Battery monomer, battery and electric device

Abstract

The utility model provides a battery monomer, a battery and a power utilization device, the battery monomer comprises a shell and an electrode assembly accommodated in the shell, and the electrode assembly comprises a first pole piece and a second pole piece which are opposite in polarity; the first pole piece comprises a first current collecting main body and a first active material layer arranged on the surface of the first current collecting main body, the first active material layer comprises a main body region and a thinning region, the thickness of at least part of the thinning region is smaller than that of the main body region, and the thinning region is located on one side of the main body region in the first direction; the first direction is perpendicular to the thickness direction of the first current collecting main body; the electrode assembly further comprises an insulating part, at least part of the insulating part is arranged between the first pole piece and the second pole piece, and the insulating part is connected to the surface, away from the first current collecting body, of the thinning area and points to the direction of the first active substance layer along the first current collecting body. And the surface, deviating from the first current collecting main body, of the insulating part does not exceed the surface, deviating from the first current collecting main body, of the main body region.

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] Battery cells are widely used in electronic devices, such as mobile phones, laptops, electric vehicles, electric cars, electric ships, electric toy cars, electric toy ships, electric toy planes and electric tools, etc. In the development of battery technology, how to improve the reliability of battery cells is a research direction in battery technology. Utility Model Content

[0003] In view of the above problems, the present application provides a battery cell, a battery and an electrical device, which can improve reliability.

[0004] In the first aspect, the present application provides a battery cell, comprising a housing and an electrode assembly contained in the housing, wherein the electrode assembly comprises a first electrode piece and a second electrode piece of opposite polarity; the first electrode piece comprises a first current collector and a first active material layer disposed on the surface of the first current collector, the first active material layer comprises a main body region and a thinning region, the thickness of at least a portion of the thinning region is less than the thickness of the main body region, and the thinning region is located on one side of the main body region along a first direction. The electrode assembly further comprises an insulating member, at least a portion of the insulating member is disposed between the first electrode piece and the second electrode piece, and is disposed on one side of the first active material layer along the first direction; the insulating member comprises a first insulating portion, the first insulating portion is connected to the surface of the thinning region away from the first current collector, and along the direction of the first current collector pointing to the first active material layer, the first insulating portion does not exceed the surface of the main body region away from the first current collector.

[0005] In the above scheme, the insulating member is at least partially disposed between the first pole piece and the second pole piece, which can prevent the metal burr from conducting the first pole piece and the second pole piece, and reduce the possibility of thermal runaway caused by short circuit. The provision of the first insulating portion can increase the connection strength between the insulating member and the first pole piece, while reducing the possibility of increasing the overall thickness of the electrode assembly, reducing the thickness difference between the middle area and the end area of ​​the electrode assembly, reducing the risk of winding misalignment caused by inconsistent tension at both ends of the electrode assembly along the first direction during winding, and improving the reliability of the battery cell.

[0006] In some embodiments, the insulating member includes a first insulating portion, the first insulating portion includes a first part and a second part, the second part is located at an end of the first part close to the main region, and the thickness of the second part is less than the thickness of the first part.

[0007] In the above scheme, it is beneficial to increase the process error of the insulating part, reduce the possibility that the first insulating part protrudes out of the main area due to its own excessive thickness and the influence of process error, and thus reduce the thickness difference between the middle area and the end area of ​​the electrode assembly.

[0008] In some embodiments, the thickness of the thinned region gradually decreases in a direction from the main region to the thinned region.

[0009] In the above scheme, the above arrangement is helpful to reduce the difficulty of manufacturing the thinning area, reduce the manufacturing accuracy of the thinning area, and improve the production efficiency.

[0010] In some embodiments, the insulating member includes a first insulating portion connected to a surface of the thinning region away from the first current collecting body, and a thickness of the first insulating portion gradually increases in a direction from the main region to the thinning region.

[0011] In the above scheme, the above arrangement is helpful to increase the process error of the insulating component and reduce the possibility that the insulating component increases the overall thickness of the first pole piece.

[0012] In some embodiments, the insulating member includes a first insulating portion and a second insulating portion, the first insulating portion is connected to the surface of the thinned region away from the first current collector. The first current collector includes a coated region and an uncoated region arranged along a first direction, and the second insulating portion is arranged in the uncoated region.

[0013] In the above scheme, the above arrangement is helpful to increase the blocking area of ​​the insulating member to the first pole piece, and further reduce the possibility of metal burrs conducting the first pole piece and the second pole piece.

[0014] In some embodiments, one end of the first current collecting body along the first direction has a first end surface, and the second insulating portion extends from one end of the first insulating portion along the first direction and covers the first end surface.

[0015] In the above scheme, through the above arrangement, the connection area between the insulating member and the first pole piece is further increased, the connection strength between the insulating member and the first pole piece is improved, and the possibility of the burrs on the first end face of the first current collector conducting the first pole piece and the second pole piece is reduced.

[0016] In some embodiments, the surface of the thinned area on one side away from the main area along the first direction is the second end face, the first end face and the second end face are arranged flush, and the second insulating portion covers the first end face and the second end face. The embodiment of the present application can reduce the difference in size between the first current collector and the first active material layer along the first direction, reduce the waste of the first current collector, improve the energy density, increase the connection area between the second insulating portion and the first pole piece, reduce the risk of the insulating member falling off from the first pole piece, and improve reliability.

[0017] In some embodiments, the uncoated area includes a hollow foil area and a first pole lug, the first pole lug is arranged to protrude from the hollow foil area, and a portion of the insulating member is arranged on the surface of the first pole lug.

[0018] In the above scheme, by setting up the empty foil area, the connection area between the insulating member and the first pole piece is increased, the connection difficulty between the insulating member and the first pole piece is improved, the risk of the first pole piece cutting the first active material layer during the cutting process is reduced, and the waste of active materials is reduced. By setting up part of the insulating member on the surface of the first pole ear, the possibility of the burr formed on the edge of the first pole ear after cutting to conduct the first pole piece and the second pole piece is reduced, and the reliability of the battery cell is further improved.

[0019] In some embodiments, the second insulating portion completely covers the uncoated area to reduce the possibility of conduction between the uncoated area and the second pole piece, reduce the risk of short circuit, and improve reliability.

[0020] In some embodiments, a minimum thickness of the second insulating portion is greater than a minimum thickness of the first insulating portion.

[0021] In the above scheme, through the above arrangement, the difficulty of manufacturing the insulating component can be reduced, the manufacturing cost of the insulating component can be reduced, the tensile strength of the insulating component can be increased, and the risk of the insulating component falling off can be reduced.

[0022] In some embodiments, first active material layers are disposed on both side surfaces of the first current collecting body, insulating members are disposed on both sides of the first current collecting body, and the two insulating members are connected.

[0023] In the above solution, by providing two insulating members and connecting the second insulating parts of the two insulating members, the connection area between the insulating member and the first pole piece can be increased, and the risk of the insulating member falling off can be reduced. The second insulating part can separate the burr on the first end face from the second pole piece, thereby reducing the risk of short circuit.

[0024] In some embodiments, the porosity of the insulating member is 30%-40%. The insulating member has a higher porosity to reduce the resistance of ions passing through the insulating member.

[0025] In some embodiments, the battery cell further includes a separator, which is used to separate the first pole piece from the second pole piece. In the first direction, the insulating member does not extend beyond the separator, thereby reducing the extra space occupied by the insulating member in the first direction.

[0026] In a second aspect, an embodiment of the present application provides a battery, comprising a battery cell in any of the aforementioned embodiments.

[0027] In a third aspect, an embodiment of the present application provides an electrical device, comprising a battery in any of the aforementioned embodiments, and the battery is used to provide electrical energy.

[0028] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application;

[0031] Figure 2 An exploded schematic diagram of a battery provided in some embodiments of the present application;

[0032] Figure 3 An exploded schematic diagram of a battery cell provided in some embodiments of the present application;

[0033] Figure 4 A schematic top view of an electrode assembly provided in some embodiments of the present application;

[0034] Figure 5 for Figure 4 A schematic partial cross-sectional view taken along the AA direction;

[0035] Figure 6 for Figure 5 An enlarged structural diagram of the middle box P;

[0036] Figure 7 A schematic diagram of a first pole piece and an insulating member of an electrode assembly provided in some embodiments of the present application after being connected and in a flattened state;

[0037] Figure 8 for Figure 7 A partial cross-sectional schematic diagram taken along the BB direction;

[0038] Fig. 9 for Figure 7 Another partial cross-sectional schematic diagram taken along direction BB.

[0039] Marking Description

[0040] 1. Vehicle; 2. Battery; 3. Controller; 4. Motor; 5. Box; 5a. First box part; 5b. Second box part; 5c. Accommodation space; 6. Battery cell;

[0041] 100. electrode assembly; 200. housing;

[0042] 10, first pole piece; 11, first current collecting body; 111, first end face; 112, coating area; 113, uncoated area; 113a, first pole ear; 113b, empty foil area; 12, first active material layer; 121, main body area; 122, thinning area; 122a, second end face;

[0043] 20. Second pole piece;

[0044] 30, insulating member; 31, first insulating portion; 311, first portion; 312, second portion; 32, second insulating portion;

[0045] 40. Isolation parts;

[0046] X, thickness direction; Y, first direction; V, winding direction. DETAILED DESCRIPTION

[0047] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein 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 figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0049] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0050] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations 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. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0051] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may 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 article generally indicates that the associated objects before and after are in an "or" relationship.

[0052] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0053] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0054] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0055] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0056] The battery cell can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead storage battery, etc., which is not limited in the embodiments of the present application.

[0057] A battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are embedded and 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 and negative electrodes from short-circuiting, while allowing active ions to pass through.

[0058] In some embodiments, the positive electrode may be a positive electrode sheet, and the positive electrode sheet may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0059] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is disposed on either or both of the two facing surfaces of the positive electrode current collector.

[0060] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium with silver surface treatment may be used. The composite current collector may include a polymer material base and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0061] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0062] As an example, the negative electrode current collector can be a metal foil, a foamed metal, a foamed carbon or a composite current collector. For example, as a metal foil, a silver surface treated stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium can be used. The foamed metal can be a foamed nickel, a foamed copper, a foamed aluminum or a foamed alloy. The composite current collector may include a polymer material base and a metal layer. The composite current collector may 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 polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0063] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0064] As an example, the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode active material is disposed on either or both of the two facing surfaces of the negative electrode current collector.

[0065] As an example, the negative electrode active material may adopt the negative electrode active material for battery cells known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc.

[0066] In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0067] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0068] In some embodiments, the separator is a separator. The present application has no particular limitation on the type of separator, and any known separator with a porous structure having good chemical stability and mechanical stability can be selected.

[0069] As an example, the main material of the isolation membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramics.

[0070] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transmit ions and isolate the positive and negative electrodes.

[0071] In some embodiments, the battery cell further includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The present application has no specific restrictions on the type of electrolyte, which can be selected according to needs. The electrolyte can be liquid, gel or solid.

[0072] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into the wound structure.

[0073] In some embodiments, the electrode assembly is a laminate structure.

[0074] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0075] In some embodiments, the electrode assembly is provided with tabs, which can lead current out of the electrode assembly. The tabs include a positive tab and a negative tab.

[0076] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing may be a steel housing, an aluminum housing, a plastic housing (such as polypropylene), a composite metal housing (such as a copper-aluminum composite housing), or an aluminum-plastic film.

[0077] In some embodiments, the housing may be provided with functional components such as electrode terminals, etc. The electrode terminals may be used to electrically connect to the electrode assembly to output or input electrical energy of the battery cell.

[0078] In some embodiments, a current collecting member may be disposed in the housing, and the electrode assembly may be electrically connected to the housing or an electrode terminal disposed on the housing through the current collecting member.

[0079] As an example, the battery cell may be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. The prismatic battery cell includes a square-shell battery cell, a blade-shaped battery cell, a polygonal battery, such as a hexagonal battery.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] In some embodiments, the battery may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.

[0085] A battery cell generally includes an electrode assembly and a housing, and the electrode assembly is contained in the housing. The electrode assembly includes a positive electrode and a negative electrode. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are embedded and removed back and forth between the positive electrode and the negative electrode. In some embodiments, the electrode assembly also includes a separator, which is arranged between the positive electrode and the negative electrode to prevent the positive and negative electrodes from short-circuiting and allow active ions to pass through.

[0086] The shell is used to encapsulate the electrode assembly and electrolyte and other components. The shell can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell) or an aluminum-plastic film.

[0087] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material layer disposed on at least one surface of the positive electrode current collector. The negative electrode may be a negative electrode sheet, which may include a negative electrode current collector and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector.

[0088] In the process of preparing the electrode sheet (positive electrode sheet or negative electrode sheet), it is usually necessary to cut (such as the die-cutting process of the electrode ear) to form the required size and shape. However, after cutting, the current collector is prone to burrs at the cutting position; and in the process of preparing the electrode assembly formed by the electrode sheet, the electrode ear or the metal wire generated by the outside during the cutting process is easy to fall between the electrode sheets. The burrs and metal wires will connect the positive and negative electrodes during the charging and discharging process of the battery cell, causing the risk of short circuit and affecting the reliability of the battery cell.

[0089] Based on the above technical problems, the present application provides a technical solution, which arranges an insulating part on the pole piece to prevent burrs or metal wires from overlapping pole pieces with opposite polarities, thereby reducing the risk of burrs turning on pole pieces with opposite polarities and improving the reliability of battery cells.

[0090] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical devices using batteries, such as mobile phones, portable devices, laptop computers, electric vehicles, electric cars, ships, spacecraft, electric toys and electric tools, etc., wherein spacecrafts 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., and electric tools include metal cutting power tools, grinding power tools, assembly power tools and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators and electric planers.

[0091] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0092] Figure 1 A schematic diagram of the structure of a vehicle provided for some embodiments of the present application.

[0093] like Figure 1 As shown, a battery 2 is disposed inside the vehicle 1, and the battery 2 may be disposed at the bottom, head, or tail of the vehicle 1. The battery 2 may be used to power the vehicle 1, for example, the battery 2 may be used as an operating power source for the vehicle 1.

[0094] The vehicle 1 may further include a controller 3 and a motor 4 , wherein the controller 3 is used to control the battery 2 to supply power to the motor 4 , for example, to meet the power requirements of starting, navigating, and driving the vehicle 1 .

[0095] In some embodiments of the present application, the battery 2 can not only serve as an operating power source for the vehicle 1, but also serve as a driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0096] Figure 2Schematic diagram of an explosion of a battery provided in some embodiments of the present application. Figure 2 As shown, the battery 2 includes a box body 5 and a battery cell 6 , and the battery cell 6 is accommodated in the box body 5 .

[0097] The box 5 is used to accommodate the battery cell 6, and the box 5 can be of various structures. In some embodiments, the box 5 can include a first box portion 5a and a second box portion 5b, the first box portion 5a and the second box portion 5b cover each other, and the first box portion 5a and the second box portion 5b jointly define a storage space 5c for accommodating the battery cell. The second box portion 5b can be a hollow structure with one end open, the first box portion 5a is a plate-like structure, and the first box portion 5a covers the open side of the second box portion 5b to form a box 5 with a storage space 5c; the first box portion 5a and the second box portion 5b can also be hollow structures with one side open, and the open side of the first box portion 5a covers the open side of the second box portion 5b to form a box 5 with a storage space 5c. Of course, the first box portion 5a and the second box portion 5b can be of various shapes, such as a cylinder, a cuboid, etc.

[0098] In order to improve the sealing performance after the first box body part 5a and the second box body part 5b are connected, a sealing member, such as a sealant, a sealing ring, etc., may also be provided between the first box body part 5a and the second box body part 5b.

[0099] Assuming that the first box body portion 5a covers the top of the second box body portion 5b, the first box body portion 5a can also be called an upper box cover, and the second box body portion 5b can also be called a lower box.

[0100] In the battery 2, the battery cell 6 can be one or more. If there are more than one battery cell 6, the battery cells 6 can be connected in series, in parallel or in mixed connection. Mixed connection means that the battery cells 6 are both connected in series and in parallel. The battery cells 6 can be directly connected in series, in parallel or in mixed connection, and then the whole formed by the battery cells 6 is accommodated in the box 5; of course, the battery cells can also be connected in series, in parallel or in mixed connection to form a battery module, and then the battery modules are connected in series, in parallel or in mixed connection to form a whole, and then accommodated in the box 5.

[0101] Illustratively, a battery cell may be the smallest unit constituting a battery.

[0102] Figure 3 An exploded schematic diagram of a battery cell provided in some embodiments of the present application.

[0103] like Figure 3 As shown, in some embodiments, the battery cell 6 includes a housing 200 and an electrode assembly 100 accommodated in the housing 200 .

[0104] The electrode assembly 100 includes a positive electrode and a negative electrode. During the charge and discharge process of the battery cell 6, active ions (such as lithium ions) are inserted and removed back and forth between the positive electrode and the negative electrode. Optionally, the electrode assembly 100 also includes a separator 40 disposed between the positive electrode and the negative electrode, and the separator 40 can reduce the risk of short circuit between the positive and negative electrodes, while allowing active ions to pass through.

[0105] The housing 200 is used to encapsulate the electrode assembly 100 and the electrolyte and other components. The housing 200 can be a steel housing, an aluminum housing, a plastic housing (such as polypropylene), a composite metal housing (such as a copper-aluminum composite housing 200), or an aluminum-plastic film.

[0106] Figure 4 A schematic top view of an electrode assembly provided in some embodiments of the present application. Figure 5 for Figure 4 Schematic diagram of the local section taken along the AA direction. Figure 6 for Figure 5 Schematic diagram of the enlarged structure of the box P. Figure 7 A schematic diagram of the electrode assembly provided in some embodiments of the present application in a flattened state after the first pole piece and the insulating member are connected. Figure 8 for Figure 7 A schematic partial cross-sectional view taken along the BB direction. Fig. 9 for Figure 7 Another partial cross-sectional schematic diagram taken along direction BB.

[0107] Reference Figure 4 and Figure 5 The electrode assembly 100 of the embodiment of the present application includes a first pole piece 10 and a second pole piece 20 with opposite polarities.

[0108] Exemplarily, one of the first pole piece 10 and the second pole piece 20 is a positive pole piece, and the other is a negative pole piece.

[0109] In some embodiments, the positive electrode sheet may include a positive electrode current collector and a positive electrode active material layer disposed on at least one surface of the positive electrode current collector.

[0110] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material layer is disposed on any one or both of the two facing surfaces of the positive electrode current collector.

[0111] As an example, the positive electrode current collector may be carbon, metal foil or composite current collector. For example, as the metal foil, stainless steel, copper, aluminum, nickel, carbon electrode, nickel, titanium, silver surface treated aluminum or stainless steel, etc. may be used. The composite current collector may include a polymer material base and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0112] As an example, the positive electrode active material layer includes a positive electrode active material, and the positive electrode active material may include at least one of the following materials: a lithium-containing phosphate, a lithium transition metal oxide, and their respective modified compounds. The positive electrode active material may also use other traditional materials that can be used as a positive electrode active material layer of a battery. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium-containing phosphates may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon. Examples of lithium transition metal oxides may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3Mn 1 / 3 O2 (also referred to as NCM 333 )、LiNi 0.5 Co 0.2 Mn 0.3 O2 (also referred to as NCM523), LiNi 0.5 Co 0.25 Mn 0.25 O2 (also referred to as NCM211), LiNi 0.6 Co 0.2 Mn 0.2 O2 (also referred to as NCM622), LiNi 0.8 Co 0.1 Mn 0.1 O2 (also referred to as NCM811), lithium nickel cobalt aluminum oxide (such as LiNi 0.80 Co 0.15 Al 0.05 O2) and its modified compounds, etc.

[0113] In some embodiments, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector.

[0114] As an example, the negative electrode current collector can be a metal foil, a foamed metal or a composite current collector. For example, as a metal foil, aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrode, nickel or titanium with a silver surface treatment can be used. The foamed metal can be a nickel foam, a copper foam, an aluminum foam, an alloy foam, or a carbon foam. The composite current collector can include a polymer material base and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0115] As an example, the negative electrode active material layer includes a negative electrode active material. The negative electrode active material may adopt a negative electrode active material for a battery cell that is well known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc. The silicon-based material may include at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may include at least one of elemental tin, tin oxide compounds, and tin alloys. The negative electrode active material of the present application may also use other traditional materials that can be used as negative electrode active materials for batteries. These negative electrode active materials may be used alone or in combination of two or more.

[0116] In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0117] In some embodiments, the electrode assembly 100 is a wound structure. Exemplarily, the first pole piece 10 and the second pole piece 20 are both strip-shaped structures, and the first pole piece 10, the separator 40 and the second pole piece 20 are wound into a wound structure.

[0118] In some embodiments, the electrode assembly 100 is a laminate structure.

[0119] As an example, a plurality of the first pole pieces 10 and a plurality of the second pole pieces 20 may be provided respectively, and the plurality of first pole pieces 10 and the plurality of second pole pieces 20 may be alternately stacked.

[0120] As an example, a plurality of first pole sheets 10 may be provided, and the second pole sheet 20 may be folded to form a plurality of stacked folded segments, with one first pole sheet 10 being sandwiched between adjacent folded segments.

[0121] As an example, the first pole piece 10 and the second pole piece 20 are both folded to form a plurality of stacked folded segments.

[0122] As an example, a plurality of spacers 40 may be provided, respectively disposed between any adjacent first pole pieces 10 or second pole pieces 20 .

[0123] As an example, the spacer 40 may be disposed continuously, and disposed between any adjacent first pole sheets 10 or second pole sheets 20 by folding or winding.

[0124] In some embodiments, the shape of the electrode assembly 100 can be cylindrical, flat, or polygonal.

[0125] Please refer to Figures 4 to 6 , an embodiment of the present application provides an electrode assembly 100, which includes a first pole piece 10 and a second pole piece 20 with opposite polarities.

[0126] The first electrode sheet 10 includes a first current collecting body 11 and a first active material layer 12 disposed on a surface of the first current collecting body 11 .

[0127] Exemplarily, the first current collector 11 includes two first surfaces arranged opposite to each other along its thickness direction X, and the first active material layer 12 may be arranged on one first surface, or on both first surfaces. The first active material layer 12 may be arranged on the first surface as a whole. Alternatively, a portion of the first active material layer 12 may also be arranged at other locations. For example, the first pole piece 10 further includes a first pole ear 113a connected to the first current collector 11, and a portion of the first active material layer 12 may be arranged at the root of the first pole ear 113a close to the first current collector 11.

[0128] In some examples, the first electrode 10 is a positive electrode, and the second electrode 20 is a negative electrode. In other examples, the first electrode 10 is a negative electrode, and the second electrode 20 is a positive electrode.

[0129] In some embodiments, see Figure 5 The first active material layer 12 includes a main body region 121 and a thinning region 122, wherein the thinning region 122 is located on one side of the main body region 121 along the first direction Y, and the thickness of at least part of the thinning region 122 is less than the thickness of the main body region 121. The first direction Y is perpendicular to the thickness direction X of the first current collecting body 11.

[0130] Exemplarily, one end of the thinned region 122 close to the main region 121 is directly connected to the main region 121. In some examples, the thickness of the end of the thinned region 122 close to the main region 121 is less than the thickness of the end of the main region 121 close to the thinned region 122, and a step is formed at the connection between the thinned region 122 and the main region 121. In other examples, the thickness of the end of the thinned region 122 close to the main region 121 is equal to the thickness of the end of the main region 121 close to the thinned region 122.

[0131] Exemplarily, the main body region 121 is substantially a structure of equal thickness. The average thickness of the thinned region 122 is less than the thickness of the main body region 121 .

[0132] In some embodiments, see Figure 5 The electrode assembly 100 further includes an insulating member 30. In the thickness direction X, at least a portion of the insulating member 30 is disposed between the first electrode sheet 10 and the second electrode sheet 20. The insulating member 30 is disposed on one side of the first active material layer 12 along the first direction Y.

[0133] Exemplarily, in the thickness direction X of the first current collecting body 11 , at least a portion of the first end surface 111 overlaps with the insulating member 30 . In the first direction Y, two ends of the insulating member 30 are located on both sides of the first end surface 111 , respectively.

[0134] The number of the insulating member 30 may be one or more.

[0135] In some embodiments, see Figure 5 and Figure 6 The insulating member 30 is connected to the surface of the thinning area 122 away from the first current collecting body 11, and along the direction from the first current collecting body 11 to the first active material layer 12, the surface of the insulating member 30 away from the first current collecting body 11 does not exceed the surface of the main area 121 away from the first current collecting body 11.

[0136] In some examples, the insulating member 30 is connected to the entire surface of the thinned region 122 away from the first current collecting body 11 . In other examples, the insulating member 30 is connected to a portion of the surface of the thinned region 122 away from the first current collecting body 11 .

[0137] Exemplarily, the distance between the surface of the insulating member 30 facing away from the first current collector 11 and the first current collector 11 is less than or equal to the distance between the surface of the main region 121 facing away from the first current collector 11 and the first current collector 11. In some examples, at least a portion of the surface of the insulating member 30 facing away from the first current collector 11 is flush with the surface of the main region 121 facing away from the first current collector. In other examples, along the direction from the first current collector 11 to the first active material layer 12, the surface of the main region 121 facing away from the first current collector protrudes from the surface of the insulating member 30 facing away from the first current collector 11.

[0138] In the electrode assembly 100 provided in the embodiment of the present application, the insulating member 30 is at least partially disposed between the first pole piece 10 and the second pole piece 20, which can prevent metal burrs from conducting the first pole piece 10 and the second pole piece 20, and reduce the possibility of thermal runaway caused by short circuit. This is beneficial for increasing the connection strength between the insulating member 30 and the first pole piece 10, while reducing the possibility of increasing the overall thickness of the electrode assembly 100, reducing the thickness difference between the middle area and the end area of ​​the electrode assembly 100, reducing the risk of winding misalignment caused by inconsistent tension at both ends of the electrode assembly 100 along the first direction Y during winding, and improving the reliability of the battery cell 6.

[0139] In some optional embodiments, see Figure 5 and Figure 6 The insulating member 30 includes a first insulating portion 31 , the first insulating portion 31 includes a first portion 311 and a second portion 312 , the second portion 312 is located at one end of the first portion 311 close to the main area 121 , and the thickness of the second portion 312 is less than the thickness of the first portion 311 .

[0140] Exemplarily, the first insulating portion 31 includes a first end, a second end, and an intermediate section between the first end and the second end, the second portion 312 is the first end, the first portion 311 is the second end and the intermediate section, the first end is an end of the first insulating portion 31 close to the main body region 121, and the second end is an end of the first insulating portion 31 away from the main body region 121. In some examples, the thickness of the first end is less than the thickness of the second end, and the thickness of the first end is less than the thickness of the intermediate section. In other examples, the thickness of the first end is only less than the thickness of the second end. In other examples, the thickness of the first end is less than the thickness of the intermediate section.

[0141] The above arrangement is helpful to increase the process error of the insulating member 30, reduce the possibility that the first insulating portion 31 is too thick and protrudes out of the main area 121 due to the influence of the process error, and thus reduce the thickness difference between the middle area and the end area of ​​the electrode assembly 100.

[0142] In some optional embodiments, see Figure 5 and Figure 6 , in the direction from the main area 121 to the thinning area 122, the thickness of the thinning area 122 gradually decreases.

[0143] Exemplarily, the thickness of one end of the thinned region 122 close to the main region 121 may be equal to the thickness of the main region 121 , and the thickness of one end of the thinned region 122 away from the main region 121 may be a predetermined value or zero.

[0144] In these optional embodiments, the above-mentioned configuration is helpful to reduce the difficulty of manufacturing the thinning area 122, reduce the manufacturing accuracy of the thinning area 122, and improve the production efficiency.

[0145] In some optional embodiments, see Figure 5 and Figure 6 The insulating member 30 includes a first insulating portion 31 , which is connected to a surface of the thinning region 122 away from the first current collecting body 11 , and the thickness of the first insulating portion 31 gradually increases in a direction from the main region 121 to the thinning region 122 .

[0146] Exemplarily, the thickness of the first insulating portion 31 may increase gradually in a stepwise manner or may increase smoothly.

[0147] In these optional embodiments, the above configuration is helpful to increase the process error of the insulating member 30 and reduce the possibility that the insulating member 30 increases the overall thickness of the first pole piece 10 .

[0148] In some other examples, the first insulating portion 31 includes two parts, the thickness of one part of the first insulating portion 31 gradually increases along the direction from the main region 121 to the thinning region 122, and the thickness of the other part of the first insulating portion 31 is uniform. Optionally, the first insulating portion 31 with gradually increasing thickness is located on one side of the other part of the first insulating portion 31 close to the main region 121.

[0149] In some optional embodiments, see Figures 5 to 8 The insulating member 30 includes a first insulating portion 31 and a second insulating portion 32. The first insulating portion 31 is connected to the surface of the thinned area 122 away from the first current collector 11. The first current collector 11 includes a coated area 112 and an uncoated area 113 arranged along the first direction Y. The second insulating portion 32 is arranged in the uncoated area 113.

[0150] The first current collector 11 includes a coating area 112 and an uncoated area 113. In other words, the surface of the coating area 112 is coated with the first active material layer 12, and the surface of the uncoated area 113 is not coated with the first active material layer 12. The first insulating portion 31 is connected to the surface of the thinned area 122 away from the first current collector 11. In some examples, at least part of the first insulating portion 31 is projected onto the first current collector 11 within the coating area 112.

[0151] Optionally, the first insulating portion 31 and the second insulating portion 32 may be an integral structure, and the first insulating portion 31 extends from the coated area 112 to the uncoated area 113 and is connected to the second insulating portion 32 .

[0152] Optionally, the first insulating portion 31 and the second insulating portion 32 may be separate structures, and the first insulating portion 31 may be connected to the second insulating portion 32 by bonding or the like.

[0153] In some examples, the second insulating portion 32 is disposed in the uncoated area 113 , and the second insulating portion 32 may cover the entire surface of the uncoated area 113 . In other examples, the second insulating portion 32 may cover a portion of the surface of the uncoated area 113 .

[0154] In these optional embodiments, the above configuration is helpful to increase the blocking area of ​​the insulating member 30 to the first pole piece 10 , and further reduce the possibility of metal burrs conducting the first pole piece 10 and the second pole piece 20 .

[0155] In some optional embodiments, see Figures 7 to 9 One end of the first current collecting body 11 along the first direction Y has a first end surface 111 , and the second insulating portion 32 extends from one end of the first insulating portion 31 along the first direction Y and covers the first end surface 111 .

[0156] Exemplarily, the first current collecting body 11 has a relatively small thickness, the first end surface 111 has a relatively small size in the thickness direction X of the first current collecting body 11 , and the first end surface 111 may be approximately a line.

[0157] Exemplarily, at least a portion of the first end surface 111 is formed during a cutting process of the first pole piece 10 .

[0158] Exemplarily, the first end surface 111 connects the two first surfaces.

[0159] In some examples, in the thickness direction X, the projection of the first insulating portion 31 is located within the projection of the first pole piece 10, and the projection of the second insulating portion 32 does not overlap with the projection of the first pole piece 10. In other examples, in the thickness direction X, the projection of the first insulating portion 31 is located within the projection of the first pole piece 10, a portion of the projection of the second insulating portion 32 overlaps with the projection of the first pole piece 10, and another portion of the projection of the second insulating portion 32 does not overlap with the projection of the first pole piece 10.

[0160] In these optional embodiments, through the above-mentioned configuration, the connection area between the insulating member 30 and the first pole piece 10 is further increased, the connection strength between the insulating member 30 and the first pole piece 10 is improved, and the possibility of the burrs on the first end surface 111 of the first current collector 11 conducting the first pole piece 10 and the second pole piece 20 is reduced.

[0161] In some optional embodiments, see Figure 7 and Figure 8, the surface of the thinning area 122 on one side away from the main area 121 along the first direction Y is the second end face 122a, the first end face 111 and the second end face 122a are arranged flush, and the second insulating portion 32 covers the first end face 111 and the second end face 122a. The embodiment of the present application can reduce the size difference between the first current collector 11 and the first active material layer 12 along the first direction Y, reduce the waste of the first current collector 11, improve the energy density, increase the connection area between the second insulating portion 32 and the first pole piece 10, reduce the risk of the insulating member 30 falling off from the first pole piece 10, and improve reliability.

[0162] In some optional embodiments, see Figures 5 to 7 The uncoated area 113 includes an empty foil area 113b and a first pole tab 113a. The first pole tab 113a is protruding from the empty foil area 113b, and a portion of the insulating member 30 is disposed on the surface of the first pole tab 113a.

[0163] For example, Figure 7 As shown, the first pole piece 10 can be a strip-shaped flat surface in a flattened state, the empty foil area 113b is located at one end of the coating area 112 along the first direction Y, and the extension length of the empty foil area 113b can be equal to the extension length of the first pole piece 10. The first pole tab 113a can be located on the side of the empty foil area 113b facing away from the coating area 112, and the number of the first pole tabs 113a can be multiple, and the multiple first pole tabs 113a are arranged at intervals along the extension direction of the first pole piece 10.

[0164] Optionally, the first pole tab 113a may include first walls arranged opposite to each other along the thickness direction X and a second wall located between the two first walls. In some examples, the insulating member 30 covers at least a portion of the first wall and at least a portion of the second wall. In other examples, the insulating member 30 covers at least a portion of the first wall. In other examples, the insulating member 30 covers at least a portion of the second wall.

[0165] Optionally, one end of the hollow foil area 113 b away from the coating area 112 forms a first end surface 111 , and the first electrode tab 113 a is disposed protruding from the first end surface 111 .

[0166] In these optional embodiments, by providing the empty foil area 113b, the connection area between the insulating member 30 and the first pole piece 10 is increased, the connection difficulty between the insulating member 30 and the first pole piece 10 is improved, the risk of the first pole piece 10 cutting the first active material layer 12 during the cutting process is reduced, and the waste of active materials is reduced. By providing part of the insulating member 30 on the surface of the first pole ear 113a, the possibility of the burrs formed on the edge of the first pole ear 113a after cutting to conduct the first pole piece 10 and the second pole piece 20 is reduced, and the reliability of the battery cell is further improved.

[0167] In some optional embodiments, see Figure 7 and Fig. 9 The second insulating portion 32 completely covers the uncoated area 113 to reduce the possibility of conduction between the uncoated area and the second pole piece 20, reduce the risk of short circuit, and improve reliability.

[0168] In some optional embodiments, see Figures 7 to 9 , the minimum thickness of the second insulating portion 32 is greater than the minimum thickness of the first insulating portion 31 .

[0169] It can be seen from the foregoing that the thickness of the first insulating part 31 tends to gradually increase in the direction from the main area 121 to the thinning area 122. The first insulating part 31 may include a maximum thickness and a minimum thickness. The minimum thickness of the second insulating part 32 may be the thickness of the uniform film layer of the second insulating part 32. Through the above arrangement, the difficulty of manufacturing the insulating part 30 can be reduced, the manufacturing cost of the insulating part 30 can be reduced, the tensile strength of the insulating part 30 can be increased, and the risk of the insulating part 30 falling off can be reduced.

[0170] In some optional embodiments, see Figures 7 to 9 The first active material layer 12 is disposed on both side surfaces of the first current collecting body 11 , and insulating members 30 are disposed on both sides of the first current collecting body 11 , and the two insulating members 30 are connected.

[0171] Exemplarily, the first active material layer 12 is provided on both sides of the first current collector 11, and an insulating member 30 is provided on both sides of the first current collector 11. The two insulating members 30 each include a first insulating portion 31 and a second insulating portion 32. The shapes of the two first insulating portions 31 may be the same or different. The projections of the two first insulating portions 31 along the thickness direction X may overlap or may be partially overlapped. At least parts of the two second insulating portions 32 are arranged in abutment with each other.

[0172] By providing two insulating members 30 and connecting the second insulating portions 32 of the two insulating members 30, the connection area between the insulating member 30 and the first pole piece 10 can be increased, and the risk of the insulating member 30 falling off can be reduced. The second insulating portion 32 can separate the burrs on the first end surface 111 from the second pole piece 20, thereby reducing the risk of short circuit.

[0173] In some optional embodiments, the porosity of the insulating member is 30%-40%. The insulating member has a higher porosity to reduce the resistance of ions passing through the insulating member.

[0174] Exemplarily, the porosity of the insulating member is 30%, 32%, 34%, 35%, 36%, 38% or 40%.

[0175] Optionally, it can be known from the foregoing that the insulating member may include a first insulating portion, and the porosity of the first insulating portion is 30%-40%.

[0176] In some embodiments, the porosity of the insulating member is less than that of the isolating member. Compared with the isolating member, the insulating member is less likely to shrink, thereby improving the insulation effect.

[0177] Exemplarily, the porosity of the insulating member has a well-known meaning in the art and can be measured using known methods. For example, the test can be performed with reference to standard GB / T36363-2018.

[0178] In some optional embodiments, see Figure 4 and Figure 5 The electrode assembly 100 further includes a separator 40, which is used to separate the first pole piece 10 from the second pole piece 20. In the first direction Y, the insulating member 30 does not exceed the separator 40, thereby reducing the extra space occupied by the insulating member 30 in the first direction Y.

[0179] The insulating member 30 can also support the spacer 40 from the inside, reducing the risk of the spacer being wrinkled or folded.

[0180] In some embodiments, the first pole piece 10 , the isolating member 40 and the second pole piece 20 are wound. In the winding direction V, both ends of the insulating member 30 do not extend beyond the isolating member 40 .

[0181] For example, Figure 4 As shown, the positive direction of the winding direction V is counterclockwise, and the negative direction of the winding direction V is clockwise. In the positive direction of the winding direction V, the insulating member 30 does not exceed the tail end of the isolating member 40; in the negative direction of the winding direction V, the insulating member 30 does not exceed the head end of the isolating member 40.

[0182] The isolation member can restrain the insulating member 30 , maintain the fit between the insulating member and the first pole piece 10 , and reduce the risk of the insulating member 30 falling off the first pole piece 10 .

[0183] According to some embodiments of the present application, the present application also provides a battery, comprising a plurality of battery cells according to any one of the above embodiments.

[0184] According to some embodiments of the present application, the present application further provides an electric device, comprising a battery cell of any of the above embodiments, the battery cell is used to provide electric energy for the electric device. The electric device can be any of the above equipment or systems using the battery cell.

[0185] According to some embodiments of the present application, please refer to Figures 4 to 9The battery cell 6 includes a shell 200 and an electrode assembly 100 accommodated in the shell 200, the electrode assembly 100 includes a first electrode sheet 10 and a second electrode sheet 20 with opposite polarities; the first electrode sheet 10 includes a first current collecting body 11 and a first active material layer 12 arranged on the surface of the first current collecting body 11, the first active material layer 12 includes a main area 121 and a thinning area 122, the thickness of at least part of the thinning area 122 is less than the thickness of the main area 121, and the thinning area 122 is located on one side of the main area 121 along the first direction Y. The electrode assembly 100 also includes an insulating member 30, at least a portion of which is arranged between the first electrode piece 10 and the second electrode piece 20, and is arranged on one side of the first active material layer 12 along the first direction Y; the insulating member 30 includes a first insulating portion 31, the first insulating portion 31 is connected to the surface of the thinning area 122 away from the first current collecting body 11, and along the direction of the first current collecting body 11 pointing to the first active material layer 12, the first insulating portion 31 does not exceed the surface of the main area 121 away from the first current collecting body 11.

[0186] The insulating member 30 includes a first insulating portion 31 and a second insulating portion 32, wherein the first insulating portion 31 is connected to the surface of the thinned area 122 away from the first current collector 11. The first current collector 11 includes a coated area 112 and an uncoated area arranged along the first direction Y, and the second insulating portion 32 is arranged in the uncoated area 113. The uncoated area 112 includes an empty foil area 113b and a first pole tab 113a, wherein the first pole tab 113a is arranged protruding from the empty foil area 113b, and a portion of the insulating member 30 is arranged on the surface of the first pole tab 113a.

[0187] In the direction from the main area 121 to the thinning area 122, the thickness of the thinning area gradually decreases, and the thickness of the first insulating part 31 gradually increases. The first active material layer 12 is provided on both sides of the first current collector 11, and the insulating member 30 also includes a second insulating part 32. The first current collector 11 has a first end surface 111 at one end along the first direction Y, and the second insulating part extends from one end of the first insulating part 31 along the first direction Y and exceeds the first end surface 111. The insulating members 30 are provided on both sides of the first current collector 11, and the second insulating parts 32 of the two insulating members 30 are connected. The porosity of the first insulating part 31 is 30%-40%.

[0188] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that: It comprises a housing and an electrode assembly contained in the housing, wherein the electrode assembly comprises a first pole piece and a second pole piece with opposite polarities; The first pole piece includes a first current collecting body and a first active material layer disposed on a surface of the first current collecting body, the first active material layer includes a main body region and a thinning region, the thickness of at least a portion of the thinning region is less than the thickness of the main body region, the thinning region is located on one side of the main body region along a first direction, and the first direction is perpendicular to the thickness direction of the first current collecting body; The electrode assembly also includes an insulating member, at least a portion of which is disposed between the first pole piece and the second pole piece, the insulating member being connected to a surface of the thinned region that is away from the first current collecting body, and along a direction from the first current collecting body to the first active material layer, a surface of the insulating member that is away from the first current collecting body does not exceed a surface of the main region that is away from the first current collecting body.

2. The battery cell according to claim 1, characterized in that: The insulating member includes a first insulating portion, the first insulating portion includes a first part and a second part, the second part is located at an end of the first part close to the main region, and the thickness of the second part is smaller than the thickness of the first part.

3. The battery cell according to claim 1, characterized in that: In a direction from the main area to the thinning area, the thickness of the thinning area gradually decreases.

4. The battery cell according to claim 3, characterized in that: The insulating member comprises a first insulating portion, which is connected to a surface of the thinning region away from the first current collecting body, and the thickness of the first insulating portion gradually increases in a direction from the main region to the thinning region.

5. The battery cell according to claim 1, characterized in that: The insulating member comprises a first insulating portion and a second insulating portion, wherein the first insulating portion is connected to a surface of the thinned region away from the first current collecting body; The first current collecting body includes a coated area and an uncoated area arranged along the first direction, and the second insulating portion is arranged in the uncoated area.

6. The battery cell according to claim 5, characterized in that: One end of the first current collecting body along the first direction has a first end surface, and the second insulating portion extends from one end of the first insulating portion along the first direction and covers the first end surface.

7. The battery cell according to claim 6, characterized in that: A surface of the thinned area along the first direction away from the main area is a second end surface, the first end surface and the second end surface are arranged flush with each other, and the second insulating portion covers the first end surface and the second end surface.

8. The battery cell according to claim 5, characterized in that: The uncoated area includes a hollow foil area and a first pole lug, the first pole lug is arranged to protrude from the hollow foil area, and part of the insulating member is arranged on the surface of the first pole lug.

9. The battery cell according to claim 8, characterized in that: The second insulating portion completely covers the empty foil area.

10. The battery cell according to claim 5, characterized in that: A minimum thickness of the second insulating portion is greater than a minimum thickness of the first insulating portion.

11. The battery cell according to claim 1, characterized in that: The first active material layer is disposed on both side surfaces of the first current collecting body, the insulating member is disposed on both sides of the first current collecting body, and the two insulating members are connected.

12. The battery cell according to claim 1, characterized in that: The porosity of the insulating member is 30%-40%.

13. The battery cell according to claim 1, characterized in that: The electrode assembly further includes a separator, which is used to separate the first pole piece from the second pole piece; In the first direction, the insulating member does not extend beyond the isolating member.

14. A battery, characterized in that: The invention comprises a battery cell as claimed in any one of claims 1 to 13.

15. An electrical device, characterized in that: Comprising a battery as claimed in claim 14, the battery is used to provide electrical energy.

Images