Battery cell, battery, and electrical device

Abstract

A battery cell, a battery, and an electrical device. The battery cell (20) comprises a casing (21) and an electrode assembly (23), the casing (21) having an accommodating space (2111). The casing (21) comprises an end wall assembly (212), the side of the end wall assembly (212) facing the accommodating space (2111) being provided with a first accommodating groove (21222). The electrode assembly (23) is accommodated in the accommodating space (2111). The electrode assembly (23) comprises a tab (231), at least part of the tab (231) being accommodated in the first accommodating groove (21222).

Description

Battery cells, batteries and electrical equipment

[0001] Cross-references

[0002] This application refers to Chinese patent application No. 202420027640.0, filed on January 5, 2024, entitled “Battery Cell, Battery and Electrical Equipment”, which is incorporated into this application in its entirety by reference. Technical Field

[0003] The present application relates to the field of battery technology, and in particular to a battery cell, a battery, and an electrical device. Background Art

[0004] Energy conservation and emission reduction are key to the sustainable development of the automotive industry. Electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important part of the sustainable development of the automotive industry. For electric vehicles, battery technology is a key factor in their development.

[0005] The battery includes a battery cell, the battery cell includes an electrode assembly, the electrode assembly includes a pole ear, and the pole ear has a bending portion. Since the bending portion of the pole ear needs to occupy more internal space of the battery cell, the volume energy density of the battery cell decreases, which is not conducive to improving the endurance performance of electric vehicles.

[0006] Summary of the Invention

[0007] One of the purposes of the embodiments of the present application is to provide a battery cell, a battery, and an electrical device, aiming to solve the technical problem of low volume energy density of battery cells in the related art.

[0008] In order to solve the above technical problems, the technical solution adopted in the embodiment of the present application is: a battery cell is provided, including a shell and an electrode assembly, the shell has a accommodating space, the shell includes an end wall assembly, and a first accommodating groove is opened on the side of the end wall assembly facing the accommodating space, the electrode assembly is accommodated in the accommodating space, the electrode assembly includes a pole ear, and at least part of the pole ear is accommodated in the first accommodating groove.

[0009] The beneficial effect of the battery cell provided by the embodiment of the present application is that: the end wall assembly of the battery cell provided by the embodiment of the present application is provided with a first accommodating groove on the side facing the accommodating space, and at least part of the bent portion of the pole ear protruding toward the direction close to the end wall assembly can be accommodated in the first accommodating groove, so that the bending space reserved for the pole ear can be reduced, and the assembly structure between the end wall assembly and the pole ear can be made more compact, effectively reducing the space occupied by the end wall assembly and the pole ear, thereby effectively improving the volume energy density of the battery cell.

[0010] In some embodiments of the present application, the end wall assembly includes an end wall body and a first insulating member, the first insulating member is arranged on the side of the end wall body facing the electrode assembly, and the first accommodating groove is opened on the side of the first insulating member facing the electrode assembly.

[0011] By adopting the above technical solution, it is convenient to accommodate at least a portion of the tab in the first accommodating groove.

[0012] In some embodiments of the present application, a second accommodating groove is formed on a side of the end wall body facing the electrode assembly, and at least a portion of the first insulating member is accommodated in the second accommodating groove.

[0013] By adopting the above technical solution, the structure of the end wall assembly can be made more compact, further reducing the space occupied by the end wall assembly, thereby further improving the volume energy density of the battery cell.

[0014] In some embodiments of the present application, the first insulating member includes an insulating body and a first boss, the first accommodating groove is opened on the side of the insulating body facing the electrode assembly, the first boss is protruded on the side of the insulating body facing the end wall body and is arranged opposite to the first accommodating groove, and at least a portion of the first boss is accommodated in the second accommodating groove.

[0015] By adopting the above technical solution, on the one hand, the thickness of the portion of the first insulating member corresponding to the first accommodating groove can be effectively increased, thereby effectively improving the structural strength of the first insulating member. On the other hand, by accommodating at least part of the first boss in the second accommodating groove, the structure of the end wall assembly can be made more compact, thereby further improving the volume energy density of the battery cell.

[0016] In some embodiments of the present application, the outer wall of the first boss is loosely matched with the groove wall of the second accommodating groove.

[0017] By adopting the above technical solution, it is convenient to assemble the first boss into the second receiving groove.

[0018] In some embodiments of the present application, the width of the gap between the outer wall of the first boss and the groove wall of the second receiving groove is 0.1 mm-0.3 mm.

[0019] By adopting the above technical solution, it is not only convenient to assemble the first boss into the second accommodating groove, but also the first boss can have a sufficient covering area so that the first boss can fully cover the first accommodating groove, effectively increasing the thickness of the part of the first insulating member corresponding to the first accommodating groove, thereby effectively improving the structural strength of the first insulating member.

[0020] In some embodiments of the present application, the first insulating member includes an insulating body and a protrusion, the first receiving groove is opened on the insulating body, and the protrusion is arranged on the side of the insulating body and protrudes from the insulating body toward the electrode assembly.

[0021] By adopting the above technical solution, the insulation performance between the tab and the shell can be improved.

[0022] In some embodiments of the present application, the ratio of the depth of the second receiving groove to the maximum thickness of the end wall is 0.1-0.7.

[0023] By adopting the above technical solution, not only can the second accommodating groove have sufficient space to accommodate at least part of the first insulating member, but the situation where the thickness of the portion of the end wall corresponding to the second accommodating groove is too small can also be effectively improved, so that the end wall has sufficient structural strength.

[0024] In some embodiments of the present application, the housing further includes a peripheral wall defining an accommodation space, and the end wall body is an end cover, which is provided on the end side of the peripheral wall to seal the accommodation space.

[0025] By adopting the above technical solution, the space occupied by the end caps and the tabs is effectively reduced, thereby effectively improving the volume energy density of the battery cell.

[0026] In some embodiments of the present application, the distance between the surface of the inner wall of the end cover facing the peripheral wall and the second receiving groove is 1 mm-5 mm.

[0027] By adopting the above technical solution, a sufficient welding area can be provided between the end cover and the peripheral wall, thereby effectively improving the connection strength between the end cover and the peripheral wall.

[0028] In some embodiments of the present application, the battery cell also includes a terminal assembly connected to the pole ear, a third accommodating groove is provided on the side of the end wall body facing away from the first insulating member, the terminal assembly is arranged on the end wall body and at least a part of the terminal assembly located outside the accommodating space is accommodated in the third accommodating groove, and the third accommodating groove and the second accommodating groove are staggered along a direction perpendicular to the thickness direction of the end wall assembly.

[0029] By adopting the above-mentioned technical solution, not only can the protruding height of the terminal assembly from the end wall to the outside of the battery cell be effectively reduced, thereby further improving the volume energy density of the battery cell, but also the overlap of the second accommodating groove and the third accommodating groove along the thickness direction of the end wall be effectively improved, so that the parts of the end wall corresponding to the second accommodating groove and the third accommodating groove have sufficient thickness, thereby effectively improving the structural strength of the end wall.

[0030] In some embodiments of the present application, the battery cell also includes a terminal assembly connected to the electrode tab, a third accommodating groove is provided on the side of the end wall body facing away from the first insulating member, the terminal assembly is arranged on the end wall body and at least a portion of the end of the terminal assembly away from the electrode assembly is accommodated in the third accommodating groove.

[0031] By adopting the above technical solution, the protruding height of the terminal assembly from the end wall to the outside of the battery cell is effectively reduced, thereby further improving the volume energy density of the battery cell.

[0032] In some embodiments of the present application, the terminal assembly includes an electrode terminal and a second insulating member disposed between the electrode terminal and the end wall body, and at least a portion of the second insulating member is accommodated in the third accommodating groove.

[0033] By adopting the above technical solution, the protruding height of the terminal assembly from the end wall to the outside of the battery cell is effectively reduced, thereby further improving the volume energy density of the battery cell.

[0034] In some embodiments of the present application, the end wall body includes a main body and a second boss, the third accommodating groove is opened on the side of the main body facing away from the first insulating member, and the second boss is protruded on the side of the main body facing the first insulating member and is arranged opposite to the third accommodating groove.

[0035] By adopting the above technical solution, the thickness of the portion of the end wall corresponding to the third receiving groove is effectively increased, thereby effectively improving the structural strength of the end wall.

[0036] In some embodiments of the present application, a protruding height of the second boss relative to a side of the main body facing the first insulating member is 0.1 mm-0.3 mm.

[0037] By adopting the above technical solution, not only the thickness of the portion of the end wall corresponding to the third receiving groove is effectively increased, thereby effectively improving the structural strength of the end wall, but also the second boss will not occupy too much space due to the excessive protruding height of the second boss, thereby further improving the volume energy density of the battery cell.

[0038] In some embodiments of the present application, the battery cell further includes a terminal assembly connected to the tab, a fourth accommodating groove is provided on the side of the end wall assembly facing the electrode assembly, and at least a portion of the terminal assembly located in the accommodating space is accommodated in the fourth accommodating groove.

[0039] By adopting the above technical solution, the assembly structure between the terminal assembly and the end wall assembly can be made more compact, effectively reducing the space occupied by the terminal assembly and the end wall assembly, thereby further improving the volume energy density of the battery cell.

[0040] In some embodiments of the present application, the shell also includes a peripheral wall, the end wall assembly is connected to the end side of the peripheral wall, the battery cell also includes a terminal assembly arranged on the end wall assembly, the terminal assembly includes a first connecting portion arranged in the accommodating space, the accommodating space includes a first accommodating area located between the first connecting portion and the inner wall surface of the peripheral wall, the electrode assembly also includes an electrode body, the electrode ear includes a second connecting portion connected to the first connecting portion and a bending portion connected between the second connecting portion and the electrode body, at least a portion of the bending portion is accommodated in the first accommodating groove, and at least another portion of the bending portion is accommodated in the first accommodating area.

[0041] By adopting the above technical solution, the bent portion of the tab can fully utilize the first accommodating area of ​​the accommodating space, effectively optimizing the internal space layout structure of the battery cell, effectively improving the space utilization rate of the battery cell, and further improving the volume energy density of the battery cell.

[0042] In some embodiments of the present application, the second connection portion is directly connected to the first connection portion.

[0043] By adopting the above technical solution, there is no need to set up additional adapters, which effectively reduces the number of components of the battery cell, thereby effectively reducing the volume of the battery cell and further improving the volume energy density of the battery cell.

[0044] An embodiment of the present application further provides a battery, comprising the battery cell described in any of the above embodiments.

[0045] The beneficial effect of the battery provided by the embodiment of the present application is that the battery provided by the embodiment of the present application effectively improves the volume energy density of the battery due to the use of the battery cell described in any of the above embodiments.

[0046] An embodiment of the present application also provides an electrical device including the above-mentioned battery.

[0047] The beneficial effect of the electric device provided by the embodiment of the present application is that the electric device provided by the embodiment of the present application effectively improves the endurance performance of the electric device due to the use of the above-mentioned battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or exemplary technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0049] FIG1 is a schematic structural diagram of a vehicle provided in an embodiment of the present application;

[0050] FIG2 is a schematic diagram of an exploded structure of a battery provided in an embodiment of the present application;

[0051] FIG3 is a schematic structural diagram of a battery cell provided in an embodiment of the present application;

[0052] FIG4 is a schematic diagram of the exploded structure of the battery cell shown in FIG3 ;

[0053] FIG5 is a schematic diagram of the top view of the battery cell shown in FIG3 ;

[0054] FIG6 is a schematic cross-sectional view of the battery cell shown in FIG5 along line AA;

[0055] FIG7 is an enlarged structural diagram of the battery cell at position B shown in FIG6 ;

[0056] FIG8 is an enlarged structural diagram of a portion C of the battery cell shown in FIG7 .

[0057] Description of reference numerals:

[0058] 1000, vehicle;

[0059] 100. Battery;

[0060] 10. Box body; 11. First part; 12. Second part;

[0061] 20. Battery cell; 21. Housing; 211. Housing; 2111. Accommodation space; 21111. First accommodation area; 21112. Second accommodation area; 212. End wall assembly; 2121. End wall body; 21211. Main body; 21212. Second accommodation groove; 21213. Third accommodation groove; 21214. Second boss; 2122. First insulating member; 21221. Insulating body; 21222. First accommodation groove; 21223. Fourth accommodation groove; 21224. First boss; 21225. Protrusion; 23. Electrode assembly; 231. Tab; 2311. Bend; 2312. Second connecting portion; 232. Electrode body; 24. Terminal assembly; 241. Electrode terminal; 2411. First connecting portion; 242. Second insulating member; 243. Sealing member; 25. Pressure relief mechanism;

[0062] 200, controller;

[0063] 300. Motor. DETAILED DESCRIPTION

[0064] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0065] It should be noted that when a component is referred to as being "fixed on" or "disposed on" another component, it may be directly on the other component or indirectly on the other component. When a component is referred to as being "connected to" another component, it may be directly or indirectly connected to the other component. The terms "upper", "lower", "left", "right", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of description and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on this application. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances. The terms "first" and "second" are only used for the purpose of convenience of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0066] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of the present application shown in the drawings are for illustrative purposes only and should not constitute any limitation on the present application.

[0067] As the smallest unit that makes up a battery, a battery cell generally includes a casing, an electrode assembly, and a terminal assembly. The casing is used to provide a storage space for the electrode assembly. The casing includes an end wall assembly for sealing the above-mentioned storage space. The electrode assembly is the component in the battery cell where the electrochemical reaction occurs. The electrode assembly includes an electrode body and a tab, and the tab is connected to the electrode body. The terminal assembly is arranged on the end wall assembly. A part of the terminal assembly extends into the storage space of the casing and is connected to the tab, and the other part of the terminal assembly is exposed to the external environment of the battery cell and is connected to the busbar to output the electrical energy of the battery cell or input electrical energy into the battery cell.

[0068] In the related art, since the distance between the electrode body and the terminal assembly is usually small, if the tab is directly bent once after being led out from the electrode body and extended to the terminal assembly, it is easy for the tab to break due to the excessive bending angle. At present, in order to reduce the risk of the tab breaking, a large bending space is usually reserved between the end wall assembly of the battery cell and the electrode assembly. The tab can be led out from the electrode body toward the end wall assembly into the bending space, and then be bent in multiple sections or in an arc-shaped structure in the bending space before extending to the terminal assembly. This can effectively reduce the bending angle of the bending part of the tab to reduce the risk of the tab breaking. However, since a large amount of bending space needs to be reserved between the end wall assembly and the electrode assembly of the battery cell, this will cause the volume of the battery cell to increase, thereby causing the volume energy density of the battery cell to decrease.

[0069] In order to improve the volume energy density of the battery cell, the end wall assembly of the battery cell provided in the embodiment of the present application is provided with a first accommodating groove on the side facing the accommodating space, so that at least part of the bent portion of the pole ear protruding toward the end wall assembly can be accommodated in the first accommodating groove. This can reduce the bending space reserved for the pole ear, make the assembly structure between the end wall assembly and the pole ear more compact, effectively reduce the space occupied by the end wall assembly and the pole ear, and thus effectively improve the volume energy density of the battery cell.

[0070] The battery cells, batteries and electrical equipment using the batteries as power sources disclosed in the embodiments of the present application, wherein the electrical equipment may be, but is not limited to, vehicles, mobile phones, portable devices, laptop computers, ships, spacecraft, electric toys and electric tools, etc. The vehicle may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. Spacecraft include airplanes, rockets, space shuttles and spacecraft, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys and electric airplane toys, etc. Electric tools include 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, etc.

[0071] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device in an embodiment of the present application.

[0072] Please refer to Figure 1, which is a structural schematic diagram of a vehicle 1000 provided in an embodiment of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 can be provided at the bottom, head or tail of the vehicle 1000. The battery 100 can be used to power the vehicle 1000. For example, the battery 100 can serve as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0073] In some embodiments of the present application, the battery 100 can serve not only as an operating power source for the vehicle 1000 , but also as a driving power source for the vehicle 1000 , replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000 .

[0074] Please refer to Figure 2, which is an exploded view of a battery 100 according to an embodiment of the present application. The battery 100 includes a housing 10 and a battery cell 20, which is housed within the housing 10. The housing 10 provides space for accommodating the battery cell 20 and can have various structures. In some embodiments, the housing 10 can include a first portion 11 and a second portion 12, which cover each other and together define a space for accommodating the battery cell 20. The second portion 12 can be a hollow structure with one end open. The first portion 11 can be a plate-like structure, with the first portion 11 covering the open side of the second portion 12, so that the first portion 11 and the second portion 12 together define a space for accommodating the battery cell 20. Alternatively, the first portion 11 and the second portion 12 can each be a hollow structure with one end open, with the open side of the first portion 11 covering the open side of the second portion 12. Of course, the housing 10 formed by the first portion 11 and the second portion 12 can have various shapes, such as a cylinder or a rectangular parallelepiped.

[0075] In some embodiments, the box 10 may serve as part of the chassis structure of the vehicle 1000. For example, a portion of the box 10 may form at least a portion of the floor of the vehicle 1000, or a portion of the box 10 may form at least a portion of the cross member and longitudinal member of the vehicle 1000.

[0076] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 may be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 20. The multiple battery cells 20 may be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery cell 20 may be housed within the housing 10. Of course, the battery 100 may also be a battery module formed by first connecting multiple battery cells 20 in series, in parallel, or in a hybrid connection, and then the multiple battery modules are further connected in series, in parallel, or in a hybrid connection to form an entire battery cell, which is then housed within the housing 10. The battery 100 may also include other functional components, such as a busbar for electrically connecting the multiple battery cells 20.

[0077] Each battery cell 20 may be a secondary battery or a primary battery. A secondary battery refers to a battery cell 20 that can be recharged to activate the active material after discharge and continue to be used. A primary battery refers to a battery cell 20 that cannot be recharged to activate the active material after the battery cell 20's power is exhausted and continues to be used. The battery cell 20 may also be a lithium-ion battery, a sodium-ion battery, a sodium-lithium-ion battery, a lithium metal battery, a sodium metal battery, a lithium-sulfur battery, a magnesium-ion battery, a nickel-hydrogen battery, a nickel-cadmium battery, a lead-acid battery, etc., but is not limited thereto. The battery cell 20 may be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell, or a battery cell 20 of another shape. Prismatic battery cells include square-shell battery cells, blade-shaped battery cells, and polygonal prismatic batteries. Polygonal prismatic batteries, for example, hexagonal prismatic batteries, are not particularly limited in this application.

[0078] Of course, in some embodiments, the battery 100 may not include the box body 10 , but instead a plurality of battery cells 20 are electrically connected and formed into a whole through necessary fixing structures and then assembled into an electrical device.

[0079] In order to illustrate the technical solution provided by this application, a detailed description is given below with reference to specific drawings and embodiments.

[0080] First, please refer to Figures 3 to 8 together. An embodiment of the present application provides a battery cell 20, including a shell 21 and an electrode assembly 23. The shell 21 has a accommodating space 2111. The shell 21 includes an end wall assembly 212. The end wall assembly 212 is provided with a first accommodating groove 21222 on the side facing the accommodating space 2111. The electrode assembly 23 is accommodated in the accommodating space 2111. The electrode assembly 23 includes a pole ear 231, and at least a portion of the pole ear 231 is accommodated in the first accommodating groove 21222.

[0081] The outer shell 21 is a component for providing a storage space 2111 for the electrode assembly 23. The outer shell 21 may include a shell 211 and an end cover assembly, wherein the shell 211 may be an independent component, and an opening may be provided on the shell 211. The end cover assembly is covered on the opening to isolate the storage space 2111 from the external environment of the battery cell 20. Specifically, the shell 211 and the end cover assembly may form a common connection surface before other components are put into the shell. When the interior of the shell 211 needs to be encapsulated, the end cover assembly is covered on the opening of the shell 211. Optionally, the shape of the shell 211 may be, but is not limited to, a rectangular parallelepiped, a cylindrical shape, a hexagonal prism, etc. Specifically, the shape of the shell 211 may be determined according to the specific shape and size of the electrode assembly 23. The material of the shell 211 may be, but is not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0082] The end wall assembly 212 refers to a component that covers the opening of the shell 211 to isolate the above-mentioned accommodation space 2111 from the external environment of the battery cell 20. In some embodiments, the end wall assembly 212 can be the above-mentioned end cover assembly. In other embodiments, the end wall assembly 212 can be a bottom wall structure of the shell 211. The shape of the end wall assembly 212 can be adapted to the shape of the shell 211 to match the shell 211. The side of the end wall assembly 212 facing the accommodation space 2111 (that is, the side of the end wall assembly 212 facing the electrode assembly 23) is recessed in the direction away from the electrode assembly 23 to form the above-mentioned first accommodation groove 21222. In some embodiments, the number of the first accommodation groove 21222 can be one. When the number of the pole tabs 231 is multiple, at least part of the multiple pole tabs 231 are accommodated in the first accommodation groove 21222. In other embodiments, there may be multiple first receiving grooves 21222. When there are multiple tabs 231, multiple first receiving grooves 21222 are provided in a one-to-one correspondence with the multiple tabs 231. The shape of the first receiving grooves 21222 may be, but is not limited to, cylindrical, prismatic, etc. In some embodiments, the end wall assembly 212 may also be provided with a pressure relief mechanism 25 for relieving internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold.

[0083] The electrode assembly 23 is the component in the battery cell 20 where the electrochemical reaction occurs. The battery cell 20 may include one or more electrode assemblies 23. In some embodiments, the electrode assembly 23 also includes an electrode body 232. The electrode body 232 is primarily made of a positive electrode sheet, a negative electrode sheet, and a separator using a winding process or a stacking process. Multiple positive and negative electrode sheets may be provided, with multiple positive and negative electrode sheets alternately stacked. In some embodiments, multiple positive electrode sheets may be provided, and the negative electrode sheet is folded to form multiple stacked folded sections, with a positive electrode sheet sandwiched between adjacent folded sections. In other embodiments, both the positive and negative electrode sheets are folded to form multiple stacked folded sections. In some embodiments, multiple separators may be provided, each disposed between any adjacent positive or negative electrode sheets. In other embodiments, the separator may be provided continuously, folded or wound between any adjacent positive or negative electrode sheets. The shape of the electrode body 232 may be, but is not limited to, cylindrical, flat, or polygonal.

[0084] During the charge and discharge process of the battery cell 20, active ions (such as lithium ions) are inserted and removed between the positive and negative electrodes. The separator is arranged between the positive and negative electrodes to prevent short circuits between the positive and negative electrodes while allowing the active ions to pass through.

[0085] The positive electrode sheet may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector. In some embodiments, the positive electrode current collector has two surfaces that are opposite to each other in its thickness direction, and the positive electrode active material is disposed on either or both of the two opposing surfaces of the positive electrode current collector.

[0086] As an example, the positive electrode current collector may be a metal foil, a composite current collector, or a metal foam. For example, the metal foil may be aluminum or stainless steel with a silver surface treatment, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate (such as a substrate made of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.). The metal foam may be nickel foam, copper foam, aluminum foam, alloy foam, or carbon foam. When the metal foam is used as the positive electrode, the positive electrode active material may or may not be provided on the surface of the metal foam. As an example, a lithium source material, potassium metal, or sodium metal may also be filled or / and deposited in the metal foam, where the lithium source material is lithium metal and / or a lithium-rich material.

[0087] As an example, the positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active materials for the battery cell 20 may also be used. These positive electrode active materials may be used alone or in combination of two or more. Among them, examples of lithium-containing phosphates may include but are not limited to at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon. Examples of lithium transition metal oxides may include but are not limited to lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O2), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also referred to as NCM333), LiNi 0.5 Co 0.2 Mn 0.3 O2 (also referred to as NCM523), LiNi 0.5 Co 0.25 Mn 0.25 O2 (also referred to as NCM211), LiNi0.6 Co 0.2 Mn 0.2 O2 (also referred to as NCM622), LiNi 0.8 Co 0.1 Mn 0.1 O2 (also referred to as NCM811), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.1 Al 0.05 O2) and at least one of its modified compounds, etc.

[0088] The negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector. In some embodiments, the negative electrode current collector has two opposing surfaces in its thickness direction, and the negative electrode active material is disposed on either or both of the two opposing surfaces of the negative electrode current collector.

[0089] As an example, the negative electrode current collector can be a metal foil, a composite current collector or a metal foam. For example, as the metal foil, aluminum or stainless steel with a silver surface treatment, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. can be used. The composite current collector may include a polymer material base and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.). The metal foam can be nickel foam, copper foam, aluminum foam, alloy foam, or carbon foam, etc.

[0090] As an example, the negative electrode active material may adopt the negative electrode active material for the battery cell 20 that is well known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for the battery cell 20 may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0091] In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0092] In some embodiments, the separator is an isolation membrane. The present application has no particular restrictions on the type of isolation membrane, and any well-known porous structure isolation membrane with good chemical stability and mechanical stability can be selected. For example, the main material of the isolation membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramics. The isolation membrane can be a single-layer film or a multi-layer composite film. In the case where the isolation membrane is a multi-layer composite film, the materials of each layer can be the same or different. The separator can be a separate component located between the positive electrode sheet and the negative electrode sheet, or it can be attached to the surface of the positive electrode sheet and the surface of the negative electrode sheet.

[0093] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode, and serves to transmit ions and isolate the positive and negative electrodes.

[0094] In some embodiments, the battery cell 20 further includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. This application does not specifically limit the type of electrolyte, and the electrolyte may be selected based on needs. The electrolyte may be, but is not limited to, a liquid electrolyte, a gel electrolyte, a solid electrolyte, or the like.

[0095] The tabs 231 are components for conducting current from the electrode body 232. The tabs 231 include a positive tab and a negative tab. The positive tab is connected to the positive electrode sheet, and the negative tab is connected to the negative electrode sheet.

[0096] In some embodiments, the battery cell 20 may further include a terminal assembly 24, which is disposed on the end wall assembly 212. A portion of the terminal assembly 24 extends into the accommodation space 2111 of the housing 21 and is connected to the electrode tab 231. Another portion of the terminal assembly 24 is exposed to the external environment of the battery cell 20 and is connected to the busbar to output electrical energy from the battery cell 20 or input electrical energy into the battery cell 20. In some embodiments, there may be two terminal assemblies 24, which are spaced apart along the width direction of the battery cell 20 (the X direction as shown in Figures 3 and 4). The pressure relief mechanism 25 may be disposed between the two terminal assemblies 24. One terminal assembly 24 is connected to the positive electrode tab of the electrode assembly 23, and the other terminal assembly 24 is connected to the negative electrode tab of the electrode assembly 23.

[0097] The end wall assembly 212 of the battery cell 20 provided in the embodiment of the present application is provided with a first accommodating groove 21222 on the side facing the accommodating space 2111, so that at least a portion of the bent portion 2311 of the pole ear 231 protruding toward the direction close to the end wall assembly 212 can be accommodated in the first accommodating groove 21222. In this way, the bending space reserved for the pole ear 231 can be reduced, and the assembly structure between the end wall assembly 212 and the pole ear 231 can be made more compact, thereby effectively reducing the space occupied by the end wall assembly 212 and the pole ear 231, thereby effectively improving the volume energy density of the battery cell 20.

[0098] In some embodiments of the present application, please refer to Figures 7 and 8 together. The end wall assembly 212 includes an end wall body 2121 and a first insulating member 2122. The first insulating member 2122 is arranged on the side of the end wall body 2121 facing the electrode assembly 23, and the first accommodating groove 21222 is opened on the side of the first insulating member 2122 facing the electrode assembly 23.

[0099] The end wall 2121 is the main component of the end wall assembly 212. It covers the opening of the housing 211 to isolate the accommodation space 2111 from the external environment of the battery cell 20. In some embodiments, the end wall 2121 can be made of a material with a certain hardness and strength. This prevents the end wall 2121 from deforming when subjected to compression or collision, thereby providing the battery cell 20 with greater structural strength and improved safety. For example, the end wall 2121 can be made of copper, iron, aluminum, stainless steel, aluminum alloy, plastic, or other materials.

[0100] The first insulating member 2122 is an insulating component of the end wall assembly 212. It is disposed between the end wall 2121 and the electrode assembly 23 and serves to isolate the end wall 2121 from the electrode assembly 23, thereby reducing the risk of short circuits. Optionally, the first insulating member 2122 can be made of, but not limited to, plastic, rubber, or the like. In some embodiments, the first insulating member 2122 can be plate-shaped and disposed substantially parallel to the end wall 2121. The first insulating member 2122 can be connected to the end wall 2121 using, but not limited to, bonding or riveting.

[0101] By adopting the above technical solution, it is convenient to accommodate at least a portion of the tab 231 in the first receiving groove 21222 .

[0102] In some embodiments of the present application, please refer to FIG. 7 and FIG. 8 . A second receiving groove 21212 is defined on the side of the end wall 2121 facing the electrode assembly 23 . At least a portion of the first insulating member 2122 is received in the second receiving groove 21212 .

[0103] The side of the end wall 2121 facing the electrode assembly 23 is recessed away from the electrode assembly 23 to form the aforementioned second receiving groove 21212. In some embodiments, there can be one second receiving groove 21212, with at least a portion of the first insulating member 2122 accommodated within the second receiving groove 21212. In other embodiments, there can be multiple second receiving grooves 21212, with multiple portions of the first insulating member 2122 corresponding to the multiple second receiving grooves 21212. The shape of the second receiving groove 21212 can be, but is not limited to, cylindrical, prismatic, or the like.

[0104] By adopting the above technical solution, the structure of the end wall assembly 212 can be made more compact, and the space occupied by the end wall assembly 212 can be further reduced, thereby further improving the volume energy density of the battery cell 20.

[0105] In some embodiments of the present application, please refer to Figures 7 and 8 together. The first insulating member 2122 includes an insulating body 21221 and a first boss 21224. The first accommodating groove 21222 is opened on the side of the insulating body 21221 facing the electrode assembly 23. The first boss 21224 is protruded on the side of the insulating body 21221 facing the end wall body 2121 and is arranged opposite to the first accommodating groove 21222. At least a portion of the first boss 21224 is accommodated in the second accommodating groove 21212.

[0106] The insulating body 21221 is the main portion of the first insulating member 2122 and is disposed between the end wall 2121 and the electrode assembly 23 to insulate and separate the end wall 2121 from the electrode assembly 23. In some embodiments, the insulating body 21221 is a plate-like structure and is disposed over the side of the end wall 2121 facing the electrode assembly 23.

[0107] The first boss 21224 is a portion of the insulating body 21221 that is provided with the first receiving groove 21222 and that protrudes away from the electrode assembly 23. The first boss 21224 can be entirely or partially accommodated within the second receiving groove 21212. The shape of the first boss 21224 can be compatible with the shape of the second receiving groove 21212. For example, the shape of the first boss 21224 and the shape of the second receiving groove 21212 are cylindrical. In another example, the shape of the first boss 21224 and the shape of the second receiving groove 21212 are rectangular. In some embodiments, the first boss 21224 and the insulating body 21221 are integrally formed using an injection molding process. The relative arrangement of the first boss 21224 and the first receiving groove 21222 means that any plane perpendicular to the thickness direction of the end wall assembly 212 (the Z direction as shown in Figures 7 and 8) is defined as a reference plane, and the projection image of the first receiving groove 21222 on the reference plane is located within the coverage range of the projection image of the first boss 21224 on the reference plane, so as to increase the thickness of the portion of the insulating body 21221 where the first receiving groove 21222 is opened.

[0108] By adopting the above technical solution, on the one hand, the thickness of the portion of the first insulating member 2122 corresponding to the first accommodating groove 21222 can be effectively increased, thereby effectively improving the structural strength of the first insulating member 2122; on the other hand, by accommodating at least part of the first boss 21224 in the second accommodating groove 21212, the structure of the end wall assembly 212 can be made more compact, thereby further improving the volume energy density of the battery cell 20.

[0109] In some embodiments of the present application, referring to FIG. 8 , the outer wall of the first boss 21224 is clearance-matched with the groove wall of the second receiving groove 21212 .

[0110] In other words, when the first boss 21224 is accommodated in the second receiving groove 21212 , there is a gap between the outer wall of the first boss 21224 and the groove wall of the second receiving groove 21212 , and the width of the gap can be determined according to actual application requirements.

[0111] By adopting the above technical solution, it is convenient to assemble the first boss 21224 into the second receiving groove 21212.

[0112] In some embodiments of the present application, referring to FIG. 8 , a width W1 of a gap between an outer wall of the first boss 21224 and a wall of the second receiving groove 21212 is 0.1 mm to 0.3 mm.

[0113] The width W1 of the gap between the outer wall of the first boss 21224 and the groove wall of the second receiving groove 21212 can be determined according to actual application needs, and can be specifically 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, etc.

[0114] In the related art, when the dimension of the second receiving groove 21212 along the direction perpendicular to the thickness direction of the end wall assembly 212 is constant, if the width W1 of the gap between the outer wall of the first boss 21224 and the groove wall of the second receiving groove 21212 is too small, it will increase the difficulty of assembling the first boss 21224 into the second receiving groove 21212. If the width W1 of the gap between the outer wall of the first boss 21224 and the groove wall of the second receiving groove 21212 is too large, the projection area of ​​the first boss 21224 along the thickness direction of the end wall assembly 212 will be reduced, resulting in the first boss 21224 being unable to fully cover the first receiving groove 21222, thereby resulting in a local reduction in the thickness of the portion of the insulating body 21221 where the first receiving groove 21222 is opened.

[0115] By adopting the above technical solution, it is not only convenient to assemble the first boss 21224 into the second accommodating groove 21212, but also the first boss 21224 can have a sufficient covering area so that the first boss 21224 can fully cover the first accommodating groove 21222, effectively increasing the thickness of the part of the first insulating member 2122 corresponding to the first accommodating groove 21222, thereby effectively improving the structural strength of the first insulating member 2122.

[0116] In some embodiments of the present application, please refer to Figure 8, the first insulating member 2122 includes an insulating body 21221 and a protrusion 21225, the first accommodating groove 21222 is opened on the insulating body 21221, and the protrusion 21225 is arranged on the side of the insulating body 21221 and protrudes from the insulating body 21221 toward the electrode assembly 23.

[0117] There may be a certain distance between the protrusion 21225 and the peripheral side of the tab 231 in a direction parallel to the end wall 2121. The protrusion 21225 may be located between the tab 231 and the housing 211 to improve the insulation performance between the tab 231 and the housing 211.

[0118] In some embodiments of the present application, referring to FIG. 8 , a ratio of a depth H1 of the second receiving groove 21212 to a maximum thickness H2 of the end wall 2121 is 0.1-0.7.

[0119] The depth H1 of the second receiving groove 21212 refers to the dimension of the second receiving groove 21212 along the thickness direction of the end wall assembly 212. The maximum thickness H2 of the end wall body 2121 refers to the maximum dimension of the end wall body 2121 along the thickness direction of the end wall assembly 212. The ratio of the depth H1 of the second receiving groove 21212 to the maximum thickness H2 of the end wall body 2121 can be determined based on actual application requirements, and can specifically be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, etc.

[0120] In the related art, if the ratio of the depth H1 of the second accommodating groove 21212 to the maximum thickness H2 of the end wall body 2121 is too small, that is, the depth H1 of the second accommodating groove 21212 is too small, the internal space of the second accommodating groove 21212 will be reduced, thereby causing the second accommodating groove 21212 to be unable to effectively accommodate the first insulating member 2122, resulting in an increase in the space occupied by the end wall assembly 212. If the ratio of the depth H1 of the second accommodating groove 21212 to the maximum thickness H2 of the end wall body 2121 is too large, that is, the depth H1 of the second accommodating groove 21212 is too large, the thickness of the portion of the end wall body 2121 where the second accommodating groove 21212 is opened will be greatly reduced, thereby causing the structural strength of the end wall body 2121 to be greatly reduced.

[0121] By adopting the above technical solution, not only can the second accommodating groove 21212 have sufficient space to accommodate at least part of the first insulating member 2122, but the situation in which the thickness of the portion of the end wall body 2121 corresponding to the second accommodating groove 21212 is too small can also be effectively improved, so that the end wall body 2121 has sufficient structural strength.

[0122] In some embodiments of the present application, please refer to Figure 8, the outer shell 21 includes a peripheral wall, and the end wall assembly 212 is the above-mentioned end cover assembly, wherein the end wall body 2121 is the end cover in the end cover assembly, and the end cover is arranged on the end side of the peripheral wall to seal the accommodating space 2111, and the distance W2 between the surface of the inner wall of the end cover facing the peripheral wall and the second accommodating groove 21212 is 1mm-5mm.

[0123] In some embodiments, the surface of the end cap facing the inner wall surface of the peripheral wall is a first connecting surface, and the first connecting surface is used to connect to the inner wall surface of the peripheral wall. It can be understood that when the end cap is arranged at the opening of the peripheral wall, the first connecting surface is arranged opposite to the inner wall surface of the peripheral wall.

[0124] In other embodiments, the end cover further has a second connecting surface. When the end cover is arranged at the opening of the peripheral wall, the second connecting surface is arranged opposite to the open end surface of the peripheral wall and connected to the open end surface of the peripheral wall.

[0125] In the related art, the end cap is connected to the peripheral wall by welding. Specifically, when the end cap is installed at the opening of the peripheral wall, the inner wall surface of the peripheral wall is welded to the first connecting surface of the end cap, and the open end surface of the peripheral wall is welded to the second connecting surface of the end cap. If the distance W2 between the second receiving groove 21212 and the first connecting surface is too small, the width of the portion of the end cap located between the first connecting surface and the second receiving groove 21212 will be too small, causing the portion of the end cap located between the first connecting surface and the second receiving groove 21212 to melt due to heat, causing the first connecting surface to collapse, thereby reducing the welding area between the end cap and the peripheral wall.

[0126] By adopting the above technical solution, a sufficient welding area can be provided between the end cover and the peripheral wall, thereby effectively improving the connection strength between the end cover and the peripheral wall.

[0127] In some embodiments of the present application, please refer to Figures 7 and 8. A third accommodating groove 21213 is provided on the side of the end wall 2121 facing away from the first insulating member 2122, and at least a portion of the terminal assembly 24 located outside the accommodating space 2111 is accommodated in the third accommodating groove 21213.

[0128] The side of the end wall 2121 facing away from the first insulating member 2122 is recessed toward the first insulating member 2122 to form the aforementioned third receiving groove 21213. In some embodiments, there can be one third receiving groove 21213. When there are two terminal assemblies 24, at least the portions of the two terminal assemblies 24 located outside the receiving space 2111 are accommodated within the third receiving groove 21213. In other embodiments, there can also be two third receiving grooves 21213. When there are two terminal assemblies 24, the two terminal assemblies 24 are provided in a one-to-one correspondence with the two third receiving grooves 21213. The shape of the third accommodating groove 21213 can be adapted to the outer contour shape of the portion of the terminal assembly 24 accommodated in the third accommodating groove 21213. For example, the shape of the third accommodating groove 21213 and the outer contour shape of the portion of the terminal assembly 24 accommodated in the third accommodating groove 21213 are cylindrical. For another example, the shape of the third accommodating groove 21213 and the outer contour shape of the portion of the terminal assembly 24 accommodated in the third accommodating groove 21213 are prismatic.

[0129] At least part of the terminal assembly 24 located outside the accommodating space 2111 is accommodated in the third accommodating groove 21213. It can be understood that at least part of the terminal assembly 24 exposed to the external environment of the battery cell 20 is accommodated in the third accommodating groove 21213.

[0130] By adopting the above technical solution, the protruding height of the terminal assembly 24 from the end wall 2121 to the outside of the battery cell 20 is effectively reduced, thereby further improving the volume energy density of the battery cell 20.

[0131] In some embodiments of the present application, please refer to Figures 7 and 8 together. The terminal assembly 24 includes an electrode terminal 241 and a second insulating member 242 arranged between the electrode terminal 241 and the end wall body 2121. At least a portion of the second insulating member 242 is accommodated in the third accommodating groove 21213.

[0132] The electrode terminal 241 is a component that is electrically connected to the tab 231 of the electrode assembly 23 to output electrical energy from the battery cell 20 or input electrical energy into the battery cell 20. In some embodiments, a first through hole is defined in the end wall 2121, and a second through hole is defined in the first insulating member 2122, which is disposed opposite the first through hole. The electrode terminal 241 is inserted through the first through hole and the second through hole, so that a portion of the electrode terminal 241 extends into the internal environment of the battery cell 20 and connects to the tab 231 of the electrode assembly 23, while another portion of the electrode terminal 241 is exposed to the external environment of the battery cell 20 and connects to the busbar. The electrode terminal 241 can be made of a single metal material or a plurality of metal materials, such as, but not limited to, copper, aluminum, nickel, zinc, iron, etc. The electrode terminal 241 can be an integrally formed component or can be composed of multiple parts that are separately formed and then connected to each other.

[0133] The second insulating member 242 is an insulating component of the terminal assembly 24. The second insulating member 242 is disposed between the electrode terminal 241 and the end wall 2121 to insulate and separate the electrode terminal 241 from the end wall 2121, thereby reducing the risk of short circuits. In some embodiments, the second insulating member 242 can be annular and disposed around the electrode terminal 241. The material of the second insulating member 242 can include, but is not limited to, polyester, epoxy, polyurethane, polybutadiene, silicone, polyesterimide, and polyimide. At least a portion of the second insulating member 242 is housed within the third receiving groove 21213. In other embodiments, at least a portion of the second insulating member 242 and at least a portion of the electrode terminal 241 can also be housed within the third receiving groove 21213.

[0134] In some embodiments, the terminal assembly 24 further includes a seal 243, which is disposed between the terminal assembly 24 and the end wall assembly 212 to seal the gap between the terminal assembly 24 and the end wall assembly 212. The seal 243 can be an annular structure, disposed around the electrode terminal 241 and pressed between the hole wall of the first through hole and the outer peripheral wall of the electrode terminal 241. The material of the seal 243 can be, but is not limited to, rubber, silicone, synthetic resin, etc.

[0135] By adopting the above technical solution, the protruding height of the terminal assembly 24 from the end wall 2121 to the outside of the battery cell 20 is effectively reduced, thereby further improving the volume energy density of the battery cell 20.

[0136] In some embodiments of the present application, please refer to Figures 7 and 8 together. The end wall body 2121 includes a main body 21211 and a second boss 21214. The third accommodating groove 21213 is opened on the side of the main body 21211 facing away from the first insulating member 2122. The second boss 21214 is protruded on the side of the main body 21211 facing the first insulating member 2122 and is arranged opposite to the third accommodating groove 21213.

[0137] The main body 21211 is the main portion of the end wall 2121. The main body 21211 is used to isolate the storage space 2111 of the housing 21 from the external environment of the battery cell 20. The main body 21211 is also used to provide an installation environment for the terminal assembly 24. In some embodiments, when the end wall assembly 212 is an end cap assembly, part of the surface of the outer portion of the main body 21211 constitutes the first connection surface and the second connection surface. The first connection surface and the second connection surface can be arranged perpendicular to each other, wherein the first connection surface is connected to the inner wall surface of the peripheral wall, and the second connection surface is connected to the open end surface of the peripheral wall. The side of the main body 21211 facing away from the first insulating member 2122 is recessed in a direction closer to the first insulating member 2122 to form the third storage groove 21213.

[0138] The second boss 21214 refers to a portion that is provided on the portion of the main body 21211 where the third receiving groove 21213 is provided and that protrudes toward the electrode assembly 23. The shape of the second boss 21214 may be, but is not limited to, cylindrical, prismatic, or the like. In some embodiments, the second boss 21214 and the main body 21211 are integrally formed using a die-casting process. The relative arrangement of the second boss 21214 and the third receiving groove 21213 means that any plane perpendicular to the thickness direction of the end wall assembly 212 is defined as a reference plane, and the projection image of the third receiving groove 21213 on the reference plane is within the coverage range of the projection image of the second boss 21214 on the reference plane, so as to increase the thickness of the portion of the main body 21211 where the third receiving groove 21213 is provided.

[0139] By adopting the above technical solution, the thickness of the portion of the end wall body 2121 corresponding to the third receiving groove 21213 is effectively increased, thereby effectively improving the structural strength of the end wall body 2121.

[0140] In some embodiments of the present application, referring to FIG. 8 , a protruding height H3 of the second boss 21214 relative to the side of the main body 21211 facing the first insulating member 2122 is 0.1 mm-0.3 mm.

[0141] The protruding height H3 of the second boss 21214 relative to the side of the main body 21211 facing the first insulating member 2122 can be determined according to actual application requirements, and can be specifically 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, etc.

[0142] By adopting the above technical solution, not only the thickness of the portion of the end wall body 2121 corresponding to the third accommodating groove 21213 is effectively increased, thereby effectively improving the structural strength of the end wall body 2121, but also the second boss 21214 will not occupy too much space due to the excessive protruding height of the second boss 21214, thereby further improving the volume energy density of the battery cell 20.

[0143] In some embodiments of the present application, please refer to FIG. 7 and FIG. 8 , the third receiving groove 21213 and the second receiving groove 21212 are staggered along a direction perpendicular to the thickness direction of the end wall component 212 .

[0144] The staggered arrangement of the third accommodating groove 21213 and the second accommodating groove 21212 in a direction perpendicular to the thickness direction of the end wall assembly 212 means that any plane perpendicular to the thickness direction of the end wall assembly 212 is defined as a reference plane, and the projection image of the third accommodating groove 21213 on the reference plane does not overlap with the projection image of the second accommodating groove 21212 on the reference plane.

[0145] By adopting the above-mentioned technical solution, not only can the protruding height of the terminal assembly 24 from the end wall body 2121 to the outside of the battery cell 20 be effectively reduced, thereby further improving the volume energy density of the battery cell 20, but also the overlapping of the second accommodating groove 21212 and the third accommodating groove 21213 along the thickness direction of the end wall body 2121 be effectively improved, so that the parts of the end wall body 2121 corresponding to the second accommodating groove 21212 and the third accommodating groove 21213 have sufficient thickness, thereby effectively improving the structural strength of the end wall body 2121.

[0146] In some embodiments of the present application, please refer to Figures 7 and 8. A fourth accommodating groove 21223 is provided on the side of the first insulating member 2122 facing away from the end wall body 2121, and at least a portion of the terminal assembly 24 located in the accommodating space 2111 is accommodated in the fourth accommodating groove 21223.

[0147] The side of the first insulating member 2122 facing away from the end wall 2121 is recessed toward the end wall 2121 to form the aforementioned fourth receiving groove 21223. In some embodiments, there can be one fourth receiving groove 21223. When there are two terminal assemblies 24, at least the portions of the two terminal assemblies 24 located within the receiving space 2111 are accommodated within the fourth receiving groove 21223. In other embodiments, there can also be two fourth receiving grooves 21223. When there are two terminal assemblies 24, the two terminal assemblies 24 are provided in a one-to-one correspondence with the two fourth receiving grooves 21223. The shape of the fourth accommodating groove 21223 can be adapted to the outer contour shape of the portion of the terminal assembly 24 accommodated in the fourth accommodating groove 21223. For example, the shape of the fourth accommodating groove 21223 and the outer contour shape of the portion of the terminal assembly 24 accommodated in the fourth accommodating groove 21223 are cylindrical. For another example, the shape of the fourth accommodating groove 21223 and the outer contour shape of the portion of the terminal assembly 24 accommodated in the fourth accommodating groove 21223 are prismatic.

[0148] At least part of the terminal assembly 24 located in the accommodating space 2111 is accommodated in the fourth accommodating groove 21223. It can be understood that at least part of the portion of the terminal assembly 24 extending into the accommodating space 2111 of the shell 211 is accommodated in the fourth accommodating groove 21223.

[0149] By adopting the above technical solution, the assembly structure between the terminal assembly 24 and the first insulating member 2122 can be made more compact, effectively reducing the space occupied by the terminal assembly 24 and the first insulating member 2122, thereby further improving the volume energy density of the battery cell 20.

[0150] In some embodiments of the present application, please refer to Figures 7 and 8 together. The shell 21 includes a peripheral wall, the end wall assembly 212 is connected to the end side of the peripheral wall, the terminal assembly 24 includes a first connecting portion 2411 arranged in the accommodating space 2111, the accommodating space 2111 includes a first accommodating area 21111 located between the first connecting portion 2411 and the inner wall surface of the peripheral wall, the pole ear 231 includes a second connecting portion 2312 connected to the first connecting portion 2411 and a bending portion 2311 connected between the second connecting portion 2312 and the electrode body 232, at least a portion of the bending portion 2311 is accommodated in the first accommodating groove 21222, and at least another portion of the bending portion 2311 is accommodated in the first accommodating area 21111.

[0151] The first connecting portion 2411 is the portion of the electrode terminal 241 that extends into the receiving space 2111 and connects to the tab 231. In some embodiments, when a fourth receiving groove 21223 is defined on the side of the first insulating member 2122 facing away from the end wall 2121, at least a portion of the first connecting portion 2411 is received in the fourth receiving groove 21223.

[0152] The first accommodating area 21111 is the portion of the space between the inner wall of the accommodating space 2111 and the outer wall of the first connecting portion 2411. In some embodiments, there may be two first accommodating areas 21111, with the two first accommodating areas 21111 being located on opposite sides of the first connecting portion 2411 along the thickness direction of the battery cell 20 (the Y direction as shown in Figures 7 and 8). The positive and negative tabs of the electrode assembly 23 are disposed in a one-to-one correspondence with the two first accommodating areas 21111.

[0153] In some embodiments, the accommodating space 2111 further includes a second accommodating area 21112 , and the second accommodating area 21112 is used to accommodate the electrode body 232 .

[0154] A portion of the electrode ear 231 can be led out from the electrode body 232 toward the direction close to the end wall component 212 to the first accommodating area 21111, and then bent in multiple sections or in an arc-shaped structure in the first accommodating area 21111 to form a bent portion 2311. The portion of the bent portion 2311 close to the end wall component 212 is accommodated in the first accommodating groove 21222, and the portion of the bent portion 2311 close to the electrode component 23 is accommodated in the first accommodating area 21111.

[0155] The second connection portion 2312 is connected to one end of the bent portion 2311 away from the electrode body 232 . The second connection portion 2312 extends from the bent portion 2311 toward the first connection portion 2411 and is connected to the first connection portion 2411 .

[0156] By adopting the above technical solution, the bent portion 2311 of the tab 231 can fully utilize the first accommodating area 21111 of the accommodating space 2111, effectively optimizing the internal space layout structure of the battery cell 20, and effectively improving the space utilization rate of the battery cell 20, thereby further improving the volume energy density of the battery cell 20.

[0157] In some embodiments of the present application, the second connection portion 2312 is directly connected to the first connection portion 2411 .

[0158] In other words, there is no transition component between the second connection portion 2312 and the first connection portion 2411 , but the second connection portion 2312 is directly connected to the first connection portion 2411 .

[0159] By adopting the above technical solution, there is no need to set up additional adapters, which effectively reduces the number of components of the battery cell 20, thereby effectively reducing the volume of the battery cell 20 and further improving the volume energy density of the battery cell 20.

[0160] In the second aspect, referring to FIG. 2 , an embodiment of the present application provides a battery 100 , comprising the battery cell 20 described in any one of the above embodiments.

[0161] The battery 100 provided in the embodiment of the present application effectively improves the volume energy density of the battery 100 because it adopts the battery cell 20 described in any of the above embodiments.

[0162] In the third aspect, please refer to FIG1 , an embodiment of the present application provides an electrical device including the above-mentioned battery 100 .

[0163] The electric device provided in the embodiment of the present application effectively improves the battery life performance of the electric device due to the use of the above-mentioned battery 100.

[0164] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A battery cell, characterized in that, The battery cell includes: A housing having an accommodation space. The housing includes an end wall assembly, and a first accommodation groove is formed on a side of the end wall assembly facing the accommodation space. An electrode assembly accommodated in the accommodation space. The electrode assembly includes a tab, and at least a part of the tab is accommodated in the first accommodation groove.

2. The battery cell according to claim 1, wherein The end wall assembly includes an end wall body and a first insulating member. The first insulating member is disposed on a side of the end wall body facing the electrode assembly, and the first accommodation groove is formed on a side of the first insulating member facing the electrode assembly.

3. The battery cell according to claim 2, wherein A second accommodation groove is formed on a side of the end wall body facing the electrode assembly, and at least a part of the first insulating member is accommodated in the second accommodation groove.

4. The battery cell according to claim 3, characterized in that, The first insulating member includes an insulating body and a first boss. The first accommodation groove is formed on a side of the insulating body facing the electrode assembly. The first boss protrudes from a side of the insulating body facing the end wall body and is disposed opposite to the first accommodation groove. At least a part of the first boss is accommodated in the second accommodation groove.

5. The battery cell according to claim 4, characterized in that, A clearance fit is provided between an outer wall of the first boss and a wall of the second accommodation groove.

6. The battery cell according to claim 5, wherein, The width of the clearance between the outer wall of the first boss and the wall of the second accommodation groove is 0.1 mm - 0.3 mm.

7. The battery cell according to claim 3, wherein The first insulating member includes an insulating body and a protrusion. The first accommodation groove is formed on the insulating body. The protrusion is disposed on a side edge of the insulating body and protrudes from the insulating body toward the electrode assembly.

8. The battery cell according to any one of claims 3-7, characterized in that, The ratio of the depth of the second accommodation groove to the maximum thickness of the end wall body is 0.1 - 0.

7.

9. The battery cell according to any one of claims 3-8, characterized in that, The housing further includes a peripheral wall that defines the accommodation space. The end wall body is an end cover that covers an end side of the peripheral wall to seal the accommodation space.

10. The battery cell according to claim 9, characterized in that, The distance between a surface of an inner wall surface of the end cover facing the peripheral wall and the second accommodation groove is 1 mm - 5 mm.

11. The battery cell according to any one of claims 3-10, characterized in that, The battery cell further includes a terminal assembly connected to the tab. A third accommodation groove is formed on a side of the end wall body facing away from the first insulating member. The terminal assembly is disposed on the end wall body and at least a part of the terminal assembly is accommodated in the third accommodation groove. The third accommodation groove and the second accommodation groove are arranged in a staggered manner in a direction perpendicular to the thickness direction of the end wall assembly.

12. The battery cell according to any one of claims 2-10, characterized in that, The battery cell further includes a terminal assembly connected to the tab. A third accommodation groove is formed on a side of the end wall body facing away from the first insulating member. The terminal assembly is disposed on the end wall body and at least a part of the terminal assembly located outside the accommodation space is accommodated in the third accommodation groove.

13. The battery cell according to claim 12, wherein The terminal assembly includes an electrode terminal and a second insulating member disposed between the electrode terminal and the end wall body. At least a part of the second insulating member is accommodated in the third accommodation groove.

14. The battery cell according to claim 12 or 13, characterized in that, The end wall body includes a main body portion and a second boss. The third accommodation groove is formed on a side of the main body portion facing away from the first insulating member. The second boss protrudes from a side of the main body portion facing the first insulating member and is disposed opposite to the third accommodation groove.

15. The battery cell according to claim 14, wherein The protruding height of the second boss relative to the side of the main body facing the first insulating member is 0.1 mm - 0.3 mm.

16. The battery cell according to any one of claims 1-10, characterized in that, The battery cell further includes a terminal assembly connected to the tab. A fourth receiving groove is formed on the side of the end wall assembly facing the electrode assembly, and at least a part of the terminal assembly located in the receiving space is received in the fourth receiving groove.

17. The battery cell according to any one of claims 1-8, characterized in that, The outer casing further includes a peripheral wall. The end wall assembly is connected to the end side of the peripheral wall. The battery cell further includes a terminal assembly disposed on the end wall assembly. The terminal assembly includes a first connecting portion disposed in the receiving space. The receiving space includes a first receiving area located between the first connecting portion and the inner wall surface of the peripheral wall. The electrode assembly further includes an electrode main body. The tab includes a second connecting portion connected to the first connecting portion and a bent portion connected between the second connecting portion and the electrode main body. At least a part of the bent portion is received in the first receiving groove, and at least another part of the bent portion is received in the first receiving area.

18. The battery cell according to claim 17, characterized in that, The second connecting portion is directly connected to the first connecting portion.

19. A battery, characterized in that, The battery includes the battery cell according to any one of claims 1 - 18.

20. An electrical device, characterized in that, The electrical device includes the battery according to claim 19.

Images