 and the second avoiding hole 3212, and too small volume of the area on the second conductive plate 331 between the third avoiding hole 3311 and the missing gap, thereby reducing the structural strength and overcurrent capacity of the first conductive plate 320 and the second conductive plate 331. If W1 / L2>0.19, the distance between the first protrusion 3111 and the second protrusion 3112 is too large, which will result in too large volume of the area on the first conductive plate 320 between the first avoiding hole 3211 and the second avoiding hole 3212, and too large volume of the area on the second conductive plate 331 between the third avoiding hole 3311 and the missing gap, thereby increasing the weight of the first conductive plate 320 and the second conductive plate 331, which is not conducive to improving the weight energy density of the battery cell. Moreover, if the distance between the first protrusion 3111 and the second protrusion 3112 is too large, the size of the first capacity-increasing groove 3111c and the second capacity-increasing groove 3112a in the first direction D1 is too small, which will reduce the size of the fourth capacity-increasing portion 260 and the fifth capacity-increasing portion 270 in the first direction D1, reducing the capacity improvement range of the pole group 200, which is not conducive to meeting the high-rate fast charging demand of the battery cell.

[0073] Optionally, in the second direction D2, the size of the thickness-reduced region 3111a is W2, and the size of the non-thickness-reduced region 3111b is W3, 16mm≤W3-W2≤32mm, and exemplarily, W3-W2 can be 16mm, 18mm, 25mm, 30mm, or 32mm, etc., and preferably, 18mm≤W3-W2≤30mm. If W3-W2<16mm, the size of the thickness-reduced region 3111a in the second direction D2 is too large, which reduces the size of the through hole 3113 in the second direction D2, and further reduces the size of the cooling pipe 400 in the second direction D2, and further reduces the flow of the cooling medium in the cooling pipe 400, reduces the cooling effect of the pole group 200, and increases the risk of thermal runaway of the battery cell. If W3-W2>32mm, the size of the thickness-reduced region 3111a in the second direction D2 is too small, which reduces the structural strength of the thickness-reduced region 3111a, and further reduces the structural strength of the first protruding portion 3111, increases the risk of deformation of the cover plate 310, and if the size of the thickness-reduced region 3111a in the second direction D2 is too small, the size of the first capacity-increasing groove 3111c at the position of the thickness-reduced region 3111a in the second direction D2 is too small, and further, in the second direction D2, the size of the fourth capacity-increasing portion 260 corresponding to the thickness-reduced region 3111a is reduced, not only reducing the structural strength of the fourth capacity-increasing portion 260 at this position, but also reducing the capacity improvement amplitude of the pole group 200, reducing the support and limiting effect of the cover plate 310 on the pole group 200, and being not conducive to meeting the high-rate fast charging demand of the battery cell.

[0074] In the embodiment, the size of the second protruding portion 3112 in the second direction D2 is W3, and the size of the non-thickness-reduced region 3111b in the second direction D2 is W3, so as to improve the structural consistency of the cover plate 310, so as to facilitate reducing the production difficulty of the cover plate 310, and improving the production yield of the cover plate 310.

[0075] Optionally, in the first direction D1, the size of the wall body portion 1311 is L1, and the distance between the two second side walls 132 away from each other is A, 0.51≤L1 / A≤0.94, and exemplarily, L1 / A can be 0.51, 0.65, 0.7, 0.85, 0.9, or 0.94, etc., and preferably, 0.65≤L1 / A≤0.9. If L1 / A<0.51, the size of the wall body portion 1311 in the first direction D1 is too small, which reduces the size of the second capacity-increasing portion 240 in the first direction D1, and further reduces the capacity improvement amplitude of the pole group 200, which is not conducive to meeting the high-rate fast charging demand of the battery cell. If L1 / A>0.94, the size of the wall body portion 1311 in the first direction D1 is too large, which makes the included angle between the folded portion 1312 and the wall body portion 1311 too small, and further increases the manufacturing difficulty of the shell 100 and the cover plate 310, not only increases the production cost, but also reduces the production yield.

[0076] Optionally, the size of the second plate body 312 in the second direction D2 is B1, the size of the first plate body 311 in the second direction D2 is B2, 10mm≤B2-B1≤30mm, and exemplarily, B2-B1 can be 10mm, 15mm or 30mm, etc., that is, the size of the second side wall 132 in the second direction D2 is B1, the distance between the two wall body parts 1311 on the side away from each other in the second direction D2 is B2, if B2-B1<10mm, the size of the second side wall 132 in the second direction D2 is too large, which will increase the included angle between the folding part 1312 and the wall body part 1311, and further increase the production difficulty of the shell 100. If B2-B1 is greater than 30mm, the size of the second side wall 132 in the second direction D2 is too small, which will reduce the size of the first capacity-increasing part 230 in the second direction D2, and further reduce the improvement range of the volume and capacity of the pole group 200.

[0077] Optionally, 0.5≤W3 / B1≤0.8, and exemplarily, W3 / B1 can be 0.5, 0.6 or 0.8, etc., if W3 / B1<0.5, the size of the non-thickening area 3111b in the second direction D2 is too small, which further reduces the structural strength of the first protruding part 3111, and also reduces the size of the fourth capacity-increasing part 260 in the second direction D2, and reduces the improvement range of the volume and capacity of the pole group 200. If W3 / B1>0.8, the size of the non-thickening area 3111b in the second direction D2 is too large, which further reduces the size of the area on both sides of the first avoiding hole 3211 in the second direction D2 where the first conductive plate 320 is located, and the size of the area on both sides of the third avoiding hole 3311 in the second direction D2 where the second conductive plate 331 is located, which reduces the structural strength of the first conductive plate 320 and the second conductive plate 331, and also reduces the flow capacity of both.

[0078] Optionally, the thickness of the cover plate 310 is T1, 1.5mm≤T1≤3mm, and exemplarily, T1 can be 1.5mm, 2mm or 3mm, etc., so that the cover plate 310 has certain structural strength and at the same time maintains a lighter weight as much as possible.

[0079] Optionally, the thickness of the first conductive plate 320 is T2, 1.5mm≤T2≤3.5mm, and exemplarily, T2 can be 1.5mm, 2mm or 3.5mm, etc., so that the first conductive plate 320 has certain structural strength and at the same time maintains a lighter weight as much as possible.

[0080] Optionally, the included angle between the two second plates 312 is N, where 50° ≤ N ≤ 110°. For example, N can be 50°, 85°, or 110°, etc. If N < 50°, the size of the capacity expansion space 314 in the first direction D1 will be reduced, thereby reducing the size of the third capacity expansion part 250 in the first direction D1 and decreasing the increase in volume and capacity of the electrode assembly 200. If N > 110°, the structural strength of the cover plate 310 will be reduced, increasing the risk of deformation of the cover plate 310.

[0081] Optionally, such as Figures 1 to 12 As shown, on the third direction D3, the distance between the side of the first protrusion 3111 and the second protrusion 3112 opposite to the first plate 311 and the side of the first plate 311 opposite to the housing 100 is H1, 8.5mm≤H1≤40mm. For example, H1 can be 8.5mm, 20mm, or 40mm, etc., ensuring that the first protrusion 3111 and the second protrusion 3112 provide reliable protection for the first conductive plate 320 and the busbar, while reducing the manufacturing difficulty of the cover plate 310. The size of the cover plate assembly 300 on the third direction D3 is H2, 30mm≤H2≤80mm. For example, H2 can be 30mm, 55mm, or 80mm, etc.

[0082] In this embodiment, the cover plate 310 and the shell 100 are manufactured using metal stamping and stretching processes, the first insulating plate 410 and the second insulating plate 420 are manufactured using injection molding, and the tabs 210 and the second conductive plate 331, the column 332 and the first conductive plate 320 are connected using laser welding. The aforementioned metal stamping, stretching, injection molding, and laser welding processes are all common manufacturing processes in the art, which are beneficial for achieving mass automated production.

[0083] Table 1 below provides six sets of embodiments and six sets of comparative examples. In all six sets of embodiments and six sets of comparative examples, the housing 100 is made of aluminum, the insulating film wrapped around the outer surface of the electrode group 200 is polypropylene (PP) film, the first insulating plate 410 is made of polyphenylene sulfide (PPS) material, and the second insulating plate 420 is made of PP material.

[0084]

[0085] In Example 1, H1 is 8.5mm, H2 is 30mm, W1 / L2 is 0.075, L1 / A is 0.65, B2-B1 is 10mm, W3 / B1 is 0.5, W3-W2 is 18mm, T1 is 1.5mm, T2 is 1.5mm, N is 50°, and the qualified rate of the battery cell is >98%. No abnormal positioning or strength of the cover plate 310, the shell 100, and the cooling pipe 400 occurs. No damage or deformation of the first protruding part 3111, the second protruding part 3112, the pole group 200, and the tab 210 occurs. The flow capacity of the cover plate assembly 300 meets the demand of high rate and fast charging of the battery cell.

[0086] In Example 2, H1 is 14mm, H2 is 48mm, W1 / L2 is 0.09, L1 / A is 0.71, B2-B1 is 14mm, W3 / B1 is 0.56, W3-W2 is 20mm, T1 is 1.8mm, T2 is 1.8mm, N is 65°, and the qualified rate of the battery cell is >98%. No abnormal positioning or strength of the cover plate 310, the shell 100, and the cooling pipe 400 occurs. No damage or deformation of the first protruding part 3111, the second protruding part 3112, the pole group 200, and the tab 210 occurs. The flow capacity of the cover plate assembly 300 meets the demand of high rate and fast charging of the battery cell.

[0087] In Example 3, H1 is 20mm, H2 is 55mm, W1 / L2 is 0.11, L1 / A is 0.75, B2-B1 is 18mm, W3 / B1 is 0.65, W3-W2 is 22mm, T1 is 2mm, T2 is 2.5mm, N is 80°, and the qualified rate of the battery cell is >98%. No abnormal positioning or strength of the cover plate 310, the shell 100, and the cooling pipe 400 occurs. No damage or deformation of the first protruding part 3111, the second protruding part 3112, the pole group 200, and the tab 210 occurs. The flow capacity of the cover plate assembly 300 meets the demand of high rate and fast charging of the battery cell.

[0088] In Example 4, H1 is 25mm, H2 is 64mm, W1 / L2 is 0.13, L1 / A is 0.82, B2-B1 is 20mm, W3 / B1 is 0.69, W3-W2 is 24mm, T1 is 2.2mm, T2 is 2.5mm, N is 90°, and the qualified rate of the battery cell is >98%. No abnormal positioning or strength of the cover plate 310, the shell 100, and the cooling pipe 400 occurs. No damage or deformation of the first protruding part 3111, the second protruding part 3112, the pole group 200, and the tab 210 occurs. The flow capacity of the cover plate assembly 300 meets the demand of high rate and fast charging of the battery cell.

[0089] In Example 5, H1 is 34 mm, H2 is 72 mm, W1 / L2 is 0.145, L1 / A is 0.86, B2-B1 is 24 mm, W3 / B1 is 0.74, W3-W2 is 27 mm, T1 is 2.5 mm, T2 is 3 mm, N is 100°, and the qualified rate of the battery cell is >98%; no abnormal positioning or strength of the cover plate 310, the shell 100, and the cooling pipe 400; no damage or deformation of the first protruding part 3111, the second protruding part 3112, the pole group 200, and the tab 210; and the overcurrent capacity of the cover plate assembly 300 meets the demand of high-rate fast charging of the battery cell.

[0090] In Example 6, H1 is 40 mm, H2 is 80 mm, W1 / L2 is 0.165, L1 / A is 0.9, B2-B1 is 30 mm, W3 / B1 is 0.8, W3-W2 is 30 mm, T1 is 3 mm, T2 is 3.5 mm, N is 110°, and the qualified rate of the battery cell is >98%; no abnormal positioning or strength of the cover plate 310, the shell 100, and the cooling pipe 400; no damage or deformation of the first protruding part 3111, the second protruding part 3112, the pole group 200, and the tab 210; and the overcurrent capacity of the cover plate assembly 300 meets the demand of high-rate fast charging of the battery cell.

[0091] In Comparative Example 1, H1 is 20 mm, H2 is 55 mm, W1 / L2 is 0.05, L1 / A is 0.75, B2-B1 is 18 mm, W3 / B1 is 0.65, W3-W2 is 22 mm, T1 is 2 mm, T2 is 2.5 mm, N is 80°, and the qualified rate of the battery cell is <98%; the first conductive plate 320 and the second conductive plate 331 have low structural strength and weak overcurrent capacity, which cannot meet the demand of high-rate fast charging of the battery cell.

[0092] In Comparative Example 2, H1 is 20 mm, H2 is 55 mm, W1 / L2 is 0.2, L1 / A is 0.75, B2-B1 is 18 mm, W3 / B1 is 0.65, W3-W2 is 22 mm, T1 is 2 mm, T2 is 2.5 mm, N is 80°, and the qualified rate of the battery cell is <98%; the first conductive plate 320 and the second conductive plate 331 are too heavy, and the weight energy density of the battery cell is low; the capacity of the pole group 200 cannot be improved significantly, and the demand of high-rate fast charging of the battery cell cannot be met.

[0093] In Comparative Example 3, H1 is 20 mm, H2 is 55 mm, W1 / L2 is 0.11, L1 / A is 0.5, B2-B1 is 18 mm, W3 / B1 is 0.65, W3-W2 is 22 mm, T1 is 2 mm, T2 is 2.5 mm, N is 80°, and the qualified rate of the battery cell is <98%; the volume and capacity of the pole group 200 cannot be improved significantly, and the demand of high-rate fast charging of the battery cell cannot be met.

[0094] In the comparative example 4, H1 is 20 mm, H2 is 55 mm, W1 / L2 is 0.11, L1 / A is 0.95, B2-B1 is 18 mm, W3 / B1 is 0.65, W3-W2 is 22 mm, T1 is 2 mm, T2 is 2.5 mm, N is 80°, and the qualified rate of the battery cell is less than 98%; the manufacturing difficulty of the shell 100 and the cover plate 310 is large, the production cost is high, and the production yield is low.

[0095] In the comparative example 5, H1 is 20 mm, H2 is 55 mm, W1 / L2 is 0.11, L1 / A is 0.75, B2-B1 is 18 mm, W3 / B1 is 0.65, W3-W2 is 15 mm, T1 is 2 mm, T2 is 2.5 mm, N is 80°, and the qualified rate of the battery cell is less than 98%; the flow of the cooling medium in the cooling pipe 400 is small, the cooling effect of the pole group 200 is poor, and the risk of thermal runaway of the battery cell is high.

[0096] In the comparative example 6, H1 is 20 mm, H2 is 55 mm, W1 / L2 is 0.11, L1 / A is 0.75, B2-B1 is 18 mm, W3 / B1 is 0.65, W3-W2 is 33 mm, T1 is 2 mm, T2 is 2.5 mm, N is 80°, and the qualified rate of the battery cell is less than 98%; the deformation risk of the cover plate 310 is high, the structural strength of the fourth volume-increasing part 260 is low, the support and limiting effect of the cover plate 310 on the pole group 200 is poor, the capacity of the pole group 200 is small, and the high-rate fast charging demand of the battery cell cannot be met.

[0097] In summary, when the above parameters satisfy 8.5 mm≤H1≤40 mm, 30 mm≤H2≤80 mm, 0.06≤W1 / L2≤0.19, 0.51≤L1 / A≤0.94, 10 mm≤B2-B1≤30 mm, 0.5≤W3 / B1≤0.8, 16 mm≤W3-W2≤32 mm, 1.5 mm≤T1≤3 mm, 1.5 mm≤T2≤3.5 mm, and 50°≤N≤110°, the deformation risk of the cover plate 310 can be reduced, the probability of the first conductive plate 320 being knocked can be reduced, the volume of the pole group 200 can be increased, the overcurrent capacity of the cover plate assembly 300 can be improved, the overcurrent between the pole group 200, the cover plate assembly 300, and the bus bar can be increased, and the high-rate fast charging demand of the battery cell can be met.

[0098] Obviously, the above embodiments of the present application are merely exemplary but not intended to limit the embodiments of the present application. Various obvious changes, re-adjustments and substitutions can be made by those skilled in the art without departing from the scope of the present application. It is not necessary or possible to enumerate all the embodiments. Any modification, equivalent replacement and improvement made 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. An electric cell, characterized by, The application relates to a battery pack, which comprises the following components: a shell (100) provided with a cavity (110) and an opening (120); a pole group (200) arranged in the cavity (110); a cover plate assembly (300) comprising a cover plate (310) arranged at the opening (120), the cover plate (310) comprising a first plate body (311) and two second plate bodies (312), the first plate body (311) being provided with a first protruding part (3111) and two second protruding parts (3112) on a side thereof away from the shell (100), the two second protruding parts (3112) being respectively arranged on two sides of the first protruding part (3111) and being spaced apart from the first protruding part (3111), the two second plate bodies (312) being respectively connected to two opposite sides of the first plate body (311) in a direction in which the two second plate bodies (312) point to each other, the two second plate bodies (312) being inclined in a direction in which the two second plate bodies (312) approach each other in a direction in which the shell (100) points to the cover plate (310), the two second protruding parts (3112) extending in a direction in which the two second protruding parts (3112) are away from each other and being respectively connected to a side of a corresponding one of the second plate bodies (312) away from the shell (100).

2. The electric cell of claim 1, wherein, The cover plate assembly (300) further comprises a first conductive plate (320) comprising a first conductive part (321) and two second conductive parts (322), the first conductive part (321) being insulatively connected to a side of the first plate body (311) away from the shell (100), the two second conductive parts (322) corresponding to the two second plate bodies (312) one by one, each second conductive part (322) being insulatively connected to a side of a corresponding one of the second plate bodies (312) away from the shell (100), the two second conductive parts (322) being connected to the first conductive part (321), and the first conductive part (321) and the two second conductive parts (322) being used for being connected to busbars.

3. The electric cell of claim 2, wherein, The first conductive part (321) is provided with a first avoiding hole (3211) and two second avoiding holes (3212), the two second avoiding holes (3212) being respectively arranged on two opposite sides of the first avoiding hole (3211) in a direction in which the two second conductive parts (322) point to each other, the two second avoiding holes (3212) being spaced apart from the first avoiding hole (3211), and the two second avoiding holes (3212) extending in a direction in which the two second conductive parts (322) are away from each other to a corresponding one of the second conductive parts (322). The first protruding part (3111) is arranged in the first avoiding hole (3211), and two second protruding parts (3112) correspond to two second avoiding holes (3212) one by one, each second protruding part (3112) is arranged in a corresponding second avoiding hole (3212), and at least one of the first protruding part (3111) and the second protruding part (3112) protrudes from the first conductive plate (320) in the direction of the cover plate (310) of the shell (100).

4. The electric cell of claim 3, wherein, In the direction in which the two second protruding parts (3112) point to each other, the distance between one of the two second protruding parts (3112) and the side of the first protruding part (3111) facing the second protruding part (3112) is W1, and the distance between the two sides of the two second protruding parts (3112) facing away from each other is L2, 0.06≤W1 / L2≤0.

19.

5. The cell of any of claims 2-4, wherein, The pole group (200) is provided with a lug (210) on the side facing the cover plate (310), and the cover plate assembly (300) further comprises a pole column structure (330), the pole column structure (330) comprises a second conductive plate (331) and a column body (332), the second conductive plate (331) is insulated and covered on the side of the first plate body (311) facing the shell (100), and is connected with the lug (210), the column body (332) is arranged in the first plate body (311), and two ends of the column body (332) are connected with the first conductive plate (320) and the second conductive plate (331) respectively.

6. The electric cell of claim 5, wherein, The column body (332) and the second conductive plate (331) are in a split structure; And / or, the number of column bodies (332) is multiple.

7. The cell of any of claims 1-4, wherein, The width direction of the battery cell is a first direction (D1), the direction in which the two second plate bodies (312) point to each other is the first direction (D1), the thickness direction of the battery cell is a second direction (D2), and the first plate body (311) is provided with two through holes (3113); The first protruding part (3111) comprises a thickness-reduced area (3111a) and two non-thickness-reduced areas (3111b), along the first direction (D1), two ends of the thickness-reduced area (3111a) are connected with two non-thickness-reduced areas (3111b) respectively, along the second direction (D2), the size of the thickness-reduced area (3111a) is smaller than the size of the non-thickness-reduced area (3111b), the through hole (3113) is located between the two non-thickness-reduced areas (3111b), and the two through holes (3113) are located on both sides of the thickness-reduced area (3111a) in the second direction (D2) respectively; The battery cell further comprises cooling pipes (400) insulatedly penetrating the pole group (200), a cooling medium flows in the cooling pipes (400), the number of the cooling pipes (400) is two, the two cooling pipes (400) correspond to the two through holes (3113) one by one, and each cooling pipe (400) penetrates a corresponding through hole (3113).

8. The electric cell of claim 7, wherein, In the second direction (D2), the size of the reduced-thickness area (3111a) is W2, and the size of the non-reduced-thickness area (3111b) is W3, 16mm≤W3-W2≤32mm.

9. The cell of any of claims 1-4, wherein, The width direction of the battery cell is a first direction (D1), the direction in which the two second plate bodies (312) point to each other is the first direction (D1), the thickness direction of the battery cell is a second direction (D2), the shell (100) comprises two first side walls (131) and two second side walls (132), the two first side walls (131) are oppositely arranged along the second direction (D2), the two second side walls (132) are oppositely arranged along the first direction (D1), the first side wall (131) and the second side wall (132) are sequentially connected end to end to form the cavity (110), the first side wall (131) comprises a wall body part (1311) and two folded parts (1312), along the first direction (D1), the two sides of the wall body part (1311) are connected to the two second side walls (132) through the two folded parts (1312) respectively, one of the two first side walls (131) is inclined in a direction away from the other, the two folded parts (1312) of the first side wall (131) are inclined in a direction close to each other, the pole group (200) comprises a pole group body (220), two first capacity-increasing parts (230) and two second capacity-increasing parts (240), the two first capacity-increasing parts (230) are respectively protruded on the two sides of the pole group body (220) in the first direction (D1), and the two second capacity-increasing parts (240) are respectively protruded on the two sides of the pole group body (220) in the second direction (D2).

10. The electric cell of claim 9, wherein, Along the first direction (D1), the size of the wall body part (1311) is L1, and the distance between the sides of the two second side walls (132) away from each other is A, 0.51≤L1 / A≤0.94.

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