A battery cell and a battery pack

Abstract

This application provides a battery cell and a battery pack, relating to the field of battery technology. The battery cell includes: an end cap, a terminal post disposed on the end cap, an electrode assembly electrically connected to the terminal post, and a housing housing the electrode assembly. The housing includes an end wall and a side wall, the end wall being connected to the side wall, and the end cap being welded to the side wall. The end cap is located on one side of the side wall along a first direction, and the end wall is located on the side of the side wall along the first direction away from the end cap. A reinforcing structure protrudes from the side wall along the first direction near the end cap, and a connecting structure is provided on the edge of the end cap. The position of the connecting structure corresponds to the position of the reinforcing structure, and the reinforcing structure is welded and fixed to the connecting structure. The battery cell provided in this application increases the weld penetration and weld width between the end cap and the housing, thereby increasing the effective weld area and enhancing the weld strength, thus reducing the risk of battery cell explosion.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery cell and a battery pack. Background Technology

[0002] Battery cells are an important component of battery packs. In a battery cell, the connection between the end cap and the casing is usually welded. When a battery cell experiences thermal runaway, the pressure inside the casing continues to rise, and the weld between the end cap and the casing is prone to cracking and exploding due to pressure concentration, thus affecting the safety of the battery cell. Utility Model Content

[0003] In view of this, the purpose of this application is to provide a battery cell and a battery pack, which aims to solve the technical problem that the weld between the end cap and the housing is prone to cracking and explosion due to pressure concentration.

[0004] To achieve the above objectives, the technical solution adopted in this application is as follows:

[0005] In a first aspect, embodiments of this application provide a battery cell having a first orientation and comprising: an end cap; a terminal post disposed on the end cap; an electrode assembly electrically connected to the terminal post; and a housing housing the electrode assembly. The housing includes an end wall and a side wall, the end wall being connected to the side wall, the end cap being welded to the side wall, the end cap being located on one side of the side wall along the first orientation, and the end wall being located on the side of the side wall along the first orientation away from the end cap. A reinforcing structure protrudes from the side wall along the first orientation near the end cap, and a connecting structure is provided on the edge of the end cap. The position of the connecting structure corresponds to the position of the reinforcing structure, and the reinforcing structure is welded and fixed to the connecting structure.

[0006] In some embodiments of the first aspect, the reinforcing structure is located on the side of the sidewall opposite to the electrode assembly, and the connecting structure is a protrusion located on the side of the end cap close to the electrode assembly along the first direction.

[0007] In some embodiments of the first aspect, the reinforcing structure is located on the side of the sidewall facing the electrode assembly, the connecting structure is a recessed portion recessed in a direction away from the sidewall, the recessed portion is located on the outer peripheral side of the end cap, and the reinforcing structure is disposed in close contact with the recessed portion.

[0008] In some embodiments of the first aspect, the shape of the reinforcing structure and the recessed portion as orthogonal projections of the end wall along the first direction is trapezoidal.

[0009] In some embodiments of the first aspect, both the number of reinforcing structures and the number of connecting structures are multiple, and the multiple reinforcing structures and the multiple connecting structures are distributed at circumferential intervals along the electrode assembly, with the multiple connecting structures being welded and fixed to the multiple reinforcing structures in a one-to-one correspondence.

[0010] In some embodiments of the first aspect, a thermally conductive coating is provided on the side of the reinforcing structure opposite to the sidewall.

[0011] In some embodiments of the first aspect, a gap exists between the reinforcing structure and the electrode assembly along the first direction.

[0012] In some embodiments of the first aspect, the sidewall has a corner portion; a gap exists between the reinforcing structure and the corner portion along the circumferential direction of the electrode assembly.

[0013] In some embodiments of the first aspect, the battery cell further includes an insulating member located on the side of the end cap away from the electrode assembly along the first direction, and the insulating member is disposed between the terminal post and the end cap; a gap is formed between the reinforcing structure and the insulating member along the first direction.

[0014] In some embodiments of the first aspect, the reinforcing structure and the sidewall are integrally formed; and / or, the connecting structure and the end cap are integrally formed.

[0015] In some embodiments of the first aspect, the reinforcing structure includes a gradient portion and a non-gradient portion, the positions of which correspond to the positions of the connecting structure. The gradient portion is connected to the side of the non-gradient portion near the end wall along the first direction. Both the gradient portion and the non-gradient portion are welded and fixed to the connecting structure. The dimension of the gradient portion in the thickness direction of the side wall is T1, and the dimension of the non-gradient portion in the thickness direction of the side wall is T2, satisfying: T1≤T2. Along the first direction, the dimension of the gradient portion in the thickness direction of the side wall gradually decreases in the direction near the end wall.

[0016] Secondly, embodiments of this application provide a battery pack including the battery cells described in any of the embodiments of the first aspect above.

[0017] The beneficial effects of this application are as follows:

[0018] In the battery cell provided in this application, the end cap is welded to the side wall, and a reinforcing structure is protruding on the side of the side wall near the end cap along the first direction. A connecting structure is provided on the edge of the end cap, and the position of the connecting structure corresponds to the position of the reinforcing structure. The connecting structure is welded and fixed to the reinforcing structure. This increases the weld depth and width between the end cap and the shell, thereby increasing the effective welding area and achieving the effect of enhancing the weld strength, thereby reducing the risk of battery cell explosion.

[0019] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This application shows a schematic diagram of the structure of a single battery cell from one perspective in some embodiments;

[0022] Figure 2 It shows Figure 1 A schematic diagram of the decomposed structure;

[0023] Figure 3 It shows Figure 2 Enlarged structural diagram of region A in the middle;

[0024] Figure 4 This application shows a schematic diagram of the battery cell from another perspective in some embodiments;

[0025] Figure 5 This illustration shows another perspective structural diagram of a battery cell in some embodiments of this application;

[0026] Figure 6 It shows Figure 5 A magnified structural diagram of region B in the middle;

[0027] Figure 7 A schematic diagram of the battery cell from one perspective is shown in some other embodiments of this application;

[0028] Figure 8 It shows Figure 7 A schematic diagram of the decomposed structure;

[0029] Figure 9 It shows Figure 8 A magnified structural diagram of region C in the middle;

[0030] Figure 10 It shows Figure 8 A magnified structural diagram of region D in the middle;

[0031] Figure 11 It shows Figure 10 A schematic diagram showing a thermally conductive coating on a reinforced structure.

[0032] Explanation of key component symbols:

[0033] 100 - Battery cell; 110 - End cap; 111 - Connection structure; 1111 - Protrusion; 1112 - Recess; 120 - Terminal post; 130 - Electrode assembly; 140 - Housing; 141 - End wall; 142 - Side wall; 1421 - Corner; 143 - Reinforcing structure; 1431 - Gradient section; 1432 - Non-gradient section; 144 - Thermally conductive coating; 150 - Pressure relief structure; 160 - Insulating component; X - Third direction; Y - Second direction; Z - First direction. Detailed Implementation

[0034] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0035] In the description of this application, the terms "center", "longitudinal", "lateral", "length", "width", "height", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, 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 this application.

[0036] Furthermore, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Moreover, "above" or "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below" or "below" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0037] In the description of this application, the terms "first," "second," etc., are used to distinguish different objects and should not be construed as indicating or implying a specific order or primary / secondary relationship, or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature.

[0038] In the description of this application, the term "multiple" means two or more, unless otherwise explicitly specified. The term "multiple A and multiple B in one-to-one correspondence" can be understood as: the number of A and the number of B are the same, and there is a one-to-one mapping relationship, that is, each A corresponds to only one B, and each B also corresponds to only one A.

[0039] In the description of this application, unless otherwise explicitly specified, the terms "installation," "connection," "attachment," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0040] In the description of this application, the term "and / or" can be understood to mean three possibilities. For example, A and / or B can represent: A alone; A and B simultaneously; or B alone. Additionally, the character " / " generally indicates that the preceding and following objects have an "or" relationship.

[0041] In the description of this application, "parallel" includes not only the case of absolute parallelism, but also the case of approximate parallelism as commonly understood in engineering; similarly, "perpendicular" also includes not only the case of absolute perpendicularity, but also the case of approximate perpendicularity as commonly understood in engineering. For example, if the angle between two directions is 80° to 90°, the two directions can be considered perpendicular; if the angle between two directions is 0° to 10°, the two directions can be considered parallel.

[0042] The battery cell is a crucial component of the battery pack. Within a battery cell, the connection between the end cap and the casing is typically welded. During welding, the portion of the end cap that melts due to heat and the portion of the casing that melts due to heat form a weld. When a battery cell experiences thermal runaway, the pressure inside the casing continues to rise, and this weld is prone to cracking and exploding due to pressure concentration, thus affecting the safety of the battery cell.

[0043] like Figure 1 and Figure 7As shown, to solve the above-mentioned technical problems, embodiments of this application provide a battery cell 100, which relates to the field of battery technology and is mainly used in battery packs, so as to be indirectly used in electrical devices or energy storage devices in the form of battery packs. Of course, the battery cell 100 can also be directly used in electrical devices or energy storage devices without taking the form of a battery pack, and no specific limitation is made to the application scenarios of the battery cell 100 here.

[0044] For example, electrical devices can be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools. Vehicles can be gasoline-powered cars, natural gas-powered cars, new energy vehicles, etc., and new energy vehicles can be pure electric vehicles, hybrid electric vehicles, range-extended electric vehicles, etc.; spacecraft can be airplanes, rockets, space shuttles, drones, spacecraft, etc.; electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys; power tools can be metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers; energy storage devices include energy storage containers, energy storage cabinets, energy storage power stations, wind power generation devices, solar power generation devices, mobile power devices, temporary power supply devices, etc.; no specific limitations are made on the types of electrical devices and energy storage devices here.

[0045] like Figure 1 , Figure 2 , Figure 7 and Figure 8 As shown, the battery cell 100 provided in this embodiment includes: end cap 110, terminal post 120, electrode assembly 130 and housing 140.

[0046] The electrode post 120 is disposed on the end cap 110; the electrode assembly 130 is electrically connected to the electrode post 120; the housing 140 houses the electrode assembly 130 (i.e., the electrode assembly 130 is located inside the housing 140), the housing 140 includes an end wall 141 and a side wall 142, the end wall 141 is connected to the side wall 142, the end cap 110 is welded to the side wall 142, the end cap 110 is located on the side of the side wall 142 along the first direction Z, and the end wall 141 is located on the side of the side wall 142 away from the end cap 110 along the first direction Z; the side wall 142 is provided with a reinforcing structure 143 protruding on the side of the side wall 142 close to the end cap 110 along the first direction Z, and a connecting structure 111 is provided on the edge of the end cap 110, the position of the connecting structure 111 corresponds to the position of the reinforcing structure 143, and the reinforcing structure 143 is welded and fixed to the connecting structure 111.

[0047] For example, the material of the end cap 110 and / or the housing 140 can be aluminum, aluminum alloy, copper, iron, stainless steel, plastic, etc., and no specific limitation is made here.

[0048] It should be noted that "the position of the connecting structure 111 corresponds to the position of the reinforcing structure 143" can be understood as: along the thickness direction of the side wall 142, the orthographic projection of the connecting structure 111 on the side wall 142 and the orthographic projection of the reinforcing structure 143 on the side wall 142 at least partially overlap.

[0049] For example, the material of the electrode 120 can be a metallic conductive material such as copper, aluminum, silver, gold, iron, nickel, etc., or a non-metallic conductive material such as carbon-based material, superconductor, semiconductor, etc., without specific limitations.

[0050] It is understood that in the battery cell 100 provided in this embodiment, the end cap 110 is welded to the side wall 142. The side wall 142 is provided with a reinforcing structure 143 protruding along the first direction Z near the end cap 110. The edge of the end cap 110 is provided with a connecting structure 111. The position of the connecting structure 111 corresponds to the position of the reinforcing structure 143. The connecting structure 111 and the reinforcing structure 143 are welded and fixed. This increases the weld depth and width between the end cap 110 and the shell 140, thereby increasing the effective welding area and achieving the effect of enhancing the weld strength, thereby reducing the risk of the battery cell 100 exploding.

[0051] like Figures 1 to 3 As shown, in some embodiments, the reinforcing structure 143 is located on the side of the sidewall 142 opposite to the electrode assembly 130 (i.e., the reinforcing structure 143 is located on the outer periphery of the sidewall 142), and the connecting structure 111 is a protrusion 1111, which is located on the side of the end cap 110 close to the electrode assembly 130 along the first direction Z. Thus, by welding the reinforcing structure 143 to the protruding structure, the weld penetration and width between the end cap 110 and the housing 140 are increased, thereby increasing the effective welding area and achieving the effect of enhancing weld strength.

[0052] like Figures 7 to 9 As shown, in some other embodiments, the reinforcing structure 143 is located on the side of the sidewall 142 facing the electrode assembly 130 (i.e., the reinforcing structure 143 is located on the inner peripheral side of the sidewall 142), the connecting structure 111 is a recessed portion 1112 recessed in a direction away from the sidewall 142, the recessed portion 1112 is located on the outer peripheral side of the end cap 110, and the reinforcing structure 143 is disposed in contact with the recessed portion 1112.

[0053] It is understandable that by strengthening the welding of structure 143 and recess 1112, the weld penetration and width of end cap 110 and shell 140 are also increased, thereby increasing the effective welding area and achieving the effect of enhancing weld strength.

[0054] Furthermore, since the reinforcing structure 143 is fitted to the recessed portion 1112, this fitting design can be understood as the reinforcing structure 143 being housed in the recessed portion 1112, and the shape of the reinforcing structure 143 matching the shape of the recessed portion 1112. This increases the contact area between the reinforcing structure 143 and the recessed portion 1112, thereby improving the reliability of their welding.

[0055] like Figure 5 as well as Figures 8 to 10 As shown, further, the shapes of the orthogonal projections of the reinforcing structure 143 and the recessed portion 1112 along the first direction Z on the end wall 141 are both trapezoidal. The trapezoidal shape design can increase the contact area between the reinforcing structure 143 and the recessed portion 1112, thereby improving the reliability of their welding.

[0056] Of course, the shape of the orthographic projection of the reinforcing structure 143 and the recess 1112 along the first direction Z onto the end wall 141 is not limited to a trapezoid. The shape can also be an arc, a rectangle, a triangle, etc., without specific limitations here.

[0057] like Figure 5 and Figure 6 As shown, in some embodiments, the reinforcing structure 143 includes a gradient portion 1431 and a non-gradient portion 1432. The positions of the gradient portion 1431 and the non-gradient portion 1432 correspond to the positions of the connecting structure 111. The gradient portion 1431 is connected to the side of the non-gradient portion 1432 along the first direction Z near the end wall 141. Both the gradient portion 1431 and the non-gradient portion 1432 are welded and fixed to the connecting structure 111. The dimension of the gradient portion 1431 in the thickness direction of the side wall 142 is T1, and the dimension of the non-gradient portion 1432 in the thickness direction of the side wall 142 is T2, satisfying: T1≤T2; along the first direction Z, the dimension of the gradient portion 1431 in the thickness direction of the side wall 142 gradually decreases along the direction near the end wall 141.

[0058] It should be noted that the thickness direction of the sidewall 142 can be understood as the direction perpendicular to the first direction Z, that is, the thickness direction of the sidewall 142 is perpendicular to the first direction Z. "The positions of the gradient portion 1431 and the non-gradient portion 1432 correspond to the positions of the connecting structure 111" can be understood as follows: along the thickness direction of the sidewall 142, the orthographic projection of the connecting structure 111 on the sidewall 142 and the orthographic projection of the gradient portion 1431 on the sidewall 142 at least partially coincide, and the orthographic projection of the connecting structure 111 on the sidewall 142 and the orthographic projection of the non-gradient portion 1432 on the sidewall 142 at least partially coincide.

[0059] Understandably, adopting this size gradient design can reduce the volume and weight of the reinforcing structure 143, thereby helping to improve the energy density and structural compactness of the battery cell 100.

[0060] like Figure 2 As shown, in some embodiments, there are multiple reinforcing structures 143 and multiple connecting structures 111. The multiple reinforcing structures 143 and multiple connecting structures 111 are distributed at intervals along the circumference of the electrode assembly 130. The multiple connecting structures 111 are welded and fixed to the multiple reinforcing structures 143 in a one-to-one correspondence. This further increases the weld penetration and weld width between the end cap 110 and the shell 140, thereby further increasing the effective welding area and achieving the effect of further enhancing the weld strength.

[0061] like Figure 8 and Figure 11 As shown, in some embodiments, a thermally conductive coating 144 is provided on the side of the reinforcing structure 143 facing away from the sidewall 142.

[0062] Understandably, the thermally conductive coating 144 can enhance the heat dissipation efficiency of the reinforced structure 143, thereby reducing welding quality problems caused by excessive heat concentration during welding.

[0063] For example, the material of the thermally conductive coating 144 can be aluminum nitride, silicon carbide, boron nitride, etc., without specific limitations.

[0064] It should be noted that, as Figure 10 and Figure 11 As shown, when the reinforcing structure 143 includes a gradient portion 1431 and a non-gradient portion 1432, both the side of the gradient portion 1431 facing away from the sidewall 142 and the side of the non-gradient portion 1432 facing away from the sidewall 142 are covered by a thermally conductive coating 144.

[0065] In some embodiments, a gap exists between the reinforcing structure 143 and the electrode assembly 130 along the first direction Z. This reduces the likelihood of the reinforcing structure 143 interfering with or compressing the electrode assembly 130, thus helping to improve the lifespan of the battery cell 100.

[0066] In some embodiments, the sidewall 142 has a corner portion 1421; along the circumference of the electrode assembly 130, there is a gap between the reinforcing structure 143 and the corner portion 1421, which can be understood as the reinforcing structure 143 being arranged to avoid the corner portion 1421, so that the corner portion 1421 can be extended uniformly during the manufacturing process of the housing 140, reducing the possibility of burrs and deformation of the corner portion 1421 causing indentations.

[0067] It should be noted that the sidewall 142 can be understood as the part of the housing 140 surrounding the outer periphery of the electrode assembly 130. The sidewall 142 includes multiple wall portions, and adjacent two wall portions are connected and transitioned through a corner portion 1421. That is, the corner portion 1421 is the part where adjacent two wall portions of the sidewall 142 are connected and transitioned.

[0068] like Figure 7 and Figure 8 As shown, in some embodiments, the battery cell 100 further includes an insulating member 160, which is located on the side of the end cap 110 away from the electrode assembly 130 along the first direction Z, and the insulating member 160 is disposed between the terminal post 120 and the end cap 110 to achieve insulation between the end cap 110 and the terminal post 120; along the first direction Z, there is a gap between the reinforcing structure 143 and the insulating member 160, which can reduce the impact of the heat generated during the welding of the reinforcing structure 143 on the insulating member 160, thereby reducing the risk of insulation failure caused by the insulating member 160 melting due to heat.

[0069] For example, the materials of the insulating component 160 can be selected from the following categories: 1. Synthetic organic insulating materials: plastics such as polyethylene, polyvinyl chloride, polypropylene, polytetrafluoroethylene, epoxy resin, etc.; synthetic rubbers such as silicone rubber, nitrile rubber, etc.; synthetic fibers such as polyester fiber, nylon, etc.; 2. Natural organic insulating materials: wood, natural rubber, etc.; 3. Inorganic insulating materials: ceramics, glass, mica, quartz, asbestos, etc.; 4. Polymer insulating materials: polycarbonate, polyimide, etc., without specific limitations.

[0070] like Figures 8 to 10 As shown, in some embodiments, the reinforcing structure 143 and the sidewall 142 are integrally formed; and / or, the connecting structure 111 and the end cap 110 are integrally formed. This facilitates processing and manufacturing, reduces manufacturing costs, and the integral structure has higher strength and stability.

[0071] It should be noted that a unibody structure can be understood as a structure made using a unibody molding process, such as stamping, injection molding, die casting, extrusion, blow molding, 3D printing, etc., without any specific limitations here.

[0072] like Figure 1 , Figure 2 and Figure 4 As shown, in one embodiment, the battery cell 100 further includes a pressure relief structure 150 disposed on the housing 140, and the pressure relief structure 150 and the end cap 110 are disposed opposite each other along the first direction Z. This ensures that the terminal post 120 and the pressure relief structure 150 are far apart, achieving thermoelectric separation. That is, when the high-temperature, high-pressure gas generated by thermal runaway of the battery cell 100 is discharged through the pressure relief structure 150, it is less likely to affect the terminal post 120, thereby improving the safety of the battery cell 100.

[0073] It should be noted that the battery cell 100 provided in this embodiment mainly relies on the movement of metal ions between the positive and negative electrode plates to operate. The battery cell 100 can be cuboid, cylindrical, flat, or other shapes, and no specific limitation is made here. According to the packaging method, the battery cell 100 provided in this embodiment can be a square battery, a cylindrical battery, a pouch battery, etc., and no specific limitation is made here.

[0074] Furthermore, according to the classification of the physical state of the electrolyte, the battery cell 100 provided in this embodiment can be a liquid battery, that is, it uses a liquid electrolyte. Exemplarily, the electrode post 120 may include a positive electrode post and a negative electrode post. The electrode assembly 130 can be manufactured using a winding process or a stacking process, and the number can be one or more. The electrode assembly 130 may include an electrode body and electrode tabs, the electrode tabs including a positive electrode tab and a negative electrode tab. The electrode body is immersed in the liquid electrolyte and includes a positive electrode sheet, a negative electrode sheet, and a separator layer. The separator layer is disposed between the positive electrode sheet and the negative electrode sheet, and the material of the separator layer can be polypropylene, polyethylene, etc. The positive electrode sheet includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector. The positive electrode tab is connected to the positive current collector and to the positive electrode post. The negative electrode sheet includes a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative current collector. The negative electrode tab is connected to the negative current collector and to the negative electrode post. Taking lithium ions as an example, the materials for the positive electrode current collector and the positive electrode tab can be aluminum, and the materials for the positive electrode active material layer can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, lithium manganese oxide, etc.; the materials for the negative electrode current collector and the negative electrode tab can be copper, and the negative electrode active material can be graphite, silicon, etc.

[0075] Of course, the battery cell 100 provided in this embodiment can also be a solid-state battery, that is, a solid electrolyte, such as sulfide, oxide or polymer electrolyte. Solid electrolyte can replace the separator and liquid electrolyte, and has both ion conduction and isolation functions. The type of battery cell 100 is not specifically limited here.

[0076] It should be noted that when the battery cell 100 has a first direction Z, a second direction Y and a third direction X that are perpendicular to each other, the multiple electrode assemblies 130 are arranged along the second direction Y, and the positive electrode post and the negative electrode post are arranged alternately along the third direction X.

[0077] To address the aforementioned technical problems, embodiments of this application also provide a battery pack, including the battery cell 100 from any of the above embodiments.

[0078] It should be noted that in the battery pack, the side wall 142 of the housing 140 is usually limited by the side plate and the end plate to fix the battery cell 100. On this basis, when the reinforcing structure 143 is located on the side of the side wall 142 away from the electrode assembly 130, the side plate and / or the end plate can be provided with a recessed area to accommodate the reinforcing structure 143, so as to avoid the protruding reinforcing structure 143. This helps to avoid the battery cell 100 from being affected by uneven local stress in the housing 140 in the battery pack.

[0079] It is understood that since the battery pack provided in this embodiment has the battery cell 100 in any of the above embodiments, it has all the beneficial effects of the battery cell 100, which will not be described in detail here.

[0080] In the description of this application, the terms "some embodiments," "one embodiment," "example," "specific example," "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In the description of this application, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0081] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A battery cell, characterized in that, It has a first direction (Z) and includes: End cap (110); A pole post (120) is disposed on the end cap (110); Electrode assembly (130) is electrically connected to the electrode post (120); A housing (140) houses the electrode assembly (130). The housing (140) includes an end wall (141) and a side wall (142). The end wall (141) is connected to the side wall (142). An end cap (110) is welded to the side wall (142). The end cap (110) is located on one side of the side wall (142) along the first direction (Z). The end wall (141) is located on the side of the side wall (142) along the first direction (Z) away from the end cap (110). A reinforcing structure (143) is provided on the side of the side wall (142) along the first direction (Z) near the end cap (110). A connecting structure (111) is provided on the edge of the end cap (110). The position of the connecting structure (111) corresponds to the position of the reinforcing structure (143). The reinforcing structure (143) is welded and fixed to the connecting structure (111).

2. The battery cell according to claim 1, characterized in that, The reinforcing structure (143) is located on the side of the sidewall (142) away from the electrode assembly (130), and the connecting structure (111) is a protrusion (1111) located on the side of the end cap (110) close to the electrode assembly (130) along the first direction (Z).

3. The battery cell according to claim 1, characterized in that, The reinforcing structure (143) is located on the side of the sidewall (142) facing the electrode assembly (130), and the connecting structure (111) is a recessed portion (1112) recessed in a direction away from the sidewall (142). The recessed portion (1112) is located on the outer periphery of the end cap (110), and the reinforcing structure (143) is fitted to the recessed portion (1112).

4. The battery cell according to claim 3, characterized in that, The shape of the reinforcing structure (143) and the recess (1112) along the first direction (Z) on the end wall (141) is trapezoidal.

5. The battery cell according to any one of claims 1 to 4, characterized in that, The number of the reinforcing structure (143) and the number of the connecting structure (111) are both multiple. The multiple reinforcing structures (143) and the multiple connecting structures (111) are distributed circumferentially along the electrode assembly (130). The multiple connecting structures (111) are welded and fixed to the multiple reinforcing structures (143) one by one.

6. The battery cell according to any one of claims 1 to 4, characterized in that, The reinforcing structure (143) has a thermally conductive coating (144) on the side opposite to the sidewall (142).

7. The battery cell according to any one of claims 1 to 4, characterized in that, Along the first direction (Z), there is a gap between the reinforcing structure (143) and the electrode assembly (130).

8. The battery cell according to any one of claims 1 to 4, characterized in that, The sidewall (142) has a corner portion (1421); a gap exists between the reinforcing structure (143) and the corner portion (1421) along the circumference of the electrode assembly (130).

9. The battery cell according to any one of claims 1 to 4, characterized in that, The battery cell further includes an insulating element (160), which is located on the side of the end cap (110) away from the electrode assembly (130) along the first direction (Z), and the insulating element (160) is disposed between the terminal post (120) and the end cap (110); along the first direction (Z), there is a gap between the reinforcing structure (143) and the insulating element (160).

10. The battery cell according to any one of claims 1 to 4, characterized in that, The reinforcing structure (143) and the side wall (142) are integrally formed; and / or, the connecting structure (111) and the end cap (110) are integrally formed.

11. The battery cell according to claim 1, characterized in that, The reinforcing structure (143) includes a gradient portion (1431) and a non-gradient portion (1432). The positions of the gradient portion (1431) and the non-gradient portion (1432) correspond to the positions of the connecting structure (111). The gradient portion (1431) is connected to the side of the non-gradient portion (1432) along the first direction (Z) near the end wall (141). Both the gradient portion (1431) and the non-gradient portion (1432) are welded and fixed to the connecting structure (111). The dimension of the gradient portion (1431) in the thickness direction of the side wall (142) is T1, and the dimension of the non-gradient portion (1432) in the thickness direction of the side wall (142) is T2, satisfying: T1≤T2; along the first direction (Z), the dimension of the gradient portion (1431) in the thickness direction of the side wall (142) gradually decreases along the direction near the end wall (141).

12. A battery pack, characterized in that, Includes the battery cell according to any one of claims 1 to 11.

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