Battery cell, battery and electric device

Abstract

A battery cell (10), a battery (100) and an electric device. The battery cell (10) comprises a case (11), electrode assemblies (12), a positive terminal (13a), a positive current-collecting member (15a) and a first protection mechanism (161). The case (11) has a first wall (112). The electrode assemblies (12) are accommodated in the case (11) and comprise positive tabs (121). The positive terminal (13a) is arranged on the first wall (112) in an insulated manner and is electrically connected to the positive tabs (121). In the direction (Z) of the thickness of the first wall (112), the first protection mechanism (161) is arranged between the positive current-collecting member (15a) and the first wall (112), and is configured to electrically connect the positive current-collecting member (15a) and the first wall (112) when the temperature or pressure inside the battery cell (10) reaches a threshold value. The first protection mechanism (161) can effectively improve the reliability of the battery cell (10).

Description

Battery cell, battery and electric device

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese Patent Application No. 202410824229.0, filed on June 25, 2024, entitled “Battery cell, battery and electric device”, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present application relates to the technical field of batteries, in particular to a battery cell, a battery and an electric device. BACKGROUND

[0004] With the development of new energy technology, batteries are increasingly widely used. Batteries have high energy density, high reliability, long service life and green environmental protection to the society, and have been widely used in passenger cars, commercial vehicles, electric bicycles, heavy trucks, energy storage facilities, battery replacement stations, engineering manufacturing, intelligent instruments and the like, and also promote the development and research of communication terminals, medical instruments, energy development and the like.

[0005] In the battery production process, how to improve the reliability of the battery is a technical problem to be solved.

[0006] SUMMARY

[0007] The embodiments of the present application provide a battery cell, a battery and an electric device, which can effectively improve the reliability of the battery cell.

[0008] In a first aspect, the embodiments of the present application provide a battery cell, comprising a housing, an electrode assembly, a positive terminal, a positive current collecting member and a first protection mechanism, the housing having a first wall; the electrode assembly is accommodated in the housing, the electrode assembly comprising a positive tab; the positive terminal is insulatedly arranged on the first wall, and the positive terminal is electrically connected with the positive tab; the protection mechanism is configured to electrically connect the positive terminal and the housing when the temperature or pressure inside the battery cell reaches a threshold value.

[0009] The positive terminal and the positive tab are electrically connected through the positive current collecting member; along the thickness direction of the first wall, the first protection mechanism is arranged between the positive current collecting member and the first wall, and the first protection mechanism is configured to electrically connect the positive current collecting member and the first wall when the temperature or pressure inside the battery cell reaches a threshold value.

[0010] In the technical solution, when the battery monomer is in thermal runaway, the positive electrode lug is fused, the high voltage of the battery continuously acts on the fusion part to generate an arc, and secondary hazards are caused. Since the positive electrode current collecting member is electrically connected with the positive electrode terminal, the first protection mechanism is arranged between the first wall and the positive electrode current collecting member, the first protection mechanism is electrically connected with the first wall and the positive electrode current collecting member, the shell is electrically connected with the positive electrode terminal, the current passes through the shell, the high voltage of the battery does not continuously act on the fusion part, the arc phenomenon is alleviated, the reliability of the battery monomer is improved, and the reliability of the battery using the battery monomer is improved.

[0011] In addition, the first protection mechanism is arranged between the first wall and the positive electrode current collecting member, the first protection mechanism is located in the battery monomer, the influence of external foreign matters on the first protection mechanism is reduced, and the protection reliability is improved.

[0012] In some embodiments, the positive electrode current collecting member includes a first connecting part and a second connecting part, the first connecting part is connected with the positive electrode terminal, the second connecting part is connected with the positive electrode lug, and the first protection mechanism is arranged between the second connecting part and the first wall along the thickness direction of the first wall.

[0013] In the technical solution, the first protection mechanism is arranged between the second connecting part and the first wall, so that the first protection mechanism does not affect the connection between the first connecting part and the positive electrode terminal.

[0014] In some embodiments, the first protection mechanism includes a first insulating part, the first insulating part is arranged between the first wall and the positive electrode current collecting member to insulate the first wall and the positive electrode current collecting member; a first conductive part is connected with the first insulating part, and the first conductive part is configured to electrically connect the first wall and the positive electrode current collecting member after the first insulating part is melted.

[0015] In the technical solution, when the internal temperature of the battery monomer does not reach the threshold value, the first insulating part insulates the first wall and the positive electrode current collecting member to make the battery monomer work stably. When the internal temperature of the battery monomer reaches the threshold value, the first insulating part is melted, the insulation fails, and the first wall and the positive electrode current collecting member are electrically connected.

[0016] In some embodiments, the first conductive part is connected with the positive electrode current collecting member, and the first insulating part is arranged between the first conductive part and the first wall; or the first conductive part is connected with the first wall, and the first insulating part is arranged between the first conductive part and the positive electrode current collecting member.

[0017] In the technical solution, the first conductive member is connected to the positive current collecting member, so that the contact stability of the first conductive member and the positive current collecting member is improved. The first conductive member is connected to the first wall, so that the contact stability of the first conductive member and the first wall is improved.

[0018] In some embodiments, the first insulating member is wrapped on the outer surface of the first conductive member.

[0019] In the technical solution, the first insulating member is wrapped on the outer surface of the first conductive member, so that when the internal temperature of the battery cell does not reach the threshold value, the insulation reliability between the first conductive member and the first wall is high, so that the battery cell can work stably.

[0020] In some embodiments, the first conductive member includes a first sub-conductive member and a second sub-conductive member, the first sub-conductive member is connected to the first wall, the second sub-conductive member is connected to the positive current collecting member, and the first insulating member is arranged between the first sub-conductive member and the second sub-conductive member.

[0021] In the technical solution, the contact stability of the first sub-conductive member and the positive current collecting member is improved, the contact stability of the second sub-conductive member and the first wall is improved, and the failure risk of the first protection mechanism is reduced.

[0022] In some embodiments, the material of the first insulating member includes at least one of polypropylene, polyethylene terephthalate, polyformaldehyde, polyethylene, polyvinyl chloride, modified polypropylene, polystyrene, and polyester resin; and / or the material of the first conductive member includes at least one of bismuth, tin, lead, indium, and mercury.

[0023] In some embodiments, the first protection mechanism includes a first conductive member, the first conductive member is connected to one of the first wall and the positive current collecting member, and is arranged in a gap from the other of the first wall and the positive current collecting member, and the first conductive member includes a thermal expansion material.

[0024] In the technical solution, the first conductive member includes a thermal expansion material, so that part or all of the first conductive member can expand in response to an increase in temperature to fill the gap, so as to be in contact with the first wall and the positive current collecting member, and the first wall and the positive current collecting member are electrically connected. The first conductive member of the structure can reduce the manufacturing difficulty of the first protection mechanism.

[0025] In some embodiments, the thermal expansion material includes graphite.

[0026] In some embodiments, the battery cell further comprises a second insulation member, the second insulation member is arranged between the first wall and the electrode assembly along a thickness direction of the first wall, at least a portion of the positive current collecting member is arranged on a side of the second insulation member away from the first wall, the second insulation member is provided with a first through hole, and at least a portion of the first protection mechanism is accommodated in the first through hole.

[0027] In the above technical solution, at least a portion of the first protection mechanism is accommodated in the first through hole, so that the first protection mechanism and the second insulation member can share a part of space, thereby improving the space utilization.

[0028] In some embodiments, the shell comprises a housing and an end cover, one end of the housing forms an opening, the end cover covers the opening, and the end cover is the first wall.

[0029] In some embodiments, the electrode assembly further comprises a negative tab, and the negative tab is electrically connected to the first wall.

[0030] In some embodiments, the electrode assembly has a jelly-roll structure, the outermost coil of the electrode assembly is a negative coil, and the electrode assembly further comprises a negative tab; the battery cell further comprises a negative terminal, the negative terminal is arranged on the first wall in an insulated manner, and the negative terminal is electrically connected to the negative tab.

[0031] In a second aspect, the embodiments of the present application further provide a battery, which comprises the battery cell of any one of the first aspect.

[0032] In some embodiments, the battery further comprises a controller, the protection mechanism comprises a second protection mechanism, the second protection mechanism is electrically connected to the controller, and the controller is configured to control the second protection mechanism of the battery cell to act when an internal temperature or pressure of the battery cell reaches a threshold value, so as to turn on the positive terminal and the shell.

[0033] In a third aspect, the embodiments of the present application further provide a power consumption device, which comprises the battery cell described above and / or the battery described above, and the battery cell and / or the battery are used to supply power to the power consumption device. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0035] Fig. 1 is a structural schematic of a vehicle according to some embodiments of the present application;

[0036] Fig. 2 is an exploded schematic of a battery according to some embodiments of the present application;

[0037] Fig. 3 is an exploded schematic of a battery cell according to some embodiments of the present application;

[0038] Fig. 4 is a structural schematic of a battery cell according to some embodiments of the present application;

[0039] Fig. 5 is a top view of a battery cell according to some embodiments of the present application;

[0040] Fig. 6 is a sectional view of Fig. 5 along A-A according to some embodiments of the present application;

[0041] Fig. 7 is a circuit logic schematic of battery thermal runaway according to some embodiments of the present application;

[0042] Fig. 8 is a circuit logic schematic of a battery with a protection mechanism according to some embodiments of the present application;

[0043] Fig. 9 is a structural schematic of a positive current collector member and a first protection mechanism from one perspective according to some embodiments of the present application;

[0044] Fig. 10 is a structural schematic of a positive current collector member and a first protection mechanism from another perspective according to some embodiments of the present application;

[0045] Fig. 11 is a partial sectional view of Fig. 5 along C-C according to some embodiments of the present application;

[0046] Fig. 12 is a partial sectional view of Fig. 5 along C-C according to other embodiments of the present application;

[0047] Fig. 13 is a partial sectional view of Fig. 5 along C-C according to yet other embodiments of the present application;

[0048] Fig. 14 is a partial sectional view of Fig. 5 along C-C according to still other embodiments of the present application;

[0049] Fig. 15 is a partial sectional view of Fig. 5 along C-C according to yet still other embodiments of the present application;

[0050] Fig. 16 is a partial sectional view of Fig. 5 along C-C according to other embodiments of the present application;

[0051] Fig. 17 is a structural schematic of a second insulating member according to one embodiment of the present application.

[0052] Icon: 1000 - vehicle; 1611 - first insulating member; 16121 - first sub-conductive member; 16122 - second sub-conductive member; 1612 - first conductive member; 161 - first protection mechanism; 171 - first through-hole; 172 - second through-hole; 173 - third through-hole; 17 - second insulating member; 200 - motor; 20 - case; 21 - first sub-case; 22 - second sub-case; 23 - accommodation space; 300 - vehicle controller; 40 - confluence member; D - fusing portion; Z - thickness direction; 100 - battery; 10 - battery cell; 111 - case; 112a - end cover; 112 - first wall; 11 - outer shell; 121 - positive electrode tab; 122 - negative electrode tab; 12 - electrode assembly; 13a - positive electrode terminal; 13b - negative electrode terminal; 14 - insulating film; 151 - first connecting portion; 152 - second connecting portion; 15a - positive electrode current collecting member; 15b - negative electrode current collecting member.

[0053] The accompanying drawings are not drawn to scale. DETAILED DESCRIPTION

[0054] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0055] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as those commonly understood by one of ordinary skill in the art to which this application belongs; the terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion. The terms "first", "second" and the like in the specification and claims of the present application and the above description of drawings are used to distinguish different objects, rather than to describe a particular order or primary and secondary relationship.

[0056] In the present application, the phrase "embodiment" means that the specific features, structures or characteristics described in connection with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase at various places in the specification does not necessarily mean the same embodiment, nor is it an independent or alternative embodiment to other embodiments.

[0057] In the description of the present application, it should be noted that, unless otherwise specified, the meaning of "a plurality of" is more than two; the orientation or position relationship indicated by the terms "upper", "lower", "left", "right", "inner", "outer" and the like only indicates or implies the specific orientation, structure and operation of the device or element referred to, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not strictly vertical, but within the allowable range of error. "Parallel" is not strictly parallel, but within the allowable range of error.

[0058] The term "and / or" in the present application only describes the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can mean that A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in the present application generally represents an "or" relationship between the front and rear associated objects.

[0059] The term "or" in the present application only describes the association relationship of the associated objects, which means that there can be two relationships, for example, A or B, which can mean that A exists alone, and B exists alone.

[0060] In the embodiments of the present application, the same reference signs represent the same components, and for the sake of brevity, detailed description of the same components is omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device, are only exemplary and should not constitute any limitation on the present application.

[0061] "Plurality" appearing in the present application means more than two (including two).

[0062] In the present application, the battery cell can include, but is not limited to, a lithium ion secondary battery, a lithium ion primary battery, a lithium-sulfur battery, a sodium lithium ion battery, a sodium ion battery or a magnesium ion battery, etc. The battery cell includes, but is not limited to, a cylinder, a flat body, a cuboid or other shapes, etc. The battery cell generally includes cylindrical battery cells, square battery cells in the form of packaging.

[0063] The battery cell includes an electrode assembly and an electrolyte, and the electrode assembly is composed of a positive electrode sheet, a negative electrode sheet and a separator. The battery cell mainly works by moving metal ions between the positive electrode sheet and the negative electrode sheet, and the metal ions (such as lithium ions) are embedded and extracted between the positive electrode and the negative electrode. The separator is arranged between the positive electrode and the negative electrode, which can prevent the positive electrode sheet and the negative electrode sheet from short-circuiting, and at the same time can make the active ions pass through.

[0064] The positive electrode tab includes a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode current collector. The positive electrode current collector without the positive electrode active material layer protrudes from the positive electrode current collector with the positive electrode active material layer. The positive electrode current collector without the positive electrode active material layer serves as a positive electrode tab.

[0065] For example, the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganate. The positive electrode current collector can be a metal foil or a composite current collector. For example, as the metal foil, aluminum with silver plating on the surface, stainless steel with silver plating on the surface, stainless steel, copper, aluminum, a carbon electrode, carbon, nickel, or titanium can be used. 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 (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy) on a polymer material base material (e.g., a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, or the like).

[0066] The negative electrode tab includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector. The negative electrode current collector without the negative electrode active material layer protrudes from the negative electrode current collector with the negative electrode active material layer. The negative electrode current collector without the negative electrode active material layer serves as a negative electrode tab.

[0067] The negative electrode current collector can be a metal foil or a composite current collector. For example, as the metal foil, aluminum with silver plating on the surface, stainless steel with silver plating on the surface, stainless steel, copper, aluminum, a carbon electrode, carbon, nickel, or titanium can be used. The negative electrode active material can be carbon or silicon.

[0068] To reduce the risk of melting of the tabs by a large current, the number of positive electrode tabs is multiple and stacked together, and the number of negative electrode tabs is multiple and stacked together. The material of the separator film can be polypropylene (PP), polyethylene (PE), or the like. In addition, the electrode assembly can be a wound structure or a stacked structure.

[0069] The battery referred to 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. For example, the battery referred to in the present application can include a battery module, a battery pack, or the like. The battery generally includes a case for packaging one or more battery cells. The case can reduce the influence of liquid or other foreign matter on the charging or discharging of the battery cells.

[0070] In some embodiments, the battery can be a battery module, and when the number of battery cells is multiple, the multiple battery cells are arranged and fixed to form a battery module.

[0071] In some embodiments, the battery can be a battery pack, the battery pack comprising a box body and battery cells, the battery cells or battery modules being accommodated in the box body.

[0072] In some embodiments, the plurality of battery cells can be first integrated into at least one battery module, and then the battery module is installed in the box body to form a battery pack. In this embodiment, auxiliary structural members such as cross beams can be provided between the battery modules to improve the installation stability of the battery modules in the box body.

[0073] In some embodiments, the box body can be part of the chassis structure of the vehicle. For example, part of the box body can be at least part of the floor of the vehicle, or part of the box body can be at least part of the cross beams and longitudinal beams of the vehicle.

[0074] In some embodiments, the battery can be an energy storage device. The energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0075] The development of battery technology needs to consider various design factors, such as energy density, cycle life, discharge capacity, charge-discharge rate, and other performance parameters. In addition, the reliability of the battery also needs to be considered.

[0076] In the battery cell, the electrode terminal can be connected to the tab of the electrode assembly through the current collecting member to achieve electrical connection between the electrode terminal and the tab. The electrode terminal can also be directly connected to the tab. Based on the performance requirements of the electrode assembly, the melting point of the material suitable for making the positive tab of the electrode assembly is generally relatively low, and the melting point of the material suitable for making the positive tab of the electrode assembly is generally relatively high. When the battery cell is in thermal runaway, the positive tab is easily melted.

[0077] The battery includes a plurality of battery cells, and the battery can be understood as a high-voltage system, and each battery cell is electrically connected to work in the high-voltage system. When the positive tab is melted, the high voltage of the battery continuously acts on the melted part to generate an arc, causing secondary hazards and reducing the reliability of the battery.

[0078] In view of this, in order to solve the problem of melting of the positive tab, the high voltage of the battery continuously acting on the melted part to generate an arc, and reducing the reliability of the battery, the embodiments of the present application provide a technical solution. By providing a protection mechanism between the shell and the positive current collecting member, the protection mechanism electrically connects the shell and the positive current collecting member when the battery cell is in thermal runaway, so that the current passes through the shell, so that the high voltage of the battery does not continuously act on the melted part, and the arc phenomenon is alleviated, thereby improving the reliability of the battery cell and the reliability of the battery using the battery cell.

[0079] The protection mechanism is a component for electrically connecting the positive current collector and the shell when the battery cell is in thermal runaway, thereby relieving the internal arc of the battery cell. The protection mechanism can be understood as a low-impedance short-circuit path intentionally designed between the shell and the positive current collector, which is a protection path for connecting the shell and the positive current collector.

[0080] It should be understood that the protection mechanism does not work when the battery cell is in stable operation, at which time the positive current collector and the shell have good insulation effect. When the temperature or pressure inside the battery cell reaches a threshold value, the protection mechanism works to electrically connect the shell and the positive current collector to form a protection path.

[0081] The technical solutions disclosed in the embodiments of the present application are applicable to but not limited to batteries and electric devices using the batteries 100.

[0082] The electric device can be a vehicle, a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy, and an electric tool, etc. The vehicle can be a fuel automobile, a gas automobile, or a new energy automobile, and the new energy automobile can be a pure electric automobile, a hybrid electric automobile, or a range extended automobile, etc.; the spacecraft includes an airplane, a rocket, a space shuttle, and a spacecraft, etc.; the electric toy includes a fixed or mobile electric toy, for example, a game console, an electric automobile toy, an electric ship toy, and an electric airplane toy, etc.; the electric tool includes a metal cutting electric tool, a grinding electric tool, an assembling electric tool, and a railway electric tool, for example, an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact electric drill, a concrete vibrator, and an electric planer, etc.

[0083] The following embodiments are described by taking the electric device as a vehicle for convenience of description.

[0084] Please refer to FIG. 1, which is a structural schematic diagram of a vehicle 1000 according to some embodiments of the present application. The vehicle 1000 is internally provided with a battery 100, which can be arranged at the bottom, the head, or the tail of the vehicle 1000. The battery 100 can be used for power supply of the vehicle 1000, for example, the battery 100 can be used as an operating power source of the vehicle 1000.

[0085] The vehicle 1000 can further include a vehicle controller 300 and a motor 200, and the vehicle controller 300 is used to control the battery 100 to supply power to the motor 200, for example, for the working power demand of the vehicle 1000 during starting, navigation, and driving.

[0086] In some embodiments of the present application, the battery 100 can not only be used as an operating power source of the vehicle 1000, but also be used as a driving power source of the vehicle 1000, to replace or partially replace fuel or natural gas to provide driving power for the vehicle 1000.

[0087] In some embodiments, referring to FIG. 2, which is an exploded schematic view of a battery 100 including a plurality of battery cells 10 according to some embodiments of the present application, the plurality of battery cells 10 can be connected in series, in parallel, or in a mixed connection.

[0088] In some embodiments, the battery 100 can further include a busbar component 40, and the plurality of battery cells 10 can be electrically connected through the busbar component 40 to achieve series connection, parallel connection, or mixed connection of the plurality of battery cells 10.

[0089] The busbar component 40 can be a metal conductor, such as copper, iron, aluminum, steel, aluminum alloy, etc.

[0090] In some embodiments, the battery 100 can further include a box 20 for accommodating the battery cells 10. The box 20 can include a first sub-box 21 and a second sub-box 22, and the first sub-box 21 and the second sub-box 22 are overlapped with each other to define an accommodation space 23 for accommodating the battery cells 10. Of course, the connection between the first sub-box 21 and the second sub-box 22 can be sealed by a sealing element (not shown in the figure), which can be a sealing ring, sealing glue, etc.

[0091] The first sub-box 21 and the second sub-box 22 can be various shapes, such as a cuboid, a cylinder, etc. The first sub-box 21 can be a hollow structure with one side open, and the second sub-box 22 can also be a hollow structure with one side open. The open side of the second sub-box 22 is overlapped with the open side of the first sub-box 21 to form the box 20 with the accommodation space 23. Of course, the first sub-box 21 can be a hollow structure with one side open, and the second sub-box 22 can be a plate structure. The second sub-box 22 is overlapped with the open side of the first sub-box 21 to form the box 20 with the accommodation space 23.

[0092] FIG. 3 is an exploded schematic view of a battery cell 10 according to some embodiments of the present application; FIG. 4 is a structural schematic view of the battery cell 10 according to some embodiments of the present application; FIG. 5 is a top view of the battery cell 10 according to some embodiments of the present application; and FIG. 6 is a sectional view of FIG. 5 along A-A according to some embodiments of the present application.

[0093] Referring to FIGS. 3-6, FIG. 3 is an exploded schematic view of a battery cell 10 according to some embodiments of the present application. The battery cell 10 can include a shell 111, an electrode assembly 12, an end cover 112a, an electrode terminal, and other functional components.

[0094] The shell 111 and the end cover 112a can be understood as an outer shell 11 of the battery cell 10.

[0095] The shell 111 is a component for accommodating the electrode assembly 12. The shell 111 can be a hollow structure with an opening formed at one end, or a hollow structure with openings formed at both ends. The shell 111 can be made of various materials, such as copper, iron, aluminum, steel, aluminum alloy, etc. The shell 111 can have various shapes, such as a cylinder, a cuboid, etc. In an example, the shell 111 is a cuboid in FIG. 3.

[0096] The end cap 112a is a component that covers the opening of the shell 111 to isolate the internal environment of the battery cell 10 from the external environment. The end cap 112a covers the opening of the shell 111, and the end cap 112a and the shell 111 together define a sealed space for accommodating the electrode assembly 12, the electrolyte, and other functional components. The shape of the end cap 112a can be adapted to the shape of the shell 111, such as a rectangular plate structure adapted to the cuboid structure of the shell 111, or a circular plate structure adapted to the cylindrical structure of the shell 111. The end cap 112a can also be made of various materials. In an example, the end cap 112a can be made of metal, such as copper, iron, aluminum, steel, aluminum alloy, etc. The material of the shell 111 and the material of the end cap 112a can be the same or different.

[0097] In the battery cell 10, there can be one or two end caps 112a. If the shell 111 is a hollow structure with an opening formed at one end, one end cap 112a is provided. If the shell 111 is a hollow structure with openings formed at both ends, two end caps 112a are provided, which cover the two openings of the shell 111, respectively.

[0098] The electrode assembly 12 is a component that undergoes chemical reactions in the battery cell 10, responsible for storing and releasing electrical energy. The electrode assembly 12 has a positive electrode tab 121 and a negative electrode tab 122.

[0099] The electrode terminal is a component for leading out current. The electrode terminal can be provided on the end cap 112a or other wall of the shell 111. Optionally, the electrode terminal is provided on the end cap 112a. In some embodiments, two electrode terminals can be provided. They are the positive electrode terminal 13a and the negative electrode terminal 13b. The positive electrode tab 121 is electrically connected to the positive electrode terminal 13a, and the negative electrode tab 122 is electrically connected to the negative electrode terminal 13b.

[0100] In some embodiments, the positive electrode terminal 13a and the positive electrode tab 121 can be connected to the positive current collector 15a to achieve electrical connection, and the negative electrode terminal 13b and the negative electrode tab 122 can be connected to the negative current collector 15b to achieve electrical connection. Of course, the positive electrode terminal 13a can also be directly connected to the positive electrode tab 121, and the negative electrode terminal 13b can also be directly connected to the negative electrode tab 122.

[0101] In some other embodiments, the shell 11 can be designed to be in direct contact with the negative tab 122 (not shown in the figure), thereby becoming part of the negative electrode of the battery cell 10.

[0102] In some embodiments, the material of the positive tab 121 includes aluminum, which has a lower potential, good electrical conductivity, and a higher energy density, and thus is suitable to be used as the material of the positive tab 121.

[0103] In some embodiments, the material of the negative tab 122 includes nickel, and optionally, the material of the positive tab 121 is copper plated with nickel. The nickel material has good electrical conductivity and chemical stability, and thus is suitable to be used as the material of the negative tab 122.

[0104] Referring to FIG. 3, in some embodiments, the battery cell 10 can further include an insulating film 14, which covers the outer periphery of the electrode assembly 12 to insulate the shell 11 from the electrode assembly 12.

[0105] Embodiments of the present application provide a battery cell 10, which can improve the reliability of a battery 100. The specific structure of the battery cell 10 is described in detail below in combination with the accompanying drawings.

[0106] FIG. 7 is a circuit logic diagram of thermal runaway of a battery 100 according to some embodiments of the present application; FIG. 8 is a circuit logic diagram of the battery 100 after a protection mechanism is set according to some embodiments of the present application. FIG. 9 is a structure diagram of a positive current collecting member 15a and a first protection mechanism 161 from one perspective according to some embodiments of the present application; FIG. 10 is a structure diagram of the positive current collecting member 15a and the first protection mechanism 161 from another perspective according to some embodiments of the present application; and FIG. 11 is a partial sectional view of FIG. 5 along C-C according to some embodiments of the present application.

[0107] Referring to FIGS. 3-11, and in conjunction with FIGS. 7 and 8, embodiments of the application provide a battery cell 10 including a housing 11, an electrode assembly 12, a positive terminal 13a, a positive current collector 15a, and a first protection mechanism 161. The housing 11 has a first wall 112. The electrode assembly 12 is housed in the housing 11, and the electrode assembly 12 includes a positive tab 121. The positive terminal 13a is insulatedly disposed on the first wall 112, and the positive terminal 13a is electrically connected to the positive tab 121. The positive terminal 13a and the positive tab 121 are electrically connected by the positive current collector 15a. The first protection mechanism 161 is disposed between the positive current collector 15a and the first wall 112 along a thickness direction Z of the first wall 112, and the first protection mechanism 161 is configured to electrically connect the positive current collector 15a and the first wall 112 when a temperature or a pressure inside the battery cell 10 reaches a threshold value.

[0108] The first wall 112 can be an end cap 112a, or can be another wall portion of the housing 111.

[0109] It can be understood that the first protection mechanism 161 is a component for electrically connecting the positive current collector 15a and the first wall 112 when a temperature or a pressure inside the battery cell 10 reaches a threshold value.

[0110] The first protection mechanism 161 can be a mechanical switch, or can be an electronic switch.

[0111] The first protection mechanism 161 can be connected to one of the first wall 112 and the positive current collector 15a by bonding, welding, or the like. The first protection mechanism 161 can also be connected to the first wall 112 and the positive current collector 15a, respectively, by bonding, welding, or the like. The first protection mechanism 161 can also be abutted between the first wall 112 and the positive current collector 15a.

[0112] It should be understood that the first wall 112 is part of the housing 11, and the housing 11 is usually made of a metal material for support and protection. In the case where the first wall 112 is electrically connected to the positive current collector 15a, the housing 11 is electrically connected to the positive terminal 13a.

[0113] The first protection mechanism 161 can include a mechanical structure, or can include an electronic structure. As long as the positive current collector 15a can be electrically connected to the housing 11.

[0114] The threshold is a trigger condition for the first protection mechanism 161 to act, and the threshold is related to the temperature or pressure of thermal runaway of the battery cell 10. The threshold is different according to the system of the battery cell 10, and the threshold can be a temperature value or a pressure value. The threshold can be exactly the temperature value or pressure value inside the battery cell 10 when the battery cell 10 is in thermal runaway, or the threshold can be less than the temperature value or pressure value inside the battery cell 10 when the battery cell 10 is in thermal runaway, in order to improve the response speed.

[0115] It should be understood that when the battery cell 10 is in stable operation, the first protection mechanism 161 does not work, and at this time the positive electrode terminal 13a and the shell 11 have good insulation effect. When the temperature or pressure inside the battery cell 10 reaches the threshold, the first protection mechanism 161 works, and the first wall 112 is electrically connected to the positive electrode current collecting member 15a to electrically connect the shell 11 and the positive electrode terminal 13a to form a protection path.

[0116] Referring to FIGS. 7 and 8, the battery 100 can be understood as a high-voltage system, and there are a plurality of battery cells 10 inside the battery 100. FIGS. 7 and 8 show the circuit of a battery cell 10 in the battery 100. It should be understood that there can be a plurality of battery cells 10 in the circuit.

[0117] As shown in FIG. 7, the positive electrode can be understood as the positive electrode terminal 13a of the battery cell 10, the negative electrode can be understood as the negative electrode terminal 13b of the battery cell 10, the cathode can be understood as the positive electrode tab 121 of the electrode assembly 12, and the anode can be understood as the negative electrode tab 122 of the electrode assembly 12. R1 can be understood as a large resistance between the positive electrode terminal 13a and the shell 11, and the electrode terminal and the shell 11 need to be insulated in order for the battery cell 10 to operate stably. The current passes through the total positive electrode of the battery 100, the positive electrode of the battery cell 10, the negative electrode of the battery cell 10, and returns to the total negative electrode of the battery 100. When the battery cell 10 is in thermal runaway, the temperature or pressure of the battery cell 10 increases sharply, and under the action of high temperature, the positive electrode tab 121 is fused, and the electrical connection between the positive electrode tab 121 and the positive electrode terminal 13a is lost. Since the battery cell 10 is still electrically connected to the high-voltage system, the high voltage of the battery 100 continuously acts on the fusion part D, generating an arc, causing secondary damage.

[0118] As shown in FIG. 8, the first protection mechanism 161 is provided, and when the battery cell 10 is in thermal runaway, the current passes through the total positive electrode of the battery 100, the positive electrode of the battery cell 10, the positive electrode current collecting member 15a, the shell 11, and returns to the total negative electrode of the battery 100. Thus, the high voltage of the battery 100 will not act on the fusion part D.

[0119] In this embodiment, when the battery monomer 10 is in thermal runaway, the positive electrode tab 121 is fused, and the high voltage of the battery 100 continuously acts on the fusion part D to generate an arc, which causes secondary damage. Since the positive electrode current collecting member 15a and the positive electrode terminal 13a are already electrically connected, by arranging the first protection mechanism 161 between the first wall 112 and the positive electrode current collecting member 15a, the first protection mechanism 161 electrically connects the first wall 112 and the positive electrode current collecting member 15a, thereby achieving electrical connection between the shell 11 and the positive electrode terminal 13a, so that the current passes through the shell 11, so that the high voltage of the battery 100 does not continuously act on the fusion part D, thereby alleviating the arc phenomenon, thereby improving the reliability of the battery monomer 10 and the reliability of the battery 100 using the battery monomer 10.

[0120] The first protection mechanism 161 is arranged between the first wall 112 and the positive electrode current collecting member 15a, so that the first protection mechanism 161 is located in the battery monomer 10, which can reduce the influence of external foreign matters on the first protection mechanism 161 and improve the protection reliability.

[0121] It should be noted that:

[0122] For the battery monomer 10 with a negative shell 11, by electrically connecting the positive electrode current collecting member 15a and the first wall 112 with the first protection mechanism, the positive electrode terminal 13a and the shell 11 are electrically connected, so that the current can pass through the total positive electrode of the battery 100, the positive electrode terminal 13a of the battery monomer 10, the shell 11, and reach the total negative electrode of the battery 100. This path can be understood as a protection path.

[0123] For the battery monomer 10 with the positive electrode terminal 13b and the shell 11 insulated, since the insulating film of the electrode assembly 12 is melted and the insulating part fails when the battery 100 is in thermal runaway, the electrode assembly 12 and the shell 11 are already conductive. By electrically connecting the positive electrode terminal 13a and the shell 11 with the protection mechanism, the current can pass through the total positive electrode of the battery 100, the positive electrode terminal 13a of the battery monomer 10, the shell 11, the negative electrode tab 122, and the negative electrode terminal 13b to reach the total negative electrode of the battery 100. This path can also be understood as a protection path.

[0124] Referring to FIGS. 9 and 10, in some embodiments, the positive electrode current collecting member 15a includes a first connecting part 151 connected with the positive electrode terminal 13a and a second connecting part 152 connected with the positive electrode tab 121. The first protection mechanism 161 is arranged between the second connecting part 152 and the first wall 112 along the thickness direction Z of the first wall 112.

[0125] In some embodiments, the first connecting part 151 protrudes from the surface of the second connecting part 152 facing the positive electrode terminal 13a. This facilitates the connection of the first connecting part 151 with the positive electrode terminal 13a.

[0126] Further, the first connecting portion 151 includes a top wall and a side wall connecting the top wall with the second connecting portion 152. On the side of the positive current collector 15a facing away from the electrode assembly 12, the top wall and the side wall enclose a protrusion. On the side of the positive current collector 15a facing the electrode assembly 12, the top wall and the side wall enclose a recess. In some embodiments, the positive current collector 15a is punched to form the first connecting portion 151.

[0127] In the present embodiment, the first protection mechanism 161 is arranged between the second connecting portion 152 and the first wall 112, such that the first protection mechanism 161 does not affect the connection of the first connecting portion 151 with the positive terminal 13a.

[0128] In some embodiments, the second connecting portion 152 is welded with the positive tab 121 to form a first weld, and a projection of the first weld along the thickness direction Z of the first wall 112 does not overlap with a projection of the first protection mechanism 161. This reduces the influence of the first protection mechanism 161 on the welding position of the second connecting portion 152 with the positive tab 121.

[0129] The specific structure of the first protection mechanism 161 is described in detail below.

[0130] FIG. 12 is a partial sectional view of FIG. 5 along C-C according to some embodiments of the present application; FIG. 13 is a partial sectional view of FIG. 5 along C-C according to some other embodiments of the present application; FIG. 14 is a partial sectional view of FIG. 5 along C-C according to some further embodiments of the present application; and FIG. 15 is a partial sectional view of FIG. 5 along C-C according to some yet further embodiments of the present application.

[0131] Referring to FIGS. 12 to 15, in some embodiments, the first protection mechanism 161 includes a first insulating member 1611 and a first conductive member 1612. The first insulating member 1611 is arranged between the first wall 112 and the positive current collector 15a to insulate the first wall 112 and the positive current collector 15a. The first conductive member 1612 is connected with the first insulating member 1611, and is configured to electrically connect the first wall 112 and the positive current collector 15a after the first insulating member 1611 is melted.

[0132] The threshold value described above can be related to the melting point of the first insulating member 1611. The threshold value described above can be the melting point of the first insulating member 1611.

[0133] The first insulating member 1611 is a component that insulates the first wall 112 and the positive current collector 15a.

[0134] The first conductive member 1612 is a component that electrically connects the first wall 112 and the positive current collector 15a after the first insulating member 1611 is melted.

[0135] The first insulating member 1611 can be made of a low-melting-point material to improve the response speed of the first protection mechanism 161.

[0136] The first insulating member 1611 and the first conductive member 1612 can be stacked (as shown in FIGS. 12, 13, and 15), or the first insulating member 1611 can be wrapped around the outer periphery of the first conductive member 1612 (as shown in FIG. 14).

[0137] When the internal temperature of the battery cell 10 does not reach the threshold value, the first insulating member 1611 insulates the first wall 112 from the positive current collector member 15a to allow the battery cell 10 to operate stably. When the internal temperature of the battery cell 10 reaches the threshold value, the first insulating member 1611 melts and loses insulation, thereby allowing the first wall 112 to be electrically connected to the positive current collector member 15a.

[0138] Referring to FIG. 12, in some embodiments, the first conductive member 1612 is connected to the positive current collector member 15a, and the first insulating member 1611 is disposed between the first conductive member 1612 and the first wall 112.

[0139] It should be understood that, after the first insulating member 1611 melts, the first insulating member 1611 loses insulation, and the first conductive member 1612 comes into contact with the first wall 112, thereby allowing the first wall 112 to be electrically connected to the positive current collector member 15a.

[0140] The first conductive member 1612 being connected to the positive current collector member 15a can improve the contact stability of the first conductive member 1612 and the positive current collector member 15a.

[0141] Referring to FIG. 13, in some embodiments, the first conductive member 1612 is connected to the first wall 112, and the first insulating member 1611 is disposed between the first conductive member 1612 and the positive current collector member 15a.

[0142] It should be understood that, after the first insulating member 1611 melts, the first insulating member 1611 loses insulation, and the first conductive member 1612 comes into contact with the positive current collector member 15a, thereby allowing the first wall 112 to be electrically connected to the positive current collector member 15a.

[0143] The first conductive member 1612 being connected to the first wall 112 can improve the contact stability of the first conductive member 1612 and the first wall 112.

[0144] In some embodiments, to facilitate the contact between the first conductive member 1612 and the first wall 112 or the positive current collector member 15a, the first conductive member 1612 can also be made of a low-melting-point metal material, so that the first conductive member 1612 has a certain fluidity when the internal temperature of the battery cell 10 reaches the threshold value, and forms other forms to contact the first wall 112 or the positive current collector member 15a.

[0145] Of course, in other embodiments, the first conductive member 1612 can also not have fluidity. For example, the first protection mechanism 161 always abuts between the first wall 112 and the positive current collector member 15a, and after the first insulating member 1611 melts, the first conductive member 1612 always remains in an abutting state under the interaction force between the positive current collector member 15a and the first wall 112, thereby contacting the first wall 112 and the positive current collector member 15a.

[0146] Referring to FIG. 14, in some embodiments, the first insulating member 1611 is coated on the outer surface of the first conductive member 1612.

[0147] An insulating layer can be coated on the outer periphery of the first conductive member 1612.

[0148] In the present embodiment, the first insulating member 1611 is coated on the outer surface of the first conductive member 1612, so that when the internal temperature of the battery monomer 10 does not reach the threshold value, the first conductive member 1612 has high insulation reliability with the first wall 112, so as to make the battery monomer 10 work stably.

[0149] Referring to FIG. 15, in some embodiments, the first conductive member 1612 includes a first sub-conductive member 16121 and a second sub-conductive member 16122, the first sub-conductive member 16121 is connected to the first wall 112, the second sub-conductive member 16122 is connected to the positive current collector member 15a, and the first insulating member 1611 is arranged between the first sub-conductive member 16121 and the second sub-conductive member 16122.

[0150] The first sub-conductive member 16121, the first insulating member 1611, and the second sub-conductive member 16122 can be arranged in layers.

[0151] The contact stability of the first sub-conductive member 16121 and the positive current collector member 15a can be improved, and the contact stability of the second sub-conductive member 16122 and the first wall 112 can be improved, and the failure risk of the first protection mechanism 161 can be reduced.

[0152] In some embodiments, the material of the first insulating member 1611 includes at least one of polypropylene, polyethylene terephthalate, polyformaldehyde, polyethylene, polyvinyl chloride, modified polypropylene, polystyrene, and polyester resin.

[0153] These low-melting-point materials can improve the response speed of the first protection mechanism 161.

[0154] In some embodiments, the material of the first conductive member 1612 includes at least one of bismuth, tin, lead, indium, and mercury.

[0155] These low-melting-point metal materials melt or melt when the temperature of the battery monomer 10 reaches the threshold value, and have a certain fluidity.

[0156] Fig. 16 is a partial sectional view of Fig. 5 along C-C according to some embodiments of the present application;

[0157] Referring to Fig. 16, in some embodiments, the first protection mechanism 161 includes a first conductive member 1612, the first conductive member 1612 is connected to one of the first wall 112 and the positive current collector member 15a, and is spaced apart from the other of the first wall 112 and the positive current collector member 15a, the first conductive member 1612 includes a thermal expansion material.

[0158] The thermal expansion material is a material that causes the first conductive member 1612 to expand by heat, and the volume of the first conductive member 1612 locally or entirely increases.

[0159] It can be that the first conductive member 1612 is connected to the first wall 112 and is spaced apart from the positive current collector member 15a, and when the temperature inside the battery cell 10 reaches a threshold value, the first conductive member 1612 expands by heat to contact the positive current collector member 15a, thereby electrically connecting the first wall 112 and the positive current collector member 15a.

[0160] It can also be that the first conductive member 1612 is connected to the positive current collector member 15a and is spaced apart from the first wall 112, and when the temperature inside the battery cell 10 reaches a threshold value, the first conductive member 1612 expands by heat to contact the first wall 112, thereby electrically connecting the first wall 112 and the positive current collector member 15a.

[0161] In the present embodiment, the first conductive member 1612 includes a thermal expansion material, so that part or all of the first conductive member 1612 can expand in response to an increase in temperature to fill the gap, thereby contacting both the first wall 112 and the positive current collector member 15a, and achieving electrical connection between the first wall 112 and the positive current collector member 15a. The first conductive member 1612 of this structure can reduce the difficulty of manufacturing the first protection mechanism 161.

[0162] In some embodiments, the thermal expansion material includes graphite.

[0163] Fig. 17 is a structural schematic view of the second insulating member 17 according to an embodiment of the present application.

[0164] Referring to Fig. 17, and in combination with Figs. 11 to 16, in some embodiments, the battery cell 10 further includes a second insulating member 17, the second insulating member 17 is disposed between the first wall 112 and the electrode assembly 12 along the thickness direction Z of the first wall 112, at least a portion of the positive current collector member 15a is disposed on a side of the second insulating member 17 away from the first wall 112, the second insulating member 17 is provided with a first through hole 171, and at least a portion of the first protection mechanism 161 is accommodated in the first through hole 171.

[0165] The first through hole 171 can match the shape of the first containing mechanism, and can be configured in a circular, rectangular, or irregular shape, etc.

[0166] The first protection mechanism 161 can be wholly contained in the first through hole 171, or can be partially contained in the first through hole 171.

[0167] The material of the second insulation member 17 includes, but is not limited to, plastic, rubber, etc. The second insulation member 17 can be arranged on the inner surface of the first wall 112. The inner surface of the first wall 112 is the surface of the first wall 112 facing the inside of the battery cell 10.

[0168] Optionally, the second insulation member 17 is made of plastic.

[0169] In this embodiment, at least a part of the first protection mechanism 161 is contained in the first through hole 171, so that the first protection mechanism 161 and the second insulation member 17 can share a part of space, and the space utilization is improved.

[0170] In some embodiments, referring to FIG. 2, and in combination with FIG. 6, the second insulation member 17 is provided with a second through hole 172, and at least a part of the positive current collector member 15a is contained in the second through hole 172. In some embodiments, the first connecting part 151 of the positive current collector member is contained in the second through hole 172.

[0171] In some embodiments, referring to FIG. 2, and in combination with FIG. 6, the second insulation member 17 is provided with a third through hole 173, and at least a part of the negative current collector member 15b is contained in the third through hole 173.

[0172] In some embodiments, the shell 11 includes a housing 111 and an end cover 112a, one end of the housing 111 forms an opening, and the end cover 112a covers the opening, and the end cover 112a is the first wall 112.

[0173] In some embodiments, the electrode assembly 12 further includes a negative tab 122, and the negative tab 122 is electrically connected to the first wall 112.

[0174] In some embodiments, the electrode assembly 12 is in a jelly-roll structure, the outermost circle of the electrode assembly 12 is a negative electrode tab, and the electrode assembly 12 further includes a negative tab 122. The battery cell 10 further includes a negative terminal 13b, which is arranged on the first wall 112 in an insulated manner, and the negative terminal 13b is electrically connected to the negative tab 122.

[0175] The embodiments of the present application also provide a battery 100, which includes the battery cell 10 of any of the above embodiments.

[0176] In some embodiments, the battery 100 further comprises a controller, the protection mechanism comprises a second protection mechanism, the second protection mechanism is electrically connected with the controller, and the controller is configured to control the second protection mechanism of the battery monomer 10 to act when the internal temperature or pressure of the battery monomer 10 reaches a threshold value, so as to turn on the positive electrode terminal 13a and the shell 11.

[0177] The controller can be a battery management system (BMS) of the battery 100, and the second protection mechanism can also be electrically connected with a wire harness plate of the battery 100. The controller collects temperature or pressure information through the wire harness plate and sends instructions to control the second protection mechanism to act.

[0178] The second protection mechanism can be understood as an electronic switch, and the second protection mechanism acts, that is, the electronic switch changes from an open state to a closed state. The position of the second protection mechanism can be the same as the setting position of the first protection mechanism 161, and the second protection mechanism can also be set at other positions as long as the positive electrode terminal 13a and the shell 11 can be electrically connected.

[0179] Optionally, the second protection mechanism is a relay.

[0180] The controller controls the second protection mechanism to act, so as to realize the electrical connection between the positive electrode terminal 13a and the shell 11, thereby improving the intelligent management of the battery 100.

[0181] It should be understood that the protection mechanism comprises at least one of the first protection mechanism 161 and the second protection mechanism, that is, the electrical connection between the positive electrode terminal 13a and the shell 11 can be realized. Of course, the first protection mechanism 161 and the second protection mechanism can also exist at the same time.

[0182] The embodiments of the present application also provide a use electric device.

[0183] In some embodiments, the use electric device comprises the battery monomer 10 described above, and the battery monomer 10 is used to supply power for the use electric device.

[0184] In some embodiments, the use electric device comprises the battery 100 described above, and the battery 100 is used to supply power for the use electric device.

[0185] The embodiments of the present application also provide a battery 100 control method, which is applied to a battery 100 comprising a plurality of battery monomers 10, and the battery 100 control method comprises:

[0186] S1, detecting information of the plurality of battery monomers 10;

[0187] The information of the battery monomer 10 can be temperature information, pressure information, or temperature information and pressure information.

[0188] S2, upon detecting that the internal temperature or pressure of any battery cell 10 reaches a threshold value, control the positive terminal 13a of the battery cell 10 to be conductive with the housing 11.

[0189] Specifically, the BMS can control the second protection mechanism or other electronic switch to act so that the positive terminal 13a is electrically connected with the housing 11.

[0190] Referring to FIGS. 3-6, 9-12, the present embodiments also provide a battery cell 10, which includes a housing 11, an electrode assembly 12, a positive electrode terminal 13a, a negative electrode terminal 13b, a positive electrode current collector 15a, a negative electrode current collector 15b, a second insulating member 17, an insulating film 14, and a first protection mechanism 161. The housing 11 includes a shell 111 and an end cover 112a, the shell 111 has an opening at one end, and the end cover 112a covers the opening. The electrode assembly 12 is accommodated in the housing 11, the electrode assembly 12 has a jelly-roll structure, the outermost coil of the electrode assembly 12 has negative electrode tabs, the electrode assembly 12 has positive electrode tabs 121 and negative electrode tabs 122, and the insulating film 14 is wrapped around the outer periphery of the electrode assembly 12 to insulate the electrode assembly 12 from the housing 11. The positive electrode terminal 13a is insulated and arranged on the end cover 112a, and the negative electrode terminal 13b is insulated and arranged on the end cover 112a. The positive electrode current collector 15a includes a first connecting portion 151 and a second connecting portion 152, the positive electrode terminal 13a is welded to the first connecting portion 151, and the positive electrode tabs 121 are welded to the second connecting portion 152. The negative electrode terminal 13b and the negative electrode tabs 122 are respectively connected to the negative electrode current collector 15b. Along the thickness direction Z of the end cover 112a, the first protection mechanism 161 is arranged between the second connecting portion 152 and the first wall 112, and the first protection mechanism 161 is configured to electrically connect the second connecting portion 152 and the end cover 112a when the temperature or pressure inside the battery cell 10 reaches a threshold value. Along the thickness direction Z of the end cover 112a, the second insulating member 17 is arranged between the end cover 112a and the electrode assembly 12, at least a portion of the positive electrode current collector 15a is arranged on the side of the second insulating member 17 away from the first wall 112, the second insulating member 17 is provided with a first through hole 171, a second through hole 172, and a third through hole 173, the first protection mechanism 161 is accommodated in the first through hole 171, and the first connecting portion 151 of the positive electrode current collector is accommodated in the second through hole 172. The second connecting portion 152 is welded to the positive electrode tabs 121 to form a first welding mark, and along the thickness direction Z of the end cover 112a, the projection of the first welding mark does not overlap the projection of the first protection mechanism 161. The first protection mechanism 161 includes a first insulating member 1611 and a first conductive member 1612 connected to each other, the first conductive member 1612 is connected to the positive electrode current collector 15a, and the first insulating member 1611 is arranged between the first conductive member 1612 and the end cover 112a to insulate the first conductive member 1612 and the end cover 112a. The first conductive member 1612 is configured to contact the end cover 112a after the first insulating member 1611 melts to electrically connect the end cover 112a and the positive electrode current collector 15a.

[0191] Referring to FIGS. 3-6, 9-11, and 13, the present embodiments also provide a battery cell 10 including a housing 11, an electrode assembly 12, a positive electrode terminal 13a, a negative electrode terminal 13b, a positive electrode current collector 15a, a negative electrode current collector 15b, a second insulating member 17, an insulating film 14, and a first protection mechanism 161. The housing 11 includes a casing 111 and an end cover 112a, the casing 111 having an open end, and the end cover 112a covering the open end. The electrode assembly 12 is accommodated in the housing 11, the electrode assembly 12 being in a jelly-roll structure, the outermost coil of the electrode assembly 12 having negative electrode tabs, the electrode assembly 12 having positive electrode tabs 121 and negative electrode tabs 122, and the insulating film 14 being wrapped around the outer periphery of the electrode assembly 12 to insulate the electrode assembly 12 from the housing 11. The positive electrode terminal 13a is insulatedly disposed on the end cover 112a, and the negative electrode terminal 13b is insulatedly disposed on the end cover 112a. The positive electrode current collector 15a includes a first connecting portion 151 and a second connecting portion 152, the positive electrode terminal 13a being welded to the first connecting portion 151, and the positive electrode tabs 121 being welded to the second connecting portion 152. The negative electrode terminal 13b and the negative electrode tabs 122 are respectively connected to the negative electrode current collector 15b. The first protection mechanism 161 is disposed between the second connecting portion 152 and the first wall 112 in the thickness direction Z of the end cover 112a, and is configured to electrically connect the second connecting portion 152 and the end cover 112a when the temperature or pressure inside the battery cell 10 reaches a threshold value. The second insulating member 17 is disposed between the end cover 112a and the electrode assembly 12 in the thickness direction Z of the end cover 112a, at least a portion of the positive electrode current collector 15a being disposed on the side of the second insulating member 17 facing away from the first wall 112, the second insulating member 17 being provided with a first through hole 171, a second through hole 172, and a third through hole 173, the first protection mechanism 161 being accommodated in the first through hole 171, and the first connecting portion 151 of the positive electrode current collector 15a being accommodated in the second through hole 172. The second connecting portion 152 is welded to the positive electrode tabs 121 to form a first weld, and the projection of the first weld in the thickness direction Z of the end cover 112a does not overlap the projection of the first protection mechanism 161. The first protection mechanism 161 includes a first insulating member 1611 and a first conductive member 1612 connected to each other, the first conductive member 1612 being connected to the positive electrode current collector 15a, and the first insulating member 1611 being disposed between the first conductive member 1612 and the end cover 112a to insulate the first conductive member 1612 and the end cover 112a. The first conductive member 1612 is configured to contact the end cover 112a after the first insulating member 1611 melts to electrically connect the end cover 112a and the positive electrode current collector 15a. The first protection mechanism 161 includes the first insulating member 1611 and the first conductive member 1612 connected to each other, the first conductive member 1612 being connected to the end cover 112a, and the first insulating member 1611 being disposed between the first conductive member 1612 and the positive electrode current collector 15a to insulate the first conductive member 1612 and the positive electrode current collector 15a.The first conductive member 1612 is configured to contact the positive current collector 15a after the first insulating member 1611 melts, to electrically connect the end cover 112a and the positive current collector 15a.

[0192] With reference to FIGS. 3-6, 9-11, and 14, the present embodiment also provides a battery cell 10, which includes a housing 11, an electrode assembly 12, a positive terminal 13a, a negative terminal 13b, a positive current collector 15a, a negative current collector 15b, a second insulating member 17, an insulating film 14, and a first protection mechanism 161. The housing 11 includes a shell 111 and an end cover 112a, the shell 111 having an open end, and the end cover 112a covering the open end. The electrode assembly 12 is accommodated in the housing 11, the electrode assembly 12 being in a jelly-roll structure, the outermost layer of the electrode assembly 12 being a negative electrode tab, the electrode assembly 12 having a positive electrode tab 121 and a negative electrode tab 122, and the insulating film 14 being wrapped around the outer periphery of the electrode assembly 12 to insulate the electrode assembly 12 from the housing 11. The positive terminal 13a is insulated and arranged on the end cover 112a, and the negative terminal 13b is insulated and arranged on the end cover 112a. The positive current collector 15a includes a first connecting portion 151 and a second connecting portion 152, the positive terminal 13a being welded to the first connecting portion 151, and the positive electrode tab 121 being welded to the second connecting portion 152. The negative terminal 13b and the negative electrode tab 122 are respectively connected to the negative current collector 15b. In the thickness direction Z of the end cover 112a, the first protection mechanism 161 is arranged between the second connecting portion 152 and the first wall 112, and the first protection mechanism 161 is configured to electrically connect the second connecting portion 152 and the end cover 112a when the temperature or pressure inside the battery cell 10 reaches a threshold value. In the thickness direction Z of the end cover 112a, the second insulating member 17 is arranged between the end cover 112a and the electrode assembly 12, at least a portion of the positive current collector 15a being arranged on the side of the second insulating member 17 facing away from the first wall 112, the second insulating member 17 being provided with a first through hole 171, a second through hole 172, and a third through hole 173, the first protection mechanism 161 being accommodated in the first through hole 171, and the first connecting portion 151 of the positive current collector 15a being accommodated in the second through hole 172. The second connecting portion 152 is welded to the positive electrode tab 121 to form a first weld mark, and in the thickness direction Z of the end cover 112a, the projection of the first weld mark does not overlap the projection of the first protection mechanism 161. The first protection mechanism 161 includes a first insulating member 1611 and a first conductive member 1612, the first insulating member 1611 being wrapped around the outer surface of the first conductive member 1612 to insulate the first conductive member 1612 from the end cover 112a and to insulate the first conductive member 1612 and the positive current collector 15a, and the first conductive member 1612 being configured to contact the end cover 112a and the positive current collector 15a after the first insulating member 1611 melts, to electrically connect the end cover 112a and the positive current collector 15a.

[0193] Referring to FIGS. 3-6, 9-11, and 15, the present embodiments also provide a battery cell 10 including a housing 11, an electrode assembly 12, a positive electrode terminal 13a, a negative electrode terminal 13b, a positive electrode current collector 15a, a negative electrode current collector 15b, a second insulating member 17, an insulating film 14, and a first protection mechanism 161. The housing 11 includes a shell 111 having an open end and an end cap 112a covering the open end. The electrode assembly 12 is received in the housing 11 and has a jelly-roll structure with negative electrode tabs on the outermost turns. The electrode assembly 12 has positive and negative electrode tabs 121 and 122, and the insulating film 14 is wrapped around the outer periphery of the electrode assembly 12 to insulate the electrode assembly 12 from the housing 11. The positive electrode terminal 13a is insulatedly disposed on the end cap 112a, and the negative electrode terminal 13b is insulatedly disposed on the end cap 112a. The positive electrode current collector 15a includes a first connecting portion 151 and a second connecting portion 152, and the positive electrode terminal 13a is welded to the first connecting portion 151 and the positive electrode tab 121 is welded to the second connecting portion 152. The negative electrode terminal 13b and the negative electrode tab 122 are respectively connected to the negative electrode current collector 15b. The first protection mechanism 161 is disposed between the second connecting portion 152 and the first wall 112 in the thickness direction Z of the end cap 112a and is configured to electrically connect the second connecting portion 152 and the end cap 112a when the temperature or pressure inside the battery cell 10 reaches a threshold value. The second insulating member 17 is disposed between the end cap 112a and the electrode assembly 12 in the thickness direction Z of the end cap 112a, and at least a portion of the positive electrode current collector 15a is disposed on a side of the second insulating member 17 facing away from the first wall 112. The second insulating member 17 is provided with a first through hole 171 in which the first protection mechanism 161 is received, a second through hole 172 in which the first connecting portion 151 of the positive electrode current collector 15a is received, and a third through hole 173. The second connecting portion 152 is welded to the positive electrode tab 121 to form a first weld, and a projection of the first weld does not overlap a projection of the first protection mechanism 161 in the thickness direction Z of the end cap 112a. The first protection mechanism 161 includes a first sub-conductive member 16121, a first insulating member 1611, and a second sub-conductive member 16122 stacked together. The first sub-conductive member 16121 is connected to the first wall 112, the second sub-conductive member 16122 is connected to the positive electrode current collector 15a, and the first insulating member 1611 is disposed between the first sub-conductive member 16121 and the second sub-conductive member 16122 to insulate the first sub-conductive member 16121 and the second sub-conductive member 16122. The first sub-conductive member 16121 and the second sub-conductive member 16122 are configured to contact each other after the first insulating member 1611 melts to electrically connect the end cap 112a and the positive electrode current collector 15a.

[0194] Referring to FIGS. 3-6, 9-11, and 16, the present embodiments also provide a battery cell 10, which includes a housing 11, an electrode assembly 12, a positive electrode terminal 13a, a negative electrode terminal 13b, a positive electrode current collector 15a, a negative electrode current collector 15b, a second insulating member 17, an insulating film 14, and a first protection mechanism 161. The housing 11 includes a shell 111 and an end cover 112a, the shell 111 has an open end, and the end cover 112a covers the open end. The electrode assembly 12 is accommodated in the housing 11, the electrode assembly 12 has a jelly-roll structure, the outermost winding of the electrode assembly 12 has negative electrode tabs, the electrode assembly 12 has positive electrode tabs 121 and negative electrode tabs 122, and the insulating film 14 is wrapped around the outer periphery of the electrode assembly 12 to insulate the electrode assembly 12 from the housing 11. The positive electrode terminal 13a is insulated and arranged on the end cover 112a, and the negative electrode terminal 13b is insulated and arranged on the end cover 112a. The positive electrode current collector 15a includes a first connecting portion 151 and a second connecting portion 152, the positive electrode terminal 13a is welded to the first connecting portion 151, and the positive electrode tabs 121 are welded to the second connecting portion 152. The negative electrode terminal 13b and the negative electrode tabs 122 are respectively connected to the negative electrode current collector 15b. Along the thickness direction Z of the end cover 112a, the first protection mechanism 161 is arranged between the second connecting portion 152 and the first wall 112, and the first protection mechanism 161 is configured to electrically connect the second connecting portion 152 and the end cover 112a when the temperature or pressure inside the battery cell 10 reaches a threshold value. Along the thickness direction Z of the end cover 112a, the second insulating member 17 is arranged between the end cover 112a and the electrode assembly 12, at least a portion of the positive electrode current collector 15a is arranged on the side of the second insulating member 17 away from the first wall 112, the second insulating member 17 is provided with a first through hole 171, a second through hole 172, and a third through hole 173, the first protection mechanism 161 is accommodated in the first through hole 171, and the first connecting portion 151 of the positive electrode current collector 15a is accommodated in the second through hole 172. The second connecting portion 152 is welded to the positive electrode tabs 121 to form a first welding mark, and along the thickness direction Z of the end cover 112a, the projection of the first welding mark does not overlap the projection of the first protection mechanism 161. The first protection mechanism 161 includes a first conductive member 1612, the first conductive member 1612 is connected to one of the first wall 112 and the positive electrode current collector 15a and is arranged in a gap with the other one of the first wall 112 and the positive electrode current collector 15a, the material of the first conductive member 1612 is expanded graphite, and the first conductive member 1612 is configured to expand to contact the other one of the first wall 112 and the positive electrode current collector 15a in response to a stable increase.

[0195] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0196] The above examples are only used to illustrate the technical solutions of the present application, and are not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery cell, characterized in that, include: The outer shell has a first wall; An electrode assembly, housed within the housing, the electrode assembly including a positive electrode tab; The positive terminal is insulated from the first wall and is electrically connected to the positive electrode tab. A positive current collector, wherein the positive terminal and the positive tab are electrically connected through the positive current collector; A first protection mechanism is disposed between the positive current collector and the first wall along the thickness direction of the first wall. The first protection mechanism is configured to electrically connect the positive current collector and the first wall when the temperature or pressure inside the battery cell reaches a threshold.

2. The battery cell according to claim 1, characterized in that, The positive current collector includes a first connecting part and a second connecting part. The first connecting part is connected to the positive terminal, and the second connecting part is connected to the positive electrode tab. Along the thickness direction of the first wall, the first protection mechanism is disposed between the second connecting part and the first wall.

3. The battery cell according to claim 1 or 2, characterized in that, The first protection mechanism includes: A first insulating element is disposed between the first wall and the positive current collector to insulate the first wall from the positive current collector. A first conductive element is connected to the first insulating element, and the first conductive element is configured to electrically connect the first wall and the positive current collector after the first insulating element melts.

4. The battery cell according to claim 3, characterized in that, The first conductive element is connected to the positive current collector, and the first insulating element is disposed between the first conductive element and the first wall; or, The first conductive element is connected to the first wall, and the first insulating element is disposed between the first conductive element and the positive current collector.

5. The battery cell according to claim 3 or 4, characterized in that, The first insulating element covers the outer surface of the first conductive element.

6. The battery cell according to any one of claims 3-5, characterized in that, The first conductive element includes a first sub-conductive element and a second sub-conductive element. The first sub-conductive element is connected to the first wall, the second sub-conductive element is connected to the positive current collector, and the first insulating element is disposed between the first sub-conductive element and the second sub-conductive element.

7. The battery cell according to any one of claims 3-6, characterized in that, The material of the first insulating element includes at least one selected from polypropylene, polyethylene terephthalate, polyoxymethylene, polyethylene, polyvinyl chloride, modified polypropylene, polystyrene, and polyester resin; and / or, The material of the first conductive element includes at least one of bismuth, tin, lead, indium, and mercury.

8. The battery cell according to claim 1, characterized in that, The first protective mechanism includes a first conductive element, which is connected to one of the first wall and the positive current collector, and is spaced apart from the other of the first wall and the positive current collector. The first conductive element includes a thermally expanding material.

9. The battery cell according to claim 8, characterized in that, The thermally expanding material includes graphite.

10. The battery cell according to any one of claims 1-9, characterized in that, The battery cell also includes: The second insulating member is disposed between the first wall and the electrode assembly along the thickness direction of the first wall. At least a portion of the positive current collector is disposed on the side of the second insulating member opposite to the first wall. The second insulating member is provided with a first through hole, and at least a portion of the first protection mechanism is accommodated in the first through hole.

11. The battery cell according to any one of claims 1-10, characterized in that, The outer casing includes a housing and an end cap, one end of the housing forming an opening, the end cap covering the opening, and the end cap being the first wall.

12. The battery cell according to any one of claims 1-11, characterized in that, The electrode assembly also includes a negative electrode tab, which is electrically connected to the first wall.

13. The battery cell according to any one of claims 1-12, characterized in that, The electrode assembly has a wound structure, the outermost electrode of the electrode assembly is a negative electrode, and the electrode assembly also includes a negative electrode tab; The battery cell also includes: The negative terminal is insulated from the first wall and is electrically connected to the negative electrode ear.

14. A battery, characterized in that, Includes the battery cell described in any one of claims 1-13.

15. The battery according to claim 14, characterized in that, The battery also includes: Controller; The protection mechanism includes a second protection mechanism electrically connected to the controller, which is configured to activate the second protection mechanism of the battery cell when the internal temperature or pressure of the battery cell reaches a threshold, so as to connect the positive terminal to the casing.

16. An electrical appliance, characterized in that, Includes a battery cell according to any one of claims 1-13, the battery cell being used to supply power to the electrical device; and / or, The battery of claim 14 or 15, wherein the battery is used to supply power to the electrical device.

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