Battery cell and battery pack

Abstract

The invention relates to the technical field of batteries, in particular to a battery cell and a battery pack. The battery cell comprises a pole group and a shell, wherein the pole group comprises a pole group body and a first tab which protrudes outwards from the pole group body, and the pole group is arranged in the shell; the cover plate assembly comprises a pole column and a supporting piece, the first tab is connected with the pole column, the supporting piece is arranged between the pole group body and the pole column, a bending space for accommodating the first tab is defined by the supporting piece, and a guide part which is bent towards the pole column is formed on the side wall of one end, facing the pole group, of the supporting piece; the first tab is firstly bent towards the direction close to the guide part and then bent towards the direction close to the pole, so that the guide part is arranged between the pole group body and the first tab. According to the invention, a proper space for bending the tab is formed in the battery cell, so that the assembly stability of the tab is improved, the stability of the battery cell is improved, and the capacity of the battery cell is ensured. And the guide part can separate the pole group body from the first tab, so that the situation that the tab is inversely inserted into the pole group is avoided, and the safety performance of the battery cell is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery cell and a battery pack. Background Art

[0002] As lithium-ion battery technology matures, it is widely used as a power battery in electric vehicles and energy storage applications, leading to increasing demands for performance and safety. Lithium-ion power batteries generally consist of an internal structure and an external structure. The internal structure primarily comprises the cell electrode assembly, while the external structure primarily comprises the cell cover and cell casing. The cell casing houses the cell electrode assembly, and the cell cover and casing are welded together to secure the electrode assembly within the internal space. The tabs on the cell electrode assembly connect to the posts on the cell cover to provide positive and negative leads to the electrode assembly. If the distance between the cell electrode assembly and the cell cover is too small, there will be insufficient space within the casing to accommodate the tabs, making tab connection difficult and even prone to problems such as tab insertion into the cell assembly, compromising the stability and safety of the battery cell. If the distance between the cell electrode assembly and the cell cover is too large, the connection strength between the post and tab is weakened, making vibration or impact more likely to damage the tabs, affecting the battery cell's capacity. Summary of the Invention

[0003] In view of this, the purpose of this application is to provide a battery cell and a battery pack to solve the problem that the tabs in existing battery cells are easily inserted into the pole group and the connection strength is insufficient, thereby causing damage to the tabs and affecting the capacity, stability and safety performance of the battery cell.

[0004] A first aspect of the present invention provides a battery cell, wherein the battery cell comprises:

[0005] case;

[0006] A pole group, comprising a pole group body and a first pole ear protruding outward from one end of the pole group body in a first direction, wherein the pole group is disposed in the housing;

[0007] The cover plate assembly includes a pole and a support member, wherein the first pole tab is connected to the pole post, the support member is arranged between the pole group body and the pole post, and encloses a bending space for accommodating the first pole tab, the support member includes a first side wall, and a guide portion is formed on one end of the first side wall facing the pole group and bent toward the pole post, the guide portion and the first side wall are arranged at an acute angle; the first pole tab is first bent in a direction close to the guide portion, and then bent in a direction close to the pole post, so that in the first direction, the guide portion is arranged between the pole group body and the first pole tab, and the end of the first pole tab connected to the pole group body is arranged on the side of the guide portion facing the pole post, so that the first pole tab is arranged in an S-shaped structure within the bending space;

[0008] The support member further includes a second side wall spaced apart from the first side wall along the third direction, and the second side wall has no protruding structure on a surface facing the first side wall.

[0009] Preferably, the length of the first electrode tab is M, 15 mm ≤ M ≤ 25 mm.

[0010] Preferably, the dimension H of the support member in the first direction is 5mm≤H≤7.5mm.

[0011] Preferably, the angle between the guide portion and the first side wall is α, 60°≤α≤80°.

[0012] Preferably, in the third direction, a distance between an end of the guide portion close to the second side wall and the second side wall is L, and L is ≥ 2 mm.

[0013] Preferably, the distance between the first side wall and the second side wall opposite to each other is K, and L / K=20%-50%.

[0014] Preferably, the cover plate assembly further comprises a cover plate body connected to the shell, an exhaust hole is provided on the cover plate body, and an exhaust structure connecting the exhaust hole and the interior of the battery cell is provided on the support member.

[0015] Preferably, the electrode comprises a positive electrode and a negative electrode, and the first electrode tab is connected to the positive electrode;

[0016] The electrode group further includes a second electrode tab protruding outward from the other end of the electrode group body in the first direction, the second electrode tab is connected to the negative electrode column, and the second electrode tab after connection is arranged in a C-shaped structure.

[0017] Preferably, the outer wall of the pole group body is covered with an insulating film, part of the insulating film is covered on the side wall of the circumferential outer wall of the support member, and is heat-melted to the support member to form a heat-melting area between the insulating film and the support member.

[0018] A second aspect of the present invention provides a battery pack comprising the battery cell described in any of the above technical solutions.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] In the battery cell of the present invention, a support member is arranged between the electrode group body and the electrode column, and a bending space is formed to accommodate the first electrode tab. A guide portion is formed on the side wall of the support member facing the electrode group, which is bent toward the electrode column. The guide portion is arranged at an acute angle with the first side wall. The first electrode tab is first bent toward the direction close to the guide portion, and then bent toward the direction close to the electrode column to ensure that a suitable space for bending the electrode tab is formed in the battery cell housing. The support member can support the bent first electrode tab to a certain extent, improve the assembly stability of the electrode tab, thereby improving the stability of the battery cell and ensuring the capacity of the battery cell. The guide portion is arranged between the electrode group body and the first electrode tab, thereby separating the electrode group body and the first electrode tab, avoiding the situation where the electrode tab is inserted upside down into the electrode group, ensuring the safety performance of the battery cell, and further improving the stability and safety performance of the battery pack.

[0021] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 A schematic diagram of the structure of a battery cell provided in an embodiment of the present invention;

[0024] Figure 2 A schematic structural diagram of a battery cell provided by an embodiment of the present invention from another perspective;

[0025] Figure 3 For the Figure 2 Cross-section taken at AA in the middle;

[0026] Figure 4 A schematic diagram of the connection structure between the second tab and the pole in the battery cell provided by an embodiment of the present invention;

[0027] Figure 5 A schematic structural diagram of a support member in a battery cell provided by an embodiment of the present invention;

[0028] Figure 6 A schematic structural diagram of a support member in a battery cell provided by an embodiment of the present invention from another perspective;

[0029] Figure 7 For the Figure 6 Cross-section taken at BB in the middle;

[0030] Figure 8 A structural diagram illustrating the positional relationship between the guide portion, the first side wall, and the second side wall of the support member in the battery cell provided by an embodiment of the present invention;

[0031] Figure 9 This is a schematic diagram of the structure of the electrode group in the battery cell before assembly provided by an embodiment of the present invention.

[0032] Icons: 100-shell; 200-cover assembly; 10-pole group body; 11-first pole ear; 12-second pole ear; 20-pole column; 21-connecting part; 30-support member; 31-guide part; 32-bending space; 33-first side wall; 34-second side wall; 35-exhaust structure; 40-cover body; 41-exhaust hole; 50-insulating film; 51-hot melt area; 60-first insulating member; 70-second insulating member; 80-sealing member; 90-connecting member; D1-first direction; D2-second direction; D3-third direction. DETAILED DESCRIPTION

[0033] The following detailed description is provided to help the reader gain a comprehensive understanding of the methods, devices, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, devices, and / or systems described herein will be apparent upon understanding the disclosure of this application. For example, the order of operations described herein is merely illustrative and is not limited to the order set forth herein. Rather, except for operations that must occur in a particular order, changes may be made that will be apparent upon understanding the disclosure of this application. Furthermore, descriptions of features known in the art may be omitted for clarity and brevity.

[0034] The features described herein may be implemented in different forms and should not be construed as being limited to the examples described herein. Rather, the examples described herein have been provided merely to illustrate some of the many possible ways to implement the methods, devices, and / or systems described herein that will be apparent upon understanding the disclosure of this application.

[0035] Throughout the specification, when an element (such as a layer, region, or substrate) is described as being “on,” “connected to,” “coupled to,” “over,” or “overlaying” another element, it may be directly “on,” “connected to,” “coupled to,” “over,” or “overlaying” another element, or one or more other elements may be present between them. In contrast, when an element is described as being “directly on,” “directly connected to,” “directly coupled to,” “directly over,” or “directly covering” another element, there may be no other elements intervening therebetween.

[0036] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more items.

[0037] Although terms such as "first," "second," and "third" may be used herein to describe various members, components, regions, layers, or portions, these members, components, regions, layers, or portions are not limited by these terms. Rather, these terms are used only to distinguish one member, component, region, layer, or portion from another member, component, region, layer, or portion. Thus, a first member, component, region, layer, or portion in the examples described herein may also be referred to as a second member, component, region, layer, or portion without departing from the teachings of the examples.

[0038] For ease of description, spatial relational terms such as "above," "upper," "below," and "lower" may be used herein to describe the relationship of one element to another element as shown in the accompanying drawings. Such spatial relational terms are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the accompanying drawings. For example, if the device in the accompanying drawings is turned over, an element described as being "above" or "upper" relative to another element would subsequently be "below" or "lower" relative to the other element. Thus, the term "above" includes both the orientations "above" and "below," depending on the spatial orientation of the device. The device may also be positioned in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relational terms used herein will be interpreted accordingly.

[0039] The terms used herein are intended only to describe various examples and are not intended to limit the present disclosure. Unless the context clearly indicates otherwise, the singular is intended to include the plural. The terms "comprise," "include," and "have" list the presence of stated features, quantities, operations, components, elements, and / or combinations thereof, but do not preclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0040] Due to manufacturing techniques and / or tolerances, variations in the shapes shown in the drawings may occur. Therefore, the examples described herein are not limited to the specific shapes shown in the drawings but include changes in shapes that occur during manufacturing.

[0041] The features of the examples described herein can be combined in various ways that will be apparent after understanding the disclosure of the present application. In addition, although the examples described herein have various configurations, other configurations are possible as will be apparent after understanding the disclosure of the present application.

[0042] According to a first aspect of the present invention, a battery cell is provided, which specifically includes a housing 100 , an electrode group, and a cover plate assembly 200 .

[0043] Hereinafter, the specific structure of the battery cell according to the present embodiment as described above will be described.

[0044] In this embodiment, if Figure 1 As shown, the battery cell is formed as a rectangular body structure as a whole. This embodiment is preferably applicable to battery cells with a length dimension of 300mm to 2000mm, a width dimension of 80mm to 150mm and a thickness dimension of 10mm to 30mm.

[0045] It should be noted that, in this embodiment, Figure 1 As shown, the first direction D1 is the length direction of the battery cell, the second direction D2 is the width direction of the battery cell, and the third direction D3 is the thickness direction of the battery cell.

[0046] like Figures 1 to 4 As shown, the housing 100 has a cavity inside for containing the electrode group and part of the cover plate assembly 200. In this embodiment, the housing 100 has a rectangular structure, and the cover plate assembly 200 is assembled at the opening of the cavity to form an enclosed space enclosing the electrode group together with the housing 100. Specifically, the cover plate assembly 200 includes a cover plate body 40 formed into a plate-like structure, which is welded to the housing 100.

[0047] like Figure 3 and Figure 4 As shown, the electrode group is arranged in the shell 100. Specifically, the electrode group includes a electrode group body 10 and a first electrode ear 11 protruding outward from one end of the electrode group body 10 in the first direction D1. The electrode group body 10 is formed by winding or stacking the positive electrode sheet and the negative electrode sheet, and the first electrode ear 11 protrudes outward toward the direction close to the cover plate assembly 200.

[0048] In this embodiment, if Figures 1 to 4 As shown, the cover assembly 200 includes a pole 20 and a support member 30. The pole 20 is installed on the cover body 40. Part of the pole 20 is arranged inside the battery cell, and part of the pole 20 is arranged inside the battery cell and connected to the first pole lug 11, so as to realize the internal and external transmission of electric energy. The end of the pole 20 located inside the battery cell is formed as a connecting portion 21 with a side wall protruding outward. The connecting portion 21 can be formed into a plate-like structure with a polygonal, circular or elliptical shape, that is, the connection area between the pole 20 and the pole lug (including the first pole lug 11 and the second pole lug 12 described below) is increased to ensure that the pole 20 is reliably connected to the pole lug. In this embodiment, the end of the pole lug away from the pole group body 10 is welded to the side of the connecting portion 21 facing the inside of the battery cell.

[0049] In this embodiment, if Figures 1 to 7 As shown, the support member 30 is formed into a strip structure extending along the second direction D2; in the first direction D1, the support member 30 is arranged between the pole group body 10 and the pole 20, and encloses a bending space 32 for accommodating the first pole tab 11, and the support member 30 includes a first side wall 33, and the first side wall 33 has a guide portion 31 bent toward the pole 20 at one end facing the pole group, and the guide portion 31 is arranged at an acute angle to the first side wall 33; the first pole tab 11 is first bent toward the direction close to the guide portion 31, and then bent toward the direction close to the pole 20 to achieve the connection between the first pole tab 11 and the pole 20. The support member 30 is provided to ensure that a suitable space for bending the pole tab is formed in the battery cell housing 100, and to a certain extent, it can support the bent first pole tab 11, thereby improving the assembly stability of the first pole tab 11, thereby improving the stability of the battery cell and ensuring the capacity of the battery cell. In the first direction D1, the guide portion 31 is arranged between the pole group body 10 and the first pole lug 11, and the end of the first pole lug 11 connected to the pole group body 10 is arranged on the side of the guide portion 31 facing the pole column 20 (that is, the end of the first pole lug 11 close to the pole group body 10 is arranged on the side of the guide portion 31 facing the pole column 20, so that the first pole lug 11 is completely arranged in the bending space 32). In this way, the guide portion 31 separates the pole group body 10 and the first pole lug 11 and enables the first pole lug 11 to be installed in the area enclosed by the guide portion 31 and the pole column 20 in the first direction D1, thereby avoiding the situation where the pole lug is inserted upside down into the pole group and ensuring the safety performance of the battery cell.

[0050] In this embodiment, if Figure 2 and Figure 3 As shown, the first pole tab 11 is arranged in an S-shaped structure in the bending space 32, that is, the first pole tab 11 connected to the pole post 20 is formed into an S-shaped structure including two bends in opposite bending directions. Specifically, the end of the first pole tab 11 connected to the pole group body 10 is bent toward the direction close to the guide portion 31 to form a bend in the S-shaped structure, and then the bending direction is changed to form another bend close to the pole post 20. The guide portion 31 guides and supports the structural shape of the first pole tab 11 between the pole group body 10 and the pole post 20 to a certain extent, which facilitates the connection of the first pole tab 11 and can still ensure the connection stability between the first pole tab 11 and the pole post 20 when the battery cell is subjected to vibration and impact, thereby avoiding the situation where the first pole tab 11 is upside down inserted into the pole group body 10.

[0051] In this embodiment, if Figure 9As shown, the length of the first tab 11 is M, 15mm≤M≤25mm. If the length of the first tab 11 is too small, the installation process requirements for it and the cover plate assembly 200 are high, and there is a defect of difficulty in welding, low battery cell production yield, and high manufacturing cost. If the size of the first tab 11 is too large, the bending space 32 requirement is high, and it occupies a large amount of internal space of the battery cell, affecting the battery cell capacity and easily causing redundancy during the bending process. It should be noted that the tabs (including the first tab 11 and the second tab 12 described below) are a structure of multiple layers of aluminum foil or copper foil welded together, with a thickness of 0.2 to 1 mm.

[0052] Furthermore, in this embodiment, Figure 8 As shown, the dimension of the support member 30 in the first direction D1 is H, 5mm≤H≤7.5mm, that is, the height dimension of the first side wall 33 is H, which meets the installation requirement of the first tab 11 with a length dimension of 15mm to 25mm and ensures effective compatibility.

[0053] Furthermore, in this embodiment, if Figures 3 to 7 As shown, the support member 30 includes a first side wall 33 and a second side wall 34. The first side wall 33 and the second side wall 34 can be plate-like structures. The first side wall 33 and the second side wall 34 are spaced apart along the thickness direction of the battery cell (i.e., the third direction D3) to enclose a bending space 32 in the thickness direction of the battery cell; there is no protruding structure on the surface of the second side wall 34 facing the first side wall 33. The guide portion 31 is connected to the first side wall 33 and is arranged at an acute angle to the first side wall 33, so that the guide portion 31 is formed as an inclined plate-like structure extending from the end of the first side wall 33 away from the cover plate body 40 toward the direction close to the cover plate body 40. In this way, only the first side wall 33 is formed with a protruding structure (i.e., the guide portion 31) protruding toward the second side wall 34, ensuring that the guide portion 31 supports and guides the first electrode tab 11, thereby ensuring the stability of the first electrode tab 11 in the bending space 32 and facilitating the installation of the first electrode tab 11. In addition, in the third direction D3 , the first side wall 33 and the second side wall 34 are respectively disposed between the first electrode tab 11 and the housing 100 , thereby preventing the first electrode tab 11 from contacting the housing 100 and causing a short circuit.

[0054] Furthermore, in this embodiment, if Figure 8As shown, the angle α between the guide portion 31 and the first side wall 33 is 60°≤α≤80°. This avoids the situation where α is too small, resulting in insufficient space for the first pole tab 11, which would cause the root of the first pole tab 11 to be redundant and easily contact the pole 20. It also avoids the situation where α is too large, which would prevent the guide portion 31 from effectively supporting the first pole tab 11, which would easily cause the root of the first pole tab 11 to be redundant and / or cause a short circuit due to inverted insertion of the pole group, ultimately causing battery cell failure. It should be noted that the root of the first pole tab 11 is the side of the first pole tab 11 close to the pole group body 10.

[0055] Taking into account the thickness of the first tab 11 and the positioning tolerance and size requirements required for the first tab 11 to pass through the support member 30, in this embodiment, as shown in FIG. Figure 8 As shown, in the third direction D3 , the distance between the end of the guide portion 31 close to the second side wall 34 and the second side wall 34 is L, and L is ≥ 2 mm to prevent the guide portion 31 from damaging the first electrode tab 11 .

[0056] Furthermore, in this embodiment, Figure 8 As shown, the distance between the first side wall 33 and the second side wall 34 on the opposite sides is K, that is, the dimension of the support member 30 in the third direction D3 is K, and L / K = 20% to 50%. If the ratio of L / K is too small, it will be difficult for the first electrode tab 11 to pass through the support member 30. If the ratio of L / K is too small, the structure of the guide portion 31 will be affected, and the bending space 32 that can support the first electrode tab 11 will be reduced, resulting in unsatisfactory bending of the first electrode tab 11 and the possibility of reverse insertion. In a preferred embodiment, K is the same as the thickness of the electrode assembly body 10.

[0057] Next, support members 30 and pole groups of different sizes are assembled to form battery cells, and the assembly of the battery cells is tested to verify the validity of the limiting conditions of L ≥ 2 mm, L / K = 20% to 50%, 60° ≤ α ≤ 80°, 5 mm ≤ H ≤ 7.5 mm, and 15 mm ≤ M ≤ 25 mm. The test results are shown in the table below.

[0058]

[0059] Referring to the parameters in the above table, it can be seen that in Examples 1 to 12, L, L / K, α, H, and M are all within the limits specified above. This demonstrates that the limits specified above can ensure that the support member 30 can provide a good bending space 32 for bending the first tab 11, and that the first tab 11 does not have redundancy or inverted insertion issues after installation. However, in Comparative Examples 1 to 12, at least one of L, L / K, α, H, and M is no longer within the limits specified above, resulting in redundant tabs and / or inverted tab insertion issues in the assembled battery cell. Consequently, the support member 30 in Comparative Examples 1 to 12 cannot reliably provide bending space for the tabs, and the safety and yield of the battery cell cannot be guaranteed.

[0060] In addition, in this embodiment, Figure 5 and Figure 6 As shown, the dimension of the guide portion 31 in the second direction D2 is 5 mm to 15 mm larger than the dimension of the first tab 11 in the second direction D2. For example, if the dimension of the first tab 11 in the second direction D2 is 70 mm, the dimension of the guide portion 31 in the second direction D2 is preferably 75 mm to 85 mm to ensure that the guide portion 31 effectively supports and reliably guides the first tab 11. In a preferred embodiment, the first tab 11 is positioned in the middle of the guide portion 31 in the second direction D2 to prevent abrasion between the first tab 11 and the support member 30.

[0061] Furthermore, in this embodiment, Figure 2 、 Figure 5 and Figure 6 As shown, an exhaust hole 41 is provided on the cover plate body 40, and the exhaust hole 41 is a through-hole structure running through the cover plate body 40. A pressure relief part is installed on the exhaust hole 41, and the pressure relief part can be an explosion-proof valve. When gas is produced inside the battery cell and the air pressure inside the battery cell reaches a preset pressure, the pressure relief part opens, so that the gas inside the battery cell can be discharged from the exhaust hole 41. The support member 30 is provided with an exhaust structure 35 connecting the exhaust hole 41 and the interior of the battery cell. The exhaust structure 35 can be one or more through-holes arranged in an array to avoid the support member 30 from blocking the exhaust hole 41, ensuring that the gas inside the battery cell can be discharged in time when the battery cell fails, thereby ensuring the safety performance of the battery cell.

[0062] In this embodiment, if Figure 3 and Figure 4 As shown, the pole 20 includes a positive pole 20 and a negative pole 20, and the first pole tab 11 is connected to the positive pole 20; the pole group also includes a second pole tab 12 protruding outward from the other end of the pole group body 10 in the first direction D1, and the second pole tab 12 is connected to the negative pole 20. The second pole tab 12 after connection is arranged in a C-shaped structure, so that the end of the second pole tab 12 away from the pole group body 10 is directly bent toward the pole 20 and connected to the connecting portion 21.

[0063] In an optional embodiment, the first electrode tab 11 and the second electrode tab 12 protrude in opposite directions, so that the first electrode tab 11 and the second electrode tab 12 are respectively disposed at both ends of the electrode group body 10 in the first direction D1. The housing 100 is provided with openings at both ends in the first direction D1. The cover plate assembly 200 is provided with two openings that respectively close the two ends, one of which is a positive electrode cover plate, and the electrode post 20 on the positive electrode cover plate is the positive electrode post 20 connected to the first electrode tab 11. The other is a negative electrode cover plate, and the electrode post 20 on the negative electrode cover plate is the negative electrode post 20 connected to the second electrode tab 12. In the longitudinal direction of the battery cell, the support member 30 is disposed between the positive electrode cover plate and the electrode group.

[0064] In this embodiment, if Figure 3 As shown, the outer wall of the electrode group body 10 is covered with an insulating film 50. The insulating film 50 has insulating properties and is made of, for example, PP (polypropylene). The insulating film 50 separates the electrode group body 10 from the shell 100 to provide insulation protection for the electrode group. In the length direction of the battery cell, one end of the insulating film 50 is covered on the side wall of the circumferential outer wall of the support member 30 and is heat-fused to the support member 30 to form a heat-fusion area 51 between the insulating film 50 and the support member 30, thereby achieving fixation between the insulating film 50 and the support member 30. The heat-fusion area 51 can be formed as an annular structure surrounding the circumferential side wall of the support member 30, or as a plurality of spaced-apart dot structures or strip structures surrounding the circumferential side wall of the support member 30, as long as the insulating film 50 and the support member 30 are reliably fixed.

[0065] In addition, in this embodiment, Figures 1 to 4 As shown, the cover assembly 200 also includes a first insulating member 60, a second insulating member 70, a sealing member 80 and a connecting member 90, wherein the connecting member 90 is formed into a block structure, and one end of the pole 20 extending outside the battery cell is riveted and / or welded to the connecting member 90 to fix the pole 20 to the cover body 40 through the connecting member 90.

[0066] The first insulating member 60 and the second insulating member 70 have insulating properties. The first insulating member 60 and / or the second insulating member 70 can be made of PP or PPS (polyphenylene sulfide). Specifically, the first insulating member 60 is arranged between the connecting member 90 and the cover body 40 to avoid the pole 20 being arranged at one end outside the battery cell and / or the connecting member 90 contacting the cover body 40 to cause a short circuit. Part of the first insulating member 60 is covered on the circumferential side wall of the connecting member 90 to improve the insulating performance; the second insulating member 70 is arranged on the side of the cover body 40 facing the inside of the battery cell, and part of the second insulating member 70 is arranged between the connecting part 21 and the cover body 40, so as to avoid the pole 20 being arranged at one end inside the battery cell and / or the pole group contacting the cover body 40 to cause a short circuit.

[0067] It should be noted that, in this embodiment, Figure 3 As shown, the support member 30 is connected to the second insulating member 70 on the positive electrode cover as described above, as shown in FIG. Figure 4 As shown, the second insulating member 70 on the negative electrode cover as described above encloses a space for the second electrode tab 12 to bend, that is, at least part of the second insulating member 70 is arranged around the circumferential side wall of the second electrode tab 12 to separate the second electrode tab 12 from the shell 100, thereby playing a role of insulation protection; the other end of the insulating film 50 in the length direction of the battery cell is connected to the second insulating member 70 on the negative electrode cover, and the connection method can be a hot melt connection to achieve the fixation of the insulating film 50.

[0068] like Figure 3 and Figure 4 As shown, the seal 80 is formed into an annular structure and is mounted on a portion of the circumferential sidewall of the terminal 20. The seal 80 can be a sealing ring made of fluororubber. Along the length of the battery cell, a portion of the seal 80 is sandwiched between the cover body 40 and the connecting portion 21 to ensure the sealing of the cover assembly 200. Preferably, the first insulating member 60 and the second insulating member 70 are respectively crimped to the seal 80, improving the sealing while completely separating the cover body 40 from the terminal 20 and ensuring insulation reliability.

[0069] According to a battery cell provided by the present invention, a support member is disposed between the electrode group body and the electrode column, and encloses a bending space for accommodating a first electrode tab. A guide portion is formed on the side wall of the support member at one end facing the electrode group, and is bent toward the electrode tab. The first electrode tab is first bent toward the guide portion, and then toward the electrode column, to ensure that a suitable space for bending the electrode tab is formed within the battery cell housing. The support member can, to a certain extent, support the bent first electrode tab, thereby improving the assembly stability of the electrode tab, thereby improving the stability of the battery cell and ensuring the capacity of the battery cell. The guide portion is disposed between the electrode group body and the first electrode tab, thereby separating the electrode group body and the first electrode tab, preventing the electrode tab from being inserted upside down into the electrode group, and ensuring the safety performance of the battery cell.

[0070] A battery pack provided according to the present invention includes the battery cells as described above, wherein a plurality of battery cells are provided, and the plurality of battery cells are connected in series and / or in parallel to form a battery module. The battery module is assembled inside the battery pack shell, and each battery cell in the battery pack has good stability, so that the stability and safety of the battery pack are effectively improved.

[0071] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The scope of protection of the present application is not limited thereto. Although the present application has been described in detail with reference to the above-described embodiments, those skilled in the art should understand that any person skilled in the art can modify or easily conceive of changes to the technical solutions described in the above-described embodiments within the technical scope disclosed in the present application, or perform equivalent replacements for some of the technical features thereof. These modifications, changes, or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application shall be subject to the scope of protection of the claims.

Claims

1. A battery cell, characterized in that: The battery cell comprises: case; A pole group, comprising a pole group body and a first pole ear protruding outward from one end of the pole group body in a first direction, wherein the pole group is arranged in the housing; The cover plate assembly includes a pole and a support member, wherein the first pole tab is connected to the pole post, the support member is arranged between the pole group body and the pole post, and encloses a bending space for accommodating the first pole tab, the support member includes a first side wall, and a guide portion is formed on one end of the first side wall facing the pole group and bent toward the pole post, the guide portion and the first side wall are arranged at an acute angle; the first pole tab is first bent in a direction close to the guide portion, and then bent in a direction close to the pole post, so that in the first direction, the guide portion is arranged between the pole group body and the first pole tab, and the end of the first pole tab connected to the pole group body is arranged on the side of the guide portion facing the pole post, so that the first pole tab is arranged in an S-shaped structure in the bending space; The support member further includes a second side wall spaced apart from the first side wall along the third direction, and the second side wall has no protruding structure on a surface facing the first side wall.

2. The battery cell according to claim 1, characterized in that The length of the first tab is M, 15 mm ≤ M ≤ 25 mm.

3. The battery cell according to claim 1 or 2, characterized in that: The dimension of the support member in the first direction is H, 5mm≤H≤7.5mm.

4. The battery cell according to claim 1, characterized in that An angle α between the guide portion and the first side wall is 60°≤α≤80°.

5. The battery cell according to claim 1, characterized in that In the third direction, a distance between an end of the guide portion close to the second side wall and the second side wall is L, and L is ≥ 2 mm.

6. The battery cell according to claim 5, characterized in that In the third direction, a distance between the first side wall and the second side wall opposite to each other is K, where L / K=20%-50%.

7. The battery cell according to claim 1, characterized in that The cover plate assembly further comprises a cover plate body connected to the shell, an exhaust hole is provided on the cover plate body, and an exhaust structure communicating with the exhaust hole and the interior of the battery cell is provided on the support member.

8. The battery cell according to claim 1, characterized in that The poles include a positive pole and a negative pole, and the first tab is connected to the positive pole; The electrode group further includes a second electrode tab protruding outward from the other end of the electrode group body in the first direction, the second electrode tab is connected to the negative electrode column, and the second electrode tab after connection is arranged in a C-shaped structure.

9. The battery cell according to claim 1, characterized in that: The outer wall of the pole group body is covered with an insulating film, part of the insulating film is covered on the side wall of the circumferential outer wall of the support member, and is heat-melted to the support member to form a heat-melting area between the insulating film and the support member.

10. A battery pack, characterized in that: A battery cell comprising the battery cell according to any one of claims 1 to 9.

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