Battery cell, battery, and electric device

Abstract

A battery monomer (20), a battery (100) and a power utilization device. The battery monomer (20) comprises: an electrode leading-out part (201) for leading out electric energy of the battery monomer (20); an electrode assembly (22) comprising a main body (222) and a tab (221), the tab (221) comprising a transition part (2211) and a connecting part (2212), the connecting part (2212) being arranged to be bent relative to the transition part (2211), the transition part (2211) being connected between the main body (222) and the connecting part (2212), and the connecting part (2212) being used for connecting with the electrode leading-out part (201); and an insulation member (24) arranged at the inner side of the bending of the tab (221), the insulation member (24) comprising a first insulation body (241) fixed to the main body (222) and a third insulation body (243) fixed to the connecting part (2212), the insulation member (24) further comprising a second insulation body (242) connected between the first insulation body (241) and the third insulation body (243), and at least part of the transition part (2211) being unfixed to the insulation member (24). The battery monomer (20), the battery (100) and the power utilization device thus arranged are conducive to reducing the risk of the tab (221) being torn.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese patent application 202322661304.X, filed on September 28, 2023, entitled “Battery Cell, Battery and Electrical Device”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of batteries, and more particularly to a battery cell, a battery, and an electrical device. Background Technology

[0004] Currently, secondary batteries mainly consist of a casing and an electrode assembly housed within the casing. The casing has electrode terminals, while the electrode assembly has tabs that are electrically connected to the electrode terminals. Related technologies often cover the tabs with insulating components to protect them. However, covering the tabs with insulating components can lead to tearing; therefore, reducing tab tearing has become a new challenge. Summary of the Invention

[0005] In view of this, embodiments of this application provide a battery cell, a battery, and an electrical device, which helps to solve the problem of electrode tearing caused by the adhesive force between the insulating component and the electrode when the electrode is bent.

[0006] In a first aspect, a battery cell is provided, comprising: an electrode lead-out portion for drawing out electrical energy from the battery cell; an electrode assembly including a body and a tab, the tab including a transition portion and a connecting portion, the connecting portion being bent relative to the transition portion, the transition portion being connected between the body and the connecting portion, the connecting portion being used to connect to the electrode lead-out portion; and an insulating member disposed on the inner side of the bent tab, the insulating member including a first insulator fixed to the body and a third insulator fixed to the connecting portion, the insulating member further including a second insulator connected between the first insulator and the third insulator, at least a portion of the transition portion not being fixed to the insulating member.

[0007] In this embodiment, by providing a second insulator between the first and third insulators to connect them together, the connection strength between the first and third insulators on the electrode assembly can be improved, reducing the risk of detachment. Furthermore, by not fixing at least a portion of the transition portion from the tab to the insulating member, the tensile force exerted by the insulating member on the tab during tab bending can be reduced, which helps to minimize tab tearing during bending.

[0008] In one possible implementation, at least a portion of the transition section is not fixed to the second insulator.

[0009] In this embodiment, by not fixing at least a portion of the transition portion of the tab to the second insulator, the tab can release stress during the bending process, reducing the tensile force exerted on the tab by the insulating member and lowering the risk of tab breakage.

[0010] In one possible implementation, the transition portion includes a first portion and a second portion, the first portion being connected to the main body, the second portion being connected between the connecting portion and the first portion, the inner surface of the second portion being bent relative to the inner surface of the first portion, and the second portion not being fixed to the second insulator.

[0011] In this embodiment, since the connection points between the second part and the connecting part and the first part are all bending points, by setting the second part to not be fixed to the second insulator, the tension of the insulating member on the bending part of the electrode can be released as much as possible, thereby reducing the risk of tearing the electrode when the electrode is bent.

[0012] In one possible implementation, the first edge portion of the first part connected to the second part is not fixed to the second insulator, and / or, the second edge portion of the connecting part connected to the second part is not fixed to the second insulator.

[0013] In this embodiment, not only is the second part not fixed to the second insulator, but the first edge portion of the first part connected to the second part is also not fixed to the second insulator, and / or the second edge portion of the connecting part connected to the second part is not fixed to the second insulator. This can better release the tensile force exerted by the insulating member on the tab and reduce the risk of tab breakage.

[0014] In one possible implementation, all transition sections are not fixed to the second insulator.

[0015] In this embodiment, by setting the entire transition section to be not fixed to the second insulator, more of the tensile force exerted by the insulating member on the electrode can be released during the electrode bending process, reducing the risk of electrode breakage.

[0016] In one possible implementation, the connecting portion is welded to the electrode lead-out portion to form a fusion region, the fusion region being exposed on the side of the connecting portion closer to the body, and a third insulator covering the fusion region.

[0017] In this embodiment, by setting the third insulator to cover the welding area, the third insulator can fix the metal debris in the welding area at the welding area, which helps to reduce the probability of short circuit of battery cells caused by metal debris escaping.

[0018] In one possible implementation, the third insulator extends beyond the welded area.

[0019] In this embodiment, by setting the third insulator to extend beyond the welding area, metal debris within the welding area can be contained within the welding area, reducing the probability of short circuits in individual battery cells caused by metal debris escaping.

[0020] In one possible implementation, the tab extends from the first end face of the body, and the first insulator and the first connection are spaced apart, the first connection being the connection between the inner surface of the tab and the first end face.

[0021] In this embodiment, since the first connection is a stress concentration point between the tab and the main body, the first insulator is spaced apart from the first connection so that the first connection can be covered by the second insulator and is not fixed to the insulating member. This reduces the tensile force exerted by the insulating member on the first connection during the bending process of the tab, thereby reducing the risk of tab breakage.

[0022] In one possible implementation, the distance between the first insulator and the first connection is greater than or equal to 2 mm.

[0023] In this embodiment, by setting the distance between the first insulator and the first connection to be greater than or equal to 2 mm, the tensile force exerted by the insulating member on the tab can be further reduced, thereby reducing the risk of tab breakage.

[0024] In one possible implementation, in the first direction, the size of the first insulator fixed to the first side of the body is smaller than the size of the coating thinning area of ​​the electrode in the electrode assembly. The first side is perpendicular to the first end face, and the first direction is perpendicular to the first end face. The first end face is the end face of the body that is connected to the tab.

[0025] In this embodiment, in the first direction, the size of the first insulator fixed to the first side of the main body is set to be smaller than the size of the coating thinning area of ​​the electrode in the electrode assembly, which can reduce the impact of the bonding of the insulating component on the performance of the battery cell.

[0026] In one possible implementation, the first insulator includes a first insulating layer and a first adhesive coating, the third insulator includes a third insulating layer and a third adhesive coating, the first insulating layer is bonded to the body through the first adhesive coating, and the third insulating layer is bonded to the connection portion through the third adhesive coating; the second insulator includes a second insulating layer, and the surface of the second insulating layer facing the tab is exposed.

[0027] In this embodiment, by exposing the surface of the second insulating layer facing the tab, at least a portion of the transition portion of the tab can be freed from being fixed to the second insulator. This reduces the tensile force exerted on the tab by the insulating member during tab bending, lowering the risk of tab breakage. Furthermore, it reduces the amount of adhesive coating material used, thus lowering costs.

[0028] In one possible implementation, the first insulator includes a first insulating layer and a first adhesive coating, the second insulator includes a second insulating layer and a second adhesive coating, and the third insulator includes a third insulating layer and a third adhesive coating; the second insulator also includes a fourth insulating layer, which is bonded to the second insulating layer by the second adhesive coating, and the tab-facing surface of the fourth insulating layer is exposed.

[0029] In this embodiment, by adhering the fourth insulating layer to the second adhesive coating and exposing its surface facing the tab, the portion of the tab from the first connection point to the second connection point can be left unfixed to the insulating member. This reduces the tensile force exerted on the tab by the insulating member during bending, lowering the risk of tab breakage. Furthermore, only the fourth insulating layer needs to be adhered to the portion corresponding to the first connection point to the second connection point of the tab, reducing the manufacturing complexity of the insulating member.

[0030] In one possible implementation, the electrode lead-out portion includes an electrode terminal, which is welded to the connecting portion; or, the electrode lead-out portion includes an electrode terminal and a connecting member, the connecting portion is electrically connected to the electrode terminal through the connecting member, and the connecting portion is welded to the connecting member.

[0031] In this embodiment, the electrode terminals are directly welded to the connecting portion without the need for a connecting member, which reduces costs while improving the space utilization of the battery cell. Connecting the connecting portion to the electrode terminals using a connecting member facilitates the connection between the tabs and the electrode terminals.

[0032] In one possible implementation, the electrode lead is disposed on the first wall of the battery cell housing, and the tab extends from the first end face of the electrode assembly, with the first end face disposed opposite to the first wall.

[0033] In this embodiment, by placing the electrode lead-out portion on the first wall opposite to the first end face, the space occupied by the electrode tab can be greatly saved.

[0034] In a second aspect, a battery is provided, comprising the battery cell provided in the first aspect.

[0035] Thirdly, an electrical device is provided, including the battery of the second aspect, which is used to provide electrical energy to the electrical device. Attached Figure Description

[0036] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the structure of a vehicle disclosed in one embodiment of this application.

[0038] Figure 2 This is a schematic diagram of the structure of a battery disclosed in one embodiment of this application.

[0039] Figure 3 This is a schematic exploded view of a battery cell disclosed in an embodiment of this application.

[0040] Figure 4 A schematic exploded view of a battery cell according to another embodiment of this application is shown.

[0041] Figure 5 A schematic cross-sectional view of a battery cell according to an embodiment of this application is shown.

[0042] Figure 6 It shows Figure 5 A schematic enlarged view of part A.

[0043] Figure 7 Another schematic cross-sectional view of a battery cell according to an embodiment of this application is shown.

[0044] Figure 8 A side view of one of the electrodes in the electrode assembly before bending is shown.

[0045] Figure 9 A schematic cross-sectional view of a battery cell with the tabs of an embodiment of this application before bending is shown.

[0046] Figure 10 A schematic cross-sectional view of an insulating member in its unfolded state, according to an embodiment of this application, is shown.

[0047] Figure 11 A schematic cross-sectional view of another insulating member in the unfolded state according to an embodiment of this application is shown.

[0048] Explanation of reference numerals in the attached figures:

[0049] 1-Vehicle; 80-Motor; 60-Controller; 100-Battery; 111-First housing section; 112-Second housing section; 20-Battery cell; 211-Housing shell; 212-Cover plate; 22-Electrode assembly; 23-Connecting member; 24-Insulating member; 214-Electrode terminal; 214a-Positive electrode terminal; 214b-Negative electrode terminal; 221-Taper; 221a-First tab; 221b-Second tab; 222-Body body; 2221-First end face; 2222-First side face; 2211-Transition section; 2212-Connection section; 201-Electrode lead-out section; 202-Welding area; 203-First connection point; 204-Second connection point; 241-First insulator; 242-Second insulator; 243-Third insulator; 2411-First insulating layer; 2412-First adhesive coating; 2421-Second insulating layer; 2422-Second adhesive coating; 2431-Third insulating layer; 2432-Third adhesive coating; 2423-Fourth insulating layer; 2301-First part; 2302-Second part; 401-Inner surface of the second part; 402-Inner surface of the first part; 403-First edge; 404-Second edge; 2223-Second side; 405-Inner surface of the tab; 251-Current collector; 252-Active material; X-First direction; Y-Development direction of the insulating member. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0051] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the specification of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings of this application are used to distinguish different objects, rather than to describe a specific order or hierarchy.

[0052] The directional terms used in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of this application. It should also be noted in the description of this application that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0053] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0054] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0055] In this application, "multiple" refers to two or more (including two), and similarly, "multiple groups" refers to two or more (including two), and "multiple pieces" refers to two or more (including two).

[0056] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0057] The battery cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0058] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, prevents short circuits while allowing active ions to pass through.

[0059] In some embodiments, the positive electrode can be a positive electrode sheet, which may include a positive current collector and a positive active material disposed on at least one surface of the positive current collector.

[0060] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0061] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, it can be aluminum or stainless steel with a silver surface treatment, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors 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.).

[0062] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide and their respective modified compounds.

[0063] In some embodiments, the negative electrode can be a negative electrode sheet, and the negative electrode sheet can include a negative current collector.

[0064] As an example, the negative electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, it can be aluminum or stainless steel with a silver surface treatment, stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, or titanium, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0065] As an example, the negative electrode sheet may include a negative current collector and a negative active material disposed on at least one surface of the negative current collector.

[0066] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cells. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc.

[0067] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0068] In some embodiments, the electrode assembly further includes an isolator disposed between the positive and negative electrodes.

[0069] In some embodiments, the separator is a separator membrane. This application does not impose any particular limitation on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0070] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride, and ceramic.

[0071] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0072] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. This application does not impose specific limitations on the type of electrolyte; it can be selected according to requirements. The electrolyte can be liquid, gel, or solid.

[0073] In some embodiments, the electrode assembly is a wound structure. The positive electrode and the negative electrode are wound into a wound structure.

[0074] In some implementations, the electrode assembly is a stacked structure.

[0075] As an example, multiple positive and negative electrode plates can be set, and multiple positive and multiple negative electrode plates can be stacked alternately.

[0076] As an example, multiple positive electrode sheets can be set, and negative electrode sheets are folded to form multiple stacked folded segments, with a positive electrode sheet sandwiched between adjacent folded segments.

[0077] As an example, both the positive and negative electrode sheets are folded to form multiple stacked folded segments.

[0078] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0079] As an example, the separator can be continuously arranged between any adjacent positive or negative electrode plates by folding or rolling.

[0080] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0081] In some embodiments, the electrode assembly is provided with tabs that allow current to be drawn from the electrode assembly. The tabs include a positive tab and a negative tab.

[0082] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as electrode assemblies and electrolytes. The housing may be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc. The housing includes a shell and a cover plate.

[0083] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries. This application does not have any particular limitations.

[0084] The battery mentioned in the embodiments of this application may be a single physical module comprising one or more battery cells to provide higher voltage and capacity. When there are multiple battery cells, the multiple battery cells are connected in series, parallel, or mixed via a busbar.

[0085] In some embodiments, the battery can be a battery module, and when there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0086] In some embodiments, the battery can be a battery pack, which includes a housing and individual battery cells, with the individual battery cells or battery modules housed within the housing.

[0087] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0088] Currently, a battery cell mainly consists of a casing and an electrode assembly installed inside the casing. The casing has electrode terminals, while the electrode assembly has tabs. The tabs are directly or indirectly connected to the electrode terminals to allow the electrical energy inside the battery cell to be drawn out to the outside of the battery cell.

[0089] To protect the tabs, related technologies cover them with insulating components. However, if the insulating component is bonded to the entire tab, the tab may tear when it is bent.

[0090] In view of this, the present application provides a battery cell in which the transition portion of the tab is not fixed to the insulating member, which helps to solve the problem of tab tearing caused by the adhesive force between the insulating member and the tab when the tab is bent.

[0091] The technical solutions described in the embodiments of this application are applicable to various battery-powered devices, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, electric vehicles, ships, and spacecraft. For example, spacecraft include airplanes, rockets, space shuttles, and spacecraft.

[0092] It should be understood that the technical solutions described in the embodiments of this application are not limited to the devices described above, but can also be applied to all devices that use batteries. However, for the sake of brevity, the following embodiments are all illustrated using electric vehicles as examples.

[0093] For example, such as Figure 1 The diagram shown is a structural schematic of a vehicle 1 according to one embodiment of this application. Vehicle 1 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A motor 80, a controller 60, and a battery 100 can be installed inside vehicle 1. The controller 60 controls the battery 100 to supply power to the motor 80. For example, the battery 100 can be installed at the bottom, front, or rear of vehicle 1. The battery 100 can be used to power vehicle 1. For example, the battery 100 can serve as the operating power source for vehicle 1, for example, for the electrical system of vehicle 1, such as for the power requirements of vehicle 1's starting, navigation, and operation. In another embodiment of this application, the battery 100 can not only serve as the operating power source for vehicle 1, but also as the driving power source for vehicle 1, replacing or partially replacing gasoline or natural gas to provide driving power for vehicle 1.

[0094] For example, such as Figure 2 The diagram shown is a structural schematic of a battery 100 according to an embodiment of this application. The battery 100 may include multiple battery cells 20. In addition to the battery cells 20, the battery 100 may also include a housing, the interior of which has a hollow structure, and the multiple battery cells 20 can be accommodated within the housing. Figure 2 As shown, the housing may include two parts, referred to herein as a first housing part 111 and a second housing part 112, which are fastened together. The shapes of the first housing part 111 and the second housing part 112 may be determined according to the shape of the combination of multiple battery cells 20, and at least one of the first housing part 111 and the second housing part 112 has an opening. For example, as Figure 2 As shown, only one of the first housing portion 111 and the second housing portion 112 is a hollow cuboid with an opening, while the other is plate-shaped to cover the opening. Taking the second housing portion 112 as a hollow cuboid with only one open side and the first housing portion 111 as a plate-shaped example, the first housing portion 111 covers the opening of the second housing portion 112 to form a housing 11 with a closed chamber. This chamber can accommodate multiple battery cells 20. Multiple battery cells 20 are connected in parallel, series, or mixed configurations and placed within the housing formed by the snap-fit ​​of the first housing portion 111 and the second housing portion 112.

[0095] For example, unlike Figure 2As shown, both the first housing portion 111 and the second housing portion 112 can be hollow cuboids with only one open side each. The openings of the first housing portion 111 and the second housing portion 112 are opposite to each other, and the first housing portion 111 and the second housing portion 112 are interlocked to form a housing with a closed cavity. Multiple battery cells 20 are connected in parallel, series, or mixed and placed inside the housing formed by the interlocking of the first housing portion 111 and the second housing portion 112.

[0096] Figure 3 A schematic exploded view of a battery cell 20 according to an embodiment of this application is shown. Figure 4 A schematic exploded view of a battery cell 20 according to another embodiment of this application is shown.

[0097] like Figure 3 and Figure 4 As shown, the battery cell 20 includes one or more electrode assemblies 22, a housing 211, and a cover plate 212, wherein the walls of the housing 211 and the cover plate 212 are both referred to as the walls of the battery cell 20. The housing 211 is determined according to the shape of the one or more electrode assemblies 22 combined. For example, the housing 211 can be a hollow cuboid, cube, or cylinder, and one side of the housing 211 has an opening so that one or more electrode assemblies 22 can be placed inside the housing 211. For example, when the housing 211 is a hollow cuboid or cube, one plane of the housing 211 is an open surface, that is, this plane does not have a wall, allowing communication between the inside and outside of the housing 211. When the housing 211 can be a hollow cylinder, the end face of the housing 211 is an open surface, that is, this end face does not have a wall, allowing communication between the inside and outside of the housing 211. The cover plate 212 covers the opening and is connected to the housing 211 to form a closed cavity for placing the electrode assembly 22. The casing 211 is filled with an electrolyte, such as an electrolyte solution.

[0098] The battery cell 20 also includes two electrode terminals 214. The cover plate 212 is typically flat, and the two electrode terminals 214 are fixed to the flat surface of the cover plate 212. The two electrode terminals 214 are a positive electrode terminal 214a and a negative electrode terminal 214b, respectively.

[0099] like Figure 3 and Figure 4 As shown, each electrode assembly 22 has tabs 221, including a first tab 221a and a second tab 221b. The first tab 221a and the second tab 221b have opposite polarities. When the first tab 221a is the positive tab, the second tab 221b is the negative tab. For example, as... Figure 3 As shown, the first tab 221a of one or more electrode assemblies 22 is connected to the positive electrode terminal 214a, and the second tab 221b of one or more electrode assemblies 22 is connected to the negative electrode terminal 214b. For example, as... Figure 4As shown, the first tab 221a of one or more electrode assemblies 22 is connected to the positive electrode terminal 214a via a connecting member 23, and the second tab 221b of one or more electrode assemblies 22 is connected to the negative electrode terminal 214b via another connecting member 23.

[0100] As an example, a pressure relief mechanism 213 may also be provided on one wall of the battery cell 20. The pressure relief mechanism 213 is actuated to release the internal pressure or temperature when the internal pressure or temperature of the battery cell 20 reaches a threshold.

[0101] Optionally, the pressure relief mechanism 213 can be installed on the cover plate 212 or on any wall of the housing 211.

[0102] like Figure 3 and Figure 4 As shown, the battery cell 20 also includes an insulating member 24, which is disposed on the side of the tab 221 away from the cover plate 212 and is fixedly connected to the tab 221 to provide insulation.

[0103] Figure 5 A cross-sectional view of a battery cell 20 according to an embodiment of this application is shown. Figure 6 yes Figure 5 An enlarged schematic diagram of part A in the middle. Figure 7 This is another cross-sectional view of the battery cell 20 according to an embodiment of this application. Figure 5 As shown, the battery cell 20 includes: an electrode lead-out portion 201 for drawing out electrical energy from the battery cell 20; an electrode assembly 22 including a main body 222 and a tab 221, the tab including a transition portion 2211 and a connecting portion 2212, the connecting portion 2212 being bent relative to the transition portion 2211, the transition portion 2211 being connected between the main body 222 and the connecting portion 2212, and the connecting portion 2212 being used to connect with the electrode lead-out portion 201; and an insulating member 24 disposed on the inner side of the bent tab 221, the insulating member 24 including a first insulator 241 fixed to the main body 222 and a third insulator 243 fixed to the connecting portion 2212, the insulating member 24 also including a second insulator 242 connected between the first insulator 241 and the third insulator 243, at least a portion of the transition portion 2211 not being fixed to the insulating member 24.

[0104] It should be understood that the electrode lead-out portion 201 is used to extract electrical energy from the battery cell 20 to the outside of the battery cell 20, and to connect in series or parallel with other battery cells. The electrode lead-out portion 201 can be as follows: Figure 3 As shown, it includes electrode terminals 214, wherein the tabs 221 are directly electrically connected to the electrode terminals 214; or, the electrode leads 201 may also be as shown. Figure 4As shown, it includes an electrode terminal 214 and a connecting member 23, wherein the tab 221 is electrically connected to the electrode terminal 214 through the connecting member 23. In some embodiments, after the connecting portion 2212 of the tab 221 is welded to the electrode lead-out portion 201, a fusion region 202 can be formed.

[0105] Typically, the electrode assembly 22 is formed by overlapping multiple electrodes. Each electrode includes a current collector and an active material coated on the surface of the current collector. The portion coated with the active material can be understood as the main body 222 of the electrode assembly 22, while the portion without active material coating can be understood as the tab 221 of the electrode assembly 22. That is, the portion of the multiple electrodes coated with active material forms the main body 222, and the portion without active material coating forms the tab 221. Furthermore, since each electrode has a portion without active material coating, the portion without active material coating of the multiple electrodes needs to be gathered together before it can be electrically connected to the electrode lead 201. After gathering the portion without active material coating of the multiple electrodes, it is bent to form a transition portion 2211 and a connecting portion 2212, and the connecting portion 2212 is bent relative to the transition portion 2211.

[0106] In some embodiments, such as Figure 7 As shown, the tab 221 can be formed by extending from the first end face 2221 of the main body 222. After bending, the connecting portion 2212 of the tab 221 can be disposed opposite to the first end face 2221.

[0107] It should be explained that the insulating member 24 is located on the inside of the bent tab 221, which can be understood as the insulating member 24 being located on the side of the tab 221 away from the electrode lead-out portion 201.

[0108] In one example, tab 221 extends from a portion of the first end face 2221 of body 222. In this example, a first insulator 241 is fixed to a portion of the first end face 2221 where tab 221 is not extended and a portion of the first side face 2222 intersecting with the first end face 2221, and the first insulator 241 fixed to the portion of the first end face 2221 where tab 221 is not extended and the first insulator 241 intersecting with the first end face 2221 are connected. A third insulator 243 may be fixed at least to the portion of connection 2212 in the welded area 202. A second insulator 242 is connected between the first insulator 241 and the third insulator 243, and the surface of the second insulator 242 facing tab 221 is exposed.

[0109] In another example, the tab 221 extends entirely from the first end face 2221 of the body 222. In this example, the first insulator 241 may be fixed only to a portion of the first side face 2222 that intersects with the first end face 2221, while the second insulator 242, on the projection of the first end face 2221, almost covers the entire first end face 2221.

[0110] In some embodiments, the exposed portion of the surface of the insulating member 24 facing the tab 221 may only cover a portion of the transition portion 2211. In other embodiments, the exposed portion of the surface of the insulating member 24 facing the tab 221 may also cover the entire transition portion 2211.

[0111] In this embodiment, by providing a second insulator 242 between the first insulator 241 and the third insulator 243 to connect the first insulator 241 and the third insulator 243 together, the connection strength of the first insulator 241 and the third insulator 243 on the electrode assembly 22 can be improved, reducing the risk of detachment. Furthermore, by not fixing at least a portion of the transition portion 2211 from the tab 221 to the insulating member 24, the tensile force of the insulating member 24 on the tab 221 can be reduced during the bending process of the tab 221, which helps to reduce the problem of tab tearing during bending.

[0112] In some embodiments, at least a portion of the transition portion 2211 is not fixed to the second insulator 242.

[0113] like Figures 5 to 7 As shown, the second insulator 242 covers at least a portion of the transition portion 2211. Therefore, at least a portion of the transition portion 2211 is not fixed to the insulating member 24. It can also be understood that at least a portion of the transition portion 2211 is not fixed to the second insulator 242.

[0114] In this embodiment, by not fixing at least a portion of the transition portion 2211 of the tab 221 to the second insulator 242, the tab 221 can release stress during the bending process, reducing the tensile force exerted on the tab 221 by the insulating member 24 and reducing the risk of the tab 221 breaking.

[0115] In some embodiments, such as Figure 6 As shown, the transition portion 2211 includes a first portion 2031 and a second portion 2032. The first portion 2031 is connected to the main body 222, and the second portion 2032 is connected between the connecting portion 2212 and the first portion 2031. The inner surface 401 of the second portion 2032 is bent relative to the inner surface 402 of the first portion 2031. The second portion 2032 is not fixed to the second insulator 242.

[0116] It should be noted that the inner surface 401 of the second part 2032 is bent relative to the inner surface 402 of the first part 2031, which can also mean that there is an angle between the inner surface 401 of the second part 2032 and the inner surface 402 of the first part 2031.

[0117] In some embodiments, such as Figures 5 to 7 As shown, the outer surface of the second part 2032 and the outer surface of the first part 2031 can be on the same plane. For example, the outer surface of the second part 2032 and the outer surface of the first part 2031 can be on the same plane as the second side 2223 of the main body 222.

[0118] In this embodiment, since the connection points between the second part 2032 and the connecting part 2212 and the first part 2031 are all bending points, by setting the second part 2032 to not be fixed to the second insulator 242, the tension of the insulating member 24 on the bending part of the tab 221 can be released as much as possible, thereby minimizing the risk of tearing the tab 221 when the tab 221 is bent.

[0119] In some embodiments, such as Figure 6 As shown, the first edge portion 403 of the first portion 2031 connected to the second portion 2032 is not fixed to the second insulator 242, and / or, the second edge portion 404 of the connecting portion 2212 connected to the second portion 2032 is not fixed to the second insulator 242.

[0120] In other words, in the direction perpendicular to the first side 2222, the bending point 205 between the third insulator 243 and the transition portion 2211 and the connecting portion 2212 is spaced apart, and / or, in the direction perpendicular to the first side 2222, the second connection 204 between the first insulator 241 and the first portion 2031 and the second portion 2032 is spaced apart.

[0121] It should be noted that, for illustrative purposes only, Figure 6 Only the edge of the inner surface 402 of the first part 2031 is designated as the first edge portion 403, and the edge of the inner surface of the connecting part 2212 is designated as the second edge portion 404. However, those skilled in the art will understand that the first edge portion 403 and the second edge portion 404 should be three-dimensional structures.

[0122] In this embodiment, not only is the second part 2032 not fixed to the second insulator 242, but the first edge portion 403 of the first part 2031 connected to the second part 2032 is also not fixed to the second insulator 242, and / or the second edge portion 404 of the connecting part 2212 connected to the second part 2032 is also not fixed to the second insulator 242. This can better release the tensile force exerted by the insulating member 24 on the tab 221 and reduce the risk of the tab 221 breaking.

[0123] In other embodiments, the entire transition portion 2211 is not fixed to the second insulator 242.

[0124] In other words, not only is the second part 2032 of the transition section 2211 not fixed to the second insulator 242, but the first part 2031 of the transition section 2211 is also not fixed to the second insulator 242.

[0125] In this embodiment, by setting the entire transition portion 2211 to be not fixed to the second insulator 242, the tensile force exerted by the insulating member 24 on the electrode 221 can be released more during the bending process of the electrode 221, thereby reducing the risk of the electrode 221 breaking.

[0126] In some embodiments, the connection portion 2212 is welded to the electrode lead-out portion 201 to form a fusion region 202, the fusion region 202 is exposed on the side of the connection portion 2212 near the body 222, and the third insulator 243 covers the fusion region 202.

[0127] For example, the orthographic projection of the welded area 202 onto the first end face 2221 lies within the orthographic projection of the third insulator 243 onto the first end face 2221.

[0128] In some embodiments, the connecting portion 2212 and the electrode lead-out portion 201 can be connected by ultrasonic welding. For example, a welding head is disposed on the side of the connecting portion 2212 away from the electrode lead-out portion 201, and a welding seat is disposed on the side of the electrode lead-out portion 201 away from the connecting portion 2212. When welding the connecting portion 2212 and the electrode lead-out portion 201, the welding head and the welding seat clamp the connecting portion 2212 and the electrode lead-out portion 201, and a fusion region 202 is formed between the electrode lead-out portion 201 and the connecting portion 2212. This fusion region 202 can be exposed on the surface of the connecting portion 2212 near the body 222.

[0129] In this embodiment, by setting the third insulator 243 to cover the welding area 202, the third insulator 243 can fix the metal debris in the welding area 202 at the welding area 202, which helps to reduce the probability of short circuit of the battery cell 20 caused by the escape of metal debris.

[0130] In some embodiments, the third insulator 243 extends beyond the welded area 202.

[0131] It should be noted that, Figure 7 Although only the direction perpendicular to the first side 2222 is shown, the third insulator 243 extends beyond the weld area 202. However, those skilled in the art will understand that the third insulator 243 extending beyond the weld area 202 in the embodiments of this application can mean that the third insulator 243 extends beyond the weld area 202 in all directions on the plane parallel to the first end face 2221.

[0132] In this embodiment, by setting the third insulator 243 to extend beyond the welding area 202, metal debris within the welding area 202 can be contained within the welding area 202, reducing the probability of short circuit in the battery cell 20 due to metal debris escaping.

[0133] In some embodiments, the third insulator 243 extends beyond the welded area 202 by a dimension greater than or equal to 2 mm.

[0134] In some examples, the third insulator 243 extends beyond the welded area 202 by a dimension equal to 2 mm or 3 mm, etc. For example, Figure 7 In this case, A1 equals 3mm. For example, Figure 7 In this case, A2 equals 2mm.

[0135] In some embodiments, such as Figure 7 As shown, the tab 221 extends from the first end face 2221 of the main body 222, and the first insulator 241 and the first connection 203 are spaced apart. The first connection 203 is the connection between the inner surface 405 of the tab 221 and the first end face 2221.

[0136] First, it needs to be explained that the inner surface 405 of the tab 221 may include the inner surface 402 of the first portion 2031, the inner surface 401 of the second portion 2032, and the inner surface of the connecting portion 2212. Furthermore, as described above, the tab 221 can extend from a portion of the first end face 2221 of the body 222, thus the first insulator 241 can fix a portion of the first end face 2221. In this embodiment, the second insulator 242 can extend beyond the first connection 203, so that the second insulator 242 can also cover a portion of the first end face 2221, thereby allowing a portion of the first end face 2221 to be unfixed to the insulating member 24.

[0137] In this embodiment, since the first connection 203 is a stress concentration point between the tab 221 and the main body 222, the first insulator 241 and the first connection 203 are spaced apart, so that the first connection 203 can be covered by the second insulator 242 and is not fixed to the insulating member 24. This reduces the tensile force exerted by the insulating member 24 on the first connection 203 during the bending process of the tab 221, thereby reducing the risk of the tab 221 breaking.

[0138] In some embodiments, the distance between the first insulator 241 and the first connection 203 is greater than or equal to 2 mm.

[0139] In some examples, the distance between the first insulator 241 and the first connection 203 is equal to 2 mm or 3 mm, etc. For example, Figure 7 In this case, A3 equals 2mm.

[0140] In this embodiment, by setting the distance between the first insulator 241 and the first connection 203 to be greater than or equal to 2 mm, the tensile force exerted by the insulating member 24 on the tab 221 can be further reduced, thereby reducing the risk of tab 221 breaking.

[0141] In some embodiments, in the first direction X, the size A4 of the first insulator 241 fixed to the first side surface 2222 of the main body 222 is smaller than the size L of the coating thinning area of ​​the electrode in the electrode assembly 22. The first side surface 2222 is perpendicular to the first end face 2221, and the first direction X is perpendicular to the first end face 2221. The first end face 2221 is the end face of the main body 222 that is connected to the tab 221.

[0142] Figure 8 A side view of one of the electrodes in electrode assembly 22 before bending is shown. Figure 8 As can be seen, the region where the current collector 251 coated with active material 252 is connected to the region where the current collector 251 without active material 252 is located includes a transition region. The thickness of the active material 252 gradually decreases in this transition region; this transition region can be called the coating thinning region. Multiple Figure 8 The electrode overlap shown forms Figures 5 to 7 The structure of the electrode assembly before the tab 221 is retracted.

[0143] Typically, the first insulator 241 extends from the connection point between the first side surface 2222 and the first end surface 2221 in a direction away from the first end surface 2221, until it extends to the coating thinning area of ​​the electrode sheet.

[0144] In this embodiment, in the first direction X, the size A4 of the first insulator 241 fixed to the first side 2222 of the main body 222 is set to be smaller than the size L of the coating thinning area of ​​the electrode in the electrode assembly 22, which can reduce the impact of the bonding of the insulating member 24 on the performance of the battery cell 20.

[0145] In some embodiments, such as Figure 7 As shown, in the direction perpendicular to the first side 2222, the size A5 of the second edge portion 404 can also be greater than or equal to 2mm.

[0146] Figure 9 It shows Figures 5 to 7 A cross-sectional view of the electrode 221 in the battery cell 20 before bending. (See image) Figure 9 As shown, the distance A6 between the third insulator 243 and the second connection 204 is greater than or equal to 2 mm. The second connection 204 can refer to the connection between the first part 2031 and the second part 2032. The distance A6 between the third insulator 243 and the second connection 204 should ensure that the second part 2032 of the tab 221 is not fixed to the second insulator 242 after bending. Furthermore, it can also ensure that the second edge 404 of the connection 2212 is not fixed to the second insulator 242.

[0147] Figure 10 A schematic cross-sectional view of an insulating member 24 in an unfolded state, according to an embodiment of this application, is shown. Figure 11 A schematic cross-sectional view of another insulating member 24 in the unfolded state according to an embodiment of this application is shown.

[0148] like Figure 10 As shown, the first insulator 241 includes a first insulating layer 2411 and a first adhesive coating 2412, the third insulator 243 includes a third insulating layer 2431 and a third adhesive coating 2432, the first insulating layer 2411 is bonded to the main body 222 by the first adhesive coating 2412, the third insulating layer 2431 is bonded to the connecting portion 2212 by the third adhesive coating 2432, and the second insulator 242 includes a second insulating layer 2421, the surface of the second insulating layer 2421 facing the tab 221 is exposed.

[0149] It should be understood that the exposed surface of the second insulating layer 2421 facing the tab 221 means that no adhesive coating is provided on the side of the second insulating layer 2421 facing the tab 221.

[0150] In this embodiment, by exposing the surface of the second insulating layer 2421 facing the tab 221, at least a portion of the transition portion 2211 of the tab 221 is not fixed to the second insulator 242. This reduces the tensile force exerted on the tab 221 by the insulating member 24 during bending, thus lowering the risk of tab 221 breakage. Furthermore, it reduces the amount of adhesive coating material used, lowering costs.

[0151] like Figure 11 As shown, the first insulator 241 includes a first insulating layer 2411 and a first adhesive coating 2412; the second insulator 242 includes a second insulating layer 2421 and a second adhesive coating 2422; the third insulator 243 includes a third insulating layer 2431 and a third adhesive coating 2432; the second insulator 242 also includes a fourth insulating layer 2423, which is bonded to the second insulating layer 2421 through the second adhesive coating 2422, and the surface of the fourth insulating layer 2423 facing the tab 221 is exposed.

[0152] It should be understood that the exposed surface of the fourth insulating layer 2423 facing the tab 221 means that no adhesive coating is provided on the side of the fourth insulating layer 2423 facing the tab 221.

[0153] In this embodiment, by bonding the fourth insulating layer 2423 to the second adhesive coating 2422 and exposing its surface facing the tab 221, the portion of the tab 221 from the first connection 203 to the second connection 204 is not fixed to the second insulator 242. This reduces the tensile force exerted on the tab 221 by the insulating member 24 during bending, lowering the risk of tab 221 breakage. Furthermore, since the fourth insulating layer 2423 only needs to be bonded to at least a portion of the transition portion 2211 corresponding to the tab 221, the manufacturing complexity of the insulating member 24 is reduced.

[0154] The insulating layer in this embodiment may be made of at least one of PP, PE, PET, etc. The thickness of the insulating layer plus the adhesive coating can range from 0.001mm to 0.5mm; for example, the thickness of the first insulator 241... Figure 11 The thickness of the second insulator 242 (excluding the fourth insulating layer 2423) and the thickness of the third insulator 243 are both within the range of 0.001 mm to 0.5 mm.

[0155] In some embodiments, the third insulator 243 is spaced apart from the bend point 205, which can also be understood as the third adhesive coating 2432 being spaced apart from the bend point 205. In other embodiments, the first insulator 241 is spaced apart from the second connection 204, which can also be understood as the first adhesive coating 2412 being spaced apart from the second connection 204. In other embodiments, the first insulator 241 is spaced apart from the first connection 203, which can also be understood as the first adhesive coating 2412 being spaced apart from the first connection 203.

[0156] In some embodiments, the first insulator 241 and the third insulator 243 are different colors. For example, the first insulator 241 is yellow and the third insulator 243 is blue. Further, the different colors of the first insulator 241 and the third insulator 243 can be achieved by the first adhesive coating 2412 and the third adhesive coating 2432 having different colors.

[0157] In other embodiments, the first insulator 241 and the third insulator 243 are the same color. For example, both the first insulator 241 and the third insulator 243 are blue. Furthermore, the same color for the first insulator 241 and the third insulator 243 can be achieved by having the first adhesive coating 2412 and the third adhesive coating 2432 have the same color.

[0158] In some embodiments, the first insulating layer 2411 in the first insulator 241, the second insulating layer 2421 in the second insulator 242, and the third insulating layer 2431 in the third insulator 243 can be integrally formed. Therefore, the first insulator 241 fixed to the first end face 2221 and the first connection 203 can be spaced apart, or the first adhesive coating 2412 in the first insulator 241 can be spaced apart from the first connection 203. Similarly, the third insulator 243 and the second connection 204 can be spaced apart, or the third adhesive coating 2432 in the third insulator 243 can be spaced apart from the second connection 204.

[0159] In other embodiments, at least one of the first insulator 241, the second insulator 242, and the third insulator 243 is formed independently.

[0160] In other embodiments, the first insulator 241 can also be fixed to the main body 222 by heat fusion, and the third insulator 243 can also be fixed to the connecting part 2212 by heat fusion.

[0161] like Figure 3 As shown, the electrode lead-out portion 201 may include an electrode terminal 214, which is welded to the connection portion 2212; or, as Figure 4As shown, the electrode lead-out portion 201 may include an electrode terminal 214 and a connecting member 23. The connecting portion 2212 is electrically connected to the electrode terminal 214 through the connecting member 23, and the connecting portion 2212 is welded to the connecting member 23.

[0162] In this embodiment, the electrode terminal 214 is directly welded to the connecting portion 2212 without the need for connection via the connecting member 23, which reduces costs while improving the space utilization of the battery cell 20. Connecting the connecting portion 2212 to the electrode terminal 214 via the connecting member 23 facilitates the connection between the tab 221 and the electrode terminal 214.

[0163] In some embodiments, the electrode lead-out portion 201 may be disposed on the first wall of the housing of the battery cell 20, and the tab 221 extends from the first end face 2221 of the electrode assembly 22, the first end face 2221 being disposed opposite to the first wall.

[0164] Optionally, the first wall can be any wall of the casing of the battery cell 20, for example, the electrode lead-out portion 201 is provided Figure 3 and Figure 4 On the cover plate 212 in the middle.

[0165] In this embodiment, by providing the electrode lead-out portion 201 on the first wall opposite to the first end face 2221, the space occupied by the electrode tab 221 can be greatly saved.

[0166] In some embodiments, the battery cell 20 may include a plurality of electrode assemblies 22, for example, two adjacent electrode assemblies 22 that may share an electrode lead 201. Each electrode assembly 22 may also be provided with an insulating member 24 as described in the various embodiments above.

[0167] See you again Figures 3 to 11This application provides a battery cell 20, including an electrode lead-out portion 201 for drawing out electrical energy from the battery cell 20; an electrode assembly 22, including a body 222 and a tab 221 extending from a first end face 2221 of the body 222, the tab 221 including a transition portion 2211 and a connecting portion 2212, the transition portion 2211 connecting between the body 222 and the connecting portion 2212, the connecting portion 2212 being bent relative to the transition portion 2211, the connecting portion 2212 being used to weld to the electrode lead-out portion 201 and form a fusion region 202; an insulating member 24, disposed on the inner side of the bent tab 221, the insulating member 24 including a first insulator 241 fixed to the body 222 and a third insulator 243 fixed to the connecting portion 2212, the insulating member 24 also including a first insulator 241 fixed to the body 222 and a third insulator 243 fixed to the connecting portion 2212, the insulating member 24 further including a first insulator 241 fixed to the body 222 and a third insulator 243 fixed to the connecting portion 2212, the third insulator 243 being connected to the first insulator 2211 and the connecting portion 2212; and the electrode assembly 22 includes a first insulator 241 fixed to the body 222 and a third insulator 243 fixed to the connecting portion 2212. Between insulator 241 and third insulator 243, the entire transition portion 2211 is not fixed to the second insulator 242, and the second edge portion 404 of the connecting portion 2212 connected to the transition portion 2211 is not fixed to the second insulator 242. The third insulator 243 covers and extends beyond the fusion area 202, and the distance from the third insulator 243 to the first connection point 203 is greater than 2 mm. The first connection point 203 is the connection point between the inner surface 405 of the tab 221 and the first end face 2221. In the first direction X, the size A4 of the first insulator 241 fixed to the first side surface 2222 of the main body 222 is smaller than the size L of the coating thinning area of ​​the electrode in the electrode assembly 22. The first side surface 2222 is disposed with respect to the first end face 2221, and the first direction X is perpendicular to the first end face 2221.

[0168] In this embodiment, by not fixing the entire transition portion 2211 to the second insulator 242, and by not fixing the second edge portion 404 of the connecting portion 2212 connected to the transition portion 2211 to the second insulator 242, and by ensuring that the distance from the third insulator 243 to the first connection point 203 is greater than or equal to 2 mm, the problem of the tab 221 tearing due to the adhesive force between the insulating member 24 and the tab 221 when the tab 221 is bent can be solved. Furthermore, by setting the third insulator 243 to cover and extend beyond the welding area 202, the probability of a short circuit in the battery cell 20 caused by the escape of metal debris from the welding area 202 can be reduced.

[0169] This application also provides a battery, which includes the battery cell 20 of this application embodiment.

[0170] This application also provides an electrical device, including the battery described in the above embodiment, which is used to provide electrical energy to the electrical device.

[0171] Electrical devices can be such as Figure 1 The vehicle shown can also be any device that uses batteries.

[0172] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, include: Electrode leads are used to extract electrical energy from the battery cells; An electrode assembly includes a body and a tab, the tab including a transition portion and a connecting portion, the connecting portion being bent relative to the transition portion, the transition portion connecting between the body and the connecting portion, and the connecting portion being used to connect to the electrode lead-out portion; An insulating member is disposed on the inner side of the bent tab. The insulating member includes a first insulator fixed to the main body and a third insulator fixed to the connecting portion. The insulating member also includes a second insulator connected between the first insulator and the third insulator. At least a portion of the transition portion is not fixed to the insulating member. The first insulator includes a first insulating layer and a first adhesive coating, and the third insulator includes a third insulating layer and a third adhesive coating. The first insulating layer is bonded to the main body through the first adhesive coating, and the third insulating layer is bonded to the connecting portion through the third adhesive coating. The second insulator includes a second insulating layer, the surface of the second insulating layer facing the tab is exposed, and the first insulating layer, the second insulating layer and the third insulating layer are integrally formed.

2. The battery cell according to claim 1, characterized in that, At least a portion of the transition section is not fixed to the second insulator.

3. The battery cell according to claim 2, characterized in that, The transition portion includes a first part and a second part. The first part is connected to the main body, and the second part is connected between the connecting portion and the first part. The inner surface of the second part is bent relative to the inner surface of the first part, and the second part is not fixed to the second insulator.

4. The battery cell according to claim 3, characterized in that, The first edge portion of the first part connected to the second part is not fixed to the second insulator, and / or the second edge portion of the connecting part connected to the second part is not fixed to the second insulator.

5. The battery cell according to claim 2, characterized in that, All of the aforementioned transition portions are not fixed to the second insulator.

6. The battery cell according to claim 1, characterized in that, The connecting portion is welded to the electrode lead-out portion to form a fusion region, the fusion region being exposed on the side of the connecting portion closer to the main body, and the third insulator covering the fusion region.

7. The battery cell according to claim 6, characterized in that, The third insulator extends beyond the welded area.

8. The battery cell according to claim 1, characterized in that, The electrode extends from the first end face of the main body, and the first insulator and the first connection are spaced apart. The first connection is the connection between the inner surface of the electrode and the first end face.

9. The battery cell according to claim 8, characterized in that, The distance between the first insulator and the first connection is greater than or equal to 2 mm.

10. The battery cell according to claim 1, characterized in that, In a first direction, the size of the first insulator fixed to the first side of the main body is smaller than the size of the coating thinning area of ​​the electrode in the electrode assembly. The first side is perpendicular to the first end face, and the first direction is perpendicular to the first end face. The first end face is the end face of the main body that is connected to the tab.

11. The battery cell according to claim 1, characterized in that, The second insulator further includes a second adhesive coating and a fourth insulating layer, the fourth insulating layer being bonded to the second insulating layer via the second adhesive coating, and the surface of the fourth insulating layer facing the tab being exposed.

12. The battery cell according to claim 1, characterized in that, The electrode lead-out portion includes electrode terminals, which are welded to the connecting portion; or... The electrode lead-out portion includes an electrode terminal and a connecting member. The connecting portion is electrically connected to the electrode terminal through the connecting member, and the connecting portion is welded to the connecting member.

13. The battery cell according to any one of claims 1 to 12, characterized in that, The electrode lead-out portion is disposed on the first wall of the outer casing of the battery cell, and the electrode tab extends from the first end face of the electrode assembly, the first end face being disposed opposite to the first wall.

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

15. An electrical appliance, characterized in that, Includes the battery as described in claim 14, the battery being used to provide electrical energy to the electrical device.

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