Battery cell, battery, and electrical device

Abstract

A battery cell (20), a battery, and an electrical device. The battery cell (20) comprises a casing (21), an electrode terminal (22), and an electrode assembly (23), wherein the electrode terminal (22) is arranged on the casing (21) and is insulated from the casing (21); and the electrode assembly (23) is accommodated in the casing (21). The electrode assembly (23) comprises a first tab (232) and a second tab (233), the polarity of the first tab (232) being opposite to the polarity of the second tab (233), the first tab (232) being electrically connected to the electrode terminal (22), and the second tab (233) being electrically connected to the casing (21). The battery cell (20) eliminates the need to provide additional insulating components between the electrode assembly (23) and the casing (21), and allows the provision of only one electrode terminal (22), such that the number of electrode terminals (22) is reduced, and the number of insulating and sealing components arranged between the electrode terminal (22) and the casing (21) is also reduced, thereby effectively reducing the number of components of the battery cell (20), effectively reducing the size and weight of the battery cell (20), and thus effectively improving the energy density of the battery cell (20).

Description

Battery cells, batteries and electrical equipment Technical Field

[0001] 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

[0002] 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.

[0003] A battery typically includes multiple battery cells. Due to the large number of components in a battery cell, the volume and weight of the battery cell increase, resulting in a decrease in the energy density of the battery cell, and thus a decrease in the energy density of the battery.

[0004] Summary of the Invention

[0005] 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 in the related art that the energy density of the battery cell decreases due to the large number of components in the battery cell.

[0006] To solve the above technical problems, the technical solutions adopted in the embodiments of the present application are:

[0007] In a first aspect, a battery cell is provided, comprising:

[0008] shell;

[0009] The electrode terminal is provided on the housing and is insulated from the housing;

[0010] The electrode assembly is accommodated in the shell, and the electrode assembly includes a first pole tab and a second pole tab. The polarity of the first pole tab is opposite to that of the second pole tab. The first pole tab is electrically connected to the electrode terminal, and the second pole tab is electrically connected to the shell.

[0011] The beneficial effect of the battery cell provided by the embodiment of the present application is that: the battery cell provided by the embodiment of the present application is provided by insulating the electrode terminal from the shell, and electrically connecting the first pole ear to the electrode terminal, and electrically connecting the second pole ear to the shell. In other words, the electrode terminal can serve as one of the positive output pole and the negative output pole of the battery cell, and the shell can serve as the other of the positive output pole and the negative output pole of the battery cell. In this way, there is no need to additionally set an insulating component between the electrode assembly and the shell, and only one electrode terminal can be set, which not only reduces the number of electrode terminals, but also reduces the number of insulating components and sealing components set between the electrode terminal and the shell, thereby effectively reducing the number of components of the battery cell, effectively reducing the volume and weight of the battery cell, and thus effectively improving the energy density of the battery cell.

[0012] In some embodiments of the present application, the housing includes a first wall, the electrode terminal is disposed on the first wall and insulated from the first wall, and the second electrode tab is connected to the first wall.

[0013] By adopting the above-mentioned technical solution, the first pole ear and the second pole ear can be led out on the side of the electrode assembly facing the first wall, and the first pole ear and the second pole ear can be electrically connected to the electrode terminal and the first wall respectively, so that the first pole ear and the second pole ear can share a lead-out space, thereby optimizing the internal spatial layout structure of the battery cell and making the structure of the battery cell more compact, thereby effectively reducing the volume of the battery cell and effectively improving the volume energy density of the battery cell.

[0014] In some embodiments of the present application, the first wall includes a wall body and a first boss, the electrode terminal is arranged on the wall body and is used to electrically connect to a bus bar, and the first boss is protruding from the surface of the wall body facing away from the electrode assembly and is used to electrically connect to another bus bar.

[0015] By adopting the above technical solution, the difference between the connection height of one busbar and the electrode terminal and the connection height of another busbar and the first wall can be reduced, which facilitates the electrical connection operation between the battery cell and the busbar by the connecting equipment.

[0016] In some embodiments of the present application, the first boss has a first connection surface for connecting to the busbar, the electrode terminal has a second connection surface for connecting to the busbar, and the height of the first connection surface is equal to the height of the second connection surface.

[0017] By adopting the above technical solution, electrical connection operations can be performed between the busbar and the electrode terminal and between the busbar and the first boss at the same height, which facilitates the electrical connection operation between the battery cell and the busbar by the connecting equipment.

[0018] In some embodiments of the present application, the battery cell further includes a first adapter and a second adapter, the first adapter being connected between the electrode terminal and the first tab, and the second adapter being connected between the first wall and the second tab.

[0019] By adopting the above technical solution, it is convenient to electrically connect the electrode terminal to the first electrode tab and to electrically connect the first wall to the second electrode tab.

[0020] In some embodiments of the present application, the first adapter has a third connection surface for connecting to the first tab, the second adapter has a fourth connection surface for connecting to the second tab, and the height of the third connection surface is equal to that of the fourth connection surface.

[0021] By adopting the above technical solution, electrical connection operations can be performed between the first adapter and the first tab and between the second adapter and the second tab at the same height, which facilitates the connection device to electrically connect the electrode assembly to the electrode terminal and the shell.

[0022] In some embodiments of the present application, the first wall includes a wall body and a second boss, the electrode terminal is arranged on the wall body, the second boss is protruding from the surface of the wall body facing the electrode assembly, and the second electrode tab is connected to the second boss.

[0023] By adopting the above technical solution, the difference between the connection height between the second tab and the first wall and the connection height between the first tab and the electrode terminal can be reduced, which facilitates the electrical connection operation between the first wall and the second tab by the connection equipment.

[0024] In some embodiments of the present application, the battery cell also includes a first adapter, which is connected between the electrode terminal and the first pole lug, the first adapter has a third connecting surface for connecting to the first pole lug, the second boss has a fifth connecting surface for connecting to the second pole lug, and the height of the third connecting surface is equal to the height of the fifth connecting surface.

[0025] By adopting the above technical solution, electrical connection operations can be performed between the first adapter and the first tab and between the second boss and the second tab at the same height, which facilitates the connection device to electrically connect the electrode assembly to the electrode terminal and the shell.

[0026] In some embodiments of the present application, the second boss has a fifth connection surface for connecting to the second electrode tab, the electrode terminal has a sixth connection surface for connecting to the first electrode tab, and the height of the fifth connection surface is equal to that of the sixth connection surface.

[0027] By adopting the above technical solution, electrical connection operations can be performed between the electrode terminal and the first tab and between the second boss and the second tab at the same height, which facilitates the connection equipment to electrically connect the electrode assembly to the electrode terminal and the shell.

[0028] In some embodiments of the present application, the housing includes a first wall and a second wall, the electrode terminal is disposed on the first wall and insulated from the first wall, and the second electrode tab is connected to the second wall.

[0029] By adopting the above technical solution, it is convenient to electrically connect the second electrode tab to the shell.

[0030] In some embodiments of the present application, a through hole is formed in the second wall, the through hole connects the internal environment of the shell and the external environment of the shell, and the second tab is passed through the through hole and connected to the second wall.

[0031] By adopting the above technical solution, the second tab and the second wall can be electrically connected outside the shell, which facilitates the electrical connection of the second tab to the second wall, thereby effectively improving the assembly efficiency of the battery cell.

[0032] In some embodiments of the present application, the battery cell further includes a sealing cover, which is disposed on the through hole and cooperates with the second wall to clamp the second electrode tab.

[0033] By adopting the above technical solution, not only can the second pole ear be shaped so that the second pole ear can be tightly attached to the second wall, thereby reducing the risk of the second pole ear detaching from the second wall, but it can also effectively protect the second pole ear, thereby reducing the risk of damage to the second pole ear.

[0034] In some embodiments of the present application, a surface of the cover facing away from the electrode assembly is flush with a surface of the second wall facing away from the electrode assembly.

[0035] By adopting the above technical solution, the outer surface of the battery cell can be made flatter, so that the battery cells can be neatly arranged inside the battery.

[0036] In some embodiments of the present application, the battery cell further includes a positioning member disposed on the second wall, the positioning member being used to limit the position of the second electrode tab so that the second electrode tab contacts the second wall.

[0037] By adopting the above technical solution, after the positioning member and the electrode assembly are placed in the shell, the position of the second pole ear can be limited by the positioning member so that the second pole ear contacts the second wall, which facilitates the electrical connection of the second pole ear to the second wall, thereby effectively improving the assembly efficiency of the battery cell.

[0038] In some embodiments of the present application, the positioning member is provided with a positioning hole, and the second electrode tab is passed through the positioning hole so that the second electrode tab contacts the second wall.

[0039] By adopting the above technical solution, the second tab is effectively positioned.

[0040] In some embodiments of the present application, the first wall and the second wall are arranged opposite to each other, and the electrode assembly further includes an electrode body, the first electrode tab is connected to the side of the electrode body facing the first wall, and the second electrode tab is connected to the side of the electrode body facing the second wall.

[0041] By adopting the above technical solution, it is convenient to electrically connect the first electrode tab and the second electrode tab to the electrode terminal and the shell respectively.

[0042] In some embodiments of the present application, the housing includes a shell and a cover body provided on the shell body, and the first wall constitutes the cover body.

[0043] By adopting the above technical solution,

[0044] In some embodiments of the present application, the battery cell further includes an insulating layer, which is coated on the outer surface of the shell.

[0045] By adopting the above technical solution, two adjacent battery cells in the battery are effectively insulated and separated, thereby reducing the risk of battery short circuit and effectively improving the safety performance of the battery.

[0046] In some embodiments of the present application, the battery cell is a sodium ion battery cell.

[0047] By adopting the above technical solution, not only the production cost of battery cells is effectively reduced, but also the energy density of battery cells can be further improved.

[0048] In some embodiments of the present application, the housing is one of an aluminum shell, a steel shell and a copper shell.

[0049] By adopting the above technical solution, the risk of electrochemical corrosion of the shell is effectively reduced, thereby effectively improving the reliability of the battery cell.

[0050] In a second aspect, an embodiment of the present application further provides a battery comprising the battery cell described in any of the above embodiments.

[0051] 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 energy density of the battery because it adopts the battery cell described in any of the above embodiments.

[0052] In some embodiments of the present application, the battery further includes a busbar, the number of battery cells is multiple, and the busbar is electrically connected between the electrode terminal of one battery cell and the outer shell of another battery cell.

[0053] By adopting the above technical solution, it is convenient to electrically connect the battery cells in the battery.

[0054] In some embodiments of the present application, the busbar is connected between the electrode terminal of one battery cell and the bottom wall of the housing of another battery cell; or,

[0055] The busbar is connected between the electrode terminal of one battery cell and the side wall of the housing of another battery cell.

[0056] By adopting the above technical solution,

[0057] In a third aspect, an embodiment of the present application further provides an electrical device comprising the battery described in any of the above embodiments.

[0058] 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 battery life performance of the electric device because it adopts the battery described in any of the above embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] 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 descriptions of the prior art. 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.

[0060] FIG1 is a schematic structural diagram of a vehicle provided in an embodiment of the present application;

[0061] FIG2 is a schematic diagram of an explosion of a battery provided in an embodiment of the present application;

[0062] FIG3 is a schematic diagram of the connection structure of two adjacent battery cells in a battery provided in an embodiment of the present application;

[0063] FIG4 is a schematic diagram of the connection structure of two adjacent battery cells in a battery provided by another embodiment of the present application;

[0064] FIG5 is a schematic diagram of the connection structure of two adjacent battery cells in a battery provided in another embodiment of the present application;

[0065] FIG6 is a schematic structural diagram of a battery cell provided in one embodiment of the present application;

[0066] FIG7 is a schematic top view of the battery cell shown in FIG6 ;

[0067] FIG8 is a schematic cross-sectional view of the battery cell shown in FIG7 along line AA;

[0068] FIG9 is an enlarged structural diagram of the battery cell at position B shown in FIG8 ;

[0069] FIG10 is an enlarged structural diagram of the battery cell at position C shown in FIG8 ;

[0070] FIG11 is a schematic structural diagram of a battery cell provided in another embodiment of the present application;

[0071] FIG12 is a schematic diagram of the top structure of the battery cell shown in FIG11 ;

[0072] FIG13 is a schematic cross-sectional view of the battery cell shown in FIG12 along line DD;

[0073] FIG14 is an enlarged structural diagram of the battery cell at position E shown in FIG13 ;

[0074] FIG15 is an enlarged structural diagram of the battery cell at position F shown in FIG13 ;

[0075] FIG16 is a schematic structural diagram of a battery cell provided in another embodiment of the present application;

[0076] FIG17 is a schematic diagram of the exploded structure of the battery cell shown in FIG16 ;

[0077] FIG18 is a schematic top view of the battery cell shown in FIG16 ;

[0078] FIG19 is a schematic cross-sectional view of the battery cell shown in FIG18 along line GG;

[0079] FIG20 is an enlarged structural diagram of the battery cell at position H shown in FIG19 ;

[0080] FIG21 is a schematic structural diagram of a battery cell provided in yet another embodiment of the present application;

[0081] FIG22 is a schematic diagram of the exploded structure of the battery cell shown in FIG21 .

[0082] DESCRIPTION OF THE REFERENCE NUMERALS: 1000, vehicle; 100, battery; 10, housing; 11, first portion; 12, second portion; 20, battery cell; 21, outer casing; 211, housing; 2111, second wall; 21111, through-hole; 212, cover; 213, first wall; 2131, wall; 2132, first boss; 21321, first connecting surface; 2133, second boss; 21331, fifth connecting surface; 22, electrode terminal; 221, second connecting surface; 23, electrode assembly; 231, electrode body; 232, first tab; 233, second tab; 24, first adapter; 241, third connecting surface; 25, second adapter; 251, fourth connecting surface; 26, cover; 27, positioning member; 28, pressure relief mechanism; 30, current collector; 200, controller; 300. Motor. DETAILED DESCRIPTION

[0083] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, this application is further described in detail below 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.

[0084] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0085] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are 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, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0086] In addition, the terms "first," "second," "third," "fourth," "fifth," and "sixth" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, a feature defined as "first," "second," "third," "fourth," "fifth," and "sixth" may explicitly or implicitly include one or more of the features. In the description of this application, "plurality" means two or more, unless otherwise explicitly and specifically defined.

[0087] A battery cell, the smallest unit of a battery, typically consists of a housing, an electrode assembly, an electrolyte, and two electrode terminals. The housing provides an internal environment for the battery cell, housing the electrode assembly and electrolyte. The two electrode terminals are located on and insulated from the walls of the housing. The electrode assembly includes two tabs, one electrically connected to one electrode terminal and the other electrically connected to the other electrode terminal, to output or input electrical energy from the battery cell.

[0088] In the related art, in order to improve the safety performance of battery cells, it is usually necessary to set insulating components between the electrode terminals and the shell, and between the electrode assembly and the shell, so that the electrode terminals are insulated and separated from the shell, and the electrode assembly is insulated and separated from the shell. At the same time, in order to reduce the risk of electrolyte leakage, it is usually necessary to set sealing components between the electrode terminals and the shell to seal the gap between the electrode terminals and the shell. In this way, the number of parts of the battery cell is large, which increases the volume and weight of the battery cell, resulting in a decrease in the energy density of the battery cell, and then the energy density of the battery also decreases.

[0089] In order to improve the energy density of the battery cell, in the battery cell provided in the embodiment of the present application, the electrode terminal is insulated from the shell, the first pole ear is electrically connected to the electrode terminal, and the second pole ear is electrically connected to the shell. In other words, the electrode terminal can serve as one of the positive output electrode and the negative output electrode of the battery cell, and the shell can serve as the other of the positive output electrode and the negative output electrode of the battery cell. In this way, there is no need to additionally set an insulating component between the electrode assembly and the shell, and only one electrode terminal can be set. Not only is the number of electrode terminals reduced, but also the number of insulating components and sealing components set between the electrode terminal and the shell is reduced, thereby effectively reducing the number of components of the battery cell, effectively reducing the volume and weight of the battery cell, and thus effectively improving the energy density of the battery cell.

[0090] The battery disclosed in the embodiments of the present application can be used in electrical equipment that uses the battery as a power source, or in various energy storage systems that use the battery as an energy storage element. Electrical equipment can be, but is not limited to, vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys and electric tools, etc. The vehicle can be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. The spacecraft can be an airplane, a rocket, a space shuttle or a spacecraft, etc. The electric toy can be a fixed or mobile electric toy, for example, a game console, an electric car toy, an electric ship toy and an electric airplane toy, etc. The electric tool can be a metal cutting electric tool, a grinding electric tool, an assembly electric tool and a railway electric tool, for example, an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator and an electric planer, etc.

[0091] 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.

[0092] Please refer to Figure 1, which is a schematic structural diagram of a vehicle 1000 provided in an embodiment of the present application. 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 operating power requirements of the vehicle 1000.

[0093] 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 .

[0094] 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 battery cells 20, each of which is housed within the housing 10. The housing 10 provides a storage space for the battery cells 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 storage space for the battery cells 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 storage space. Alternatively, both the first portion 11 and the second portion 12 can be hollow structures 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.

[0095] In the battery 100, there may be multiple battery cells 20, which may be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections within the battery cells 20. The battery cells 20 may be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery cell 20 is housed within the housing 10. Alternatively, the battery 100 may be constructed by first connecting multiple battery cells 20 in series, in parallel, or in a hybrid connection to form a battery module, which is then further connected in series, in parallel, or in a hybrid connection to form a single unit housed within the housing 10.

[0096] Each battery cell 20 may be a secondary battery cell or a primary battery cell. A secondary battery cell refers to a battery cell 20 that can be recharged to activate the active material after the battery cell 20 is discharged and can continue to be used. A primary battery cell refers to a battery cell 20 that cannot be recharged to activate the active material after the battery cell 20 is exhausted and can continue to be used. The battery cell 20 may also be a lithium-ion battery cell, a sodium-ion battery cell, a sodium-lithium-ion battery cell, a lithium metal battery cell, a sodium metal battery cell, a lithium-sulfur battery cell, a magnesium-ion battery cell, a nickel-hydrogen battery cell, a nickel-cadmium battery cell, a lead-acid battery cell, 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 battery cells. Polygonal prismatic battery cells, for example, hexagonal prismatic battery cells, are not particularly limited in this application.

[0097] Of course, in some embodiments, the battery 100 may not include the box body 10 , but rather a plurality of battery cells 20 may be electrically connected and formed into a whole through necessary fixing structures before being assembled into the vehicle 1000 .

[0098] In order to illustrate the technical solution provided by this application, a detailed description is given below with reference to specific drawings and embodiments.

[0099] First, please refer to Figures 6 to 22 together. An embodiment of the present application provides a battery cell 20, including a shell 21, an electrode terminal 22 and an electrode assembly 23. The electrode terminal 22 is arranged on the shell 21 and is insulated from the shell 21. The electrode assembly 23 is accommodated in the shell 21. The electrode assembly 23 includes a first pole ear 232 and a second pole ear 233. The polarity of the first pole ear 232 is opposite to the polarity of the second pole ear 233. The first pole ear 232 is electrically connected to the electrode terminal 22, and the second pole ear 233 is electrically connected to the shell 21.

[0100] The outer shell 21 is used to provide an internal environment for the battery cell 20, which can be used to accommodate components such as the electrode assembly 23 and the electrolyte. At least the portion of the outer shell 21 electrically connected to the second tab 233 is made of a conductive material, which can be, but is not limited to, aluminum, steel, copper, etc. In some embodiments, the entire outer shell 21 is made of a conductive material. In other words, the outer shell 21 can be, but is not limited to, aluminum, steel, copper, etc.

[0101] In some embodiments, the housing 21 includes a shell 211 and a cover 212. The interior of the shell 211 forms the above-mentioned internal environment, and the shell 211 can be an independent component, and an opening can be provided on the shell 211. The cover 212 is provided at the opening of the shell 211 to isolate the internal environment of the battery cell 20 from the external environment. Specifically, the shell 211 and the cover 212 can 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 cover 212 is provided on the opening of the shell 211. Optionally, the shell 211 can be of various shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism, etc. The shape of the cover 212 can be adapted to the shape of the shell 211 to match the shell 211.

[0102] The electrode terminal 22 is a component that electrically connects to the electrode assembly 23 for outputting or inputting electrical energy. In some embodiments, the housing 21 is provided with an electrode lead-out hole. The motor lead-out hole can be provided on the cover 212 or the housing 211. The electrode terminal 22 is disposed within the electrode lead-out hole. A portion of the electrode terminal 22 protrudes into the interior of the battery cell 20 and is directly or indirectly connected to the electrode assembly 23. Another portion of the electrode terminal 22 protrudes into the exterior of the battery cell 20 and is connected to components such as the current bus 30 and the sampling device. Optionally, the electrode terminal 22 can have a columnar structure, such as a cylindrical structure or a prismatic structure. The electrode terminal 22 can also have a plate-like structure, such as a circular plate or a square plate. The electrode terminal 22 can also have other irregular three-dimensional structures, which are not specifically limited here. It is understood that the electrode terminal 22 is made of a conductive material. The electrode terminal 22 can be made of a single conductive material or multiple conductive materials. The conductive materials can include, but are not limited to, copper, aluminum, nickel, zinc, iron, etc., which are not specifically limited here.

[0103] In some embodiments, the battery cell 20 further includes an insulating member disposed between the electrode terminal 22 and the outer shell 21 to insulate and separate the electrode terminal 22 from the outer shell 21 .

[0104] In some embodiments, the battery cell 20 further includes a sealant disposed between the electrode terminal 22 and the wall of the electrode lead-out hole to seal the gap between the electrode terminal 22 and the wall of the electrode lead-out hole.

[0105] In some embodiments, the battery cell 20 further includes a pressure relief mechanism 28 , which is used to release internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold. The pressure relief mechanism 28 can be mounted on the cover 212 or the housing 211 .

[0106] 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. The electrode assembly 23 includes an electrode body 231, which 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 may be folded to form multiple stacked folded segments, with a positive electrode sheet sandwiched between two adjacent folded segments. In other embodiments, both the positive and negative electrode sheets may be folded to form multiple stacked folded segments, with the folded segments of the positive and negative electrode sheets alternately stacked. 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 assembly 23 may be, but is not limited to, cylindrical, flat, or polygonal. 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. A separator is provided between the positive and negative electrodes to prevent short circuits between the positive and negative electrodes while allowing the active ions to pass through.

[0107] 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.

[0108] 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 silver-surface-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, or titanium. The composite current collector may include a polymer substrate 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 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.

[0109] 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 battery cells 2020 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, 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 iron manganese phosphate, and at least one of a composite material of lithium iron manganese 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 LiNi1 / 3Co1 / 3Mn1 / 3O2 (also referred to as NCM333), LiNi0.5Co0.2Mn0.3O2 (also referred to as NCM523), LiNi0.5Co0.25Mn0.25O2 (also referred to as NCM211), LiNi0.6Co0.2Mn0.2O2 (also referred to as NCM622), LiNi0.8Co0.1Mn0.1O2 (also referred to as NCM811), lithium nickel cobalt aluminum oxide (such as LiNi0.85Co0.15Al0.05O2) and at least one of their modified compounds.

[0110] 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.

[0111] As an example, the negative electrode current collector can be a metal foil, a composite current collector or a foamed metal. 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 substrate 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 foamed metal can be nickel foam, copper foam, aluminum foam, alloy foam, or carbon foam, etc.

[0112] 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.

[0113] 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.

[0114] 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 arranged 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.

[0115] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode sheet and the negative electrode sheet, and serves to transport ions and isolate the positive electrode sheet from the negative electrode sheet.

[0116] In some embodiments, the battery cell 20 also includes an electrolyte, which plays a role in conducting ions between the positive electrode sheet and the negative electrode sheet. This application does not have any specific restrictions on the type of electrolyte, and it can be selected according to needs. The electrolyte can be, but is not limited to, a liquid electrolyte, a gel electrolyte, a solid electrolyte, etc. In the case where the electrolyte is a liquid electrolyte, an injection hole can be opened on the battery cell 20, and the injection hole connects the internal environment of the battery cell 20 and the external environment of the battery cell 20. The injection hole can be opened on the outer shell 21, for example, the injection hole is opened on the cover 212, and for example, the injection hole is opened on the shell 211, and the injection hole can also be opened on the electrode terminal 22. After the battery cell 20 is assembled, the electrolyte can be input into the internal environment of the battery cell 20 through the injection hole.

[0117] The electrode assembly 23 also includes tabs, which can conduct current from the electrode body 231. The tabs include a first tab 232 and a second tab 233. The polarity of the first tab 232 and the polarity of the second tab 233 are opposite, that is, one of the first tab 232 and the second tab 233 is a positive tab, and the other of the first tab 232 and the second tab 233 is a negative tab. The first tab 232 can be directly or indirectly connected to the electrode terminal 22. Similarly, the second tab 233 can be directly or indirectly connected to the housing 21.

[0118] In some embodiments, the first pole tab 232 is a positive pole tab, and the first pole tab 232 is connected between the positive electrode sheet and the electrode terminal 22. The second pole tab 233 is a negative pole tab, and the second pole tab 233 is connected between the negative electrode sheet and the shell 21. The second pole tab 233 can be connected to the cover 212 or to the shell 211. In other words, in this embodiment, the electrode terminal 22 is used as the positive output electrode of the battery cell 20, and the shell 21 is used as the negative output electrode of the battery cell 20.

[0119] In other embodiments, the first pole tab 232 is a negative pole tab, and the first pole tab 232 is connected between the negative electrode sheet and the electrode terminal 22. The second pole tab 233 is a positive pole tab, and the second pole tab 233 is connected between the positive electrode sheet and the outer shell 21. The second pole tab 233 can be connected to the cover 212 or to the shell 211. In other words, in this embodiment, the electrode terminal 22 is used as the negative output electrode of the battery cell 20, and the outer shell 21 is used as the positive output electrode of the battery cell 20.

[0120] In some embodiments, the battery cell 20 is a sodium-ion battery cell, and the outer shell 21 is an aluminum shell. Because sodium ions do not electrochemically react with aluminum, using an aluminum shell as the outer shell 21 of the battery cell 20 can reduce the risk of corrosion of the outer shell 21 and effectively improve the performance of the battery cell 20. Furthermore, sodium-ion battery cells have a high energy density and abundant sodium reserves, which effectively reduces the production cost of the battery cell 20. Furthermore, the aluminum shell is lightweight, further increasing the mass energy density of the battery cell 20. Furthermore, the aluminum shell has good structural strength, effectively improving the structural strength of the battery cell 20.

[0121] The battery cell 20 provided in the embodiment of the present application is achieved by insulating the electrode terminal 22 from the outer shell 21, electrically connecting the first pole ear 232 to the electrode terminal 22, and electrically connecting the second pole ear 233 to the outer shell 21. In other words, the electrode terminal 22 can serve as one of the positive output electrode and the negative output electrode of the battery cell 20, and the outer shell 21 can serve as the other of the positive output electrode and the negative output electrode of the battery cell 20. In this way, there is no need to additionally set an insulating component between the electrode assembly 23 and the outer shell 21, and only one electrode terminal 22 can be set. Not only is the number of electrode terminals 22 reduced, but also the number of insulating components and sealing components set between the electrode terminal 22 and the outer shell 21 is reduced, thereby effectively reducing the number of components of the battery cell 20, effectively reducing the volume and weight of the battery cell 20, and thereby effectively improving the energy density of the battery cell 20.

[0122] In addition, since the battery cell 20 provided in the embodiment of the present application has a relatively small number of components, the production cost of the battery cell 20 is effectively reduced.

[0123] In some embodiments of the present application, please refer to Figures 6 to 15 . The housing 21 includes a first wall 213 . The electrode terminal 22 is disposed on the first wall 213 and insulated from the first wall 213 . The second electrode tab 233 is electrically connected to the first wall 213 .

[0124] The first wall 213 can constitute the cover 212 or any wall of the housing 211. In some embodiments, the first wall 213 constitutes the cover 212. In other words, the electrode lead-out hole can be defined in the first wall 213 and the electrode terminal 22 can be positioned within the electrode lead-out hole. The second tab 233 is electrically connected to the first wall 213, meaning that the first tab 232 and the second tab 233 are connected to the same side of the battery cell 20.

[0125] In some embodiments, the entire first wall 213 is made of conductive material, the electrode terminal 22 is insulated from the first wall 213 , and the second electrode tab 233 can be electrically connected to any part of the first wall 213 .

[0126] Of course, in other embodiments, only the first wall 213 and the second tab 233 may be made of conductive material.

[0127] By adopting the above-mentioned technical solution, the first pole lug 232 and the second pole lug 233 can be led out on the side of the electrode assembly 23 facing the first wall 213, and the first pole lug 232 and the second pole lug 233 can be electrically connected to the electrode terminal 22 and the first wall 213 respectively, so that the first pole lug 232 and the second pole lug 233 can share a lead-out space, thereby optimizing the internal spatial layout structure of the battery cell 20 and making the structure of the battery cell 20 more compact, thereby effectively reducing the volume of the battery cell 20 and effectively improving the volume energy density of the battery cell 20.

[0128] In some embodiments of the present application, please refer to Figures 6 to 15. The first wall 213 includes a wall body 2131 and a first boss 2132. The electrode terminal 22 is arranged on the wall body 2131 and is used to be electrically connected to a bus 30. The first boss 2132 is protruded from the surface of the wall body 2131 facing away from the electrode assembly 23 and is used to be electrically connected to another bus 30.

[0129] The wall 2131 is the main portion of the first wall 213. When the first wall 213 constitutes the aforementioned cover 212, the wall 2131 covers the opening of the housing 211 to isolate the internal environment of the battery cell 20 from the external environment of the battery cell 20. In this embodiment, the aforementioned electrode lead-out hole can be defined in the wall 2131, and the electrode terminal 22 can be disposed within the electrode lead-out hole. At least a portion of the electrode terminal 22 protrudes from the surface of the wall 2131 facing away from the electrode assembly 23 and is used to electrically connect to the busbar 30.

[0130] The first boss 2132 is the portion of the first wall 213 that is connected to the manifold 30. In some embodiments, the first boss 2132 and the wall 2131 may be integrally formed. For example, the first boss 2132 and the wall 2131 may be integrally formed using a stamping process. In other embodiments, the first boss 2132 and the wall 2131 may be independently formed and then connected to form a single unit. The connection between the first boss 2132 and the wall 2131 may be, but is not limited to, welding, bonding, or fastening. It can be understood that the first boss 2132 protrudes from the surface of the wall 2131 facing away from the electrode assembly 23 in a direction away from the electrode assembly 23, and at least a portion of the electrode terminal 22 protrudes from the surface of the wall 2131 facing away from the electrode assembly 23 in a direction away from the electrode assembly 23. The protrusion height of the first boss 2132 relative to the surface of the wall 2131 facing away from the electrode assembly 23 and the protrusion height of the electrode terminal 22 relative to the surface of the wall 2131 facing away from the electrode assembly 23 can be the same or different. The shape of the first boss 2132 can be the same as that of the electrode terminal 22, or it can be different from the shape of the electrode terminal 22. The shape of the first boss 2132 can be, but is not limited to, cylindrical, prismatic, etc. The first boss 2132 is used to electrically connect to one busbar 30, and the electrode terminal 22 is used to electrically connect to another busbar 30. The connection method between the first boss 2132 and the busbar 30 may be, but is not limited to, welding, bonding, or fastening. Similarly, the connection method between the electrode terminal 22 and the busbar 30 may be, but is not limited to, welding, bonding, or fastening.

[0131] In some embodiments, among two adjacent battery cells 20 of the battery 100, one busbar 30 is connected between the electrode terminal 22 of the first battery cell 20 and the first boss 2132 of the second battery cell 20, and another busbar 30 is connected between the first boss 2132 of the first battery cell 20 and the electrode terminal 22 of the second battery cell 20, so that the two adjacent battery cells 20 of the battery 100 are connected in series.

[0132] In other embodiments, in two adjacent battery cells 20 of the battery 100, one busbar 30 is connected between the electrode terminal 22 of the first battery cell 20 and the electrode terminal 22 of the second battery cell 20, and another busbar 30 is connected between the first boss 2132 of the first battery cell 20 and the first boss 2132 of the second battery cell 20, so that the two adjacent battery cells 20 of the battery 100 are connected in parallel.

[0133] By adopting the above technical solution, the difference between the connection height between one busbar 30 and the electrode terminal 22 and the connection height between the other busbar 30 and the first wall 213 can be reduced, which facilitates the connection equipment to electrically connect the battery cell 20 and the busbar 30.

[0134] In some embodiments of the present application, please refer to Figures 9, 10, 14 and 15 together. The first boss 2132 has a first connecting surface 21321 for connecting to the busbar 30, and the electrode terminal 22 has a second connecting surface 221 for connecting to the busbar 30. The height of the first connecting surface 21321 is equal to the height of the second connecting surface 221.

[0135] The first connection surface 21321 is the surface of the first boss 2132 for connecting to the busbar 30. In some embodiments, the first connection surface 21321 is the surface of the first boss 2132 facing away from the electrode assembly 23. The first connection surface 21321 can be a flat surface or a curved surface.

[0136] The second connection surface 221 is the surface of the electrode terminal 22 used to connect to the busbar 30. In some embodiments, the second connection surface 221 is the surface of the electrode terminal 22 facing away from the electrode assembly 23. The second connection surface 221 can be a flat surface or a curved surface.

[0137] The height of the first connecting surface 21321 is equal to the height of the second connecting surface 221. In other words, in this embodiment, the protruding height of the first boss 2132 relative to the surface of the wall 2131 facing away from the electrode assembly 23 is the same as the protruding height of the electrode terminal 22 relative to the surface of the wall 2131 facing away from the electrode assembly 23. That is, electrical connection operations can be performed between the busbar 30 and the electrode terminal 22 and between the busbar 30 and the first boss 2132 at the same height position.

[0138] It should be noted that due to manufacturing tolerances, there may be a certain height difference between the first connecting surface 21321 and the second connecting surface 221. In this embodiment, the height difference between the first connecting surface 21321 and the second connecting surface 221 is less than or equal to 0.05 millimeters (mm), that is, the height of the first connecting surface 21321 is considered to be equal to the height of the second connecting surface 221.

[0139] In the related art, a connecting device is usually used to electrically connect the battery cell 20 and the busbar 30. If the protruding height of the electrode terminal 22 relative to the surface of the wall 2131 facing away from the electrode assembly 23 is significantly different from the height of the portion of the first wall 213 used to connect the busbar 30, the connecting device needs to electrically connect the electrode terminal 22 to one busbar 30 at one height position, and electrically connect the first wall 213 to another busbar 30 at another height position. This will cause the movement trajectory of the connecting head of the connecting device to become complicated, affect the welding accuracy of the connecting device, and even cause cold welding.

[0140] By adopting the above technical solution, electrical connection operations can be performed between the busbar 30 and the electrode terminal 22 and between the busbar 30 and the first boss 2132 at the same height position, which facilitates the connection equipment to electrically connect the battery cell 20 and the busbar 30.

[0141] In some embodiments of the present application, please refer to Figures 9 and 10 together. The battery cell 20 also includes a first adapter 24 and a second adapter 25. The first adapter 24 is connected between the electrode terminal 22 and the first tab 232, and the second adapter 25 is connected between the first wall 213 and the second tab 233.

[0142] The first adapter 24 is a component used to connect the electrode terminal 22 and the first tab 232. In other words, in this embodiment, the electrode terminal 22 and the first tab 232 are indirectly connected through the first adapter 24, so that the electrode terminal 22 and the first tab 232 are electrically connected. The connection between the electrode terminal 22 and the first adapter 24 can be, but is not limited to, welding, bonding, or fastening. The connection between the first tab 232 and the first adapter 24 can be, but is not limited to, welding, bonding, or fastening.

[0143] The second adapter 25 is a component used to connect the first wall 213 and the second tab 233. In other words, in this embodiment, the first wall 213 and the second tab 233 are indirectly connected via the second adapter 25, so that the first wall 213 and the second tab 233 are electrically connected. The connection between the first wall 213 and the second adapter 25 can be, but is not limited to, welding, bonding, or fastening. The connection between the second tab 233 and the second adapter 25 can be, but is not limited to, welding, bonding, or fastening.

[0144] By adopting the above technical solution, it is convenient to electrically connect the electrode terminal 22 with the first electrode tab 232 and to electrically connect the first wall 213 with the second electrode tab 233 .

[0145] In some embodiments of the present application, please refer to Figures 9 and 10 together. The first adapter 24 has a third connecting surface 241 for connecting to the first tab 232, and the second adapter 25 has a fourth connecting surface 251 for connecting to the second tab 233. The height of the third connecting surface 241 is equal to the height of the fourth connecting surface 251.

[0146] The third connection surface 241 is the surface of the first adapter 24 used to connect to the first tab 232. In some embodiments, the third connection surface 241 is the surface of the first adapter 24 facing the electrode assembly 23. The third connection surface 241 can be a flat surface or a curved surface.

[0147] The fourth connection surface 251 is the surface of the second adapter 25 for connecting to the second electrode tab 233. In some embodiments, the fourth connection surface 251 is the surface of the second adapter 25 facing the electrode assembly 23. The fourth connection surface 251 can be a flat surface or a curved surface.

[0148] The height of the third connecting surface 241 is equal to the height of the fourth connecting surface 251. In some embodiments, when the third connecting surface 241 and the fourth connecting surface 251 are planes, the third connecting surface 241 and the fourth connecting surface 251 are on the same horizontal plane (a plane perpendicular to the height direction of the battery cell 20). Accordingly, the lead-out height of the first pole tab 232 from the electrode body 231 toward the third connecting surface 241 is equal to the lead-out height of the second pole tab 233 from the electrode body 231 toward the fourth connecting surface 251, that is, electrical connection operations can be performed between the first adapter 24 and the first pole tab 232, and between the second adapter 25 and the second pole tab 233 at the same height position.

[0149] It should be noted that due to manufacturing tolerances, there may be a certain height difference between the third connecting surface 241 and the fourth connecting surface 251. In this embodiment, the height difference between the third connecting surface 241 and the fourth connecting surface 251 is less than or equal to 0.05 mm, that is, the height of the third connecting surface 241 is considered to be equal to the height of the fourth connecting surface 251.

[0150] In the related art, a connecting device is usually used to electrically connect the first pole ear 232 and the first adapter 24, and to electrically connect the second pole ear 233 and the second adapter 25. If the height of the third connecting surface 241 is significantly different from the height of the fourth connecting surface 251, the connecting device needs to electrically connect the first pole ear 232 and the first adapter 24 at one height position, and electrically connect the second pole ear 233 and the second adapter 25 at another height position. This will cause the movement trajectory of the connecting head of the connecting device to become complicated, affect the welding accuracy of the connecting device, and even cause cold soldering.

[0151] By adopting the above technical solution, electrical connection operations can be performed between the first adapter 24 and the first pole ear 232 and between the second adapter 25 and the second pole ear 233 at the same height, which facilitates the connection equipment to electrically connect the electrode assembly 23 to the electrode terminal 22 and the shell 21.

[0152] In some embodiments of the present application, referring to FIG. 15 , the first wall 213 further includes a second boss 2133 . The second boss 2133 is protruding from the surface of the wall 2131 facing the electrode assembly 23 , and the second tab 233 is connected to the second boss 2133 .

[0153] The second boss 2133 is the portion of the first wall 213 that is used to connect the second tab 233. In other words, in this embodiment, the second tab 233 is directly connected to the first wall 213. The connection between the second tab 233 and the second boss 2133 may be, but is not limited to, welding, bonding, or fastening. In some embodiments, the second boss 2133 and the wall 2131 may be integrally formed. For example, the second boss 2133 and the wall 2131 may be integrally formed using a stamping process. In other embodiments, the second boss 2133 and the wall 2131 may be independently formed and then connected to form a single unit. The connection between the second boss 2133 and the wall 2131 may be, but is not limited to, welding, bonding, or fastening. It is understood that the second boss 2133 protrudes from the surface of the wall 2131 facing the electrode assembly 23 toward the electrode assembly 23, and at least a portion of the electrode terminal 22 protrudes from the surface of the wall 2131 facing the electrode assembly 23 toward the electrode assembly 23. The protrusion height of the second boss 2133 relative to the surface of the wall 2131 facing the electrode assembly 23 and the protrusion height of the electrode terminal 22 relative to the surface of the wall 2131 facing the electrode assembly 23 may be the same or different. The shape of the second boss 2133 may be the same as or different from the shape of the electrode terminal 22, and the shape of the second boss 2133 may be, but is not limited to, cylindrical, prismatic, or the like. The first boss 2132 is electrically connected to one busbar 30, and the electrode terminal 22 is electrically connected to the other busbar 30.

[0154] By adopting the above technical solution, the difference between the connection height between the second electrode tab 233 and the first wall 213 and the connection height between the first electrode tab 232 and the electrode terminal 22 can be reduced, which facilitates the electrical connection operation between the first wall 213 and the second electrode tab 233 by the connection equipment.

[0155] In some embodiments of the present application, please refer to Figures 14 and 15 together. The battery cell 20 also includes a first adapter 24, which is connected between the electrode terminal 22 and the first pole tab 232. The first adapter 24 has a third connecting surface 241 for connecting to the first pole tab 232, and the second boss 2133 has a fifth connecting surface 21331 for connecting to the second pole tab 233. The height of the third connecting surface 241 is equal to the height of the fifth connecting surface 21331.

[0156] The fifth connection surface 21331 is the surface of the second boss 2133 for connecting to the second tab 233. In some embodiments, the fifth connection surface 21331 is the surface of the second boss 2133 facing the electrode assembly 23. The fifth connection surface 21331 can be a flat surface or a curved surface.

[0157] The height of the third connecting surface 241 is equal to the height of the fifth connecting surface 21331. In some embodiments, when the third connecting surface 241 and the fifth connecting surface 21331 are planes, the third connecting surface 241 and the fifth connecting surface 21331 are on the same horizontal plane (a plane perpendicular to the height direction of the battery cell 20). Accordingly, the lead-out height of the first pole tab 232 from the electrode body 231 toward the third connecting surface 241 is equal to the lead-out height of the second pole tab 233 from the electrode body 231 toward the fifth connecting surface 21331, that is, electrical connection operations can be performed between the first adapter 24 and the first pole tab 232, and between the second boss 2133 and the second pole tab 233 at the same height position.

[0158] It should be noted that due to manufacturing tolerances, there may be a certain height difference between the third connecting surface 241 and the fifth connecting surface 21331. In this embodiment, the height difference between the third connecting surface 241 and the fifth connecting surface 21331 is less than or equal to 0.05 mm, that is, the height of the third connecting surface 241 is considered to be equal to the height of the fifth connecting surface 21331.

[0159] In the related art, a connecting device is usually used to perform an electrical connection operation on the first pole ear 232 and the second pole ear 233. If the height of the third connecting surface 241 is significantly different from the height of the fifth connecting surface 21331, the connecting device needs to perform an electrical connection operation on the first pole ear 232 and the first adapter 24 at one height position, and perform an electrical connection operation on the second pole ear 233 and the second boss 2133 at another height position. This will cause the movement trajectory of the connecting head of the connecting device to become complicated, affect the welding accuracy of the connecting device, and even cause a cold weld.

[0160] By adopting the above technical solution, electrical connection operations can be performed between the first adapter 24 and the first pole ear 232 and between the second boss 2133 and the second pole ear 233 at the same height position, which facilitates the connection equipment to electrically connect the electrode assembly 23 to the electrode terminal 22 and the shell 21.

[0161] In some embodiments of the present application, referring to FIG. 15 , the second boss 2133 has a fifth connection surface 21331 for connecting to the second electrode tab 233 , the electrode terminal 22 has a sixth connection surface for connecting to the first electrode tab 232 , and the height of the fifth connection surface 21331 is equal to that of the sixth connection surface.

[0162] The sixth connection surface is the surface of the electrode terminal 22 used to connect to the first electrode tab 232. In some embodiments, the sixth connection surface is the surface of the electrode terminal 22 facing the electrode assembly 23. The sixth connection surface can be a flat surface or a curved surface.

[0163] The height of the fifth connecting surface 21331 is equal to the height of the sixth connecting surface. In some embodiments, when the fifth connecting surface 21331 and the sixth connecting surface are planes, the fifth connecting surface 21331 and the sixth connecting surface are on the same horizontal plane (a plane perpendicular to the height direction of the battery cell 20). Accordingly, the lead-out height of the first pole tab 232 from the electrode body 231 toward the sixth connecting surface is equal to the lead-out height of the second pole tab 233 from the electrode body 231 toward the fifth connecting surface 21331, that is, electrical connection operations can be performed between the electrode terminal 22 and the first pole tab 232 and between the second boss 2133 and the second pole tab 233 at the same height position.

[0164] It should be noted that due to manufacturing tolerances, there may be a certain height difference between the fifth connecting surface 21331 and the sixth connecting surface. In this embodiment, the height difference between the fifth connecting surface 21331 and the sixth connecting surface is less than or equal to 0.05 mm, that is, the height of the fifth connecting surface 21331 is considered to be equal to the height of the sixth connecting surface.

[0165] In the related art, a connecting device is usually used to electrically connect the first pole ear 232 and the second pole ear 233. If the height of the sixth connecting surface is significantly different from the height of the fifth connecting surface 21331, the connecting device needs to electrically connect the first pole ear 232 and the electrode terminal 22 at one height position, and electrically connect the second pole ear 233 and the second boss 2133 at another height position. This will cause the movement trajectory of the connecting head of the connecting device to become complicated, affect the welding accuracy of the connecting device, and even cause cold soldering.

[0166] By adopting the above technical solution, electrical connection operations can be performed between the electrode terminal 22 and the first pole tab 232 and between the second boss 2133 and the second pole tab 233 at the same height, which facilitates the connection equipment to electrically connect the electrode assembly 23 to the electrode terminal 22 and the shell 21.

[0167] In some embodiments of the present application, please refer to Figures 16 to 22. The housing 21 includes a first wall 213 and a second wall 2111. The electrode terminal 22 is arranged on the first wall 213 and insulated from the first wall 213. The second electrode ear 233 is connected to the second wall 2111.

[0168] The first wall 213 may be one of the bottom wall of the housing 211, the side wall of the housing 211, and the cover 212, and the second wall 2111 may be the other of the bottom wall, the side wall of the housing 211, and the cover 212. The bottom wall of the housing 211 refers to the wall portion of the housing 211 opposite the cover 212, and the side wall of the housing 211 refers to the wall portion of the housing 211 located between the cover 212 and the bottom wall of the housing 211 and connected to the periphery of the bottom wall of the housing 211. In some embodiments, the first wall 213 constitutes the cover 212, and the second wall 2111 constitutes the bottom wall of the housing 211 or the side wall of the housing 211. The connection between the second tab 233 and the second wall 2111 may be, but is not limited to, welding, bonding, or fastening.

[0169] By adopting the above technical solution, it is convenient to electrically connect the second electrode tab 233 to the housing 21 .

[0170] In some embodiments of the present application, please refer to Figures 16 to 20. The second wall 2111 is provided with a through hole 21111, which connects the internal environment of the shell 21 and the external environment of the shell 21. The second pole ear 233 is passed through the through hole 21111 and connected to the second wall 2111.

[0171] In some embodiments, the housing 21 further includes a third wall. The first wall 213 constitutes the cover 212, and the electrode terminal 22 is disposed on the cover 212. The second wall 2111 constitutes the bottom wall of the housing 211, i.e., the second wall 2111 is disposed opposite the cover 212, and the third wall constitutes a side wall of the housing 211. The first electrode tab 232 is connected to the side of the electrode body 231 facing the cover 212, so as to electrically connect the first electrode tab 232 to the electrode terminal 22. The second electrode tab 233 is connected to the side of the electrode body 231 facing the bottom wall of the housing 211, so as to electrically connect the second electrode tab 233 to the second wall 2111. The second wall 2111 and the third wall may be integrally formed components. For example, the second wall 2111 and the third wall may be integrally formed using a stamping process. The second wall 2111 and the third wall may also be independently formed and then connected to form a whole. The connection between the second wall 2111 and the third wall may be, but is not limited to, welding, bonding, or the like.

[0172] The through hole 21111 refers to a hole structure that penetrates the surface of the second wall 2111 facing the electrode assembly 23 and the surface of the second wall 2111 facing away from the electrode assembly 23. After the electrode assembly 23 is placed in the internal environment of the housing 21, the second pole tab 233 can extend through the through hole 21111 to the external environment of the housing 21, and the second pole tab 233 and the second wall 2111 are electrically connected in the external environment of the housing 21. The shape of the through hole 21111 can be adapted to the shape of the second pole tab 233. In some embodiments, the second pole tab 233 has a sheet-like structure, the through hole 21111 has a slit structure, and the width of the through hole 21111 is slightly larger than the thickness of the second pole tab 233, so that the second pole tab 233 can pass through the through hole 21111, and at the same time, it can serve as a limit for the second pole tab 233.

[0173] In some embodiments, the second electrode tab 233 is welded to the second wall 2111. Specifically, after the electrode assembly 23 is placed in the internal environment of the housing 21, the second electrode tab 233 can extend through the through hole 21111 to the external environment of the housing 21, and the second electrode tab 233 and the second wall 2111 are welded in the external environment of the housing 21.

[0174] By adopting the above technical solution, the second tab 233 and the second wall 2111 can be electrically connected outside the shell 21, which facilitates the electrical connection of the second tab 233 to the second wall 2111, thereby effectively improving the assembly efficiency of the battery cell 20.

[0175] In some embodiments of the present application, please refer to FIG. 17 to FIG. 20 . The battery cell 20 further includes a cover 26 . The cover 26 covers the through hole 21111 and cooperates with the second wall 2111 to clamp the second tab 233 .

[0176] The cover 26 is used to seal the through-hole 21111 to prevent foreign matter such as moisture and dust from entering the internal environment of the battery cell 20 through the through-hole 21111. The cover 26 also cooperates with the second wall 2111 to clamp the second tab 233. Specifically, after the second tab 233 extends into the external environment of the housing 21 through the through-hole 21111, the cover 26 cooperates with the second wall 2111 to clamp the portion of the second tab 233 located in the external environment of the housing 21, thereby shaping the portion of the second tab 233 located in the external environment of the housing 21 so that the portion of the second tab 233 located in the external environment of the housing 21 can be closely attached to the second wall 2111. In some embodiments, when the cover 26 cooperates with the second wall 2111 to clamp the second tab 233, a through-welding process can be used to weld the second tab 233 to the second wall 2111 through the cover 26.

[0177] In some embodiments, in the thickness direction of the second wall 2111 , the projection of the second electrode tab 233 is located within the projection range of the cover 26 . In other words, the cover 26 can completely cover the second electrode tab 233 to protect the second electrode tab 233 .

[0178] By adopting the above technical solution, not only can the second pole ear 233 be shaped so that the second pole ear 233 can be tightly attached to the second wall 2111, thereby reducing the risk of the second pole ear 233 detaching from the second wall 2111, but it can also effectively protect the second pole ear 233, thereby reducing the risk of damage to the second pole ear 233.

[0179] In some embodiments of the present application, the surface of the cover 26 facing away from the electrode assembly 23 is flush with the surface of the second wall 2111 facing away from the electrode assembly 23 .

[0180] In some embodiments, the surface of the cover 26 facing away from the electrode assembly 23 and the surface of the second wall 2111 facing away from the electrode assembly 23 are both planes, and the surface of the cover 26 facing away from the electrode assembly 23 and the surface of the second wall 2111 facing away from the electrode assembly 23 are on the same horizontal plane (a plane perpendicular to the height direction of the battery cell 20).

[0181] By adopting the above technical solution, the outer surface of the battery cells 20 can be made smoother, so that the battery cells 20 can be neatly arranged inside the battery 100 .

[0182] In some embodiments of the present application, please refer to Figures 20 and 21 . The battery cell 20 further includes a positioning member 27 disposed on the second wall 2111 . The positioning member 27 is used to limit the position of the second electrode tab 233 so that the second electrode tab 233 contacts the second wall 2111 .

[0183] The positioning member 27 is a component used to limit the position of the second pole ear 233. After the electrode assembly 23 and the positioning member 27 are placed in the outer shell 21, the second pole ear 233 can maintain contact with the second wall 2111 under the limiting action of the positioning member 27. In some embodiments, the electrode assembly 23 and the positioning member 27 can be assembled first so that the positioning member 27 limits the second pole ear 233 to a specific position, and then the electrode assembly 23 and the positioning member 27 are placed in the outer shell 21 together. The positioning member 27 can be an integrally molded component or a split connecting component. The material of the positioning member 27 can be, but is not limited to, plastic, aluminum, steel, copper, etc. In some embodiments, in order to further reduce the weight of the battery cell 20 and improve the mass energy density of the battery cell 20, the material of the positioning member 27 is plastic, and the plastic can be, but is not limited to, polypropylene, polyester resin, soluble polytetrafluoroethylene, etc.

[0184] In some embodiments, when the positioning member 27 defines the second electrode tab 233 at a specific position and the electrode assembly 23 and the positioning member 27 are placed in the shell 21, a penetration welding process can be used to weld the second electrode tab 233 to the second wall 2111 through the second wall 2111.

[0185] By adopting the above technical solution, after the positioning member 27 and the electrode assembly 23 are placed in the outer shell 21, the position of the second pole ear 233 can be limited by the positioning member 27 so that the second pole ear 233 contacts the second wall 2111, which facilitates the electrical connection of the second pole ear 233 to the second wall 2111, thereby effectively improving the assembly efficiency of the battery cell 20.

[0186] In some embodiments of the present application, referring to FIG. 21 , the positioning member 27 is provided with a positioning hole, and the second electrode tab 233 is passed through the positioning hole so that the second electrode tab 233 contacts the second wall 2111 .

[0187] The positioning hole is a hole structure used to limit the second pole tab 233 to a specific position. It can be understood that the second pole tab 233 can extend through the positioning hole toward the second wall 2111. When the second pole tab 233 is in a specific position, the second pole tab 233 can maintain contact with the second wall 2111. The shape of the positioning hole can be adapted to the shape of the second pole tab 233. In some embodiments, the second pole tab 233 has a sheet-like structure and the positioning hole has a slit structure. The width of the positioning hole is slightly larger than the thickness of the second pole tab 233, so that the second pole tab 233 can pass through the positioning hole, while also serving to limit the second pole tab 233.

[0188] The opening direction of the positioning hole can be parallel to the surface of the second wall 2111 facing the electrode assembly 23, can be perpendicular to the surface of the second wall 2111 facing the electrode assembly 23, or can be inclined to the surface of the second wall 2111 facing the electrode assembly 23. In some embodiments, the opening direction of the positioning hole is inclined relative to the surface of the second wall 2111 facing the electrode assembly 23. In this way, when the second electrode tab 233 is inserted into the positioning hole, the second electrode tab 233 is also inclined relative to the surface of the second wall 2111 facing the electrode assembly 23. After the electrode assembly 23 and the positioning member 27 are placed in the housing 21, the second wall 2111 can press against the end of the second electrode tab 233 away from the electrode body 231, so that the second electrode tab 233 is gradually bent until the second electrode tab 233 is in contact with the second wall 2111.

[0189] By adopting the above technical solution, the second electrode tab 233 is effectively positioned.

[0190] In some embodiments of the present application, the battery cell 20 further includes an insulating layer (not shown), which is coated on the outer surface of the housing 21 .

[0191] The insulating layer is used to insulate and separate the battery cells 20 from other conductive components. In some embodiments, the insulating layer is an insulating film that covers the outer surface of the housing 21. The insulating film can be made of, but is not limited to, polyimide, polyethylene, polyvinylidene fluoride, polytetrafluoroethylene, and the like.

[0192] Of course, in other embodiments, the insulating layer may also be an insulating coating, which is coated on the outer surface of the housing 21 .

[0193] By adopting the above technical solution, two adjacent battery cells 20 in the battery 100 are effectively insulated and separated, thereby reducing the risk of short circuit of the battery 100 and effectively improving the safety performance of the battery 100.

[0194] In the second aspect, please refer to FIG. 2 to FIG. 5 . The embodiment of the present application further provides a battery 100 , comprising the battery cell 20 described in any of the above embodiments.

[0195] The battery 100 provided in the embodiment of the present application adopts the battery cell 20 described in any of the above embodiments, thereby effectively improving the energy density of the battery 100.

[0196] In some embodiments of the present application, please refer to Figures 3 to 4 , the battery 100 further includes a busbar 30 , there are multiple battery cells 20 , and the busbar 30 is electrically connected between the electrode terminal 22 of one battery cell 20 and the housing 21 of another battery cell 20 .

[0197] The busbar 30 is a component for electrically connecting at least two battery cells 20 .

[0198] In some embodiments, referring to FIG. 3 , the second tab 233 is electrically connected to the cover 212 , and the busbar 30 is electrically connected between the electrode terminal 22 of one battery cell 20 and the cover 212 of another battery cell 20 .

[0199] In other embodiments, referring to Figures 4 and 5 , the second tab 233 is electrically connected to the housing 211, and the current bus 30 is electrically connected between the electrode terminal 22 of one battery cell 20 and the housing 211 of another battery cell 20. As an example, as shown in Figure 4 , the current bus 30 is electrically connected between the electrode terminal 22 of one battery cell 20 and the bottom wall of the housing 211 of another battery cell 20. As an example, as shown in Figure 5 , the current bus 30 is electrically connected between the electrode terminal 22 of one battery cell 20 and the side wall of the housing 211 of another battery cell 20.

[0200] By adopting the above technical solution, it is convenient to electrically connect the battery cells 20 in the battery 100 .

[0201] In a third aspect, referring to FIG1 , an embodiment of the present application further provides an electrical device, comprising the battery 100 described in any one of the above embodiments.

[0202] The electric device provided in the embodiment of the present application adopts the battery 100 described in any of the above embodiments, thereby effectively improving the battery life performance of the electric device.

[0203] 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: include: shell; an electrode terminal, disposed on the housing and insulated from the housing; An electrode assembly is accommodated in the shell, and the electrode assembly includes a first electrode tab and a second electrode tab, wherein the polarity of the first electrode tab is opposite to that of the second electrode tab, the first electrode tab is electrically connected to the electrode terminal, and the second electrode tab is electrically connected to the shell.

2. The battery cell according to claim 1, wherein: The housing includes a first wall, the electrode terminal is disposed on the first wall and is insulated from the first wall, and the second electrode tab is connected to the first wall.

3. The battery cell according to claim 2, characterized in that: The first wall includes a wall body and a first boss. The electrode terminal is arranged on the wall body and is used to be electrically connected to a busbar. The first boss is protruding from the surface of the wall body facing away from the electrode assembly and is used to be electrically connected to another busbar.

4. The battery cell according to claim 3, characterized in that The first boss has a first connection surface for connecting to the bus bar, and the electrode terminal has a second connection surface for connecting to the bus bar. The height of the first connection surface is equal to that of the second connection surface.

5. The battery cell according to any one of claims 2 to 4, characterized in that: The battery cell further includes a first adapter and a second adapter, wherein the first adapter is connected between the electrode terminal and the first tab, and the second adapter is connected between the first wall and the second tab.

6. The battery cell according to claim 5, characterized in that The first adapter has a third connection surface for connecting to the first tab, and the second adapter has a fourth connection surface for connecting to the second tab. The height of the third connection surface is equal to that of the fourth connection surface.

7. The battery cell according to any one of claims 2 to 4, characterized in that: The first wall includes a wall body and a second boss. The electrode terminal is provided on the wall body. The second boss is protruding from a surface of the wall body facing the electrode assembly. The second electrode tab is connected to the second boss.

8. The battery cell according to claim 7, characterized in that The battery cell also includes a first adapter, which is connected between the electrode terminal and the first pole tab. The first adapter has a third connecting surface for connecting to the first pole tab. The second boss has a fifth connecting surface for connecting to the second pole tab. The height of the third connecting surface is equal to the height of the fifth connecting surface.

9. The battery cell according to claim 7, characterized in that: The second boss has a fifth connection surface for connecting to the second electrode tab, the electrode terminal has a sixth connection surface for connecting to the first electrode tab, and the height of the fifth connection surface is equal to that of the sixth connection surface.

10. The battery cell according to claim 1, characterized in that The housing includes a first wall and a second wall. The electrode terminal is disposed on the first wall and insulated from the first wall. The second electrode tab is connected to the second wall.

11. The battery cell according to claim 10, characterized in that The second wall is provided with a through hole, the through hole communicating the internal environment of the housing with the external environment of the housing, and the second tab is passed through the through hole and connected to the second wall.

12. The battery cell according to claim 11, characterized in that The battery cell further includes a sealing cover, which is disposed on the through hole and cooperates with the second wall to clamp the second tab.

13. The battery cell according to claim 12, characterized in that: The surface of the cover facing away from the electrode assembly is flush with the surface of the second wall facing away from the electrode assembly.

14. The battery cell according to claim 10, characterized in that The battery cell further includes a positioning member disposed on the second wall, wherein the positioning member is used to limit the position of the second electrode tab so that the second electrode tab contacts the second wall.

15. The battery cell according to claim 14, characterized in that The positioning member is provided with a positioning hole, and the second electrode tab is passed through the positioning hole so that the second electrode tab contacts the second wall.

16. The battery cell according to any one of claims 10 to 15, characterized in that: The first wall is arranged opposite to the second wall. The electrode assembly further includes an electrode body. The first electrode tab is connected to a side of the electrode body facing the first wall. The second electrode tab is connected to a side of the electrode body facing the second wall.

17. The battery cell according to any one of claims 2 to 16, characterized in that: The housing includes a shell and a cover body provided on the shell body, and the first wall constitutes the cover body.

18. The battery cell according to any one of claims 1 to 17, characterized in that: The battery cell further includes an insulating layer, which is coated on the outer surface of the shell.

19. The battery cell according to any one of claims 1 to 18, characterized in that: The battery cell is a sodium ion battery cell.

20. The battery cell according to any one of claims 1 to 19, characterized in that: The shell is one of an aluminum shell, a steel shell and a copper shell.

21. A battery, characterized in that: The battery comprises the battery cell according to any one of claims 1 to 20.

22. The battery according to claim 21, characterized in that The battery further includes a busbar, and the number of the battery cells is plural. The busbar is electrically connected between the electrode terminal of one of the battery cells and the housing of another of the battery cells.

23. The battery according to claim 22, characterized in that The busbar is connected between the electrode terminal of one of the battery cells and the bottom wall of the housing of another of the battery cells; or The current bus is connected between the electrode terminal of one of the battery cells and a side wall of the housing of another of the battery cells.

24. An electrical device, characterized in that: The electric device comprises the battery according to any one of claims 21 to 23.

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