Battery cell, battery and electric device

Abstract

Disclosed in the present application are a battery cell, a battery and an electric device. The battery cell provided in the embodiments of the present application comprises a casing, electrode terminals, an electrode assembly and an insulating component, wherein the electrode terminals are arranged on the casing; the electrode assembly is accommodated in the casing, and the electrode assembly comprises tabs, the tabs being electrically connected to the electrode terminals; and the insulating component connects the electrode terminals to the casing and is used for insulating and isolating the electrode terminals from the casing. The insulating component can insulate and isolate the electrode terminals from the casing, and can also connect the casing to the electrode terminals, such that insulation and fixation between the electrode terminals and the casing are both implemented, thus simplifying the structure of the battery cell and increasing the energy density of the battery cell.

Description

Battery cells, batteries, and electrical devices

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application No. 202311145879.4, filed on September 6, 2023, entitled “Battery Cell, Battery, and Electrical Device,” the entire contents of which are incorporated herein by reference. Technical Field

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

[0004] With the advancement of battery technology, battery cells are being used in a growing number of fields and are gradually replacing traditional fossil fuels in the automotive powertrain sector. Battery cells store chemical energy and controllably convert it into electrical energy. In recyclable battery cells, after discharge, the active material can be activated by recharging for continued use.

[0005] How to simplify the structure of battery cells is an important research direction in the industry.

[0006] Summary of the Invention

[0007] The present application provides a battery cell, a battery, and an electrical device, which can simplify the structure of the battery cell.

[0008] In a first aspect, the present application provides a battery cell comprising a housing, electrode terminals, an electrode assembly, and an insulating member. The electrode terminals are disposed on the housing. The electrode assembly is housed within the housing and includes tabs electrically connected to the electrode terminals. The insulating member connects the electrode terminals to the housing and serves to insulate the electrode terminals from the housing.

[0009] The insulating component can not only insulate and isolate the electrode terminal from the shell, but also connect the shell and the electrode terminal, thereby simultaneously achieving insulation and fixation between the electrode terminal and the shell, so as to simplify the structure of the battery cell and improve the energy density of the battery cell.

[0010] In some embodiments, at least a portion of the insulating member is located between and attached to the electrode terminal and the housing.

[0011] The portion of the insulating component located between the outer casing and the electrode terminal not only insulates the electrode terminal from the outer casing but also allows for simultaneous attachment to both the outer casing and the electrode terminal, ensuring an insulated installation of the electrode terminal on the outer casing. This simplifies the installation and molding processes for the electrode terminal. Directly connecting the insulating component to the electrode terminal and the outer casing reduces friction between the insulating component and the electrode terminal, as well as between the outer casing and the electrode terminal, when the battery cell is subjected to external impact. This reduces the risk of damage or failure to the insulating component and improves reliability.

[0012] In some embodiments, the insulating component is bonded to the housing and the electrode terminal. The bonding process is simple, easily connects the insulating component to the housing and to the electrode terminal, and reduces the risk of damage to the insulating component during assembly and use.

[0013] In some embodiments, the insulating component is bonded to the housing and the electrode terminal by a thermocompression lamination process.

[0014] The hot pressing composite process is simple and can easily realize the connection between the insulating component and the shell and the connection between the insulating component and the electrode terminal. At the same time, it can improve the bonding strength of the composite interface between the insulating component and the shell and the bonding strength of the composite interface between the insulating component and the electrode terminal, reduce the risk of separation of the insulating component and the shell and the risk of separation of the insulating component and the electrode terminal when the electrode terminal is subjected to force, and improve the reliability of the battery cell.

[0015] In some embodiments, a passivation film is provided on the surface of the electrode terminal, and the passivation film is connected to the insulating component. The provision of the passivation film can enhance the connection strength between the electrode terminal and the insulating component and improve the corrosion resistance of the electrode terminal.

[0016] In some embodiments, a passivation film is provided on the surface of the housing, and the passivation film is connected to the insulating component. By providing the passivation film, the connection strength between the housing and the insulating component can be increased, and the corrosion resistance of the housing can be improved.

[0017] In some embodiments, the housing includes a wall portion having an electrode lead-out hole, the electrode terminal is disposed on the wall portion and covers at least a portion of the electrode lead-out hole in a thickness direction of the wall portion, and the insulating member connects the electrode terminal and the wall portion and insulates the electrode terminal from the wall portion.

[0018] In some embodiments, the insulating component is used to seal the electrode lead-out hole. The insulating component can simultaneously insulate, seal, and connect the electrode terminal and the housing, thereby simplifying the structure of the battery cell and improving the energy density of the battery cell.

[0019] In some embodiments, the electrode terminal includes a connecting portion located on one side of the wall portion along the thickness direction, with a projection of the connecting portion along the thickness direction located within a projection of the wall portion along the thickness direction. At least a portion of the insulating member is located between the wall portion and the connecting portion and is attached to the wall portion and the connecting portion.

[0020] The wall portion and the connecting portion are arranged along the thickness direction. During assembly, the wall portion and the connecting portion can apply pressure to the insulating component from both sides, thereby improving the bonding strength between the wall portion and the insulating component and the bonding strength between the connecting portion and the insulating component, reducing the risk of separation between the wall portion and the insulating component and the risk of separation between the wall portion and the electrode terminal, and improving the reliability of the battery cell.

[0021] In some embodiments, the area of ​​the projection of the portion of the insulating member located between the wall portion and the connecting portion along the thickness direction is greater than or equal to 50 mm. 2 , so as to increase the connection area between the insulating component and the wall portion and the connection area between the insulating component and the connection portion, and improve the stability of the connection between the insulating component, the wall portion and the connection portion.

[0022] In some embodiments, the area of ​​the projection of the portion of the insulating member located between the wall portion and the connecting portion along the thickness direction is greater than or equal to 100 mm 2 , so as to further increase the connection area between the insulating component and the wall portion and the connection area between the insulating component and the connection portion, and improve the stability of the connection between the insulating component, the wall portion and the connection portion.

[0023] In some embodiments, a portion of the insulating member located between the wall portion and the connecting portion has a thickness of 20 μm to 2000 μm.

[0024] The thickness of the portion of the insulating component located between the wall and the connection portion is greater than or equal to 20 μm to increase the creepage distance between the wall and the connection portion, reduce the risk of cracking of the insulating component when the battery cell is subjected to external impact, improve the insulation effect between the wall and the connection portion, and reduce the risk of insulation failure. The thickness of the portion of the insulating component located between the wall and the connection portion is less than or equal to 2000 μm to reduce the space and weight occupied by the insulating component and reduce the loss of energy density of the battery cell.

[0025] In some embodiments, the thickness of the portion of the insulating component located between the wall portion and the connecting portion is 50 μm-1000 μm, so as to further balance the insulating effect of the insulating component and the space occupied by the insulating component.

[0026] In some embodiments, the wall portion includes a first surface and a second surface disposed opposite each other along a thickness direction of the wall portion, the first surface facing the connecting portion, and the second surface facing away from the connecting portion. The insulating component includes a first insulating portion attached to the first surface, at least a portion of the first insulating portion being located between the first surface and the connecting portion and covering an area of ​​the first surface that overlaps with the connecting portion in the thickness direction.

[0027] In some embodiments, in the radial direction of the electrode lead-out hole, the first insulating portion extends beyond the connecting portion, thereby increasing a creepage distance between the connecting portion and the first surface and improving the insulation effect.

[0028] In some embodiments, both the first insulating portion and the connecting portion are disposed around the electrode lead-out hole. The contact surface between the first insulating portion and the connecting portion, and the contact surface between the first insulating portion and the wall portion, are annular. When the battery cell is subjected to external impact, the annular contact surfaces can effectively disperse stress, thereby reducing the risk of failure in the connection between the first insulating portion and the connecting portion, as well as the risk of failure in the connection between the first insulating portion and the wall portion, and improving the reliability of the battery cell. The first insulating portion surrounds the electrode lead-out hole, thereby sealing the electrode lead-out hole.

[0029] In some embodiments, the connecting portion is located on a side of the wall portion facing the electrode assembly. During normal operation of the battery cell, the wall portion can stop the connecting portion to reduce the risk of the electrode terminal falling out of the electrode lead-out hole.

[0030] In some embodiments, the wall portion and the connecting portion are both annular, and a ratio of an outer diameter D1 of the connecting portion to an outer diameter D2 of the wall portion is 0.3-0.8.

[0031] The connection strength between the connecting portion, the wall portion, and the first insulating portion is related to D1 / D2. In this embodiment of the present application, D1 / D2 is limited to greater than or equal to 0.3 to increase the effective connection area between the connecting portion and the first insulating portion, as well as the effective connection area between the wall portion and the first insulating portion. This increases the composite strength between the electrode terminal and the insulating component, and between the wall portion and the insulating component, reduces the risk of connection failure, improves the reliability of the battery cell, and extends the service life of the battery cell. A larger D1 / D2 ratio increases the space and weight occupied by the connecting portion. In this embodiment of the present application, D1 / D2 is limited to less than or equal to 0.8 to minimize energy density loss and balance the energy density and reliability of the battery cell.

[0032] In some embodiments, the ratio of the outer diameter D1 of the connecting portion to the outer diameter D2 of the wall portion is 0.5-0.7.

[0033] In some embodiments, the first surface includes a first region and a second region, the first region is covered by the first insulating portion, and the second region surrounds the first region. The battery cell further includes an insulating spacer, at least a portion of which is located between the second region and the tab in the thickness direction.

[0034] The first insulating portion can insulate the first region from the tab, and the insulating spacer can isolate at least part of the second region from the tab, thereby reducing the risk of contact between the tab and the wall when the battery cell is impacted and improving reliability.

[0035] In some embodiments, the insulating spacer completely isolates the second region from the tab in the thickness direction, thereby further reducing the risk of short circuits and improving the reliability of the battery cell.

[0036] In some embodiments, the insulating spacer overlaps with the first insulating portion in the thickness direction to increase the creepage distance between the tab and the wall, reducing the risk of contact between the tab and the wall when the battery cell is impacted, thereby improving reliability.

[0037] In some embodiments, the insulating spacer includes an insulating plate and an insulating cylinder, wherein the insulating cylinder surrounds the tab, and the insulating plate is connected to an end of the insulating cylinder facing the first surface and is located between the first surface and the tab.

[0038] The insulating plate can separate the tab from the second region, and the insulating tube can gather the tab from its periphery to separate the tab from the wall of the housing surrounding the tab, thereby reducing the risk of short circuits. The insulating plate and the connecting portion can share at least part of the space in the thickness direction, thereby improving space utilization.

[0039] In some embodiments, the battery cell further includes a current collecting member located on a side of the tab facing the first surface and connected to the tab, and the electrode terminal located on a side of the current collecting member facing away from the tab and connected to the current collecting member. At least a portion of the insulating plate is located between the current collecting member and the first surface and attached to the current collecting member.

[0040] In some embodiments, the electrode terminal includes a terminal body and a first stopper connected to each other. At least a portion of the terminal body is accommodated in the electrode lead-out hole, and the first stopper protrudes from the outer circumference of the terminal body. The first stopper includes a connecting portion. By configuring the terminal body to extend into the electrode lead-out hole, connection between the electrode terminal and other components can be facilitated. The wall portion blocks the connecting portion, thereby preventing the electrode terminal from being removed from the interior of the housing.

[0041] In some embodiments, the insulating component further includes a second insulating portion connected to the first insulating portion, surrounding the terminal body, and insulating the outer circumference of the terminal body from the wall of the electrode lead-out hole. The second insulating portion can further insulate the terminal body from the wall, thereby reducing the risk of electrical conduction between the terminal body and the housing and improving reliability.

[0042] In some embodiments, the second insulating portion is attached to the outer peripheral surface of the terminal body and the hole wall of the electrode lead-out hole to reduce the risk of external impurities entering the interior of the shell from between the second insulating portion and the terminal body and the risk of external impurities entering the electrode lead-out hole from between the second insulating portion and the hole wall of the electrode lead-out hole.

[0043] In some embodiments, the electrode terminal further includes a second stopper protruding from the outer peripheral surface of the terminal body and located on a side of the wall portion facing away from the electrode assembly. In the thickness direction, at least a portion of the wall portion is located between the connecting portion and the second stopper.

[0044] The wall portion can be limited between the first limiting portion and the second limiting portion to limit the relative movement between the electrode terminal and the wall portion. The second limiting portion can increase the connection strength between the electrode terminal and the wall portion and improve stability.

[0045] In some embodiments, the insulating component further includes a third insulating portion connected to the second insulating portion, the third insulating portion being attached to the second surface and insulating the second limiting portion from the second surface to reduce a short circuit risk.

[0046] In some embodiments, the second limiting portion has an inclined surface facing the second surface. Along the radial direction of the electrode lead-out hole, the distance between the inclined surface and the second surface in the thickness direction gradually increases. At least a portion of the third insulating portion is located between the inclined surface and the second surface and is attached to the inclined surface and the second surface.

[0047] By setting the inclined surface, the space between the second limiting portion and the second surface can be increased; during the assembly process, when the insulating component is squeezed by the second limiting portion, the material can flow between the second surface and the inclined surface, thereby reducing material overflow.

[0048] In some embodiments, the electrode terminal has a gap extending from the outer peripheral surface of the terminal body and close to the connection between the terminal body and the second limiting portion. The gap can disperse stress during the folding and forming process of the second limiting portion, thereby reducing stress concentration.

[0049] In some embodiments, the electrode terminal is formed by defining a first recess on a side facing away from the electrode assembly and folding the sidewall of the first recess outward to form a second stop. A second recess is provided on the outer side of the sidewall of the first recess to guide the bending of the sidewall of the first recess and is configured to be filled after the second stop is formed to form a gap.

[0050] The first recess is formed to create a thin sidewall on the electrode terminal. The electrode terminal is mounted on the wall by folding the sidewall of the first recess. The second recess not only guides the folding of the sidewall of the first recess but also provides space for material flow, thereby reducing material accumulation at the folded area, improving the electrode terminal's shape, and reducing the difficulty of forming the electrode terminal.

[0051] In some embodiments, the melting point of the first insulating portion is greater than or equal to 140° C. The higher melting point of the first insulating portion reduces the risk of softening of the first insulating portion during production and use of the battery cell, thereby reducing the risk of failure in the connection between the first insulating portion and the wall portion, as well as the risk of failure in the connection between the first insulating portion and the connecting portion, thereby improving reliability.

[0052] In some embodiments, the yield strength of the first insulating portion is greater than or equal to 20 MPa, so as to reduce the risk of the first insulating portion being crushed by force during the production and use of the battery cell and improve reliability.

[0053] In some embodiments, the first insulating portion includes a first insulating layer, a second insulating layer, and a third insulating layer stacked together, wherein the first insulating layer is bonded to the first surface, the second insulating layer is located between the first and third insulating layers, and at least a portion of the third insulating layer is bonded to the connecting portion. The first insulating portion employs a multi-layer composite structure, which can improve the overall performance of the first insulating portion.

[0054] In some embodiments, the melting point of the second insulating layer is greater than that of the first insulating layer, which in turn is greater than that of the third insulating layer. The second insulating layer has a higher melting point and is less susceptible to softening during battery cell production and use, thereby insulating the wall portion and the connection portion, reducing the risk of short circuits.

[0055] In some embodiments, the difference between the melting point of the second insulating layer and the melting point of the first insulating layer is greater than or equal to 20° C., so as to reduce the risk of softening or melting of the second insulating layer during the production and use of the battery cell.

[0056] In some embodiments, the difference between the melting point of the second insulating layer and the melting point of the third insulating layer is greater than or equal to 20° C., so as to reduce the risk of softening or melting of the second insulating layer during the production and use of the battery cell.

[0057] In some embodiments, the first insulating portion includes a polymer and a modified polymer, wherein the modified polymer is formed by modifying the polymer. The first insulating layer and the third insulating layer both include the modified polymer, and the second insulating layer includes a polymer.

[0058] By providing the modified polymer, the composite strength between the first insulating layer and the wall portion and the composite strength between the third insulating layer and the connection portion can be improved, thereby reducing the risk of connection failure between the first insulating layer and the wall portion and the risk of connection failure between the third insulating layer and the connection portion.

[0059] In some embodiments, the second insulating layer does not include a modified polymer, which can reduce the impact of the modification on the polymer properties and retain the original properties of the polymer.

[0060] In some embodiments, the polymer comprises polypropylene or polyethylene terephthalate.

[0061] In some embodiments, the housing includes a shell and an end cover, wherein the shell has an opening and the end cover covers the opening. The shell includes a wall portion, and the wall portion is arranged opposite to the end cover.

[0062] In a second aspect, the present application provides a battery comprising a plurality of battery cells provided according to any embodiment of the first aspect.

[0063] In a third aspect, the present application provides an electrical device, comprising a battery provided according to any embodiment of the second aspect, wherein the battery is used to provide electrical energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] The features, advantages and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

[0065] FIG1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0066] FIG2 is a schematic diagram of an explosion of a battery provided in some embodiments of the present application;

[0067] FIG3 is a schematic structural diagram of the battery module shown in FIG2 ;

[0068] FIG4 is a schematic structural diagram of a battery cell provided in some embodiments of the present application;

[0069] FIG5 is a schematic diagram of an explosion of the battery cell shown in FIG4 ;

[0070] FIG6 is a schematic cross-sectional view of the battery cell shown in FIG4 ;

[0071] FIG7 is an enlarged schematic diagram of the circle frame of FIG6;

[0072] FIG8 is an enlarged schematic diagram of block A in FIG7 ;

[0073] FIG9 is an enlarged schematic diagram of FIG7 at the circle B;

[0074] FIG10 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0075] FIG11 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0076] FIG12 is a schematic diagram of a battery cell during assembly according to some embodiments of the present application;

[0077] FIG13 is another schematic diagram of a battery cell during assembly according to some embodiments of the present application;

[0078] FIG14 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0079] FIG15 is an enlarged schematic diagram of the circle frame of FIG14;

[0080] FIG16 is a schematic cross-sectional view of a battery cell provided in some other embodiments of the present application;

[0081] FIG17 is an enlarged schematic diagram of the circle frame of FIG16;

[0082] FIG18 is a schematic structural diagram of a battery cell provided in some other embodiments of the present application;

[0083] FIG19 is a schematic cross-sectional view of a battery cell provided in some other embodiments of the present application.

[0084] The accompanying drawings are numbered as follows: 1. vehicle; 2. battery; 3. controller; 4. motor; 5. housing; 5a. first housing portion; 5b. second housing portion; 5c. storage space; 6. battery module; 7. battery cell; 10. electrode assembly; 11. tab; 12. main body; 20. outer shell; 21. shell; 211. side wall; 212. end wall; 22. end cover; 23. wall portion; 231. electrode lead-out hole; 232. first surface; 232a. first region; 232b. second region; 233. second surface; 30. electrode terminal; 31. terminal body; 31a. outer peripheral surface; 311. terminal recess; 311a. bottom wall; 312. Through hole; 32, first limiting portion; 321, connecting portion; 322, transition portion; 33, second limiting portion; 331, inclined surface; 34, gap; 35, first recess; 351, side wall of the first recess; 36, second recess; 40, insulating component; 41, first insulating portion; 411, first insulating layer; 412, second insulating layer; 413, third insulating layer; 42, second insulating portion; 43, third insulating portion; 431, fourth insulating layer; 432, fifth insulating layer; 433, sixth insulating layer; 50, insulating spacer; 51, insulating plate; 52, insulating cylinder; 60, current collecting component; 70, sealing plate; 80, sealing pin; Z, thickness direction. DETAILED DESCRIPTION

[0085] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0086] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0087] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0088] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0089] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0090] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0091] The term "plurality" used in this application refers to two or more (including two).

[0092] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0093] Battery cells may include but are not limited to lithium-ion battery cells, sodium-ion battery cells, sodium-lithium-ion battery cells, lithium metal battery cells, sodium metal battery cells, lithium-sulfur battery cells, magnesium-ion battery cells, nickel-hydrogen battery cells, nickel-cadmium battery cells, lead-acid battery cells, etc.

[0094] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. The prismatic battery cell includes a square-shell battery cell, a blade-shaped battery cell, and a polygonal battery. The polygonal battery is, for example, a hexagonal battery, etc. There is no special limitation in this application.

[0095] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.

[0096] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0097] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are housed in the case.

[0098] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0099] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0100] A battery cell generally consists of an electrode assembly and a housing, with the electrode assembly housed within the housing. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are embedded and released back and forth between the positive and negative electrodes. A separator is placed between the positive and negative electrodes to reduce the risk of short circuits while allowing active ions to pass through.

[0101] The housing is used to encapsulate the electrode assembly and electrolyte components. The housing can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film.

[0102] Battery cells typically also have electrode terminals mounted on the outer casing. These terminals are used to electrically connect to the electrode assembly and conduct the electricity generated by the electrode assembly. To reduce the risk of short circuits, the electrode terminals and the outer casing need to be insulated. The outer casing typically includes an insulating member, at least partially located between the electrode terminals and the outer casing, to insulate the two.

[0103] In the related art, the connection structure between the electrode terminals, the housing and the insulating components is relatively complex, which affects the production efficiency and energy density of the battery cells.

[0104] In view of this, an embodiment of the present application provides a technical solution, which connects the electrode terminal and the shell through an insulating component, and simultaneously achieves insulation and fixation between the electrode terminal and the shell, so as to simplify the structure of the battery cell and improve the energy density of the battery cell.

[0105] The battery cells described in the embodiments of the present application are suitable for use in batteries and electrical devices using the batteries.

[0106] The battery cells, batteries, and electrical devices disclosed in the embodiments of the present application can be used in electrical devices that use batteries as power sources or various energy storage systems that use batteries as energy storage elements. The electrical devices can be, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, battery-powered vehicles, electric vehicles, ships, spacecraft, and the like. Among them, electric toys can include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and the like, and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, and the like.

[0107] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device.

[0108] FIG1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application.

[0109] As shown in FIG1 , a battery 2 is provided inside the vehicle 1. The battery 2 may be provided at the bottom, head, or tail of the vehicle 1. The battery 2 may be used to power the vehicle 1. For example, the battery 2 may serve as an operating power source for the vehicle 1.

[0110] The vehicle 1 may further include a controller 3 and a motor 4 . The controller 3 is used to control the battery 2 to supply power to the motor 4 , for example, to meet the power requirements of the vehicle 1 during startup, navigation, and driving.

[0111] In some embodiments of the present application, the battery 2 can not only serve as the operating power source of the vehicle 1, but also serve as the driving power source of the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0112] FIG2 is an exploded view of a battery according to some embodiments of the present application. As shown in FIG2 , the battery 2 includes a housing 5 and a battery cell (not shown in FIG2 ), wherein the battery cell is housed in the housing 5 .

[0113] The housing 5 is used to house battery cells and can have various structures. In some embodiments, the housing 5 can include a first housing portion 5a and a second housing portion 5b. The first housing portion 5a and the second housing portion 5b overlap each other, and the first housing portion 5a and the second housing portion 5b together define a storage space 5c for accommodating the battery cells. The second housing portion 5b can be a hollow structure with one end open. The first housing portion 5a is a plate-like structure, and the first housing portion 5a overlaps the open side of the second housing portion 5b to form the housing 5 with the storage space 5c. The first housing portion 5a and the second housing portion 5b can also be hollow structures with one end open. The open side of the first housing portion 5a overlaps the open side of the second housing portion 5b to form the housing 5 with the storage space 5c. Of course, the first housing portion 5a and the second housing portion 5b can have various shapes, such as a cylinder, a rectangular parallelepiped, etc.

[0114] In order to improve the sealing performance after the first box body 5a and the second box body 5b are connected, a sealing member, such as a sealant, a sealing ring, etc., may also be provided between the first box body 5a and the second box body 5b.

[0115] Assuming that the first box body portion 5a covers the top of the second box body portion 5b, the first box body portion 5a can also be called an upper box cover, and the second box body portion 5b can also be called a lower box body.

[0116] In battery 2, there can be one or more battery cells. If there are multiple battery cells, they can be connected in series, in parallel, or in a hybrid configuration. A hybrid configuration refers to a combination of series and parallel connections. Multiple battery cells can be directly connected in series, in parallel, or in a hybrid configuration, and then the entire battery module can be housed within housing 5. Alternatively, multiple battery cells can be first connected in series, in parallel, or in a hybrid configuration to form a battery module 6, and then multiple battery modules 6 can be connected in series, in parallel, or in a hybrid configuration to form a single unit housed within housing 5.

[0117] A battery cell may be the smallest unit constituting a battery.

[0118] FIG3 is a schematic structural diagram of the battery module shown in FIG2 .

[0119] In some embodiments, as shown in FIG3 , there are multiple battery cells 7, which are first connected in series, in parallel, or in hybrid to form a battery module 6. The multiple battery modules 6 are then connected in series, in parallel, or in hybrid to form a whole, which is housed in a box.

[0120] The multiple battery cells 7 in the battery module 6 can be electrically connected via a busbar to achieve parallel, series, or mixed connection of the multiple battery cells 7 in the battery module 6. There can be one or more busbars, each of which is used to electrically connect at least two battery cells.

[0121] Figure 4 is a structural schematic diagram of a battery cell provided in some embodiments of the present application; Figure 5 is an exploded schematic diagram of the battery cell shown in Figure 4; Figure 6 is a cross-sectional schematic diagram of the battery cell shown in Figure 4; Figure 7 is an enlarged schematic diagram of Figure 6 at the circle frame; Figure 8 is an enlarged schematic diagram of Figure 7 at square frame A; and Figure 9 is an enlarged schematic diagram of Figure 7 at circle frame B.

[0122] 4 to 9 , an embodiment of the present application provides a battery cell 7 , which includes an electrode assembly 10 and a housing 20 , wherein the electrode assembly 10 is accommodated in the housing 20 .

[0123] The electrode assembly 10 includes a positive electrode and a negative electrode. During the charge and discharge process of the battery cell 7, active ions (e.g., lithium ions) are intercalated and released between the positive and negative electrodes. Optionally, the electrode assembly 10 also includes a separator disposed between the positive and negative electrodes. The separator can reduce the risk of short circuits between the positive and negative electrodes while allowing the active ions to pass through.

[0124] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material layer disposed on at least one surface of the positive electrode current collector.

[0125] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material layer is provided on either or both of the two facing surfaces of the positive electrode current collector.

[0126] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, titanium, silver surface treated aluminum or stainless steel, etc. may be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0127] As an example, the positive electrode active material layer includes a positive electrode active material, and the positive electrode active material may include at least one of the following materials: lithium-containing phosphate, lithium transition metal oxide and their respective modified compounds. However, the present application is not limited to these materials, and other traditional materials that can be used as battery positive electrode active material layers may also be used. These positive electrode active material layers may be used alone or in combination of two or more. Among them, examples of lithium-containing phosphates may include but are not limited to at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and 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, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also referred to as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O2 (also referred to as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O2 (also referred to as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O2 (also referred to as NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O2 (also referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.80 Co 0.15 Al 0.05 O2) and at least one of its modified compounds, etc.

[0128] In some embodiments, a positive electrode may be a metal foam. The metal foam may be nickel foam, copper foam, aluminum foam, alloy foam, or carbon foam, among others. When a metal foam is used as the positive electrode, a positive electrode active material layer may or may not be provided on the surface of the metal foam. For example, a lithium source material, potassium metal, or sodium metal may be filled and / or deposited within the metal foam, where the lithium source material is lithium metal and / or a lithium-rich material.

[0129] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0130] As an example, the negative electrode current collector can be a metal foil, a metal foam, or a composite current collector. 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 can be used. The metal foam can be nickel foam, copper foam, aluminum foam, alloy foam, or carbon foam. The composite current collector can include a polymer material base layer 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.).

[0131] As an example, 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.

[0132] As an example, the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode active material is provided on either or both of the two facing surfaces of the negative electrode current collector.

[0133] As an example, the negative electrode active material may adopt the negative electrode active material for battery cells 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 batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0134] 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.

[0135] In some embodiments, the separator includes a separator. The present application has no particular limitation on the type of separator, and any known separator with a porous structure having good chemical stability and mechanical stability can be selected.

[0136] As an example, the primary material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator can be a separate component positioned between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes.

[0137] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transport ions and isolate the positive and negative electrodes.

[0138] In some embodiments, the housing 20 includes a shell 21 and an end cover 22 . The shell 21 has an opening, and the end cover 22 is used to cover the opening.

[0139] The housing 21 is a component used to cooperate with the end cover 22 to form an internal cavity of the battery cell 7. The formed internal cavity can be used to accommodate the electrode assembly 10, electrolyte and other components.

[0140] The housing 21 and the end cap 22 may be separate components. For example, an opening may be provided on the housing 21 , and the end cap 22 may be placed over the opening to form an internal cavity of the battery cell 7 .

[0141] The housing 21 can have various shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism, etc. Specifically, the shape of the housing 21 can be determined according to the specific shape and size of the electrode assembly 10. The housing 21 can be made of various materials, including but not limited to copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0142] The shape of the end cap 22 can be adapted to the shape of the housing 21 to fit the housing 21. The material of the end cap 22 can be the same as or different from the material of the housing 21. Optionally, the end cap 22 can be made of a material with a certain hardness and strength (e.g., copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.). In this way, the end cap 22 is less likely to deform when subjected to compression or collision, thereby providing the battery cell 7 with higher structural strength and improved reliability.

[0143] The end cover 22 is connected to the housing 21 by welding, bonding, clamping or other methods.

[0144] The housing 21 may be open at one end or at both ends. In some examples, the housing 21 may be open at one end, with one end cap 22 provided to cover the housing 21. In other examples, the housing 21 may be open at both ends, with two end caps 22 provided to cover the two openings of the housing 21, respectively.

[0145] In some embodiments, the battery cell 7 includes an electrode terminal 30 . The electrode terminal 30 can be used to electrically connect to the electrode assembly 10 to output or input electrical energy of the battery cell 7 .

[0146] In some embodiments, the battery cell 7 includes an electrode assembly 10, a housing 20, an electrode terminal 30, and an insulating member 40. The electrode terminal 30 is disposed on the housing 20. The electrode assembly 10 is housed within the housing 20 and includes a tab 11 electrically connected to the electrode terminal 30. The insulating member 40 connects the electrode terminal 30 and the housing 20 and is used to insulate and isolate the electrode terminal 30 from the housing 20.

[0147] The electrode assembly 10 is a component where electrochemical reactions occur in the battery cell 7. The housing 20 may contain one or more electrode assemblies 10. The electrode assembly 10 may be a wound structure, a laminate structure, a wound laminate composite structure, or other structures.

[0148] The shape of the electrode assembly 10 can be cylindrical, flat, or polygonal.

[0149] As an example, the electrode assembly 10 includes a positive electrode sheet and a negative electrode sheet. The positive electrode sheet includes a positive electrode coating region coated with a positive electrode active material layer and a positive electrode uncoated region not coated with the positive electrode active material layer. The negative electrode sheet includes a negative electrode coating region coated with a negative electrode active material layer and a negative electrode uncoated region not coated with the negative electrode active material layer. The positive electrode uncoated region of the positive electrode sheet constitutes a positive electrode tab, while the negative electrode uncoated region of the negative electrode sheet constitutes a negative electrode tab.

[0150] The tab 11 electrically connected to the electrode terminal 30 can be either a positive tab or a negative tab. During the charge and discharge process of the battery cell 7, the positive and negative active material layers react with the electrolyte, and the tab 11 connects to the electrode terminal 30 to form a current loop.

[0151] The tab 11 can be directly connected to the electrode terminal 30, for example, by welding, abutting, or other means. Alternatively, the tab 11 can also be indirectly connected to the electrode terminal 30 through other conductive components (such as a current collecting member) to achieve electrical connection between the tab 11 and the electrode terminal 30.

[0152] The housing 20 is a hollow structure, forming an internal cavity for accommodating the electrode assembly 10. The shape of the housing 20 can be determined according to the specific shape of the electrode assembly 10. For example, if the electrode assembly 10 has a rectangular parallelepiped structure, a rectangular housing can be selected; if the electrode assembly 10 has a cylindrical structure, a cylindrical housing can be selected.

[0153] Illustratively, the outer shell 20 includes an end cap 22 and a shell 21 , and the electrode terminal 30 may be disposed on the shell 21 or on the end cap 22 .

[0154] The electrode terminal 30 and the housing 20 are electrically isolated from each other, so that charge is substantially prevented from flowing from one to the other. The insulating member 40 can, to a certain extent, block the transfer of charge between the housing 20 and the electrode terminal 30, thereby isolating the housing 20 and the electrode terminal 30.

[0155] For example, the electrode terminal 30 may be an output terminal of the battery cell 7, which is used to electrically connect to a busbar of the battery. Optionally, at least a portion of the electrode terminal 30 is exposed to facilitate connection to the busbar.

[0156] In the embodiment of the present application, the insulating component 40 can not only insulate and isolate the electrode terminal 30 from the outer shell 20, but also connect the outer shell 20 and the electrode terminal 30, thereby simultaneously achieving insulation and fixation between the electrode terminal 30 and the outer shell 20, so as to simplify the structure of the battery cell 7 and improve the energy density of the battery cell 7.

[0157] In some embodiments, at least a portion of the insulating member 40 is located between and attached to the electrode terminal 30 and the case 20 .

[0158] The insulating member 40 may be entirely located between the outer case 20 and the electrode terminal 30 , or may be only partially located between the outer case 20 and the electrode terminal 30 .

[0159] Attachment can refer to both affixing and connecting; when one component is attached to another, the two components are connected at least partially along their contact surfaces, and the fixed connection between the two components does not require any other structure. For example, one component can be attached to another component by bonding, coating, or other means.

[0160] The portion of the insulating component 40 located between the outer shell 20 and the electrode terminal 30 not only insulates the electrode terminal 30 from the outer shell 20, but is also simultaneously attached to the outer shell 20 and the electrode terminal 30 to insulate the electrode terminal 30 from the outer shell 20, thereby simplifying the installation and molding processes of the electrode terminal 30. The insulating component 40 is directly connected to the electrode terminal 30 and the outer shell 20. This reduces friction between the insulating component 40 and the electrode terminal 30, as well as friction between the outer shell 20 and the electrode terminal 30, when the battery cell 7 is subjected to external impact, thereby reducing the risk of damage or failure of the insulating component 40 and improving reliability.

[0161] In some embodiments, the insulating component 40 is tightly coupled to the outer shell 20, and the insulating component 40 is tightly coupled to the electrode terminal 30. The tightly coupled structure formed between the insulating component 40 and the outer shell 20, and the tightly coupled structure formed between the insulating component 40 and the electrode terminal 30, achieves insulation and connection between the outer shell 20 and the electrode terminal 30, and improves the reliability of the battery cell 7.

[0162] In some embodiments, the insulating component 40 is bonded to the housing 20 and the electrode terminal 30. The bonding process is simple, easily connecting the insulating component 40 to the housing 20 and to the electrode terminal 30, and reducing the risk of damage to the insulating component 40 during assembly and use.

[0163] Illustratively, by bonding, tight bonding between the insulating member 40 and the housing 20 and tight bonding between the insulating member 40 and the electrode terminal 30 can be achieved.

[0164] In some embodiments, the insulating member 40 is bonded to the housing 20 and the electrode terminal 30 by a thermocompression lamination process.

[0165] The hot pressing composite process is simple and can easily realize the connection between the insulating component 40 and the outer shell 20 and the connection between the insulating component 40 and the electrode terminal 30. At the same time, it can improve the bonding strength of the composite interface between the insulating component 40 and the outer shell 20 and the bonding strength of the composite interface between the insulating component 40 and the electrode terminal 30, reduce the risk of separation of the insulating component 40 and the outer shell 20 and the risk of separation of the insulating component 40 and the electrode terminal 30 when the electrode terminal 30 is subjected to force, and improve the reliability of the battery cell 7.

[0166] In some embodiments, the insulating component 40 is tightly combined with the housing 20 through a microscopic matching structure, and the insulating component 40 is tightly combined with the electrode terminal 30 through a microscopic matching structure.

[0167] The microscopic matching structure achieves tight integration and simple operation process. At the same time, it can improve the bonding strength of the composite interface between the insulating component 40 and the shell 20 and the bonding strength of the composite interface between the insulating component 40 and the electrode terminal 30, reduce the risk of separation of the insulating component 40 and the shell 20 and the risk of separation of the insulating component 40 and the electrode terminal 30 when the electrode terminal 30 is subjected to force, and improve the reliability of the battery cell 7.

[0168] In some embodiments, a passivation film is provided on the surface of the electrode terminal 30 , and the passivation film is connected to the insulating component 40 .

[0169] By providing a passivation film, a porous structure can be formed on the electrode terminal 30, thereby increasing the specific surface area of ​​the electrode terminal 30, enhancing the adsorption of the electrode terminal 30 on the insulating component 40, and improving the mechanical bite between the electrode terminal 30 and the insulating component 40; at the same time, the formation of hydrogen bonds in the passivation film of the electrode terminal 30 can make the electrode terminal 30 and the insulating component 40 tightly combined, thereby improving the connection strength between the electrode terminal 30 and the insulating component 40.

[0170] The passivation film can also improve the corrosion resistance of the electrode terminal 30 .

[0171] For example, the electrode terminal 30 may be passivated to form a passivation film on the surface of the electrode terminal 30 .

[0172] In some embodiments, the passivation film of the electrode terminal 30 has a thickness of 0.01 μm-1 μm.

[0173] In some embodiments, a passivation film is provided on the surface of the housing 20 , and the passivation film is connected to the insulating component 40 .

[0174] The passivation film forms a porous structure on the housing 20, thereby increasing the specific surface area of ​​the housing 20, enhancing the adsorption of the housing 20 to the insulating component 40, and improving the mechanical engagement between the housing 20 and the insulating component 40. Furthermore, the hydrogen bonds formed in the passivation film of the housing 20 allow the housing 20 to be tightly bonded to the insulating component 40, thereby increasing the connection strength between the two components. The passivation film also improves the corrosion resistance of the housing 20.

[0175] In some embodiments, the passivation film of the housing 20 has a thickness of 0.01 μm-1 μm.

[0176] In some embodiments, the material of the insulating component 40 may include thermal composite adhesive.

[0177] In some embodiments, the housing 20 and the electrode terminal 30 are both made of metal.

[0178] In some embodiments, the electrode terminal 30 , the housing 20 , and the thermal composite adhesive are heated and pressurized so that the thermal composite adhesive is composited with the electrode terminal 30 and the housing 20 .

[0179] The passivation film contains more polar groups, which can enhance the hydrogen bond between the metal surface and the thermal composite adhesive and improve the interface composite strength. The purpose of heating and pressurizing is to make the thermal composite adhesive become molten and penetrate into the microporous structure of the metal surface, so as to better react with the polar functional groups on the metal surface to form bonds.

[0180] The passivation film contains a large number of polar groups or has a porous structure, which is used to improve the bonding strength between the metal surface and the thermal composite adhesive and the corrosion resistance of the metal material, thereby increasing the service life of the battery cell 7.

[0181] The insulating component 40 can achieve insulation and connection between two metal interfaces.

[0182] In some embodiments, the housing 20 includes a wall portion 23 having an electrode lead-out hole 231 defined therein. The electrode terminal 30 is disposed on the wall portion 23 and covers at least a portion of the electrode lead-out hole 231 in the thickness direction Z of the wall portion 23. The insulating member 40 connects the electrode terminal 30 and the wall portion 23 and insulates the electrode terminal 30 from the wall portion 23.

[0183] As an example, the wall portion 23 may be the end cover 22 or a wall of the housing 21 .

[0184] As an example, the shape of the wall portion 23 may be circular, rectangular, oval, or other shapes.

[0185] Illustratively, the electrode lead-out hole 231 passes through the wall portion 23 so that the electrode terminal 30 can lead the electrical energy of the electrode assembly 10 to the outside of the housing 20. Optionally, the electrode lead-out hole 231 passes through the wall portion 23 along the thickness direction Z of the wall portion 23.

[0186] The electrode terminal 30 may cover only a portion of the electrode lead-out hole 231 or may completely cover the electrode lead-out hole 231. As an example, the electrode terminal 30 may alone seal the electrode lead-out hole 231 to isolate the interior space of the housing 20 from the exterior space, thereby improving the sealing of the battery cell 7. Alternatively, the electrode terminal 30 may cooperate with other functional components (such as the insulating component 40) to jointly seal the electrode lead-out hole 231 to isolate the interior space of the housing 20 from the exterior space, thereby improving the sealing of the battery cell 7.

[0187] In some embodiments, the housing 20 includes a shell 21 and an end cover 22 . The shell 21 has an opening, and the end cover 22 covers the opening.

[0188] Optionally, the shell 21 includes a side wall 211 and an end wall 212 , the side wall 211 surrounds the outside of the electrode assembly 10 , the end wall 212 is arranged opposite to the opening, and the wall portion 23 is the end cover 22 or the end wall 212 .

[0189] There may be one or more sidewalls 211. In some examples, there may be one sidewall 211 and it may be a cylindrical structure. In other examples, there may be multiple sidewalls 211, which are sequentially connected along the circumference of the electrode assembly 10; for example, there may be four sidewalls 211, which are sequentially connected to form a square cylindrical structure.

[0190] In some embodiments, the battery cell 7 is a cylindrical battery cell with a single cylindrical sidewall 211. Because the end cap 22 or end wall 212 is flatter than the sidewall 211, the electrode terminal 30 is disposed on the end cap 22 or end wall 212 to improve assembly efficiency of the battery cell 7.

[0191] In some embodiments, the housing 21 includes a wall portion 23 , which is disposed opposite to the end cover 22 . Exemplarily, the wall portion 23 is an end wall 212 of the housing 21 .

[0192] In some embodiments, the insulating member 40 is used to seal the electrode lead-out hole 231 .

[0193] Sealing the electrode lead-out hole 231 may mean disconnecting the connection between the electrode lead-out hole 231 and the internal space of the shell 20, and / or disconnecting the connection between the electrode lead-out hole 231 and the external space of the shell 20, thereby isolating the internal space of the shell 20 from the external space of the shell 20.

[0194] The insulating component 40 can simultaneously perform the functions of insulation, sealing, and connecting the electrode terminal 30 and the housing 20 , thereby simplifying the structure of the battery cell 7 and improving the energy density of the battery cell 7 .

[0195] The insulating component 40 is attached to the electrode terminal 30 and the outer shell 20, which can reduce the risk of foreign matter entering the inner shell 20 from between the insulating component 40 and the electrode terminal 30 and the risk of foreign matter entering the inner shell 20 from between the insulating component 40 and the outer shell 20, thereby improving the sealing performance.

[0196] In some embodiments, the insulating component 40 connects the electrode terminal 30 and the housing 20 , which can reduce the size of the electrode terminal 30 in the thickness direction Z while achieving an insulating and sealing function, thereby improving the energy density of the battery cell 7 .

[0197] In some embodiments, at least a portion of the insulating member 40 is located between the wall portion 23 and the electrode terminal 30 in the thickness direction Z and surrounds the electrode lead-out hole 231 .

[0198] In some embodiments, the electrode terminal 30 includes a connecting portion 321 , which is located on one side of the wall portion 23 along the thickness direction Z, and a projection of the connecting portion 321 along the thickness direction Z is located within a projection of the wall portion 23 along the thickness direction Z. At least a portion of the insulating member 40 is located between the wall portion 23 and the connecting portion 321 and is attached to the wall portion 23 and the connecting portion 321 .

[0199] The connecting portion 321 may be located on a side of the wall portion 23 facing the electrode assembly 10 , or may be located on a side of the wall portion 23 facing away from the electrode assembly 10 .

[0200] The connecting portion 321 may be one or more. In some examples, the connecting portion 321 is one and annular; in other examples, the connecting portion 321 is multiple and spaced apart along the circumference of the electrode lead-out hole 231 .

[0201] In the thickness direction Z of the wall portion 23 , the projection of the connection portion 321 does not overlap with the projection of the electrode lead-out hole 231 .

[0202] In the thickness direction Z of the wall portion 23 , the insulating member 40 may be entirely located between the wall portion 23 and the connecting portion 321 , or only partially located between the wall portion 23 and the connecting portion 321 .

[0203] The wall portion 23 and the connecting portion 321 are arranged along the thickness direction Z. During assembly, the wall portion 23 and the connecting portion 321 can apply pressure to the insulating component 40 from both sides, thereby improving the bonding strength between the wall portion 23 and the insulating component 40 and the bonding strength between the connecting portion 321 and the insulating component 40, reducing the risk of separation between the wall portion 23 and the insulating component 40 and the risk of separation between the wall portion 23 and the electrode terminal 30, and improving the reliability of the battery cell 7.

[0204] In some embodiments, the connecting portion 321 protrudes from the wall of the electrode lead-out hole 231 along the radial direction of the electrode lead-out hole 231. The radial direction of the electrode lead-out hole 231 may be a direction passing through the central axis of the electrode lead-out hole 231 and perpendicular to the central axis of the electrode lead-out hole 231. Optionally, the central axis of the electrode lead-out hole 231 is parallel to the thickness direction Z of the wall portion 23.

[0205] The central axis of the electrode lead-out hole 231 is a virtual line. As an example, the electrode lead-out hole 231 is rotationally symmetric about the central axis.

[0206] In some examples, the electrode lead-out hole 231 may be a circular hole, and the radial direction of the electrode lead-out hole 231 may be the radial direction of the electrode lead-out hole 231; in other examples, the electrode lead-out hole 231 may be a square hole, and the radial direction of the electrode lead-out hole 231 may be the radial direction of the circumscribed circle of the electrode lead-out hole 231.

[0207] In some embodiments, the area S of the projection of the portion of the insulating member 40 between the wall portion 23 and the connecting portion 321 along the thickness direction Z is greater than or equal to 50 mm. 2 .

[0208] In the embodiment of the present application, the connection area between the insulating component 40 and the wall portion 23 can be greater than or equal to 50 mm 2 , Make the connection area between the insulating component 40 and the connecting portion 321 greater than or equal to 50mm 2 , thereby improving the stability of the connection between the insulating component 40, the wall portion 23 and the connecting portion 321.

[0209] For example, the portion of the insulating component 40 located between the wall portion 23 and the connecting portion 321 is annular, the inner diameter r of the annular portion may be the diameter of the electrode lead-out hole 231, and the outer diameter of the annular portion may be the outer diameter R of the connecting portion 321. S=π×(R 2 -r 2 ).

[0210] In some embodiments, S is 50 mm 2 , 80mm 2 , 100mm 2 , 120mm 2 , 150mm 2 , 170mm 2 , 180mm 2 or 200mm 2 .

[0211] In some embodiments, S is greater than or equal to 100 mm.

[0212] In some embodiments, the surface of the connecting portion 321 connected to the insulating component 40 is a plane.

[0213] In some embodiments, the connecting portion 321 is annular.

[0214] In some embodiments, the thickness of the portion of the insulating member 40 between the wall portion 23 and the connecting portion 321 is 20 μm to 2000 μm.

[0215] The thickness of the portion of the insulating component 40 located between the wall portion 23 and the connecting portion 321 is greater than or equal to 20 μm. This increases the creepage distance between the wall portion 23 and the connecting portion 321, reduces the risk of cracking of the insulating component 40 when the battery cell 7 is subjected to external impact, improves the insulation effect between the wall portion 23 and the connecting portion 321, and reduces the risk of insulation failure. The thickness of the portion of the insulating component 40 located between the wall portion 23 and the connecting portion 321 is less than or equal to 2000 μm. This reduces the space and weight occupied by the insulating component 40 and reduces the loss of energy density of the battery cell 7.

[0216] Optionally, the thickness of the portion of the insulating part 40 located between the wall portion 23 and the connecting portion 321 is 20μm, 30μm, 50μm, 100μm, 150μm, 200μm, 300μm, 400μm, 500μm, 600μm, 700μm, 800μm, 900μm, 1000μm, 1200μm, 1400μm, 1500μm, 1800μm or 2000μm.

[0217] For example, the total thickness of the wall portion 23, the connecting portion 321, and the portion of the insulating member 40 located between the wall portion 23 and the connecting portion 321 can be measured first. The thickness of the connecting portion 321 and the thickness of the wall portion 23 can then be measured. The thickness of the insulating member 40 at a single location can then be calculated. In this way, the thickness of ten locations on the insulating member 40 is measured, and the average thickness can be calculated. This average thickness can be the thickness of the portion of the insulating member 40 located between the wall portion 23 and the connecting portion 321.

[0218] In some embodiments, the thickness of the portion of the insulating member 40 between the wall portion 23 and the connecting portion 321 is 50 μm to 1000 μm.

[0219] In some embodiments, the thickness of the portion of the insulating member 40 between the wall portion 23 and the connecting portion 321 is 100 μm to 500 μm.

[0220] In some embodiments, the insulation member 40 has a breakdown voltage greater than or equal to 500V.

[0221] In some embodiments, the wall portion 23 includes a first surface 232 and a second surface 233 oppositely disposed along a thickness direction Z of the wall portion 23 . The first surface 232 faces the connecting portion 321 , and the second surface 233 faces away from the connecting portion 321 .

[0222] For example, the first surface 232 may be the inner surface of the wall 23 facing the electrode assembly 10, and the second surface 233 may be the outer surface of the wall 23 facing away from the electrode assembly 10; alternatively, the second surface 233 may be the inner surface of the wall 23 facing the electrode assembly 10, and the first surface 232 may be the outer surface of the wall 23 facing away from the electrode assembly 10.

[0223] In some embodiments, the insulating component 40 includes a first insulating portion 41 attached to the first surface 232 , at least a portion of the first insulating portion 41 is located between the first surface 232 and the connecting portion 321 and covers a region of the first surface 232 that overlaps with the connecting portion 321 in the thickness direction Z.

[0224] In the thickness direction Z, the first insulating portion 41 may be entirely located between the first surface 232 and the connecting portion 321 , or only a portion thereof may be located between the first surface 232 and the connecting portion 321 .

[0225] For example, the first insulating portion 41 is attached to both the wall portion 23 and the connecting portion 321, so that the electrode terminal 30 can be insulated and mounted on the housing 20. Because the first insulating portion 41 is directly attached to the wall portion 23 and the connecting portion 321, the embodiment of the present application requires less compression of the first insulating portion 41. This means that while improving the sealing performance of the connection interface between the first insulating portion 41 and the wall portion 23 and the connection interface between the first insulating portion 41 and the connecting portion 321, the pressure on the first insulating portion 41 is reduced, thereby reducing the risk of damage to the first insulating portion 41.

[0226] In some embodiments, the thickness of the first insulating portion 41 is 50 μm-1000 μm.

[0227] In some embodiments, in the radial direction of the electrode lead-out hole 231 , the first insulating portion 41 extends beyond the connecting portion 321 , thereby increasing the creepage distance between the connecting portion 321 and the first surface 232 and improving the insulation effect.

[0228] Optionally, the thickness of the first insulating portion 41 is 50 μm, 100 μm, 150 μm, 250 μm, 350 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, or 1000 μm.

[0229] In some embodiments, the first insulating portion 41 and the connecting portion 321 are both disposed around the electrode lead-out hole 231 .

[0230] The contact surface between the first insulating portion 41 and the connecting portion 321 is annular, and the contact surface between the first insulating portion 41 and the wall portion 23 is annular. When the battery cell 7 is subjected to external impact, the annular contact surface can effectively disperse stress, thereby reducing the risk of failure in the connection between the first insulating portion 41 and the connecting portion 321 and the connection between the first insulating portion 41 and the wall portion 23, and improving the reliability of the battery cell 7. The first insulating portion 41 surrounds the electrode lead-out hole 231, thereby sealing the electrode lead-out hole 231.

[0231] In some embodiments, the connection portion 321 is located on a side of the wall portion 23 facing the electrode assembly 10 .

[0232] During normal operation of the battery cell 7 , the wall portion 23 can stop the connecting portion 321 to reduce the risk of the electrode terminal 30 falling out of the electrode lead-out hole 231 .

[0233] In some embodiments, the wall portion 23 and the connecting portion 321 are both annular.

[0234] In some embodiments, the battery cell 7 is a cylindrical battery cell.

[0235] In some embodiments, the ratio of the outer diameter D1 of the connecting portion 321 to the outer diameter D2 of the wall portion 23 is 0.3-0.8.

[0236] The connection strength among the connecting portion 321, the wall portion 23 and the first insulating portion 41 is related to D1 / D2. In the embodiment of the present application, D1 / D2 is limited to be greater than or equal to 0.3 to increase the effective connection area between the connecting portion 321 and the first insulating portion 41 and the effective connection area between the wall portion 23 and the first insulating portion 41, thereby increasing the composite strength between the electrode terminal 30 and the insulating component 40 and the composite strength between the wall portion 23 and the insulating component 40, reducing the risk of connection failure, improving the reliability of the battery cell 7, and extending the service life of the battery cell 7.

[0237] The larger D1 / D2 is, the more space and weight the connection portion 321 occupies. In the embodiment of the present application, D1 / D2 is limited to less than or equal to 0.8 to reduce the loss of energy density and balance the energy density and reliability of the battery cell 7.

[0238] Illustratively, D1 / D2 is 0.3, 0.4, 0.5, 0.6, 0.7 or 0.8.

[0239] For example, the outer diameter D2 of the wall portion 23 is the diameter of the cylindrical outer shell.

[0240] In some embodiments, D1 / D2 is 0.5-0.7.

[0241] In some embodiments, the first surface 232 includes a first region 232a and a second region 232b. The first region 232a is covered by the first insulating portion 41, and the second region 232b surrounds the first region 232a. The battery cell 7 also includes an insulating spacer 50. In the thickness direction Z, at least a portion of the insulating spacer 50 is located between the second region 232b and the tab 11.

[0242] The first insulating portion 41 can insulate the first region 232a from the tab 11, and the insulating spacer 50 can isolate at least part of the second region 232b from the tab 11, thereby reducing the risk of contact between the tab 11 and the wall portion 23 when the battery cell 7 is impacted, thereby improving reliability.

[0243] In some embodiments, in the thickness direction Z, the insulating spacer 50 completely isolates the second region 232 b and the tab 11 to further reduce the risk of short circuit and improve the reliability of the battery cell 7 .

[0244] In some embodiments, in the thickness direction Z, the insulating spacer 50 overlaps with the first insulating portion 41 .

[0245] The embodiment of the present application can increase the creepage distance between the tab 11 and the wall portion 23 , thereby reducing the risk of contact between the tab 11 and the wall portion 23 when the battery cell 7 is impacted, thereby improving reliability.

[0246] In some embodiments, the portion where the insulating spacer 50 overlaps with the first insulating portion 41 in the thickness direction Z is annular, and the width of the overlapping portion is greater than or equal to 1 mm.

[0247] In some embodiments, the insulating spacer 50 includes an insulating plate 51 and an insulating tube 52. The insulating tube 52 surrounds the electrode tab 11. The insulating plate 51 is connected to an end of the insulating tube 52 facing the first surface 232 and is located between the first surface 232 and the electrode tab 11. The insulating plate 51 surrounds the outer side of the connecting portion 321.

[0248] The insulating plate 51 can separate the tab 11 from the second region 232b, and the insulating tube 52 can gather the tab 11 from its periphery to separate the tab 11 from the wall of the housing 20 surrounding the tab 11, thereby reducing the risk of short circuits. The insulating plate 51 and the connecting portion 321 can share at least part of the space in the thickness direction Z, thereby improving space utilization.

[0249] In some embodiments, the electrode assembly 10 includes a main body 12, and the tab 11 is extended from an end of the main body 12 facing the wall 23. Exemplarily, the main body 12 includes a positive electrode coating region, a negative electrode coating region, and a separator.

[0250] In some embodiments, the insulating tube 52 further surrounds the end of the main body 12 close to the tab 11 .

[0251] In some embodiments, the insulation tube 52 is connected to the main body 12 .

[0252] In some embodiments, the insulating tube 52 is bonded to the main body 12. For example, the insulating spacer 50 is an insulating tape.

[0253] In some embodiments, the insulating spacer 50 is a heat shrink tubing.

[0254] In some embodiments, the battery cell 7 further includes a current collecting member 60 , which is located on a side of the tab 11 facing the first surface 232 and connected to the tab 11 , and the electrode terminal 30 is located on a side of the current collecting member 60 facing away from the tab 11 and connected to the current collecting member 60 .

[0255] The current collecting member 60 can play a transition role, facilitating the electrical connection between the electrode terminal 30 and the tab 11 .

[0256] In some embodiments, the current collecting member 60 extends beyond the connection portion 321 in the radial direction of the electrode lead-out hole 231. The current collecting member 60 can be connected to the outer portion of the tab 11 to reduce the difference in the conductive path between different portions of the tab 11 and the electrode terminal 30 and improve consistency.

[0257] In some embodiments, at least a portion of the insulation plate 51 is located between the current collecting member 60 and the first surface 232 and attached to the current collecting member 60 .

[0258] The insulating plate 51 can insulate the current collecting member 60 from the wall 23 to reduce the risk of short circuit. The current collecting member 60 can fix the insulating plate 51, reduce the shaking of the insulating spacer 50 when the battery cell 7 is impacted, and reduce the risk of conduction between the current collecting member 60 and the wall 23.

[0259] In some embodiments, the insulating plate 51 covers a region of the current collecting member 60 that overlaps with the second region 232 b in the thickness direction Z.

[0260] In some embodiments, the electrode terminal 30 presses against the tab 11 via the current collecting member 60. Optionally, D1 / D2 is greater than or equal to 0.5, so that the electrode terminal 30 can support a larger area of ​​the tab 11 via the current collecting member 60. During the insertion of the electrode assembly 10 into the casing, the electrode terminal 30 can effectively support the tab 11 via the current collecting member 60, thereby reducing misalignment of the positive and negative electrode sheets of the electrode assembly 10.

[0261] In some embodiments, the electrode terminal 30 includes a terminal body 31 and a first stopper 32 connected to each other. At least a portion of the terminal body 31 is accommodated in the electrode lead-out hole 231. The first stopper 32 protrudes from the outer peripheral surface 31a of the terminal body 31. The first stopper 32 includes a connecting portion 321.

[0262] The first limiting portion 32 may include only the connecting portion 321 , or may include other portions in addition to the connecting portion 321 .

[0263] The first limiting portion 32 may be one or more. Optionally, the first limiting portion 32 is one and is a circular ring structure.

[0264] The terminal body 31 may be entirely located in the electrode lead-out hole 231 , or only partially located in the electrode lead-out hole 231 .

[0265] By setting the terminal body 31 to extend into the electrode lead-out hole 231, it is easy to connect the electrode terminal 30 to other components. The wall portion 23 blocks the connecting portion 321, thereby preventing the electrode terminal 30 from being separated from the interior of the housing 20.

[0266] Exemplarily, the terminal body 31 is a columnar structure, and the first limiting portion 32 is a ring structure surrounding the outside of the terminal body 31 .

[0267] In some embodiments, the first limiting portion 32 includes a connecting portion 321 and a transition portion 322 , wherein the transition portion 322 connects the terminal body 31 and the connecting portion 321 . In the thickness direction Z of the wall portion 23 , the projection of the transition portion 322 is located within the projection of the electrode lead-out hole 231 .

[0268] Illustratively, in the thickness direction Z, the boundary between the connecting portion 321 and the transition portion 322 corresponds to the hole wall of the electrode lead-out hole 231. For example, as shown in FIG8 , the boundary between the connecting portion 321 and the transition portion 322 is illustrated by a dotted line; the dotted line is only for ease of understanding and does not exist in the electrode terminal.

[0269] In some embodiments, the thickness of the first insulating portion 41 is less than or equal to 1 mm, which can reduce the size requirement of the terminal body 31 and thus improve the energy density.

[0270] In some embodiments, the insulating component 40 further includes a second insulating portion 42 , which is connected to the first insulating portion 41 , surrounds the terminal body 31 , and insulates the outer peripheral surface 31 a of the terminal body 31 from the wall of the electrode lead-out hole 231 .

[0271] The second insulating portion 42 may be entirely or partially located in the electrode lead-out hole 231. For example, an end portion of the second insulating portion 42 along the axial direction of the electrode lead-out hole 231 may extend out of the electrode lead-out hole 231.

[0272] Exemplarily, the second insulating portion 42 is a cylindrical structure surrounding the outside of the main body portion 12 of the terminal body 31 .

[0273] The second insulating portion 42 can insulate and isolate the terminal body 31 from the wall portion 23 to reduce the risk of electrical conduction between the terminal body 31 and the housing 20 and improve reliability.

[0274] In some embodiments, the second insulating portion 42 is attached to the outer peripheral surface 31a of the terminal body 31. The terminal body 31 can fix the second insulating portion 42 to reduce the risk of the second insulating portion 42 falling off. The second insulating portion 42 is attached to the terminal body 31, which can reduce the risk of foreign matter entering the interior of the housing 20 through the gap between the second insulating portion 42 and the terminal body 31.

[0275] In some embodiments, the second insulating portion 42 is attached to the wall of the electrode lead-out hole 231. The wall of the electrode lead-out hole 231 can secure the second insulating portion 42, thereby reducing the risk of the second insulating portion 42 falling off. The second insulating portion 42 is attached to the wall of the electrode lead-out hole 231, thereby reducing the risk of foreign matter entering the electrode lead-out hole 231 through the gap between the second insulating portion 42 and the wall of the electrode lead-out hole 231.

[0276] In some embodiments, the first insulating portion 41 is connected to the second insulating portion 42 , which reduces the gap between the first insulating portion 41 and the second insulating portion 42 to further improve the insulation performance and reduce the risk of conduction between the wall portion 23 and the electrode terminal 30 .

[0277] In some embodiments, the electrode terminal 30 further includes a second stopper 33, which protrudes from the outer peripheral surface 31a of the terminal body 31 and is located on the side of the wall portion 23 facing away from the electrode assembly 10. In the thickness direction Z, at least a portion of the wall portion 23 is located between the connecting portion 321 and the second stopper 33.

[0278] The wall portion 23 can be limited between the first limiting portion 32 and the second limiting portion 33 to limit the relative movement between the electrode terminal 30 and the wall portion 23. The second limiting portion 33 can increase the connection strength between the electrode terminal 30 and the wall portion 23 and improve stability.

[0279] In some embodiments, the insulating component 40 further includes a third insulating portion 43 connected to the second insulating portion 42 . The third insulating portion 43 is attached to the second surface 233 and insulates the second limiting portion 33 from the second surface 233 to reduce the risk of short circuit.

[0280] In some embodiments, the third insulating portion 43 may be entirely located between the second limiting portion 33 and the housing 20 , or may be only partially located between the second limiting portion 33 and the housing 20 .

[0281] In some embodiments, the third insulating portion 43 is attached to the second surface 233 , which can improve the sealing performance of the connection surface between the third insulating portion 43 and the wall portion 23 .

[0282] In some embodiments, the third insulating portion 43 is connected to the second insulating portion 42 , which can reduce the gap between the third insulating portion 43 and the second insulating portion 42 to improve insulation performance and reduce the risk of conduction between the wall portion 23 and the electrode terminal 30 .

[0283] In some embodiments, in the radial direction of the electrode lead-out hole 231 , the end of the first limiting portion 32 away from the terminal body 31 exceeds the end of the second limiting portion 33 away from the terminal body 31 .

[0284] In the radial direction of the electrode lead-out hole 231, the first limiting portion 32 has a larger size than the second limiting portion 33, so that the connection area between the connecting portion 321 and the first insulating portion 41 and the connection area between the wall portion 23 and the first insulating portion 41 can be increased, so as to improve the connection strength among the wall portion 23, the first insulating portion 41 and the connecting portion 321 and reduce the risk of connection failure.

[0285] In some embodiments, the connection strength between the second limiting portion 33 and the third insulating portion 43 is smaller than the connection strength between the first insulating portion 41 and the connecting portion 321 .

[0286] Illustratively, under the same conditions, the force required to peel off the first insulating portion 41 from the connecting portion 321 is greater than the force required to peel off the third insulating portion 43 from the second limiting portion 33 .

[0287] The connection strength between the first insulating portion 41 and the connecting portion 321 is relatively high, and the first insulating portion 41 can effectively seal and connect. The embodiment of the present application can reduce the connection strength requirement between the second limiting portion 33 and the third insulating portion 43, thereby simplifying the process.

[0288] The surface of the connecting portion 321 facing the first surface 232 is smoother than the surface of the second limiting portion 33 facing the second surface 233 , thereby improving the connection strength between the first insulating portion 41 and the connecting portion 321 .

[0289] In some embodiments, the electrode terminal 30 is formed into the second limiting portion 33 by a flanging process, so as to rivet the electrode terminal 30 to the wall portion 23 .

[0290] In some embodiments, the first limiting portion 32, the second limiting portion 33, and the terminal body 31 are integrally formed. This embodiment of the present application can improve the overall structural strength of the electrode terminal 30, reduce the internal resistance of the electrode terminal 30, and improve the current capacity.

[0291] In some embodiments, the melting point of the first insulating portion 41 is greater than or equal to 140° C. The melting point refers to the melting point under normal pressure.

[0292] The first insulating part 41 has a higher melting point, so as to reduce the risk of softening of the first insulating part 41 during the production and use of the battery cell 7, thereby reducing the risk of failure in the connection between the first insulating part 41 and the wall part 23 and the risk of failure in the connection between the first insulating part 41 and the connecting part 321, thereby improving reliability.

[0293] In some embodiments, the yield strength of the first insulating portion 41 is greater than or equal to 20 MPa, so as to reduce the risk of the first insulating portion 41 being crushed by force during the production and use of the battery cell 7 and improve reliability.

[0294] In some embodiments, the melting point of the insulating member 40 is greater than or equal to 140°C.

[0295] In some embodiments, the yield strength of the insulating member 40 is greater than or equal to 20 MPa.

[0296] In some embodiments, a terminal recess 311 is provided on the outer side of the terminal body 31 , and a bottom wall 311 a of the terminal recess 311 is welded to the current collecting member 60 .

[0297] In the embodiment of the present application, the terminal body 31 and the current collecting member 60 can be welded from the outside, which can reduce the risk of metal particles generated by welding being spattered into the housing 20 and improve reliability. In this embodiment, the terminal recess 311 is provided to reduce the thickness of the terminal body 31. This can reduce the welding power required for welding the terminal body 31 and the current collecting member 60, reduce heat generation, and reduce the risk of burning the insulating component 40.

[0298] In some embodiments, the terminal recess 311 is formed in the terminal body 31 .

[0299] In some embodiments, a through hole 312 is defined in the bottom wall 311 a of the terminal recess 311 . The through hole 312 is used to connect the terminal recess 311 with the inner space of the housing 20 .

[0300] During the manufacturing process of the battery cell 7 , the through hole 312 may be used in multiple manufacturing processes. For example, the through hole 312 may be used in a liquid injection process, a formation process, or other processes.

[0301] Specifically, through-hole 312 is used to inject electrolyte into the interior of housing 20. When injection is required, the injection head of the injection device presses against the bottom wall 311a of the terminal recess 311, and then injects electrolyte into housing 20 through through-hole 312. During the formation process of battery cells 7, gas is generated within housing 21. Through-hole 312 can also be used to communicate with an external negative pressure device to extract the gas within housing 20.

[0302] In some embodiments, the battery cell 7 further includes a sealing plate 70 , at least a portion of which is received in the terminal recess 311 , connected to the terminal body 31 , and covers the sealing through-hole 312 .

[0303] After the electrolyte injection process and other processes are completed, the sealing plate 70 is mounted on the electrode terminal 30 to seal the through hole 312 to reduce the risk of electrolyte leakage.

[0304] In some embodiments, the sealing plate 70 is welded to the terminal body 31 .

[0305] In some embodiments, the battery cell 7 further includes a sealing nail 80 , which is inserted into the through hole 312 .

[0306] In some embodiments, the terminal recess 311 has a stepped surface, and at least a portion of the sealing plate 70 is received in the terminal recess 311 and supported by the stepped surface.

[0307] In some embodiments, the battery cell 7 is a cylindrical battery cell. In other embodiments, the battery cell 7 is a square-shell battery cell.

[0308] FIG10 is a schematic partial cross-sectional view of a battery cell provided in some embodiments of the present application.

[0309] As shown in FIG10 , in some embodiments, the second limiting portion 33 has an inclined surface 331 facing the second surface 233. Along the radial direction of the electrode lead-out hole 231, the distance between the inclined surface 331 and the second surface 233 in the thickness direction Z gradually increases. At least a portion of the third insulating portion 43 is located between the inclined surface 331 and the second surface 233 and is attached to the inclined surface 331 and the second surface 233.

[0310] For example, the inclined surface 331 may be formed by providing a chamfer or a rounded corner on the second limiting portion 33 .

[0311] By setting the inclined surface 331, the space between the second limiting portion 33 and the second surface 233 can be increased; during the assembly process, when the insulating component 40 is squeezed by the second limiting portion 33, the material can flow between the second surface 233 and the inclined surface 331, thereby reducing material overflow.

[0312] Figure 11 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application; Figure 12 is a schematic diagram of a battery cell provided in some embodiments of the present application during the assembly process; Figure 13 is another schematic diagram of a battery cell provided in some embodiments of the present application during the assembly process.

[0313] As shown in FIG. 11 , in some embodiments, the electrode terminal 30 is provided with a slit 34 . The slit 34 is recessed from the outer peripheral surface 31 a of the terminal body 31 and is close to the connection between the terminal body 31 and the second limiting portion 33 .

[0314] The gap 34 can disperse stress during the folding and forming process of the second limiting portion 33 to reduce stress concentration.

[0315] As shown in Figures 12 and 13, in some embodiments, the electrode terminal 30 is formed by defining a first recess 35 on a side facing away from the electrode assembly 10 and folding the sidewall 351 of the first recess outward to form a second stopper 33. A second recess 36 is provided on the outer side of the sidewall 351 of the first recess. The second recess 36 is used to guide the bending of the sidewall 351 of the first recess and is configured to be filled after the second stopper 33 is formed to form a gap 34.

[0316] The first recess 35 is provided to form a thin sidewall 211 on the electrode terminal 30. The electrode terminal 30 is mounted on the wall portion 23 by folding the sidewall 351 of the first recess. The second recess 36 not only guides the folding of the sidewall 351 of the first recess, but also provides space for material flow, thereby reducing material accumulation at the folded area, improving the shape of the electrode terminal 30, and reducing the difficulty of forming the electrode terminal 30.

[0317] In some embodiments, the cross-section of the second recess 36 is semicircular, triangular, trapezoidal, rectangular, or other shapes.

[0318] As shown in FIG. 13 , after the second limiting portion 33 is folded and formed, the remaining portion of the first recess 35 forms a terminal recess 311 .

[0319] FIG14 is a schematic partial cross-sectional view of a battery cell provided in some embodiments of the present application; FIG15 is an enlarged schematic view of the circle frame of FIG14 .

[0320] As shown in Figures 14 and 15, in some embodiments, the first insulating portion 41 includes a first insulating layer 411, a second insulating layer 412 and a third insulating layer 413 that are stacked together, the first insulating layer 411 is adhered to the first surface 232, the second insulating layer 412 is located between the first insulating layer 411 and the third insulating layer 413, and at least a portion of the third insulating layer 413 is adhered to the connecting portion 321.

[0321] The first insulating portion 41 adopts a multi-layer composite structure, which can improve the overall performance of the first insulating portion 41 .

[0322] In some embodiments, the melting point of the second insulating layer 412 is greater than the melting point of the first insulating layer 411 , and the melting point of the second insulating layer 412 is greater than the melting point of the third insulating layer 413 .

[0323] The melting point of the first insulating layer 411 may be greater than, equal to, or less than the melting point of the third insulating layer 413 .

[0324] The second insulating layer 412 has a relatively high melting point and is not easily softened during the production and use of the battery cell 7 , thereby insulating and isolating the wall portion 23 and the connecting portion 321 , reducing the risk of short circuit.

[0325] For example, even if the first insulating layer 411 and the third insulating layer 413 are melted, the second insulating layer 412 can still play an insulating isolation effect, thereby reducing the risk of short circuit.

[0326] In some embodiments, the difference between the melting point of the second insulating layer 412 and the melting point of the first insulating layer 411 is greater than or equal to 20° C., so as to reduce the risk of softening or melting of the second insulating layer 412 during the production and use of the battery cell 7 .

[0327] In some embodiments, the difference between the melting points of the second insulating layer 412 and the third insulating layer 413 is greater than or equal to 20° C., so as to reduce the risk of softening or melting of the second insulating layer 412 during the production and use of the battery cell 7 .

[0328] In some embodiments, the melting point of the first insulating layer 411 is greater than or equal to 140°, and the melting point of the third insulating layer 413 is greater than or equal to 140°.

[0329] In some embodiments, the first insulating portion 41 includes a polymer and a modified polymer, wherein the modified polymer is formed by modifying the polymer. The first insulating layer 411 and the third insulating layer 413 both include the modified polymer, and the second insulating layer 412 includes a polymer.

[0330] By providing a modified polymer, the composite strength between the first insulating layer 411 and the wall portion 23 and the composite strength between the third insulating layer 413 and the connecting portion 321 can be improved, thereby reducing the risk of connection failure between the first insulating layer 411 and the wall portion 23 and the risk of connection failure between the third insulating layer 413 and the connecting portion 321.

[0331] In some embodiments, the second insulating layer 412 does not include a modified polymer, which can reduce the impact of the modification on the polymer properties and retain the original properties of the polymer, such as strength, melting point, etc. For example, the melting point of the polymer is higher than the melting point of the modified polymer.

[0332] In some embodiments, the polymer comprises polypropylene or polyethylene terephthalate.

[0333] In some embodiments, a polymer can be modified by grafting polar functional groups to form a modified polymer.

[0334] For example, maleic anhydride can be grafted onto the polymer to form a modified polymer.

[0335] In some embodiments, the grafting rate of maleic anhydride in the first insulating layer 411 is greater than 0.1%, and the grafting rate of maleic anhydride in the third insulating layer 413 is greater than 0.1%.

[0336] In some embodiments, the first insulating layer 411 may be a modified high composite strength adhesive, and the third insulating layer 413 may be a modified high composite strength adhesive.

[0337] In some embodiments, a plate made of a polymer may be provided first, and then grafting may be performed on both sides of the plate to form the first insulating layer 411 , the second insulating layer 412 , and the third insulating layer 413 .

[0338] In some alternative embodiments, the first insulating portion 41 is a single-layer structure that is modified as a whole. In other words, the second insulating layer 412 also includes a modified polymer, and the first insulating layer 411, the second insulating layer 412, and the third insulating layer 413 have the same structure.

[0339] In some embodiments, the second insulating portion 42 and the third insulating portion 43 also have a three-layer structure.

[0340] Exemplarily, in some embodiments, the third insulating portion 43 includes a fourth insulating layer 431, a fifth insulating layer 432 and a sixth insulating layer 433 that are stacked, the fourth insulating layer 431 is adhered to the second surface 233, the fifth insulating layer 432 is located between the fourth insulating layer 431 and the sixth insulating layer 433, and at least a portion of the sixth insulating layer 433 is adhered to the second limiting portion 33.

[0341] In some embodiments, the fourth insulating layer 431 includes a polymer and a modified polymer, the sixth insulating layer 433 includes a polymer and a modified polymer, and the fifth insulating layer 432 includes a polymer and does not include a modified polymer.

[0342] FIG16 is a schematic cross-sectional view of a battery cell provided in some other embodiments of the present application; FIG17 is an enlarged schematic view of the circle frame of FIG16 .

[0343] As shown in Figures 16 and 17, in some embodiments, the connecting portion 321 is located outside the wall portion 23. The first surface 232 is the outer surface of the wall portion 23, and the second surface 233 is the inner surface of the wall portion 23.

[0344] In some embodiments, the electrode terminal 30 includes a first limiting portion 32, a second limiting portion 33 and a terminal body 31, at least a portion of the terminal body 31 is accommodated in the electrode lead-out hole 231, and the first limiting portion 32 and the second limiting portion 33 both protrude from the outer peripheral surface 31a of the terminal body 31.

[0345] The first stopper 32 is located on the side of the wall 23 away from the electrode assembly 10 and includes a connecting portion 321. The second stopper 33 is located on the side of the wall 23 facing the electrode assembly 10. In the thickness direction Z, a portion of the wall 23 is located between the second stopper 33 and the connecting portion 321.

[0346] In some embodiments, the insulating component 40 includes a first insulating portion 41, a second insulating portion 42, and a third insulating portion 43. The first insulating portion 41 is attached to the first surface 232. At least a portion of the first insulating portion 41 is located between the first surface 232 and the connecting portion 321 and covers the area of ​​the first surface 232 that overlaps with the connecting portion 321 in the thickness direction Z. The second insulating portion 42 is connected to the first insulating portion 41, surrounds the terminal body 31, and insulates the outer peripheral surface 31a of the terminal body 31 from the wall of the electrode lead-out hole 231. The third insulating portion 43 is attached to the second surface 233 and insulates the second retaining portion 33 from the second surface 233.

[0347] In some embodiments, during assembly, the electrode terminal 30 is extended into the electrode lead-out hole 231 from the outside, and the electrode terminal 30 is squeezed from the inside of the wall portion 23 to form a second limiting portion 33 and riveted to the wall portion 23 .

[0348] FIG18 is a schematic structural diagram of a battery cell provided in some other embodiments of the present application.

[0349] As shown in FIG18 , in some embodiments, the housing 20 includes a shell 21 and an end cap 22 . The end cap 22 includes a wall portion 23 . Correspondingly, the electrode terminal 30 and the insulating member 40 are disposed on the end cap 22 .

[0350] The end cap 22 , the electrode terminal 30 and the insulating component 40 can be pre-assembled into an end cap assembly and then assembled with the housing 21 , the electrode assembly 10 and other components to form a battery cell 7 .

[0351] FIG19 is a schematic cross-sectional view of a battery cell provided in some other embodiments of the present application.

[0352] As shown in FIG. 19 , in some embodiments, the electrode terminal 30 is fixed to the wall portion 23 via an insulating member 40 .

[0353] In some embodiments, the electrode terminal 30 may be in a flat plate shape and is directly fixed to the wall portion 23 through the insulating component 40 without a riveting structure, thereby simplifying the structure of the electrode terminal 30 and the installation process of the electrode terminal 30 .

[0354] In some embodiments, the electrode terminal 30 may be located inside or outside the wall portion 23 .

[0355] According to some embodiments of the present application, the present application also provides a battery comprising a plurality of battery cells according to any of the above embodiments.

[0356] According to some embodiments of the present application, the present application further provides an electrical device comprising a battery cell according to any of the above embodiments, the battery cell being used to provide electrical energy to the electrical device. The electrical device may be any of the aforementioned devices or systems using the battery cell.

[0357] 4 to 9 , an embodiment of the present application provides a cylindrical battery cell 7 , which includes an electrode assembly 10 , a housing 20 , an electrode terminal 30 , and an insulating component 40 .

[0358] The housing 20 includes a shell 21 and an end cap 22. The shell 21 has an opening, and the end cap 22 covers the opening. The shell 21 includes a wall portion 23 opposite to the end cap 22, and the wall portion 23 is provided with an electrode lead-out hole 231.

[0359] The electrode assembly 10 is accommodated in the housing 20 . The electrode assembly 10 includes a main body 12 and a tab 11 . The tab 11 is located on a side of the main body 12 facing the wall 23 .

[0360] The electrode terminal 30 includes a terminal body 31, a first stopper 32, and a second stopper 33. The terminal body 31 extends through the electrode lead-out hole 231. The first stopper 32 protrudes from the outer circumferential surface 31a of the terminal body 31 and is located on the side of the wall portion 23 facing the electrode assembly 10. The second stopper 33 protrudes from the outer circumferential surface 31a of the terminal body 31 and is located on the side of the wall portion 23 facing away from the electrode assembly 10. In the thickness direction Z, at least a portion of the wall portion 23 is located between the connecting portion 321 and the second stopper 33.

[0361] The first limiting portion 32 includes a connecting portion 321 . A projection of the connecting portion 321 along the thickness direction Z is located within a projection of the wall portion 23 along the thickness direction Z.

[0362] The wall portion 23 includes a first surface 232 and a second surface 233 that are opposite to each other in the thickness direction Z. The first surface 232 faces the connecting portion 321 , and the second surface 233 faces away from the connecting portion 321 .

[0363] The insulating member 40 connects the electrode terminal 30 and the housing 20 and is used to insulate and isolate the electrode terminal 30 from the wall portion 23. The insulating member 40 is bonded to the wall portion 23 and the electrode terminal 30 by a hot pressing process.

[0364] The insulating component 40 includes a first insulating portion 41 attached to the first surface 232 , a second insulating portion 42 attached to the second surface 233 , and a third insulating portion 43 . The second insulating portion 42 connects the first insulating portion 41 and the second insulating portion 42 .

[0365] At least a portion of the first insulating portion 41 is located between the first surface 232 and the connecting portion 321 and covers the area of ​​the first surface 232 that overlaps with the connecting portion 321 in the thickness direction Z. The second insulating portion 42 is connected to the first insulating portion 41, surrounds the terminal body 31, and insulates the outer peripheral surface 31a of the terminal body 31 from the wall of the electrode lead-out hole 231. The third insulating portion 43 insulates the second limiting portion 33 from the second surface 233.

[0366] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and components may be replaced with equivalents without departing from the scope of the present application. In particular, the various technical features described in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions within the scope of the claims.

Claims

1. A battery cell, comprising: shell; An electrode terminal, disposed on the housing; An electrode assembly, contained in the housing, the electrode assembly comprising a tab, the tab being electrically connected to the electrode terminal; as well as An insulating component connects the electrode terminal and the housing and is used to insulate and isolate the electrode terminal from the housing.

2. The battery cell according to claim 1, wherein: At least a portion of the insulating member is located between and attached to the electrode terminal and the case.

3. The battery cell according to claim 1 or 2, wherein: The insulating member is bonded to the housing and the electrode terminal.

4. The battery cell according to claim 3, wherein: The insulating component is bonded to the housing and the electrode terminal by a thermal compression composite process.

5. The battery cell according to claim 3 or 4, wherein: A passivation film is provided on the surface of the electrode terminal, and the passivation film is connected to the insulating component; and / or A passivation film is provided on the surface of the housing, and the passivation film is connected to the insulating component.

6. The battery cell according to any one of claims 1 to 5, wherein: The housing includes a wall portion, the wall portion is provided with an electrode lead-out hole, the electrode terminal is arranged on the wall portion and covers at least a portion of the electrode lead-out hole in a thickness direction of the wall portion; The insulating member connects the electrode terminal and the wall portion and insulates the electrode terminal from the wall portion.

7. The battery cell according to claim 6, wherein: The insulating component is used to seal the electrode lead-out hole.

8. The battery cell according to claim 6 or 7, wherein: The electrode terminal comprises a connection portion, the connection portion is located on one side of the wall portion along the thickness direction, and a projection of the connection portion along the thickness direction is located within a projection of the wall portion along the thickness direction; At least a portion of the insulating member is located between the wall portion and the connecting portion and is attached to the wall portion and the connecting portion.

9. The battery cell according to claim 8, wherein: The projection area of ​​the portion of the insulating component located between the wall portion and the connecting portion along the thickness direction is greater than or equal to 50 mm 2 Optionally, the projection area of ​​the portion of the insulating component located between the wall portion and the connecting portion along the thickness direction is greater than or equal to 100 mm 2 .

10. The battery cell according to claim 8 or 9, wherein: The thickness of the portion of the insulating component located between the wall portion and the connecting portion is 20 μm-2000 μm. Optionally, the thickness of the portion of the insulating component located between the wall portion and the connecting portion is 50 μm-1000 μm.

11. The battery cell according to any one of claims 8 to 10, wherein: The wall portion comprises a first surface and a second surface which are arranged opposite to each other along a thickness direction of the wall portion, wherein the first surface faces the connecting portion and the second surface faces away from the connecting portion; The insulating member includes a first insulating portion attached to the first surface, at least a portion of the first insulating portion being located between the first surface and the connecting portion and covering a region of the first surface overlapping the connecting portion in the thickness direction.

12. The battery cell according to claim 11, wherein: In the radial direction of the electrode lead-out hole, the first insulating portion exceeds the connecting portion.

13. The battery cell according to claim 11 or 12, wherein: The first insulating portion and the connecting portion are both arranged around the electrode lead-out hole.

14. The battery cell according to any one of claims 11 to 13, wherein: The connecting portion is located on a side of the wall portion facing the electrode assembly.

15. The battery cell according to claim 14, wherein: The wall portion and the connecting portion are both annular; The ratio of the outer diameter of the connecting portion to the outer diameter of the wall portion is 0.3-0.

8. Optionally, the ratio of the outer diameter of the connecting portion to the outer diameter of the wall portion is 0.5-0.

7.

16. The battery cell according to claim 14 or 15, wherein: The first surface includes a first area and a second area, the first area is covered by the first insulating portion, and the second area surrounds the first area; The battery cell further includes an insulating spacer, and in the thickness direction, at least a portion of the insulating spacer is located between the second region and the tab.

17. The battery cell according to claim 16, wherein: In the thickness direction, the insulating spacer completely isolates the second region from the tab.

18. The battery cell according to claim 16 or 17, wherein: In the thickness direction, the insulating spacer overlaps with the first insulating portion.

19. The battery cell according to any one of claims 16 to 18, wherein: The insulating spacer comprises an insulating plate and an insulating cylinder, wherein the insulating cylinder surrounds the pole lug, and the insulating plate is connected to one end of the insulating cylinder facing the first surface and is located between the first surface and the pole lug; The insulating plate surrounds the outer side of the connecting portion.

20. The battery cell according to claim 19, further comprising a current collecting member, the current collecting member being located on a side of the electrode tab facing the first surface and connected to the electrode tab, the electrode terminal being located on a side of the current collecting member facing away from the electrode tab and connected to the current collecting member; At least a portion of the insulating plate is located between the current collecting member and the first surface and is attached to the current collecting member.

21. The battery cell according to any one of claims 14 to 20, wherein: The electrode terminal comprises a terminal body and a first stopper connected to each other, at least a portion of the terminal body is accommodated in the electrode lead-out hole, and the first stopper protrudes from the outer peripheral surface of the terminal body; The first limiting portion includes the connecting portion.

22. The battery cell according to claim 21, wherein: The insulating component further includes a second insulating portion, which is connected to the first insulating portion, surrounds the terminal body, and insulates the outer peripheral surface of the terminal body from the hole wall of the electrode lead-out hole.

23. The battery cell according to claim 22, wherein: The second insulating portion is attached to an outer peripheral surface of the terminal body and a hole wall of the electrode lead-out hole.

24. The battery cell according to claim 22 or 23, wherein: The electrode terminal further includes a second limiting portion, the second limiting portion protruding from the outer peripheral surface of the terminal body and located on a side of the wall portion away from the electrode assembly; In the thickness direction, at least a portion of the wall portion is located between the connecting portion and the second limiting portion.

25. The battery cell according to claim 24, wherein: The insulating component further includes a third insulating portion connected to the second insulating portion, wherein the third insulating portion is attached to the second surface and insulates the second limiting portion from the second surface.

26. The battery cell according to claim 25, wherein: The second limiting portion has an inclined surface facing the second surface; Along the radial direction of the electrode lead-out hole, the distance between the inclined surface and the second surface in the thickness direction gradually increases; At least a portion of the third insulating portion is located between the inclined surface and the second surface and is attached to the inclined surface and the second surface.

27. The battery cell according to any one of claims 24 to 26, wherein: The electrode terminal is provided with a gap, and the gap extends from the outer peripheral surface of the terminal body and is close to the connection between the terminal body and the second limiting portion.

28. The battery cell according to claim 27, wherein: The electrode terminal is provided with a first recess on a side away from the electrode assembly and the side wall of the first recess is folded outward to form the second limiting portion; A second recess is provided on the outer side of the side wall of the first recess, the second recess is used to guide the side wall of the first recess to bend, and is configured to be filled after the second limiting portion is formed to form the gap.

29. The battery cell according to any one of claims 11 to 28, wherein: The melting point of the first insulating portion is greater than or equal to 140° C.

30. The battery cell according to any one of claims 11 to 29, wherein: The yield strength of the first insulating portion is greater than or equal to 20 MPa.

31. The battery cell according to any one of claims 11 to 30, wherein: The first insulating portion includes a first insulating layer, a second insulating layer and a third insulating layer stacked together, the first insulating layer is bonded to the first surface, the second insulating layer is located between the first insulating layer and the third insulating layer, and at least a portion of the third insulating layer is bonded to the connecting portion.

32. The battery cell according to claim 31, wherein: The melting point of the second insulating layer is greater than that of the first insulating layer, and the melting point of the second insulating layer is greater than that of the third insulating layer.

33. The battery cell according to claim 32, wherein: The difference between the melting point of the second insulating layer and the melting point of the first insulating layer is greater than or equal to 20° C.; and / or A difference between a melting point of the second insulating layer and a melting point of the third insulating layer is greater than or equal to 20°C.

34. The battery cell according to claims 31-33, wherein: The first insulating part includes a polymer and a modified polymer, and the modified polymer is formed by modifying the polymer; The first insulating layer and the third insulating layer both include the modified polymer, and the second insulating layer includes the polymer.

35. The battery cell according to claim 34, wherein: The second insulating layer does not include the modified polymer.

36. The battery cell according to claim 34 or 35, wherein: The polymer includes polypropylene or polyethylene terephthalate.

37. The battery cell according to any one of claims 6 to 36, wherein: The housing comprises a shell and an end cover, the shell has an opening, and the end cover covers the opening; The shell includes the wall portion, and the wall portion is arranged opposite to the end cover.

38. A battery comprising a plurality of battery cells according to any one of claims 1 to 37.

39. An electrical device, comprising the battery according to claim 38, wherein the battery is used to provide electrical energy.

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