Battery cells, batteries and electrical equipment

Abstract

The present application discloses a battery cell, a battery and an electrical device. The battery cell includes a housing, an electrode assembly, a positive terminal, a positive current collecting member, a first protection mechanism and a second insulating member. The housing has a first wall. The electrode assembly is accommodated in the housing, and the electrode assembly includes a positive ear. The positive terminal is insulated and arranged on the first wall, and the positive terminal is electrically connected to the positive ear. The positive terminal is insulated and arranged on the first wall, and the positive terminal is electrically connected to the positive ear. Along the thickness direction of the first wall, the first protection mechanism and the second insulating member are both 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, and 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. The first protection mechanism can effectively improve the reliability of the battery cell.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell, a battery and an electrical device. Background Art

[0002] With the development of new energy technology, batteries are being used more and more widely. Batteries have high energy density, high safety, long service life, and are green and environmentally friendly to the social environment. They have been widely used in passenger cars, commercial vehicles, electric bicycles, heavy trucks, energy storage facilities, battery swap stations, engineering manufacturing, smart equipment, etc. At the same time, they also promote technical development and research in communications, medical equipment, energy development, etc.

[0003] In the battery production process, how to improve battery reliability is a technical problem that needs to be solved urgently. Summary of the invention

[0004] The embodiments of the present application provide a battery cell, a battery and an electrical device, which can effectively improve the reliability of the battery cell.

[0005] In a first aspect, an embodiment of the present application provides a battery cell, comprising a shell, an electrode assembly, a positive terminal, a positive current collecting member and a first protective mechanism, wherein the shell has a first wall; the electrode assembly is accommodated in the shell, and the electrode assembly includes a positive ear; the positive terminal is insulated and arranged on the first wall, and the positive terminal is electrically connected to the positive ear; the protective mechanism is configured to electrically connect the positive terminal to the shell when the temperature or pressure inside the battery cell reaches a threshold value.

[0006] The positive terminal and the positive electrode ear are electrically connected through the positive current collecting component; along the thickness direction of the first wall, the first protection mechanism is arranged between the positive current collecting component and the first wall, and the first protection mechanism is configured to electrically connect the positive current collecting component and the first wall when the temperature or pressure inside the battery cell reaches a threshold value.

[0007] In the above technical solution, when the battery cell is in thermal runaway, the positive electrode ear is melted, and the battery high voltage continues to act on the fuse part to generate arcing, causing secondary hazards. Since the positive current collecting member is electrically connected to the positive terminal, by setting the first protection mechanism between the first wall and the positive current collecting member, the first protection mechanism electrically connects the first wall and the positive current collecting member, so that the shell is electrically connected to the positive terminal, so that the current passes through the shell, so that the battery high voltage will not continue to act on the fuse part, thereby alleviating the arcing phenomenon, thereby improving the reliability of the battery cell and the reliability of the battery using the battery cell.

[0008] In addition, the first protection mechanism is arranged between the first wall and the positive electrode current collecting member, so that the first protection mechanism is located inside the battery cell, which can reduce the influence of external foreign matter on the first protection mechanism and improve the protection reliability.

[0009] In some embodiments, the positive current collecting component includes a first connecting portion and a second connecting portion, the first connecting portion is connected to the positive terminal, the second connecting portion is connected to the positive ear, and along the thickness direction of the first wall, the first protection mechanism is arranged between the second connecting portion and the first wall.

[0010] In the above technical solution, the first protection mechanism is arranged between the second connection part and the first wall, so that the first protection mechanism does not affect the connection between the first connection part and the positive terminal.

[0011] In some embodiments, the first protection mechanism includes a first insulating member, which is disposed between the first wall and the positive current collecting member to insulate the first wall from the positive current collecting member; a first conductive member is connected to the first insulating member, and the first conductive member is configured to electrically connect the first wall and the positive current collecting member after the first insulating member is melted.

[0012] In the above technical solution, when the internal temperature of the battery cell does not reach the threshold value, the first insulating member insulates the first wall from the positive electrode current collecting member to enable the battery cell to operate stably. When the internal temperature of the battery cell reaches the threshold value, the first insulating member melts and the insulation fails, thereby achieving electrical connection between the first wall and the positive electrode current collecting member.

[0013] In some embodiments, the first conductive member is connected to the positive current collecting member, and the first insulating member is disposed between the first conductive member and the first wall; or, the first conductive member is connected to the first wall, and the first insulating member is disposed between the first conductive member and the positive current collecting member.

[0014] In the above technical solution, the first conductive member is connected to the positive current collecting member, which can improve the contact stability between the first conductive member and the positive current collecting member. The first conductive member is connected to the first wall, which can improve the contact stability between the first conductive member and the first wall.

[0015] In some embodiments, the first insulating component is coated on an outer surface of the first conductive component.

[0016] In the above technical solution, the first insulating member is coated on the outer surface of the first conductive member, so that when the internal temperature of the battery cell does not reach the threshold, the first conductive member and the first wall have higher insulation reliability, so that the battery cell can work stably.

[0017] 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 electrode current collecting member, and the first insulating member is disposed between the first sub-conductive member and the second sub-conductive member.

[0018] In the above technical solution, the contact stability between the first sub-conductive member and the positive electrode current collecting member can be improved, and the contact stability between the second sub-conductive member and the first wall can be improved, thereby reducing the risk of failure of the first protection mechanism.

[0019] In some embodiments, the material of the first insulating member includes at least one of polypropylene, polyethylene terephthalate, polyoxymethylene, 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.

[0020] In some embodiments, the first protection mechanism includes a first conductive member connected to one of the first wall and the positive current collecting member, and disposed with a gap between the first wall and the other of the positive current collecting member, wherein the first conductive member includes a thermal expansion material.

[0021] In the above 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 the increase in temperature to fill the gap, thereby contacting both the first wall and the positive electrode current collecting member, and realizing electrical connection between the first wall and the positive electrode current collecting member. The first conductive member of this structure can reduce the difficulty of preparing the first protection mechanism.

[0022] In some embodiments, the thermally expandable material includes graphite.

[0023] In some embodiments, the battery cell also includes a second insulating member, which is arranged between the first wall and the electrode assembly along the thickness direction of the first wall, at least a portion of the positive current collecting member is arranged on the side of the second insulating member facing away from the first wall, the second insulating member is provided with a first through hole, and at least a portion of the first protective mechanism is accommodated in the first through hole.

[0024] 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 insulating member can share a portion of space, thereby improving space utilization.

[0025] In some embodiments, the housing includes a shell and an end cover, one end of the shell forms an opening, the end cover covers the opening, and the end cover is the first wall.

[0026] In some embodiments, the electrode assembly further includes a negative electrode tab electrically connected to the first wall.

[0027] In some embodiments, the electrode assembly is a wound structure, the outermost electrode sheet of the electrode assembly is a negative electrode sheet, and the electrode assembly also includes a negative electrode ear; the battery cell also includes a negative terminal, the negative terminal is insulated and arranged on the first wall, and the negative terminal is electrically connected to the negative electrode ear.

[0028] In a second aspect, an embodiment of the present application further provides a battery, the battery comprising a battery cell according to any embodiment of the first aspect.

[0029] In some embodiments, the battery also includes a controller, the protection mechanism includes 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 operate when the internal temperature or pressure of the battery cell reaches a threshold value to connect the positive terminal to the casing.

[0030] In a third aspect, an embodiment of the present application further provides an electrical device, the electrical device comprising the above-mentioned battery cell, the battery cell being used to supply power to the electrical device; and / or the above-mentioned battery, the battery being used to supply power to the electrical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 A schematic diagram of the structure of a vehicle in some embodiments of the present application;

[0033] Figure 2 An exploded schematic diagram of a battery according to some embodiments of the present application;

[0034] Figure 3 An exploded schematic diagram of a battery cell according to some embodiments of the present application;

[0035] Figure 4 A schematic diagram of the structure of a battery cell in some embodiments of the present application;

[0036] Figure 5 A top view of a battery cell according to some embodiments of the present application;

[0037] Figure 6 For some embodiments of this application Figure 5Section view along AA;

[0038] Figure 7 A circuit logic diagram of battery thermal runaway in some embodiments of the present application;

[0039] Figure 8 A circuit logic diagram of a battery after a protection mechanism is provided in some embodiments of the present application;

[0040] Fig. 9 A schematic structural diagram of a positive electrode current collecting component and a first protection mechanism from one perspective in some embodiments of the present application;

[0041] Fig.10 A schematic structural diagram of the positive electrode current collecting component and the first protection mechanism from another perspective in some embodiments of the present application;

[0042] Fig.11 For some embodiments of this application Figure 5 Partial cross-sectional view along CC;

[0043] Fig.12 For other embodiments of this application Figure 5 Partial cross-sectional view along CC;

[0044] Fig.13 For some embodiments of this application Figure 5 Partial cross-sectional view along CC;

[0045] Fig.14 For some embodiments of this application Figure 5 Partial cross-sectional view along CC;

[0046] Fig.15 For some embodiments of this application Figure 5 Partial cross-sectional view along CC;

[0047] Fig.16 For some other embodiments of this application Figure 5 Partial cross-sectional view along CC;

[0048] Fig.17 This is a schematic structural diagram of a second insulating member according to an embodiment of the present application.

[0049] Icons: 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-box; 21-first sub-box; 22-second sub-box; 23-accommodating space; 300-vehicle controller; 40-busbar component; D-fuse part; Z-thickness direction; 100-battery; 10-battery cell; 111-shell; 112a-end cover; 112-first wall; 11-outer shell; 121-positive electrode ear; 122-negative electrode ear; 12-electrode assembly; 13a-positive electrode terminal; 13b-negative electrode terminal; 14-insulating film; 151-first connecting part; 152-second connecting part; 15a-positive electrode current collecting component; 15b-negative electrode current collecting component.

[0050] The drawings are not drawn to scale. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0052] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. 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 and secondary relationship.

[0053] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0054] In the description of the present application, it should be noted that, unless otherwise specified, "multiple" means more than two; the terms "upper", "lower", "left", "right", "inside", "outside", etc., indicating the orientation or positional relationship, are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not strictly vertical, but is within the allowable error range. "Parallel" is not strictly parallel, but is within the allowable error range.

[0055] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0056] The term "or" in this application is merely a description of the association relationship of associated objects, indicating that two relationships may exist. For example, A or B may represent two situations: A exists alone, and B exists alone.

[0057] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are 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 descriptions and should not constitute any limitation to the present application.

[0058] The term “plurality” used in this application refers to two or more (including two).

[0059] In the present application, battery cells may include but are not limited to lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries or magnesium-ion batteries, etc. Battery cells include but are not limited to cylinders, flat bodies, rectangular parallelepipeds or other shapes, etc. Battery cells generally include cylindrical battery cells and square battery cells according to the packaging method.

[0060] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly consists of a positive electrode sheet, a negative electrode sheet, and a separator. A battery cell mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. Metal ions (such as lithium ions) are embedded and removed between the positive electrode and the negative electrode. The separator is set between the positive electrode and the negative electrode to prevent the positive electrode sheet and the negative electrode sheet from short-circuiting, while allowing active ions to pass through.

[0061] The positive electrode sheet includes a positive electrode collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode collector. The positive electrode collector not coated with the positive electrode active material layer protrudes from the positive electrode collector coated with the positive electrode active material layer. The positive electrode collector not coated with the positive electrode active material layer serves as a positive electrode ear.

[0062] Taking lithium-ion batteries as an example, the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc. The positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, carbon electrode, carbon, nickel or titanium, etc. can be used. The composite current collector may 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, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0063] The negative electrode sheet includes a negative electrode collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode collector. The negative electrode collector not coated with the negative electrode active material layer protrudes from the negative electrode collector coated with the negative electrode active material layer. The negative electrode collector not coated with the negative electrode active material layer serves as a negative electrode ear.

[0064] The negative electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, carbon electrode, carbon, nickel or titanium may be used. The negative electrode active material may be carbon or silicon.

[0065] In order to ensure that a large current can pass without melting, the number of positive pole ears is multiple and stacked together, and the number of negative pole ears is multiple and stacked together. The material of the separator can be PP (polypropylene) or PE (polyethylene). In addition, the electrode assembly can be a wound structure or a laminated structure.

[0066] 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. For example, the battery mentioned in the present application may include a battery module or a battery pack. The battery generally includes a box for encapsulating one or more battery cells. The box can reduce the impact of liquid or other foreign matter on the charging or discharging of the battery cells.

[0067] 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.

[0068] 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 accommodated in the case.

[0069] In some embodiments, multiple battery cells may be first integrated into at least one battery module, and then the battery module may be installed in a box to form a battery pack. In this embodiment, auxiliary structural members such as beams may be provided between the battery modules to improve the installation stability of the battery module in the box.

[0070] 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.

[0071] In some embodiments, the battery may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.

[0072] The development of battery technology must take into account many design factors at the same time, such as energy density, cycle life, discharge capacity, charge and discharge rate and other performance parameters. In addition, battery reliability must also be considered.

[0073] In a battery cell, the electrode terminal can be connected to the electrode tab of the electrode assembly through a 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 the positive tab of the electrode assembly is usually relatively low, and the melting point of the material suitable for the positive tab of the electrode assembly is usually relatively high. When the battery cell is in thermal runaway, the positive tab is easy to melt.

[0074] The battery consists of multiple battery cells. The battery can be understood as a high-voltage system. Each battery cell is electrically connected to the high-voltage system for operation. When the positive electrode ear is blown, the battery high voltage continues to act on the blown part to produce an arc, causing secondary hazards and reducing the reliability of the battery.

[0075] In view of this, in order to solve the problem that the positive electrode ear is melted, the high voltage of the battery continues to act on the fuse to produce arcing, resulting in reduced battery reliability, the embodiment of the present application provides a technical solution, by providing a protection mechanism between the outer shell and the positive current collecting component, so that the protection mechanism electrically connects the outer shell and the positive current collecting component when the battery cell thermally runs away, so that the current passes through the outer shell, so that the high voltage of the battery will not continue to act on the fuse, alleviate the arcing phenomenon, thereby improving the reliability of the battery cell and the reliability of the battery using the battery cell.

[0076] The protection mechanism is a component used to electrically connect the positive current collecting component and the shell when the battery cell is in thermal runaway, thereby alleviating arcing inside the battery cell. The protection mechanism can be understood as a low-impedance short-circuit path deliberately designed between the shell and the positive current collecting component, which is a protective path that connects the shell and the positive current collecting component.

[0077] It should be understood that when the battery cell is working stably, the protection mechanism does not work, and there is a good insulation effect between the positive current collecting member and the shell. When the temperature or pressure inside the battery cell reaches a threshold, the protection mechanism works to electrically connect the shell and the positive current collecting member to form a protection path.

[0078] The technical solution disclosed in the embodiment of the present application is applicable to but not limited to batteries and electrical equipment using the battery 100 .

[0079] Electrical equipment can be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys and electric tools, etc. Vehicles can be fuel vehicles, gas vehicles or new energy vehicles. New energy vehicles can be pure electric vehicles, hybrid vehicles or extended-range vehicles, etc. Spacecraft include airplanes, rockets, space shuttles and spacecrafts, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys and electric airplane toys, etc. Electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators and electric planers, etc.

[0080] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0081] Please refer to Figure 1 , Figure 1 1 is a schematic diagram of the structure of a vehicle 1000 according to some embodiments of the present application. A battery 100 is disposed inside the vehicle 1000. The battery 100 may be disposed at the bottom, head, or tail of the vehicle 1000. The battery 100 may be used to power the vehicle 1000. For example, the battery 100 may be used as an operating power source for the vehicle 1000.

[0082] The vehicle 1000 may further include a vehicle controller 300 and a motor 200 . The vehicle controller 300 is used to control the battery 100 to supply power to the motor 200 , for example, to meet the power requirements of starting, navigating, and driving the vehicle 1000 .

[0083] In some embodiments of the present application, the battery 100 can not only serve as an operating power source for the vehicle 1000, but also serve as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0084] In some embodiments, please refer to Figure 2 , Figure 2 The battery 100 of some embodiments of the present application is an exploded schematic diagram, and the battery 100 includes a plurality of battery cells 10. The plurality of battery cells 10 can be connected in series, in parallel, or in mixed connection. Mixed connection means that the plurality of battery cells 10 are connected in series and in parallel.

[0085] In some embodiments, the battery 100 may further include a busbar component 40 , and the plurality of battery cells 10 may be electrically connected via the busbar component 40 to achieve series connection, parallel connection, or mixed connection of the plurality of battery cells 10 .

[0086] The busbar component 40 may be a metal conductor, such as copper, iron, aluminum, steel, aluminum alloy, etc.

[0087] In some embodiments, the battery 100 may further include a box 20, which is used to accommodate the battery cell 10. The box 20 may include a first sub-box 21 and a second sub-box 22, which cover each other to define an accommodating space 23 for accommodating the battery cell 10. Of course, the connection between the first sub-box 21 and the second sub-box 22 may be sealed by a sealing element (not shown in the figure), which may be a sealing ring, a sealant, etc.

[0088] The first sub-box 21 and the second sub-box 22 may be in various shapes, such as a cuboid, a cylinder, etc. The first sub-box 21 may be a hollow structure with one side open, and the second sub-box 22 may also be a hollow structure with one side open, and the open side of the second sub-box 22 covers the open side of the first sub-box 21, thereby forming a box 20 with a receiving space 23. Of course, the first sub-box 21 may be a hollow structure with one side open, and the second sub-box 22 may be a plate-shaped structure, and the second sub-box 22 covers the open side of the first sub-box 21, thereby forming a box 20 with a receiving space 23.

[0089] Figure 3 It is an exploded schematic diagram of a battery cell 10 according to some embodiments of the present application; Figure 4 A schematic diagram of the structure of a battery cell 10 according to some embodiments of the present application; Figure 5 A top view of a battery cell 10 according to some embodiments of the present application; Figure 6 For some embodiments of this application Figure 5 Section view along AA.

[0090] Please refer to Figures 3 to 6 , Figure 3This is a schematic diagram of an exploded view of a battery cell 10 according to some embodiments of the present application. The battery cell 10 may include a housing 111 , an electrode assembly 12 , an end cover 112 a , an electrode terminal, and other functional components.

[0091] The housing 111 and the end cover 112 a may be understood as the outer shell 11 of the battery cell 10 .

[0092] The shell 111 is a component for accommodating the electrode assembly 12. The shell 111 can be a hollow structure with an opening at one end, or a hollow structure with openings at both ends. The shell 111 can be made of a variety of materials, such as copper, iron, aluminum, steel, aluminum alloy, etc. The shell 111 can be in a variety of shapes, such as a cylinder, a cuboid, etc. For example, in Figure 3 In the embodiment, the housing 111 is a rectangular parallelepiped.

[0093] 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. For example, the shell 111 is a rectangular parallelepiped structure, and the end cap 112a is a rectangular plate structure adapted to the shell 111. For another example, the shell 111 is a cylindrical structure, and the end cap 112a is a circular plate structure adapted to the shell 111. The material of the end cap 112a can also be a variety of materials. For example, the end cap 112a can be a metal material, 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.

[0094] 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 at one end, one end cap 112a is provided accordingly; if the shell 111 is a hollow structure with openings at both ends, two end caps 112a are provided accordingly, and the two end caps 112a cover the two openings of the shell 111 respectively.

[0095] The electrode assembly 12 is a component in the battery cell 10 where chemical reactions occur and is responsible for storing and releasing electrical energy. The electrode assembly 12 has a positive electrode tab 121 and a negative electrode tab.

[0096] The electrode terminal is a component for drawing out the current. The electrode terminal can be provided on the end cap 112a or on other wall portions of the housing 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 terminal 13a and the negative terminal 13b. The positive electrode ear 121 is electrically connected to the positive terminal 13a, and the negative electrode ear 122 is electrically connected to the negative terminal 13b.

[0097] In some embodiments, the positive terminal 13a and the positive electrode ear 121 can be connected to the positive electrode current collecting member 15a to achieve electrical connection, and the negative terminal 13b and the negative electrode ear 122 can be connected to the negative electrode current collecting member 15b to achieve electrical connection. Of course, the positive terminal 13a can also be directly connected to the positive electrode ear 121, and the negative terminal 13b can also be directly connected to the negative electrode ear 122.

[0098] In some other embodiments, the housing 11 may be designed to be in direct contact with the negative electrode tab 122 (not shown in the figures), thereby becoming a part of the negative electrode of the battery cell 10 .

[0099] In some embodiments, the material of the positive electrode tab 121 includes aluminum. Aluminum has a lower potential, good electrical conductivity, and a higher energy density, and is therefore suitable for use as the material of the positive electrode tab 121 .

[0100] In some embodiments, the material of the negative electrode tab 122 includes nickel. Optionally, the material of the positive electrode tab 121 is copper-plated nickel. Nickel has good electrical conductivity and chemical stability, and is therefore suitable for use as the material of the negative electrode tab 122 .

[0101] Reference Figure 3 In some embodiments, the battery cell 10 may further include an insulating film 14 , which covers the outer circumference of the electrode assembly 12 to insulate the outer shell 11 from the electrode assembly 12 .

[0102] The embodiment of the present application provides a battery cell 10, which can improve the reliability of the battery 100. The specific structure of the battery cell 10 is described in detail below with reference to the accompanying drawings.

[0103] Figure 7 A circuit logic diagram of thermal runaway of a battery 100 according to some embodiments of the present application; Figure 8 This is a circuit logic diagram of the battery 100 after a protection mechanism is provided according to some embodiments of the present application. Figure 7 A circuit logic diagram of thermal runaway of a battery 100 according to some embodiments of the present application; Figure 8 This is a circuit logic diagram of the battery 100 after a protection mechanism is provided according to some embodiments of the present application. Fig. 9 A structural schematic diagram of a positive electrode current collecting member 15a and a first protection mechanism 161 from one perspective in some embodiments of the present application; Fig.10 Another perspective structural schematic diagram of the positive electrode current collecting member 15a and the first protection mechanism 161 in some embodiments of the present application; Fig.11 For some embodiments of this application Figure 5 Partial cross-sectional view along CC.

[0104] Reference Figures 3 to 11 , and combined with reference Figure 7 and Figure 8 The embodiment of the present application provides a battery cell 10, which includes a housing 11, an electrode assembly 12, a positive terminal 13a, a positive current collecting member 15a and a first protection mechanism 161. The housing 11 has a first wall 112. The electrode assembly 12 is accommodated in the housing 11, and the electrode assembly 12 includes a positive electrode ear 121. The positive terminal 13a is insulated and arranged on the first wall 112, and the positive terminal 13a is electrically connected to the positive electrode ear 121. The positive terminal 13a and the positive electrode ear 121 are electrically connected through the positive current collecting member 15a. Along the thickness direction Z 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 the first protection mechanism 161 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.

[0105] The first wall 112 may be an end cover 112 a or another wall portion of the housing 111 .

[0106] It can be understood that the first protection mechanism 161 is a component for electrically connecting the positive electrode current collecting member 15 a and the first wall 112 when the temperature or pressure inside the battery cell 10 reaches a threshold value.

[0107] The first protection mechanism 161 may be a mechanical switch, or an electronic switch.

[0108] The first protection mechanism 161 may be connected to one of the first wall 112 and the positive current collecting member 15a by bonding, welding, etc. The first protection mechanism 161 may also be connected to the first wall 112 and the positive current collecting member 15a respectively by bonding, welding, etc. The first protection mechanism 161 may also abut between the first wall 112 and the positive current collecting member 15a.

[0109] It should be understood that the first wall 112 is part of the outer shell 11. For support and protection, the outer shell 11 is usually made of metal material. When the first wall 112 is electrically connected to the positive electrode current collecting member 15a, the outer shell 11 is electrically connected to the positive electrode terminal 13a.

[0110] The first protection mechanism 161 may include a mechanical structure or an electronic structure, as long as the positive electrode current collecting member 15 a and the housing 11 can be electrically connected.

[0111] The threshold is a trigger condition for the first protection mechanism 161 to operate, and the threshold is related to the temperature or pressure of the battery cell 10 when it is in thermal runaway. The threshold varies 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 internal temperature value or pressure value of the battery cell 10 when it is in thermal runaway. In order to improve the response speed, the threshold can also be less than the internal temperature value or pressure value of the battery cell 10 when it is in thermal runaway.

[0112] It should be understood that when the battery cell 10 is working stably, the first protection mechanism 161 does not work, and at this time there is a good insulation effect between the positive terminal 13a and the shell 11. When the temperature or pressure inside the battery cell 10 reaches a threshold, the first protection mechanism 161 works, and the first wall 112 is electrically connected to the positive current collecting member 15a, so that the shell 11 and the positive terminal 13a are electrically connected to form a protection path.

[0113] Reference Figure 7 and Figure 8 , the battery 100 can be understood as a high voltage system, which has multiple batteries 100 inside. Figure 7 and Figure 8 FIG. 4 shows a circuit diagram of a battery cell 10 in a battery 100. It should be understood that there may be multiple battery cells 10 in the circuit.

[0114] like Figure 7 As shown, the positive electrode can be understood as the positive terminal 13a of the battery cell 10, the negative electrode can be understood as the negative terminal 13b of the battery cell 10, the cathode can be understood as the positive ear 121 of the electrode assembly 12, and the anode can be understood as the negative ear 122 of the electrode assembly 12. R1 can be understood as the insulation resistance between the positive terminal 13a and the shell 11. In order for the battery cell 10 to work stably, the electrode terminal and the shell 11 need to be insulated. 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 thermally runaway, the temperature or pressure of the battery cell 10 increases sharply. Under the action of high temperature, the positive ear 121 is melted, and the electrical connection between the positive ear 121 and the positive terminal 13a fails. Since the battery cell 10 is still electrically connected to the high-voltage system, the high voltage of the battery 100 continues to act on the fuse D, generating an arc, causing secondary hazards.

[0115] like Figure 8 As shown, a first protection mechanism 161 is provided. When the battery cell 10 is in thermal runaway, the current flows 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 housing 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 fuse D.

[0116] In this embodiment, when the battery cell 10 is in thermal runaway, the positive electrode ear 121 is fused, and the high voltage of the battery 100 continuously acts on the fuse part D to generate arcing, causing secondary hazards. Since the positive current collecting member 15a is already electrically connected to the positive terminal 13a, by setting the first protection mechanism 161 between the first wall 112 and the positive current collecting member 15a, the first protection mechanism 161 electrically connects the first wall 112 and the positive current collecting member 15a, so that the housing 11 can be electrically connected to the positive terminal 13a, so that the current passes through the housing 11, so that the high voltage of the battery 100 will not continuously act on the fuse part D, thereby alleviating the arcing phenomenon, thereby improving the reliability of the battery cell 10 and the reliability of the battery 100 using the battery cell 10.

[0117] The first protection mechanism 161 is disposed between the first wall 112 and the positive current collecting member 15 a , so that the first protection mechanism 161 is located inside the battery cell 10 , which can reduce the impact of external foreign matter on the first protection mechanism 161 and improve protection reliability.

[0118] It should be noted that:

[0119] For a battery cell 10 with a negatively charged outer shell 11, the positive terminal 13a and the outer shell 11 are electrically connected by electrically connecting the positive current collecting member 15a and the first wall 112 through the first protection mechanism. In this way, the current can pass through the total positive electrode of the battery 100, the positive terminal 13a of the battery cell 10, and the outer shell 11 to reach the total negative electrode of the battery 100. This path can be understood as a protection path.

[0120] For the battery cell 10 insulated from the negative terminal 13b and the outer shell 11, when the battery 100 is in thermal runaway, the insulating film covering the electrode assembly 12 melts and the insulating part fails, and the electrode assembly 12 and the outer shell 11 are already conducting. By making the protection mechanism electrically connect the positive terminal 13a and the outer shell 11, the current can reach the total negative electrode of the battery 100 through the total positive electrode of the battery 100, the positive terminal 13a of the battery cell 10, the outer shell 11, the negative electrode ear 122, and the negative terminal 13b. This path can also be understood as a protection path.

[0121] Reference Fig. 9 and Fig.10 In some embodiments, the positive current collecting member 15a includes a first connecting portion 151 and a second connecting portion 152, the first connecting portion 151 is connected to the positive terminal 13a, the second connecting portion 152 is connected to the positive ear 121, and along the thickness direction Z of the first wall 112, the first protection mechanism 161 is arranged between the second connecting portion 152 and the first wall 112.

[0122] In some embodiments, the first connection portion 151 protrudes from the surface of the second connection portion 152 facing the positive terminal 13 a , so as to facilitate the connection between the first connection portion 151 and the positive terminal 13 a .

[0123] Further, the first connection portion 151 includes a top wall and a side wall, and the side wall connects the top wall to the second connection portion 152. On the side of the positive current collecting member 15a away from the electrode assembly 12, the top wall and the side wall enclose a convex portion. On the side of the positive current collecting member 15a facing the electrode assembly 12, the top wall and the side wall enclose a concave portion. In some embodiments, the positive current collecting member 15a is stamped to form the first connection portion 151.

[0124] In this embodiment, the first protection mechanism 161 is disposed between the second connection portion 152 and the first wall 112 , so that the first protection mechanism 161 does not affect the connection between the first connection portion 151 and the positive terminal 13 a .

[0125] In some embodiments, the second connection portion 152 is welded to the positive electrode tab 121 to form a first weld mark, and along the thickness direction Z of the first wall 112, the projection of the first weld mark does not overlap with the projection of the first protection mechanism 161, so as to reduce the influence of the first protection mechanism 161 on the welding position of the second connection portion 152 and the positive electrode tab 121.

[0126] The specific structure of the first protection mechanism 161 is described in detail below.

[0127] Fig.12 For other embodiments of this application Figure 5 Partial cross-sectional view along CC; Fig.13 For some embodiments of this application Figure 5 Partial cross-sectional view along CC; Fig.14 For some embodiments of this application Figure 5 Partial cross-sectional view along CC; Fig.15 For some embodiments of this application Figure 5 Partial cross-sectional view along CC.

[0128] Reference Figures 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 disposed between the first wall 112 and the positive current collecting member 15a to insulate the first wall 112 from the positive current collecting member 15a; the first conductive member 1612 is connected to the first insulating member 1611, and the first conductive member 1612 is configured to electrically connect the first wall 112 and the positive current collecting member 15a after the first insulating member 1611 is melted.

[0129] The threshold value may be related to the melting point of the first insulating member 1611. The threshold value may be the melting point of the first insulating member 1611.

[0130] The first insulating member 1611 is a member that insulates the first wall 112 from the positive electrode current collecting member 15 a .

[0131] The first conductive member 1612 is a member that electrically connects the first wall 112 and the positive electrode current collecting member 15 a after the first insulating member 1611 is melted.

[0132] The first insulating member 1611 may be made of a low melting point material to increase the response speed of the first protection mechanism 161 .

[0133] The first insulating member 1611 and the first conductive member 1612 may be stacked (eg, Fig.12 , Fig.13 , Fig.15 As shown in FIG. 1 ), the first insulating member 1611 may also be coated on the outer periphery of the first conductive member 1612 (as shown in FIG. Fig.14 as shown).

[0134] When the internal temperature of the battery cell 10 does not reach the threshold, the first insulating member 1611 insulates the first wall 112 from the positive current collecting member 15a to ensure stable operation of the battery cell 10. When the internal temperature of the battery cell 10 reaches the threshold, the first insulating member 1611 melts and the insulation fails, thereby achieving electrical connection between the first wall 112 and the positive current collecting member 15a.

[0135] Reference Fig.12 In some embodiments, the first conductive member 1612 is connected to the positive current collecting member 15 a , and the first insulating member 1611 is disposed between the first conductive member 1612 and the first wall 112 .

[0136] It should be understood that after the first insulating member 1611 melts, the insulation of the first insulating member 1611 fails, and the first conductive member 1612 contacts the first wall 112 , thereby achieving electrical connection between the first wall 112 and the positive electrode current collecting member 15 a .

[0137] The first conductive member 1612 is connected to the positive current collecting member 15 a , which can improve the contact stability between the first conductive member 1612 and the positive current collecting member 15 a .

[0138] Reference 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 collecting member 15 a .

[0139] It should be understood that after the first insulating member 1611 melts, the insulation of the first insulating member 1611 fails, and the first conductive member 1612 contacts the positive current collecting member 15 a , thereby achieving electrical connection between the first wall 112 and the positive current collecting member 15 a .

[0140] The first conductive member 1612 is connected to the first wall 112 , which can improve the contact stability between the first conductive member 1612 and the first wall 112 .

[0141] In some embodiments, in order to facilitate the contact between the first conductive member 1612 and the first wall 112 or the positive current collecting member 15a, the first conductive member 1612 may also be made of a metal material with a low melting point, so that when the temperature inside the battery cell 10 reaches a threshold value, the first conductive member 1612 has a certain fluidity and forms other shapes to contact the first wall 112 or the positive current collecting member 15a.

[0142] Of course, in other embodiments, the first conductive member 1612 may not have fluidity. For example, the first protective mechanism 161 always abuts between the first wall 112 and the positive current collecting member 15a. After the first insulating member 1611 melts, under the interaction force between the positive current collecting member 15a and the first wall 112, the first conductive member 1612 always maintains an abutting state, thereby contacting the first wall 112 and the positive current collecting member 15a.

[0143] Reference Fig.14 In some embodiments, the first insulating member 1611 is coated on the outer surface of the first conductive member 1612 .

[0144] An insulating layer may be coated on the outer periphery of the first conductive member 1612 .

[0145] In this 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 cell 10 does not reach the threshold, the first conductive member 1612 and the first wall 112 have higher insulation reliability, so that the battery cell 10 can work stably.

[0146] Reference 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 electrode current collecting component 15a, and the first insulating member 1611 is disposed between the first sub-conductive member 16121 and the second sub-conductive member 16122.

[0147] The first sub-conductive member 16121 , the first insulating member 1611 , and the second sub-conductive member 16122 may be stacked.

[0148] The contact stability between the first sub-conductor 16121 and the positive current collecting member 15 a and the contact stability between the second sub-conductor 16122 and the first wall 112 can be improved, thereby reducing the risk of failure of the first protection mechanism 161 .

[0149] In some embodiments, the material of the first insulating member 1611 includes at least one of polypropylene, polyethylene terephthalate, polyoxymethylene, polyethylene, polyvinyl chloride, modified polypropylene, polystyrene, and polyester resin.

[0150] These low melting point materials can improve the response speed of the first protection mechanism 161 .

[0151] In some embodiments, the material of the first conductive member 1612 includes at least one of bismuth, tin, lead, indium, and mercury.

[0152] These low melting point metal materials melt or fuse when the temperature of the battery cell 10 reaches a threshold value and have a certain fluidity.

[0153] Fig.16 For some other embodiments of this application Figure 5 Partial cross-sectional view along CC;

[0154] Reference Fig.16 In some embodiments, the first protection mechanism 161 includes a first conductive member 1612, which is connected to one of the first wall 112 and the positive current collecting member 15a, and is provided with a gap with the other of the first wall 112 and the positive current collecting member 15a, and the first conductive member 1612 includes a thermal expansion material.

[0155] The thermal expansion material is a material that causes the first conductive member 1612 to expand when heated, thereby increasing the volume of a portion or the entirety of the first conductive member 1612 .

[0156] The first conductive member 1612 may be connected to the first wall 112 and provided with a gap with the positive current collecting member 15a. When the temperature inside the battery cell 10 reaches a threshold, the first conductive member 1612 expands due to heat and contacts the positive current collecting member 15a, thereby electrically connecting the first wall 112 and the positive current collecting member 15a.

[0157] Alternatively, the first conductive member 1612 is connected to the positive current collecting member 15a and is provided with a gap with the first wall 112. When the temperature inside the battery cell 10 reaches a threshold, the first conductive member 1612 expands due to heat and contacts the first wall 112, thereby electrically connecting the first wall 112 and the positive current collecting member 15a.

[0158] In this 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 the increase in temperature to fill the gap, thereby contacting both the first wall 112 and the positive current collecting member 15a, and achieving electrical connection between the first wall 112 and the positive current collecting member 15a. The first conductive member 1612 of this structure can reduce the difficulty of preparing the first protection mechanism 161.

[0159] In some embodiments, the thermally expandable material includes graphite.

[0160] Fig.17 Schematic diagram of the structure of the second insulating member 17 according to an embodiment of the present application.

[0161] Reference Fig.17 , and combined with reference Figures 11 to 16 In some embodiments, the battery cell 10 further includes a second insulating member 17, which 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 electrode current collecting member 15a is disposed on a side of the second insulating member 17 that is 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 protective mechanism 161 is accommodated in the first through hole 171.

[0162] The first through hole 171 may match the shape of the first including mechanism, and the first through hole 171 may be configured to be circular, rectangular, or irregular in shape.

[0163] The first protection mechanism 161 may be completely accommodated in the first through hole 171 , or the first protection mechanism 161 may be partially accommodated in the first through hole 171 .

[0164] The material of the second insulating member 17 includes but is not limited to plastic, rubber, etc. The second insulating member 17 may be disposed 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.

[0165] Optionally, the second insulating member 17 is lower plastic.

[0166] In this embodiment, at least a portion of the first protection mechanism 161 is accommodated in the first through hole 171 , so that the first protection mechanism 161 and the second insulating member 17 can share a portion of space, thereby improving space utilization.

[0167] In some embodiments, reference Figure 2 , and combined with reference Figure 6 The second insulating member 17 is provided with a second through hole 172 , and at least a portion of the positive current collecting member 15 a is received in the second through hole 172 . In some embodiments, the first connection portion 151 of the positive current collecting member is received in the second through hole 172 .

[0168] In some embodiments, reference Figure 2 , and combined with reference Figure 6 The second insulating member 17 is provided with a third through hole 173 , and at least a portion of the negative electrode current collecting member 15 b is received in the third through hole 173 .

[0169] In some embodiments, the housing 11 includes a shell 111 and an end cover 112 a . An opening is formed at one end of the shell 111 . The end cover 112 a covers the opening. The end cover 112 a is the first wall 112 .

[0170] In some embodiments, the electrode assembly 12 further includes a negative electrode tab 122 , and the negative electrode tab 122 is electrically connected to the first wall 112 .

[0171] In some embodiments, the electrode assembly 12 is a wound structure, the outermost electrode sheet of the electrode assembly 12 is a negative electrode sheet, and the electrode assembly 12 further includes a negative electrode ear 122. The battery cell 10 further includes a negative terminal 13b, which is insulated and disposed on the first wall 112, and the negative terminal 13b is electrically connected to the negative electrode ear 122.

[0172] The embodiment of the present application further provides a battery 100 , and the battery 100 includes the battery cell 10 of any of the above embodiments.

[0173] In some embodiments, the battery 100 also includes a controller, the protection mechanism includes 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 10 to operate when the internal temperature or pressure of the battery cell 10 reaches a threshold value to connect the positive terminal 13a and the outer casing 11.

[0174] The controller may be a battery 100 management system (BMS), and the second protection mechanism may also be electrically connected to a wiring harness board of the battery 100 . The controller collects temperature or pressure information through the wiring harness board and sends instructions to control the action of the second protection mechanism.

[0175] The second protection mechanism can be understood as an electronic switch. When the second protection mechanism is actuated, 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. The second protection mechanism can also be set at other positions as long as the positive terminal 13a can be electrically connected to the housing 11.

[0176] Optionally, the second protection mechanism is a relay.

[0177] The controller controls the second protection mechanism to operate so as to realize electrical connection between the positive terminal 13 a and the housing 11 , thereby improving the intelligent management of the battery 100 .

[0178] It should be understood that the protection mechanism includes at least one of the first protection mechanism 161 and the second protection mechanism, so that the positive terminal 13a can be electrically connected to the housing 11. Of course, the first protection mechanism 161 and the second protection mechanism can also exist at the same time.

[0179] The embodiment of the present application also provides an electrical device.

[0180] In some embodiments, the electrical device includes the above-mentioned battery cell 10, and the battery cell 10 is used to supply power to the electrical device.

[0181] In some embodiments, the electrical device includes the above-mentioned battery 100, and the battery 100 is used to supply power to the electrical device.

[0182] The embodiment of the present application further provides a battery 100 control method, which is applied to the battery 100. The battery 100 includes a plurality of battery cells 10. The battery 100 control method includes:

[0183] S1, detecting information of multiple battery cells 10;

[0184] The information of the battery cell 10 may be temperature information, pressure information, or both.

[0185] S2 . When it is detected that the internal temperature or pressure of any battery cell 10 reaches a threshold value, the positive terminal 13 a of the battery cell 10 is controlled to be in conduction with the housing 11 .

[0186] Specifically, the BMS may control the second protection mechanism or other electronic switches to electrically connect the positive terminal 13 a to the housing 11 .

[0187] Reference Figures 3 to 6 , Figures 9 to 12The 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 collecting member 15a, a negative current collecting member 15b, a second insulating member 17, an insulating film 14, and a first protective mechanism 161. The housing 11 includes a shell 111 and an end cover 112a, one end of the shell 111 is open, and the end cover 112a covers the opening. The electrode assembly 12 is accommodated in the housing 11, and the electrode assembly 12 is a winding structure. The outermost electrode sheet of the electrode assembly 12 is a negative electrode sheet. The electrode assembly 12 has a positive electrode ear 121 and a negative electrode ear 122. The insulating film 14 is coated on the 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 collecting member 15a includes a first connection portion 151 and a second connection portion 152, the positive terminal 13a is welded to the first connection portion 151, and the positive electrode ear 121 is welded to the second connection portion 152. The negative terminal 13b and the negative electrode ear 122 are respectively connected to the negative current collecting member 15b. Along the thickness direction Z of the end cover 112a, the first protection mechanism 161 is arranged between the second connection portion 152 and the first wall 112, and the first protection mechanism 161 is configured to electrically connect the second connection 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 disposed between the end cover 112a and the electrode assembly 12, at least a portion of the positive current collecting member 15a is disposed 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 connection portion 151 of the positive current collecting member is accommodated in the second through hole 172. The second connection portion 152 is welded to the positive electrode ear 121 to form a first weld mark, and along the thickness direction Z of the end cover 112a, the projection of the first weld mark does not overlap with 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 current collecting member 15a, and the first insulating member 1611 is 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 current collecting member 15a.

[0188] Reference Figures 3 to 6 , Figures 9 to 11 and Fig.13The 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 collecting member 15a, a negative current collecting member 15b, a second insulating member 17, an insulating film 14, and a first protective mechanism 161. The housing 11 includes a shell 111 and an end cover 112a, one end of the shell 111 is open, and the end cover 112a covers the opening. The electrode assembly 12 is accommodated in the housing 11, and the electrode assembly 12 is a winding structure. The outermost electrode sheet of the electrode assembly 12 is a negative electrode sheet. The electrode assembly 12 has a positive electrode ear 121 and a negative electrode ear 122. The insulating film 14 is coated on the 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 collecting member 15a includes a first connection portion 151 and a second connection portion 152, the positive terminal 13a is welded to the first connection portion 151, and the positive electrode ear 121 is welded to the second connection portion 152. The negative terminal 13b and the negative electrode ear 122 are respectively connected to the negative current collecting member 15b. Along the thickness direction Z of the end cover 112a, the first protection mechanism 161 is arranged between the second connection portion 152 and the first wall 112, and the first protection mechanism 161 is configured to electrically connect the second connection 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 disposed between the end cover 112a and the electrode assembly 12, at least a portion of the positive current collecting member 15a is disposed 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 connection portion 151 of the positive current collecting member is accommodated in the second through hole 172. The second connection portion 152 is welded to the positive electrode ear 121 to form a first weld mark, and along the thickness direction Z of the end cover 112a, the projection of the first weld mark does not overlap with 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 current collecting member 15a, and the first insulating member 1611 is 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 is melted to electrically connect the end cover 112a and the positive current collecting member 15a. 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 end cover 112a, and the first insulating member 1611 is disposed between the first conductive member 1612 and the positive current collecting member 15a to insulate the first conductive member 1612 and the positive current collecting member 15a.The first conductive member 1612 is configured to contact the positive current collecting member 15 a after the first insulating member 1611 is melted, so as to electrically connect the end cap 112 a and the positive current collecting member 15 a .

[0189] Reference Figures 3 to 6 , Figures 9 to 11 and Fig.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 collecting member 15a, a negative current collecting member 15b, a second insulating member 17, an insulating film 14, and a first protective mechanism 161. The housing 11 includes a shell 111 and an end cover 112a, one end of the shell 111 is open, and the end cover 112a covers the opening. The electrode assembly 12 is accommodated in the housing 11, and the electrode assembly 12 is a winding structure. The outermost electrode sheet of the electrode assembly 12 is a negative electrode sheet. The electrode assembly 12 has a positive electrode ear 121 and a negative electrode ear 122. The insulating film 14 is coated on the 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 collecting member 15a includes a first connection portion 151 and a second connection portion 152, the positive terminal 13a is welded to the first connection portion 151, and the positive electrode ear 121 is welded to the second connection portion 152. The negative terminal 13b and the negative electrode ear 122 are respectively connected to the negative current collecting member 15b. Along the thickness direction Z of the end cover 112a, the first protection mechanism 161 is arranged between the second connection portion 152 and the first wall 112, and the first protection mechanism 161 is configured to electrically connect the second connection 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 disposed between the end cover 112a and the electrode assembly 12, at least a portion of the positive current collecting member 15a is disposed 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 connection portion 151 of the positive current collecting member is accommodated in the second through hole 172. The second connection portion 152 is welded to the positive electrode ear 121 to form a first weld mark, and along the thickness direction Z of the end cover 112a, the projection of the first weld mark does not overlap with 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 is coated on the outer surface of the first conductive member 1612 to insulate the first conductive member 1612 from the end cover 112a and the first conductive member 1612 from the positive current collecting member 15a. The first conductive member 1612 is configured to contact the end cover 112a and the positive current collecting member 15a after the first insulating member 1611 is melted to electrically connect the end cover 112a and the positive current collecting member 15a.

[0190] Reference Figures 3 to 6 , Figures 9 to 11 and Fig.15 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 collecting member 15a, a negative current collecting member 15b, a second insulating member 17, an insulating film 14, and a first protective mechanism 161. The housing 11 includes a shell 111 and an end cover 112a, one end of the shell 111 is open, and the end cover 112a covers the opening. The electrode assembly 12 is accommodated in the housing 11, and the electrode assembly 12 is a winding structure. The outermost electrode sheet of the electrode assembly 12 is a negative electrode sheet. The electrode assembly 12 has a positive electrode ear 121 and a negative electrode ear 122. The insulating film 14 is coated on the 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 collecting member 15a includes a first connection portion 151 and a second connection portion 152, the positive terminal 13a is welded to the first connection portion 151, and the positive electrode ear 121 is welded to the second connection portion 152. The negative terminal 13b and the negative electrode ear 122 are respectively connected to the negative current collecting member 15b. Along the thickness direction Z of the end cover 112a, the first protection mechanism 161 is arranged between the second connection portion 152 and the first wall 112, and the first protection mechanism 161 is configured to electrically connect the second connection 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 disposed between the end cover 112a and the electrode assembly 12, at least a portion of the positive current collecting member 15a is disposed 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 connection portion 151 of the positive current collecting member is accommodated in the second through hole 172. The second connection portion 152 is welded to the positive electrode ear 121 to form a first weld mark, and along the thickness direction Z of the end cover 112a, the projection of the first weld mark does not overlap with the projection of the first protection mechanism 161. The first protection mechanism 161 includes a first sub-conductor 16121, a first insulating member 1611, and a second sub-conductor 16122, which are stacked. The first sub-conductor 16121 is connected to the first wall 112, and the second sub-conductor 16122 is connected to the positive current collecting member 15a. The first insulating member 1611 is disposed between the first sub-conductor 16121 and the second sub-conductor 16122 to insulate the first sub-conductor 16121 from the second sub-conductor 16122. The first sub-conductor 16121 and the second sub-conductor 16122 are configured to contact after the first insulating member 1611 is melted, so as to electrically connect the end cover 112a and the positive current collecting member 15a.

[0191] Reference Figures 3 to 6 , Figures 9 to 11 and Fig.16 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 collecting member 15a, a negative current collecting member 15b, a second insulating member 17, an insulating film 14, and a first protective mechanism 161. The housing 11 includes a shell 111 and an end cover 112a, one end of the shell 111 is open, and the end cover 112a covers the opening. The electrode assembly 12 is accommodated in the housing 11, and the electrode assembly 12 is a winding structure. The outermost electrode sheet of the electrode assembly 12 is a negative electrode sheet. The electrode assembly 12 has a positive electrode ear 121 and a negative electrode ear 122. The insulating film 14 is coated on the 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 collecting member 15a includes a first connection portion 151 and a second connection portion 152, the positive terminal 13a is welded to the first connection portion 151, and the positive electrode ear 121 is welded to the second connection portion 152. The negative terminal 13b and the negative electrode ear 122 are respectively connected to the negative current collecting member 15b. Along the thickness direction Z of the end cover 112a, the first protection mechanism 161 is arranged between the second connection portion 152 and the first wall 112, and the first protection mechanism 161 is configured to electrically connect the second connection 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 disposed between the end cover 112a and the electrode assembly 12, at least a portion of the positive current collecting member 15a is disposed 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 connection portion 151 of the positive current collecting member is accommodated in the second through hole 172. The second connection portion 152 is welded to the positive electrode ear 121 to form a first weld mark, and along the thickness direction Z of the end cover 112a, the projection of the first weld mark does not overlap with the projection of the first protection mechanism 161. The first protection mechanism 161 includes a first conductive member 1612, which is connected to one of the first wall 112 and the positive current collecting member 15a, and is arranged with a gap between the first wall 112 and the other of the positive current collecting member 15a. The material of the first conductive member 1612 is expanded graphite, and the first conductive member 1612 is configured to expand in response to a stable increase to contact the first conductive member 1612 and one of the first wall 112 and the positive current collecting member 15a that is not connected to the first conductive member 1612.

[0192] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0193] The above embodiments are only used to illustrate the technical solution of the present application and are not used to limit the present application. For those skilled in the art, the present application may have various modifications and variations. 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, It is characterized in that include: a housing having a first wall; An electrode assembly, contained in the housing, the electrode assembly comprising a positive electrode tab; A positive terminal, insulated and disposed on the first wall, the positive terminal being electrically connected to the positive electrode tab; A positive electrode current collecting member, through which the positive electrode terminal and the positive electrode tab are electrically connected; a first protection mechanism, disposed between the positive electrode current collecting member and the first wall along a thickness direction of the first wall, the first protection mechanism being configured to electrically connect the positive electrode current collecting member and the first wall when the temperature or pressure inside the battery cell reaches a threshold; A second insulating member is disposed along the thickness direction of the first wall between the first wall and the electrode assembly, at least a portion of the positive electrode current collecting member is disposed on a side of the second insulating member away from the first wall, the second insulating member is provided with a first through hole, and at least a portion of the first protective mechanism is accommodated in the first through hole.

2. The battery cell according to claim 1, It is characterized in that The positive current collecting member includes a first connection portion and a second connection portion, the first connection portion is connected to the positive terminal, the second connection portion is connected to the positive electrode ear, and the first protection mechanism is arranged between the second connection portion and the first wall along the thickness direction of the first wall.

3. The battery cell according to claim 1, It is characterized in that The first protection mechanism comprises: a first insulating member disposed between the first wall and the positive current collecting member to insulate the first wall from the positive current collecting member; A first conductive member is connected to the first insulating member, and the first conductive member is configured to electrically connect the first wall and the positive electrode current collecting member after the first insulating member is melted.

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

5. The battery cell according to claim 3, It is characterized in that The first insulating component is coated on the outer surface of the first conductive component.

6. The battery cell according to claim 3, It is characterized in that 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 electrode current collecting member, and the first insulating member is disposed between the first sub-conductive member and the second sub-conductive member.

7. The battery cell according to claim 3, It is characterized in that The material of the first insulating member includes at least one of polypropylene, polyethylene terephthalate, polyoxymethylene, 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.

8. The battery cell according to claim 1, It is characterized in that The first protection mechanism includes a first conductive member connected to one of the first wall and the positive current collecting member and disposed with a gap between the first wall and the other of the first wall and the positive current collecting member, and the first conductive member includes a thermal expansion material.

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

10. The battery cell according to any one of claims 1 to 9, It is characterized in that The housing includes a shell and an end cover. An opening is formed at one end of the shell. The end cover covers the opening. The end cover is the first wall.

11. The battery cell according to any one of claims 1 to 9, It is characterized in that The electrode assembly further includes a negative electrode tab, and the negative electrode tab is electrically connected to the first wall.

12. The battery cell according to any one of claims 1 to 9, It is characterized in that The electrode assembly is a wound structure, the outermost electrode sheet of the electrode assembly is a negative electrode sheet, and the electrode assembly also includes a negative electrode ear; The battery cell further comprises: A negative electrode terminal is insulated and disposed on the first wall, and the negative electrode terminal is electrically connected to the negative electrode tab.

13. A battery, It is characterized in that A battery cell comprising the battery cell according to any one of claims 1 to 12.

14. The battery according to claim 13, It is characterized in that The battery also includes: Controller; The protection mechanism includes a second protection mechanism, which is electrically connected to the controller. The controller is configured to control the second protection mechanism of the battery cell to operate when the internal temperature or pressure of the battery cell reaches a threshold value to conduct the positive terminal and the housing.

15. An electrical device, It is characterized in that A battery cell comprising the battery cell according to any one of claims 1 to 12, wherein the battery cell is used to supply power to the electrical device; and / or, The battery according to claim 13 or 14, wherein the battery is used to supply power to the electrical device.

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