Battery monomer, electrode assembly, battery device and electric equipment

Abstract

The utility model relates to the related technical field of batteries, and discloses a battery monomer, an electrode assembly, a battery device and electric equipment, the battery monomer comprises a shell and the electrode assembly, the electrode assembly is arranged in the shell, the electrode assembly comprises a pole piece and a separator, the pole piece and the separator are stacked and wound to form a roll body, the separator comprises a first separator, and the first separator is arranged in the shell. Along the winding direction of the pole piece and the separator and the stacking direction of the pole piece and the separator, the ending section of the first separator covers the outer side of the pole piece, and at least part of the ending section forms the peripheral surface of the electrode assembly; in the stacking direction, the side face, facing the winding starting section, of the first separator ending section is a first side face, the side face, deviating from the winding starting section, of the first separator ending section is arranged to be a second side face, the first side face is arranged to be a bonding face with a bonding layer, and the second side face is arranged to be a non-bonding face. The possibility of sequential lithium separation caused by gap increase of the electrode assembly is reduced, and the performance and the service life of the battery monomer are improved.

Description

Technical Field

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

[0002] This section merely provides background information related to the present application and is not necessarily prior art.

[0003] With the increasing demand for clean energy, battery devices have been widely developed. Battery devices can store electrical energy and are widely used in electronic devices such as mobile phones, laptops, electric bicycles, electric cars, electric airplanes, electric boats, electric toy cars, electric toy boats, electric toy airplanes, and power tools.

[0004] A battery device may include one or more battery cells. How to improve the performance and service life of the battery cells has always been a technical issue that continues to be concerned during the research and development of battery devices. Utility Model Content

[0005] In view of the above problems, the present application provides a battery cell, an electrode assembly, a battery device and an electrical equipment to improve the performance and service life of the battery cell by reducing the possibility of lithium plating in the electrode assembly.

[0006] According to a first aspect of the present application, a battery cell is provided, comprising a housing and an electrode assembly, wherein the electrode assembly is arranged in the housing, the electrode assembly comprising a pole piece and a separator, the separator being used to electrically insulate two adjacent pole pieces and to transmit ions between the two adjacent pole pieces, the pole piece and the separator being stacked and wound to form a roll having a winding start section and a winding end section, the separator comprising a first separator, wherein along the winding direction of the pole piece and the separator, the first separator extends from the starting end of the winding start section to the ending end of the winding end section, the first separator having a first separator end section, wherein along the stacking direction of the pole piece and the separator, the first separator end section covers the outer side of the pole piece and at least partially forms the outer peripheral surface of the electrode assembly; along the stacking direction, the side of the first separator end section facing the winding start section is the first side section, and the side of the first separator end section facing away from the winding start section is the second side section, the first side section is configured as a bonding surface having an adhesive layer, and the second side section is configured as a non-bonding surface without an adhesive layer.

[0007] In the technical solution of the embodiment of the present application, the tail section of the first insulating member is coated on the outside of the electrode piece and forms the outer side surface of the electrode assembly. The tail section of the first insulating member can be used to contact with an external active component. The first side surface is the inner side surface of the tail section of the first insulating member facing the center of the electrode assembly, and the second side surface is the outer side surface of the tail section of the first insulating member facing away from the center of the electrode assembly. The first side surface is set as a bonding surface, and the tail section of the first insulating member can be bonded to the inner ring of the electrode assembly through the first side surface. The tail section of the first insulating member has good fixing performance with the inner ring of the electrode assembly, while the second side surface is set as a non-bonding surface. The second side surface is used to contact with an external active component, and the external active component is not easily adhered to the second side surface. After the external acting component contacts the second side surface and completes the corresponding action on the electrode assembly, the external acting component can be separated from the tail section of the first isolation component more easily, reducing the possibility that when the external acting component is separated from the tail section of the first isolation component, the external acting component is stuck to the tail section of the first isolation component and pulls the tail section of the first isolation component, resulting in a large gap between the tail section of the first isolation component and the inner circle of the electrode assembly, thereby reducing the possibility of sequential lithium deposition in the electrode assembly due to the increase in the gap, and improving the performance and service life of the battery cell.

[0008] In addition, the battery cell according to the present application may also have the following additional technical features:

[0009] In some embodiments of the present application, along the winding direction, from the starting end to the ending end of the first separator, the inner side surface of the first separator is configured as a bonding surface having an adhesive layer, the inner side surface of the first separator and the first side surface are oriented in the same direction, and the inner side surface of the first separator includes the first side surface. By configuring the inner side surface of the first separator as the bonding surface, the adhesion between the first separator and the adjacent inner electrode piece can be improved.

[0010] In some embodiments of the present application, along the winding direction, from the starting end of the first separator to the starting end of the first separator's tail section, the outer side surface of the first separator is configured as a bonding surface having an adhesive layer, and the outer side surface of the first separator and the second side surface are oriented in the same direction. By configuring the outer side surface of the first separator, excluding the second side surface, as the bonding surface, the adhesion between the first separator and the adjacent outer electrode piece can be improved.

[0011] In some embodiments of the present application, along the winding direction, the tail section of the first isolating member at least partially extends beyond the terminal end of the electrode piece. The fact that the tail section of the first isolating member extends beyond the terminal end of the electrode piece can enhance the first isolating member's ability to cover and isolate the electrode piece, improve the isolation performance of the first isolating member with respect to the electrode piece, and reduce the possibility of short circuiting the electrode assembly.

[0012] In some embodiments of the present application, along the winding direction, the starting end of the first separator tail section extends beyond the terminal end of the electrode sheet, and the first separator tail section wraps around the electrode assembly at least once. The starting end of the first separator tail section begins at the rear side of the terminal end of the electrode sheet. In this way, along the winding direction, the outer side surface of the first separator within the size range of the electrode sheet can be provided with an adhesive layer, so that the outer side surface of the first separator is bonded to the adjacent outer electrode sheet from the starting end to the terminal end of the electrode sheet, thereby improving the adhesion between the first separator and the adjacent outer electrode sheet.

[0013] In some embodiments of the present application, the first separator's tail section is arranged to wrap around the electrode assembly one to three times. This arrangement can improve the first separator's ability to cover and isolate the electrode sheets, reducing the likelihood of short circuits in the electrode assembly. Furthermore, the first separator has a minimal effect on the radial dimensions of the winding core and can save consumables compared to more turns.

[0014] In some embodiments of the present application, the pole piece includes a first pole piece and a second pole piece with opposite polarities, and the separator further includes a second separator, the first pole piece, the first separator, the second pole piece, and the second separator are sequentially stacked and wound to form the roll, and the second separator has a second separator tail section; along the stacking direction, the first separator tail section is located outside the second separator tail section, the inner side surface and the outer side surface of the second separator are respectively provided as bonding surfaces having an adhesive layer, and the inner side surface and the outer side surface of the second separator are arranged oppositely along the stacking direction. The inner side surface and the outer side surface of the second separator are both provided with an adhesive layer, which can improve the adhesion between the first and second pole pieces and the second separator.

[0015] In some embodiments of the present application, along the winding direction, the adhesive layer on the inner side surface of the second isolating member extends from the starting end to the ending end of the second isolating member; and / or, along the winding direction, the adhesive layer on the outer side surface of the second isolating member extends from the starting end of the second isolating member to at least the starting end of the ending section of the second isolating member. The inner side surface of the second isolating member is provided with an adhesive layer from the starting end to the ending end, which can improve the adhesion between the inner side surface of the second isolating member and the adjacent inner pole piece. The outer side surface of the second isolating member is provided with an adhesive layer from the starting end to the ending section of the second isolating member, which can improve the adhesion between the outer side surface of the second isolating member and the adjacent outer pole piece.

[0016] In some embodiments of the present application, along the winding direction, the terminal end of the first isolating member tail section exceeds the terminal end of the second isolating member tail section or the terminal end of the first isolating member tail section is flush with the terminal end of the second isolating member tail section, and the starting end of the second isolating member tail section exceeds the terminal end of the first pole piece and the terminal end of the second pole piece. Along the winding direction, the first isolating member tail section can cover the second isolating member, reducing the possibility of the terminal end of the second isolating member being exposed to the outside of the first isolating member. After the roll is wound, the first isolating member tail section can be temporarily bound using tape or the like, which is convenient to operate. Along the winding direction, the second isolating member tail section and the first isolating member tail section both exceed the terminal end of the pole piece, which can improve the isolation effect of the isolating member on the pole piece and reduce the possibility of the pole piece short circuit.

[0017] In some embodiments of the present application, the area of ​​the first isolating member configured as the bonding surface is coated with an adhesive to form the bonding layer. The bonding layer is coated on the corresponding area of ​​the isolating member, which is easy to implement and convenient to process.

[0018] The second aspect of the present application proposes an electrode assembly, comprising a pole piece and an isolating member, wherein the pole piece and the isolating member are stacked and wound to form a roll having a winding start section and a winding end section, the isolating member comprising a first isolating member, and along the winding direction of the pole piece and the isolating member, the first isolating member extends from the starting end of the winding start section to the ending end of the winding end section, the first isolating member having a first isolating member ending section, and along the stacking direction, the first isolating member ending section is wrapped around the outside of the pole piece and at least partially forms the outer peripheral surface of the electrode assembly; along the stacking direction, the side of the first isolating member ending section facing the winding start section is the first side, and the side of the first isolating member ending section away from the winding start section is set as the second side, the first side is set as a bonding surface having an adhesive layer, and the second side is set as a non-bonding surface.

[0019] The electrode assembly of the present application has the same beneficial effects as the battery cell proposed in the present application or any embodiment of the present application.

[0020] A third aspect of the present application provides a battery device comprising a plurality of battery cells provided in the present application or any embodiment of the present application.

[0021] The battery device of the present application has the same beneficial effects as the battery cell proposed in the present application or any embodiment of the present application.

[0022] The fourth aspect of the present application proposes an electrical device, which includes multiple battery cells proposed in the present application or any embodiment of the present application, or the electrical device includes multiple battery devices proposed in the present application or any embodiment of the present application, and the battery cells are used to store or provide electrical energy.

[0023] The electrical equipment of the present application has the same beneficial effects as the battery cell proposed in the present application or any embodiment of the present application.

[0024] 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

[0025] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference numerals are used throughout the drawings to denote the same components. In the drawings:

[0026] Figure 1 A schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0027] Figure 2 A schematic diagram of a battery device according to some embodiments of the present application;

[0028] Figure 3 A schematic diagram of a battery cell according to some embodiments of the present application;

[0029] Figure 4 A schematic cross-sectional view of an electrode assembly according to some embodiments of the present application;

[0030] Figure 5 A partial cross-sectional schematic diagram of a first isolation member proposed in some embodiments of the present application;

[0031] Figure 6 A schematic diagram of a winding process of an electrode assembly according to some embodiments of the present application;

[0032] Figure 7 A schematic cross-sectional view of a second isolation member provided in some embodiments of the present application.

[0033] The accompanying drawings in the specific implementation manner are as follows:

[0034] 1000. Vehicle;

[0035] 100, battery device; 200, controller; 300, motor;

[0036] 110, box body; 1101, first box body; 1102, second box body;

[0037] 120. Battery monomer assembly;

[0038] 130. Battery cell; 131. Housing; 132. Shell; 133. End cap; 124. Tab; 135. Electrode terminal;

[0039] 10. Electrode assembly; 11. Pole piece; 111. First pole piece; 1111. Starting end of first pole piece; 1112. Ending end of first pole piece; 112. Second pole piece; 1121. Starting end of second pole piece; 1122. Ending end of second pole piece; 113. Starting end of pole piece; 114. Ending end of pole piece; 12. Isolator; 121. First isolation piece; 1211. Ending section of first isolation piece; 1212. First side surface; 1213. Second side surface; 1214, inner side surface of first separator; 1215, outer side surface of first separator; 1216, starting end of first separator; 1217, terminating end of first separator; 122, second separator; 1221, ending section of second separator; 1222, inner side surface of second separator; 1223, outer side surface of second separator; 1224, starting end of second separator; 1225, terminating end of second separator; 123, adhesive layer;

[0040] 20. Rolling needle;

[0041] A. Winding direction. DETAILED DESCRIPTION

[0042] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art 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" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0044] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0045] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0046] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0047] 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).

[0048] 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., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and 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 device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0049] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0050] Battery devices can store electrical energy and power electrical devices. With the development of new energy sources, the use of battery devices is becoming increasingly widespread. They are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but are also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace.

[0051] A battery device may include one or more battery cells. The electrode assembly is an important component in a battery cell. In some technologies, the electrode assembly is formed by winding a positive electrode sheet and a negative electrode sheet, and a separator is also provided between the positive electrode sheet and the negative electrode sheet. During the processing of the electrode assembly, the positive electrode sheet, the separator and the negative electrode sheet are first stacked and wound to form a roll, and then the roll needs to be hot pressed. The hot pressing process can shape the roll so that the electrode assembly forms the desired shape and thickness to facilitate the subsequent shelling operation of the electrode assembly; and the hot pressing process can also adjust the gap between the positive electrode sheet, the separator and the negative electrode sheet, shorten the migration distance of the active ions (for example, the active ions in lithium-ion batteries are lithium ions), reduce the internal resistance of the electrode assembly, and improve the performance and service life of the electrode assembly.

[0052] The outermost ring of the electrode assembly is usually a separator. Research has found that during the hot pressing process, the outermost separator of the electrode assembly is easily pulled by the hot pressing equipment, resulting in an increase in the gap between the electrode near the outermost ring and the separator. This can lead to lithium deposition in the outer ring, affecting the performance and service life of the battery cell.

[0053] In order to reduce the possibility of the separator of the electrode assembly being pulled, resulting in an increase in the gap between the electrode sheet and the separator, and thus causing lithium deposition in the outer cycle, the present application provides a battery cell, the electrode assembly has an separator tail section wrapped around the outer side of the electrode sheet, the side of the separator tail section facing the winding starting section is set as a bonding surface with an adhesive layer, and the side of the separator tail section facing away from the winding starting section is set as a non-bonding surface.

[0054] The insulating member tail section is wrapped around the outside of the electrode piece and can form the outermost circle of the electrode assembly, that is, the outer peripheral surface of the electrode assembly. The insulating member tail section can be used to contact external active components. The side of the insulating member tail section facing the winding starting section is the inner side of the insulating member tail section facing the center of the electrode assembly, and the side of the insulating member tail section away from the winding starting section is the outer side of the insulating member tail section away from the center of the electrode assembly. The side of the insulating member tail section facing the winding starting section is set as a bonding surface, so that the insulating member tail section can be bonded to the inner circle of the electrode assembly through the bonding surface, and the insulating member tail section has good fixing performance with the inner circle of the electrode assembly. The side of the insulating member tail section away from the winding starting section is set as a non-bonding surface, and the non-bonding surface can be exposed on the outside of the electrode assembly and used for contact with external active components. External active components are not easily adhered to the insulating member tail section. After the external acting component contacts the insulating member tail section and completes the corresponding action on the electrode assembly, the external acting component can be separated from the insulating member tail section relatively easily, reducing the possibility that when the external acting component is separated from the insulating member tail section, the external acting component will stick to the insulating member tail section and pull the insulating member tail section, resulting in a large gap between the insulating member tail section and the inner circle of the electrode assembly, thereby reducing the possibility of sequential lithium deposition in the electrode assembly due to the increase in the gap, and improving the performance and service life of the battery cell.

[0055] During the hot pressing process after the electrode assembly is wound, the external acting component may be a pressing plate of the hot pressing equipment. During the hot pressing process, the non-adhesive surface of the end section of the separator contacts and is pressed by the pressing plate. After the pressing is completed, the possibility of adhesion between the pressing plate and the end section of the separator or the generated adhesion force is reduced, while the adhesive surface of the end section of the separator can have a good adhesive effect with the inner ring of the electrode assembly, thereby improving the convenience and timeliness of separation of the pressing plate and the separator, reducing the possibility of the press plate pulling the separator, which may increase the gap between the electrode and the separator, reducing the possibility of sequential lithium deposition on the outside of the electrode assembly or the amount of lithium deposition during cyclic lithium deposition, and improving the cycle performance and service life of the battery cell.

[0056] The battery cells and battery devices disclosed in this application can form a power supply system for electrical equipment to provide electrical energy for the electrical equipment.

[0057] The embodiments of the present application provide an electric device that uses a battery as a power source. The electric device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery-powered vehicle, an electric car, a ship, a spacecraft, etc. The electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc. The spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0058] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device in an embodiment of the present application.

[0059] Please refer to Figure 1 , Figure 1 A schematic diagram of the structure of a vehicle provided for some embodiments of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery device 100 is provided inside the vehicle 1000, and the battery device 100 can be provided at the bottom, head or tail of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000. For example, the battery device 100 can serve as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0060] It is understandable that the battery device 100 can not only serve as the operating power source of the vehicle 1000, but also serve as the driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0061] The battery apparatus mentioned in the embodiments of the present application may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include multiple battery cells, which are connected in series, parallel, or hybrid via a busbar.

[0062] In some embodiments, a battery cell assembly is generally formed by arranging a plurality of battery cells.

[0063] As an example, the battery cell assembly may be a battery module, which is formed by arranging and fixing multiple battery cells to form an independent module. As an example, the battery module may be formed by bundling multiple battery cells with a cable tie.

[0064] like Figure 2 As shown, Figure 2 This is a schematic diagram of a battery device proposed in some embodiments of the present application. In some embodiments, the battery device 100 can be a battery pack, which includes a case and one or more battery cell assemblies 120, and the battery cell assembly 120 is accommodated in the case 110.

[0065] As an example, the battery cell assembly 120 may be housed in the case 110 by fixing the battery module in the case 110 .

[0066] As an example, the battery cell assembly 120 may also be housed in the case 110 by directly fixing the plurality of battery cells 130 to the case 110 .

[0067] As an example, Figure 2 As shown, the housing 110 may include a first housing 1101 and a second housing 1102. The first housing 1101 and the second housing 1102 engage to form an enclosed space within the housing 110 for accommodating the battery cell assembly 120. Enclosed here means covered or closed, and may be sealed or unsealed. The first housing 1101 may be a top cover or a bottom plate.

[0068] As an example, the box body may include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, so that a closed space is formed inside the box body to accommodate the battery cell assembly 120.

[0069] In some embodiments, the box 110 may serve as part of the chassis structure of the vehicle 1000. For example, a portion of the box 110 may form at least a portion of the floor of the vehicle 1000, or a portion of the box 110 may form at least a portion of a cross member or a longitudinal member of the vehicle 1000.

[0070] In some embodiments, the battery device 100 refers to an energy storage device, which includes a cabinet with a door on at least one side. The energy storage device includes an energy storage container, an energy storage cabinet, and the like.

[0071] like Figure 3 As shown, Figure 3 This is a schematic diagram of a battery cell proposed in some embodiments of the present application. In the embodiments of the present application, the battery cell 130 may be a secondary battery. A secondary battery refers to a battery cell 130 that can be recharged to activate the active material after being discharged and continue to be used.

[0072] The battery cell 130 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 metal hydride battery, a nickel cadmium battery, a lead storage battery, etc., which is not limited in the embodiments of the present application.

[0073] The battery cell 130 generally includes a housing 131, an electrode assembly 10 and an electrode terminal 135. The electrode terminal 135 is disposed on the housing 131. The electrode assembly 10 is disposed in the housing 131. The electrode terminal 135 is electrically connected to the tab 124 of the electrode assembly 10. Figure 4 As shown, Figure 4This is a schematic cross-sectional view of an electrode assembly according to some embodiments of the present application. The electrode assembly 10 includes a positive electrode, a negative electrode, and a separator 12, which is disposed between the negative and positive electrodes. During the charge and discharge process of the battery cell 130, active ions (e.g., lithium ions) are intercalated and released between the positive and negative electrodes. The separator 12, disposed between the positive and negative electrodes, prevents short circuits between the positive and negative electrodes while allowing active ions to pass through.

[0074] Illustratively, the outer shell 131 of the battery cell 130 includes a shell 132 and an end cover 133 . The shell is provided with an opening. The end cover 133 is covered on the shell 132 . The end cover 133 and the shell 132 cooperate to form an accommodating space. The electrode assembly 10 is provided in the accommodating space. The electrode terminal 135 is provided on the end cover 133 .

[0075] 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 disposed on at least one surface of the positive electrode current collector.

[0076] 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 provided on either or both of the two facing surfaces of the positive electrode current collector.

[0077] As an example, the positive electrode current collector may be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as the metal foil, a pure metal, an alloy, or a surface-treated metal may be used, including but not limited to stainless steel, copper, aluminum, nickel, titanium, or silver. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0078] As an example, the positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides and their respective modified compounds. However, the present application is not limited to these materials, and other traditional materials that can be used as battery positive electrode active materials may also be used. These positive electrode active materials may be used alone or in combination of two or more. Among them, examples of lithium-containing phosphates may include but are not limited to at least one of lithium iron phosphate, a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon. Examples of lithium transition metal oxides may include but are not limited to lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also referred to as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O2 (also referred to as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O2 (also referred to as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O2 (also referred to as NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O2 (also referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.8 Co 0.15 Al 0.05 O2) and at least one of its modified compounds. The modified compound refers to a substance obtained by modifying the above substances by means of doping or coating.

[0079] In some embodiments, a metal foam may be used as the positive electrode. The metal foam may be nickel foam, copper foam, aluminum foam, alloy foam, or carbon foam, among others. When the metal foam is used as the positive electrode, the surface of the metal foam may or may not be provided with a positive electrode active material. For example, the positive electrode active material may be filled and / or deposited within the metal foam.

[0080] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0081] As an example, the negative electrode current collector may be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as the metal foil, a pure metal, an alloy, or a surface-treated metal may be used, including but not limited to stainless steel, copper, aluminum, nickel, titanium, or silver. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (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.).

[0082] 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.

[0083] As an example, the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode active material is provided on either or both of the two facing surfaces of the negative electrode current collector.

[0084] As an example, the negative electrode active material may adopt the negative electrode active material for the battery cell 130 that is well known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for the battery cell 130 may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0085] In some embodiments, the negative electrode may be a metal foam. The metal foam may be nickel foam, copper foam, aluminum foam, alloy foam, or carbon foam. When the metal foam is used as the negative electrode sheet, the surface of the metal foam may or may not be provided with a negative electrode active material.

[0086] As an example, the negative electrode active material may be filled and / or deposited in the negative electrode current collector.

[0087] 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.

[0088] In some embodiments, the separator 12 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.

[0089] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator 12 can be a separate component located between the positive and negative electrodes, or it can be attached to the surface of the positive and negative electrodes. The surface of the separator can also be coated with an inorganic particle coating, an organic particle coating, or an organic / inorganic composite coating.

[0090] In some embodiments, the separator 12 is a solid electrolyte. The solid electrolyte is disposed between the positive electrode and the negative electrode, and serves to transport ions and isolate the positive and negative electrodes.

[0091] The electrode assembly 10 may be a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0092] As an example, multiple positive electrode sheets and multiple negative electrode sheets can be provided respectively, and the multiple positive electrode sheets and the multiple negative electrode sheets can be alternately stacked.

[0093] As an example, a plurality of separators 12 may be provided, each of which is disposed between any adjacent positive electrode sheets or negative electrode sheets.

[0094] As an example, the separator 12 may be provided continuously, and may be provided between any adjacent positive electrode sheets or negative electrode sheets in a winding manner.

[0095] In some embodiments, the shape of the electrode assembly 10 can be cylindrical, flat, or polygonal.

[0096] In some embodiments, the electrode assembly 10 is provided with tabs 124 that can conduct current from the electrode assembly 10 . The tabs 124 include a positive tab 124 and a negative tab 124 .

[0097] Battery cell 130 also includes an electrolyte, which conducts ions between the positive and negative electrodes. This application does not specifically limit the type of electrolyte, and the electrolyte can be selected based on needs. The electrolyte can be liquid, gel, or solid.

[0098] The liquid electrolyte includes an electrolyte salt and a solvent.

[0099] Reference Figure 3 and Figure 4 , and combined with Figure 5 As shown, Figure 5This is a partial cross-sectional schematic diagram of the first isolating member proposed in some embodiments of the present application. This embodiment provides a battery cell 130, including a shell 131 and an electrode assembly 10. The electrode assembly 10 is arranged in the shell 131. The electrode assembly 10 includes a pole piece 11 and a separator 12. The separator 12 is used to electrically insulate two adjacent pole pieces 11 and transmit ions between the two adjacent pole pieces 11. The pole piece 11 and the separator 12 are stacked and wound to form a coil having a winding start section and a winding end section. The separator 12 includes a first separator 121. Along the winding direction A of the pole piece 11 and the separator 12, the first separator 121 extends from the starting end of the winding start section to the winding end section. At the terminal end of the tail section, the first insulating member 121 has a first insulating member tail section 1211. Along the stacking direction of the pole piece 11 and the insulating member 12, the first insulating member tail section 1211 is wrapped around the outside of the pole piece 11 and at least partially forms the outer peripheral surface of the electrode assembly 10; along the stacking direction (the stacking direction of the pole piece 11 and the insulating member 12), the side of the first insulating member tail section 1211 facing the winding starting section is the first side 1212, and the side of the first insulating member tail section 1211 away from the winding starting section is set as the second side 1213, the first side 1212 is set as a bonding surface with a bonding layer 123, and the second side 1213 is set as a non-bonding surface without a bonding layer.

[0100] One or more layers of separators 12 may be provided in the electrode assembly 10 . Each layer of separator 12 is used to electrically insulate and isolate adjacent inner pole pieces 11 from adjacent outer pole pieces 11 , and each layer of separator 12 may allow ions (ie, active ions) to pass through.

[0101] For example, Figure 4 As shown, the electrode 11 may include a first electrode 111 and a second electrode 112 that are independently arranged. The first electrode 111 may be a negative electrode, and the second electrode 112 may be a positive electrode. Along the stacking direction of the electrode 11 and the separator 12, a separator 12 is provided between the adjacent first electrode 111 and the second electrode 112. In this case, the separator 12 may be provided in two layers. For another example, the electrode 11 may be an integrated structure having a positive electrode layer and a negative electrode layer that are electrically relatively isolated. Exemplarily, the positive electrode layer and the negative electrode layer of the electrode 11 may be formed by coating corresponding positive electrode materials and negative electrode materials on both sides of the insulating current collector. Along the stacking direction of the electrode 11 and the separator 12, the first separator 121 is provided between the two electrode sheets 11. In this case, the separator 12 may be provided in one layer.

[0102] The first separator 121 can be understood as the separator 12 whose tail section surrounds and forms the outer peripheral surface of the electrode assembly 10. The separator 12 can be set as a separator.

[0103] The electrode piece 11 and the separator 12 can be wound approximately around the central axis of the electrode assembly 10. The stacking direction is the direction in which the electrode piece 11 and the separator 12 are stacked in sequence. Figure 4 As shown, the pole pieces 11 and separators 12 are alternately stacked radially outward from the center of the electrode assembly 10. The stacking direction can be roughly understood with reference to the radial direction of the electrode assembly 10. The radial direction of the electrode assembly 10 is roughly perpendicular to the axial direction of the electrode assembly 10. Unless otherwise specified, the inside and outside of the pole pieces 11 and separators 12 are referenced to the central axis of the electrode assembly 10 (i.e., the winding center), with the inner side being closer to the central axis and the outer side being farther away from the central axis.

[0104] For example, refer to Figure 6 As shown, Figure 6 This is a schematic diagram of the winding process of the electrode assembly proposed in some embodiments of the present application. The separator 12 and the electrode 11 can be transported to the winding needle 20 by the conveying mechanism. The separator 12 and the electrode 11 are stacked in sequence at the winding needle 20 and wound by the winding needle 20 to form a roll. Figure 6 FIG. 1 illustrates the process of winding the electrode assembly 10 to the winding end section, and therefore only shows the positional relationship between the first separator 121 and the second separator 122 .

[0105] The winding start section is the electrode sheet 11 and / or separator 12 structure extending from the innermost winding start section of the electrode assembly 10 (i.e., the winding body) and extending backward along the winding direction A (the first winding section is the front, and the last winding section is the rear). The winding start section is located at the center of the electrode assembly 10 along the stacking direction of the electrode sheets 11 and separator 12 (i.e., the radial direction of the winding core).

[0106] The winding end section is the electrode sheet 11 and / or separator 12 structure extending forward along the winding direction A (the first wound section is the front, and the last wound section is the rear) from the outermost winding end of the electrode assembly 10 (i.e., the jelly roll). The winding end section is located outside the electrode assembly 10 along the stacking direction of the electrode sheets 11 and separator 12 (i.e., the radial direction of the winding core), and can form the outer circumference of the electrode assembly 10.

[0107] The first separator tail section 1211 is the first separator 121 that extends forward along the winding direction A (the first wound portion is the front, and the last wound portion is the back) from the winding end (termination end) of the outermost circle of the first separator 121 for a distance. Along the stacking direction of the pole piece 11 and the separator 12 (i.e., the radial direction of the winding core), the first separator tail section 1211 is configured to at least wrap around the electrode assembly 10 (i.e., the winding body) once, that is, to form at least the outermost circle of the electrode assembly 10 (i.e., the winding body), so that the exposed outer peripheral surface of the electrode assembly 10 (i.e., the winding body) is formed by the first separator 121. In the winding tail section, along the winding direction A, the pole piece 11 does not exceed the size range of the first separator 121, so that the pole piece 11 can be covered by the first separator 121.

[0108] The first side 1212 is the side of the first insulating member tail section 1211 facing the winding starting section, that is, the side of the first insulating member tail section 1211 facing the center of the winding core; the second side 1213 is the side of the first insulating member tail section 1211 away from the winding starting section, that is, the side of the first insulating member tail section 1211 away from the center of the electrode assembly 10 (i.e., the winding body) and facing outward.

[0109] The terms "adhesive surface" and "non-adhesive surface" are relative terms. A bonding surface can be understood as a surface having an adhesive layer 123, while a non-adhesive surface can be understood as a bonding surface not provided with a corresponding adhesive layer 123. Specifically, the first side surface 1212 is configured as a bonding surface having an adhesive layer 123, that is, an adhesive material such as an adhesive is provided on the first side surface 1212, while the second side surface 1213 is configured as a non-adhesive surface without an adhesive layer, that is, no adhesive material such as an adhesive is provided on the second side surface 1213. By configuring the first side surface 1212 as a bonding surface and the second side surface 1213 as a non-adhesive surface, the adhesion of the first side surface 1212 can be greater than that of the second side surface 1213 under the same environment or working conditions.

[0110] The adhesive layer 123 has the function of adhering and fixing the separator 12 to the corresponding electrode 11. The adhesive layer 123 can be formed by applying a corresponding adhesive material, such as a double-sided tape, or by coating an adhesive.

[0111] For example, the first side surface 1212 may be coated with an adhesive to form an adhesive layer, and the second side surface 1213 may be exposed or coated with other non-adhesive agents to form a non-adhesive surface.

[0112] Exemplarily, the binder may be a binder containing polycarbosilane. The binder may also be an aqueous binder, such as sodium carboxymethylcellulose and styrene-butadiene rubber. The binder may also be a ceramic diaphragm binder, such as polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polymethyl methacrylate, polyacrylonitrile, polyimide, etc.

[0113] In some technologies, adhesive is provided on both the inside and outside of the isolation member 12. When the electrode assembly 10 (i.e., the coil) is hot-pressed, the adhesive of the isolation member 12 will melt due to the heat, causing the outside of the isolation member 12 to adhere to the pressure plate of the hot-pressing equipment. When the pressure plate rises, it will adhere to the isolation member 12, stretching the isolation member 12, causing the outside of the isolation member 12 to be subjected to force and separated from the electrode 11, thereby causing the gap on the outside of the electrode 11 to increase, which will cause lithium to circulate on the outside of the isolation member 12.

[0114] In the battery cell 130 of this embodiment, by setting the first side surface 1212 as the bonding surface, the first insulating member tail section 1211 can be bonded to the inner circle of the electrode assembly 10 (i.e., the coil) through the first side surface 1212, and the first insulating member tail section 1211 has good fixing performance with the inner circle of the electrode assembly 10 (i.e., the coil); and the second side surface 1213 is set as the non-bonding layer 123. After the winding of the electrode assembly 10 is completed, when the electrode assembly 10 is subjected to the next process, the first insulating member tail section 1211 is not easily bonded to the external acting component of the next process (for example, the pressing plate of the hot pressing process), thereby reducing the adhesion of the first insulating member tail section 1211 to the external acting component, causing the first insulating member tail section 1211 to be stretched by force and separated from the inner electrode sheet 11, thereby increasing the outer circle gap of the electrode assembly 10, thereby reducing the possibility of sequential lithium deposition due to the increase in the gap of the insulating member 12, and improving the performance and service life of the battery cell 130.

[0115] At the same time, the second side surface 1213 forms the outer peripheral surface of the electrode assembly 10, which is configured as a non-adhesive layer 123. Before the electrode assembly 10 is assembled to the shell 132, the outer peripheral surface of the electrode assembly 10 (the second side surface 1213) is not easy to adhere to dust, thereby reducing the possibility of self-discharge of the electrode assembly 10 due to dust.

[0116] According to some embodiments of the present application, optionally, as Figure 4 and Figure 5 As shown, along the winding direction A, from the starting end 1216 to the ending end of the first isolating member, the inner side surface 1214 of the first isolating member is configured as a bonding surface having the bonding layer 123 , and the inner side surface 1214 of the first isolating member is oriented in the same direction as the first side surface 1212 .

[0117] The inner side surface 1214 of the first separator is the side surface of the first separator 121 facing the central axis of the electrode assembly 10 (ie, the jelly roll), wherein the inner side surface of the first separator tail section 1211 is also the first side surface 1212 .

[0118] For example, the adhesive layer 123 on the inner side surface 1214 of the first isolating member may be continuously provided from the starting end 1216 to the ending end of the first isolating member, or the adhesive layer 123 may be discontinuously and alternately provided.

[0119] By setting the inner side surface 1214 of the first isolating member as a bonding surface, the adhesion between the first isolating member 121 and the adjacent inner pole piece 11 can be improved.

[0120] According to some embodiments of the present application, optionally, as Figure 4 and Figure 5 As shown, along the winding direction A, from the starting end 1216 of the first isolating member to the starting end 1211 of the first isolating member (refer to Figure 4 and Figure 5 As understood by the dotted line B), the outer side surface 1215 of the first isolating member is configured as a bonding surface having the bonding layer 123, and the outer side surface 1215 of the first isolating member and the second side surface 1213 are oriented in the same direction.

[0121] The outer side surface 1215 of the first separator is the side of the first separator 121 facing away from the central axis of the electrode assembly 10 (ie, the jelly roll) and outward. The outer side surface of the first separator tail section 1211 is also the second side surface 1213.

[0122] Illustratively, the outer side surface 1215 of the first isolating element may be continuously provided with the adhesive layer 123 from the starting end 1216 of the first isolating element to the starting end 1216 of the first isolating element, or the adhesive layer 123 may be discontinuously and alternately provided.

[0123] By setting the area of ​​the outer side surface 1215 of the first isolating member except the second side surface 1213 as the bonding surface, the adhesion between the first isolating member 121 and the adjacent outer pole piece 11 can be improved.

[0124] According to some embodiments of the present application, optionally, as Figure 4 As shown, along the winding direction A, the first isolating member tail section 1211 at least partially exceeds the terminal end 114 of the pole piece.

[0125] The first isolating member tail section 1211 at least partially extends beyond the pole piece's terminal end 114 . This means that, along the winding direction A, the first isolating member tail section 1211's terminal end (also the first isolating member's terminal end 1217 ) is located behind the pole piece's terminal end 114 .

[0126] Exemplarily, along the winding direction A, the extension length of the first isolating member 121 is greater than the extension length of the pole piece 11, the starting end 1216 of the first isolating member exceeds the starting end 113 of the pole piece, the starting end 1216 of the first isolating member is located at the front end of the starting end 113 of the pole piece, the terminating end 1217 of the first isolating member exceeds the terminating end 114 of the pole piece, and the terminating end 1217 of the first isolating member is located on the rear side of the terminating end 114 of the pole piece.

[0127] Exemplarily, the first isolating member tail section 1211 includes a portion that fits with the tail section of the pole piece 11 and a portion that extends beyond the terminal end of the pole piece 11 , that is, along the winding direction A, the first isolating member tail section 1211 extends forward to within the size range of the pole piece 11 .

[0128] For example, the first isolating member 121 completely exceeds the terminal end 114 of the pole piece, that is, the starting end of the first isolating member tail section 1211 (refer to Figure 4 and Figure 5 The dotted line B (understood) is located on the rear side of the terminal end 114 of the electrode piece, and the first isolation member 121 is configured to be arranged around the electrode assembly 10 (ie, the winding body) in one or more turns.

[0129] The tail section 1211 of the first isolating member extends beyond the terminal end 114 of the electrode piece, which can improve the covering and isolation effect of the first isolating member 121 on the electrode piece 11, improve the isolation performance of the first isolating member 121 on the electrode piece 11, and reduce the possibility of short circuit of the electrode assembly 10.

[0130] According to some embodiments of the present application, optionally, as Figure 4 As shown, along the winding direction A, the starting end of the first isolating member tail section 1211 (refer to Figure 4 and Figure 5 The dotted line B in FIG. 1 is understood as exceeding the terminal end 114 of the electrode piece, and the first isolating member tail section 1211 is provided at least once around the electrode assembly 10 (ie, the winding body).

[0131] The starting end of the first isolating member tail section 1211 (see Figure 4 and Figure 5 The dotted line B is understood) beyond the terminal end 114 of the pole piece. It can be understood that along the winding direction A, the first isolating member 121 completely exceeds the terminal end 114 of the pole piece, and the starting end of the first isolating member tail section 1211 (refer to Figure 4 and Figure 5 The dotted line B (understood) can be located on the rear side of the terminal end 114 of the pole piece.

[0132] The first separator tail section 1211 is disposed at least once around the electrode assembly 10 (ie, the winding body), so that the outer circumference of the electrode assembly 10 is entirely formed by the first separator tail section 1211 .

[0133] The starting end of the first isolating member tail section 1211 (see Figure 4 and Figure 5 The dotted line B (understood as shown in FIG. 2 ) starts from the rear side of the terminal end 114 of the pole piece. In this way, along the winding direction A, the outer side surface 1215 of the first isolating member within the size range of the pole piece 11 can be provided with a bonding layer 123, so that from the starting end 113 to the terminal end of the pole piece, the outer side surface 1215 of the first isolating member is bonded to the adjacent outer pole piece 11, thereby improving the adhesion between the first isolating member 121 and the adjacent outer pole piece 11.

[0134] According to some embodiments of the present application, optionally, the first separator tail section 1211 is arranged to wrap around the electrode assembly 10 (ie, the coil) one to three times.

[0135] The first isolation member tail section 1211 can be arranged around the electrode assembly 10 for one circle, one and a half circles, two circles, two and a half circles, or three circles.

[0136] It can be understood that the first isolating member tail section 1211 is set to be one to three turns around the electrode assembly 10, which can improve the covering and isolation effect of the first isolating member 121 on the electrode piece 11 and reduce the possibility of short circuit of the electrode assembly 10. At the same time, the first isolating member 121 has little effect on the radial size of the winding core, and compared with more turns, it can save consumables.

[0137] According to some embodiments of the present application, optionally, as Figure 4 As shown, the pole piece 11 includes a first pole piece 111 and a second pole piece 112 with opposite polarities, and the isolating member 12 also includes a second isolating member 122. The first pole piece 111, the first isolating member 121, the second pole piece 112 and the second isolating member 122 are stacked and wound in sequence to form a roll, and the second isolating member 122 has a second isolating member tail section 1221; along the stacking direction, the first isolating member tail section 1211 is located on the outside of the second isolating member tail section 1221, and the inner side surface 1222 and the outer side surface of the second isolating member are respectively set to be bonding surfaces with a bonding layer 123, and the inner side surface 1222 and the outer side surface of the second isolating member are set oppositely along the stacking direction.

[0138] The inner side surface 1222 of the second isolation member is the side surface of the second isolation member 122 facing the central axis (i.e., the winding center) of the electrode assembly 10 (i.e., the roll body), and the outer side surface 1223 of the second isolation member is the side surface of the second isolation member 122 facing away from the central axis of the electrode assembly 10 (i.e., the roll body) and facing outward.

[0139] The second separator tail section 1221 is the second separator 122 extending forward along the winding direction A (the first wound section is the front, and the last wound section is the rear) from the outermost winding end (termination end) of the second separator 122. In the winding tail section, along the winding direction A, the first pole piece 111 and the second pole piece 112 do not exceed the size range of the second separator 122, so that the adjacent pole pieces 11 can be separated by the second separator 122.

[0140] The second separator 122 may be a separator film. Along the winding direction A, the second separator 122 may extend from the winding start section to the winding end section.

[0141] For example, the adhesive layer 123 may be provided on a partial area of ​​the inner side surface 1222 of the second isolating member. For example, the adhesive layer 123 may be provided on the entire area of ​​the inner side surface 1222 of the second isolating member.

[0142] For example, the adhesive layer 123 may be provided on a partial area of ​​the outer side surface 1223 of the second isolating member. For example, the adhesive layer 123 may be provided on the entire area of ​​the outer side surface 1223 of the second isolating member.

[0143] The inner side surface 1222 and the outer side surface of the second isolation member are both provided with an adhesive layer 123 , which can improve the adhesion between the first electrode piece 111 and the second electrode piece 112 and the second isolation member 122 .

[0144] According to some embodiments of the present application, optionally, along the winding direction A, the adhesive layer 123 of the inner side surface 1222 of the second insulating member extends from the starting end 1224 of the second insulating member to the ending end; and / or, along the winding direction A, the adhesive layer 123 of the outer side surface 1223 of the second insulating member extends from the starting end 1224 of the second insulating member to at least the starting end of the second insulating member tail section 1221.

[0145] Illustratively, the adhesive layer 123 on the inner side surface 1222 of the second isolating member continuously extends from the starting end 1224 to the ending end of the second isolating member.

[0146] For example, along the winding direction A, the adhesive layer 123 of the outer side surface 1223 of the second isolating member extends from the starting end 1224 of the second isolating member to the starting end of the second isolating member tail section 1221, or as shown in FIG. Figure 7 As shown, Figure 7 This is a cross-sectional schematic diagram of the second isolation member proposed in some embodiments of the present application, in which the adhesive layer 123 of the outer side surface 1223 of the second isolation member extends from the starting end 1224 of the second isolation member to the ending end of the second isolation member tail section 1221 (also the ending end 1225 of the second isolation member).

[0147] Among them, along the winding direction A, the termination end of one of the first pole piece 111 and the second pole piece 112 is flush with the termination end of the other or located at the rear side of the other, and the termination end of the one located at the rear side can serve as the termination end 114 of the pole piece, that is, the termination end 114 of the pole piece is the termination end of the one with the rearmost termination end among all the pole pieces 11, and the adhesive layer 123 of the outer side surface 1223 of the second insulating member can be set to extend at least to the termination end 114 of the pole piece.

[0148] The inner side surface 1222 of the second isolating member is provided with an adhesive layer 123 from the starting end to the ending end, which can improve the adhesion between the inner side surface 1222 of the second isolating member and the adjacent inner pole piece 11. The outer side surface 1223 of the second isolating member is provided with an adhesive layer 123 from the starting end to the second isolating member ending section 1221, which can improve the adhesion between the outer side surface 1223 of the second isolating member and the adjacent outer pole piece 11.

[0149] According to some embodiments of the present application, optionally, as Figure 4 As shown, along the winding direction A, the terminal end of the tail section of the first insulating member (which can be understood with reference to the terminal end 1217 of the first insulating member) exceeds the terminal end of the tail section 1221 of the second insulating member or the terminal end of the tail section 1211 of the first insulating member is flush with the terminal end of the tail section 1221 of the second insulating member, and the starting end 1224 of the second insulating member exceeds the terminal end 1112 of the first pole piece and the terminal end 1122 of the second pole piece.

[0150] Illustratively, along the winding direction A, the terminal end of the first separator tail section 1211 (which can be understood with reference to the terminal end 1217 of the first separator) can be flush with the terminal end of the second separator tail section 1221. Illustratively, along the winding direction A, the terminal end of the first separator tail section 1211 can be located behind the terminal end of the second separator tail section 1221.

[0151] The starting end of the second isolation member tail section 1221 exceeds the terminal end 1112 of the first pole piece and the terminal end 1122 of the second pole piece, that is, the starting end of the second isolation member tail section 1221 is on the rear side of the terminal end 114 of the pole piece, wherein the second isolation member tail section 1221 can exceed the terminal end 114 of the pole piece by one to three circles.

[0152] Along the winding direction A, the tail section 1211 of the first isolation member can cover the second isolation member 122, reducing the possibility of the terminal end 1225 of the second isolation member being exposed on the outside of the first isolation member 121. After the roll is wound, the tail section 1211 of the first isolation member can be temporarily restrained using only tape, which is convenient to operate.

[0153] Along the winding direction A, the second isolating member tail section 1221 and the first isolating member tail section 1211 both extend beyond the terminal end 114 of the pole piece, thereby improving the isolation effect of the isolating member 12 on the pole piece 11 and reducing the possibility of short circuit of the pole piece 11 .

[0154] According to some embodiments of the present application, optionally, an area of ​​the first isolation member 121 configured as the bonding surface is coated with an adhesive to form a bonding layer 123 .

[0155] Exemplarily, the area of ​​the second isolation member 122 configured as the bonding surface may also be coated with an adhesive to form a bonding layer 123 .

[0156] The adhesive on the inner side 1214 of the first isolating member and the adhesive on the outer side 1215 of the first isolating member can be made of the same material or different materials; the adhesive on the inner side 1222 of the second isolating member and the adhesive on the outer side 1223 of the second isolating member can be made of the same material or different materials. The adhesive on the first isolating member 121 and the adhesive on the second isolating member 122 can be made of the same material or different materials.

[0157] The adhesive layer 123 is coated on the corresponding area of ​​the isolation member 12 , which is easy to implement and convenient to process.

[0158] like Figure 4 、 Figure 5 and Figure 7 As shown, the embodiment of the present application provides an electrode assembly 10, including a pole piece 11 and a separator 12, the pole piece 11 and the separator 12 are stacked and wound to form a roll having a winding start section and a winding end section, the separator 12 includes a first separator 121, along the winding direction A of the pole piece 11 and the separator 12, the first separator 121 extends from the starting end of the winding start section to the ending end of the winding end section, the first separator 121 has a first separator end section 1211, along the pole piece 11 and the separator 12 In the stacking direction of the components 12, the first insulating member tail section 1211 is covered on the outside of the electrode 11 and at least partially forms the outer peripheral surface of the electrode assembly 10 (i.e., the coil); along the stacking direction, the side of the first insulating member tail section 1211 facing the winding starting section is the first side 1212, and the side of the first insulating member tail section 1211 away from the winding starting section is set as the second side 1213, the first side 1212 is set as the bonding surface having the bonding layer 123, and the second side 1213 is set as the non-bonding surface.

[0159] The electrode assembly 10 may be the electrode assembly 10 of the battery cell 130 proposed in this application or any embodiment of this application.

[0160] The electrode assembly 10 of this embodiment has the same beneficial effects as the battery cell 130 proposed in this application or any embodiment of this application.

[0161] The embodiment of the present application further provides a battery device 100 , comprising a plurality of battery cells 130 proposed in the present application or any embodiment of the present application.

[0162] The battery device 100 may further include a housing 110 . A plurality of battery cells 130 may form a battery cell assembly 120 and be disposed in the housing 110 .

[0163] The battery device 100 of this embodiment has the same beneficial effects as the battery cell 130 proposed in this application or any embodiment of this application.

[0164] An embodiment of the present application also provides an electrical device, which includes the battery cell 130 proposed in the present application or any embodiment of the present application, or the electrical device includes the battery device 100 proposed in the present application or any embodiment of the present application, and the battery cell 130 or the battery device 100 is used to store or provide electrical energy.

[0165] The power-consuming device may be any of the above-mentioned battery-powered systems or devices.

[0166] The electrical equipment of this embodiment has the same beneficial effects as the battery cell 130 proposed in this application or any embodiment of this application.

[0167] like Figures 3 to 5 、 Figure 7 As shown, this embodiment provides a battery cell 130, including a housing 131 and an electrode assembly 10, wherein the electrode assembly 10 is disposed within the housing 131. The electrode assembly 10 includes a first electrode sheet 111, a first separator 121, a second electrode sheet 112, and a second separator 122. The first electrode sheet 111, the first separator 121, the second electrode sheet 112, and the second separator 122 are stacked and wound in sequence to form a roll having a winding start section and a winding end section. The first electrode sheet 111 is a negative electrode sheet, the second electrode sheet 112 is a positive electrode sheet, and the first separator 121 and the second separator 122 are both separators. Along the winding direction A, the starting end 1216 of the first isolating member and the starting end 1224 of the second isolating member are both located at the front end of the starting end 113 of the pole piece (when the starting end 1111 of the first pole piece and the starting end 1121 of the second pole piece are not flush, the starting end of the one with the front starting end is the starting end 113 of the pole piece). Figure 4 and Figure 512) and the starting end 1224 of the second isolating member can be arranged roughly flush; along the winding direction A, the first isolating member 121 and the second isolating member 122 extend from the starting end of the winding starting section to the terminating end of the winding ending section respectively, the first isolating member 121 has a first isolating member terminating section 1211, and the second isolating member 122 has a second isolating member terminating section 1221. Along the stacking direction of the electrode piece 11 and the isolating member 12, the first isolating member terminating section 1211 is covered on the outside of the first electrode piece 111, the second electrode piece 112 and the second isolating member 122, and the first isolating member terminating section 1211 at least partially forms the outer peripheral surface of the electrode assembly 10 (i.e., the coil); along the winding direction A, the terminating end of the first isolating member terminating section 1211 is flush with the terminating end of the second isolating member terminating section 1221, and the starting end of the first isolating member terminating section 1211 (refer to Figure 4 and Figure 5 The first and second separator end sections 1211 and 1221 each wrap around the electrode assembly 10 more than once. The side of the first separator end section 1211 facing the winding starting section is defined as a first side 1212, and the side of the first separator end section 1211 facing away from the winding starting section is defined as a second side 1213. Along the winding direction A, from the starting end 1216 to the ending end of the first isolating member, the inner side surface 1214 of the first isolating member is configured as a bonding surface having the bonding layer 123, the inner side surface 1214 of the first isolating member and the first side surface 1212 are oriented in the same direction, and the inner side surface 1214 of the first isolating member includes the first side surface 1212, along the winding direction A, from the starting end 1216 of the first isolating member to the starting end of the first isolating member tail section 1211 (refer to Figure 4 and Figure 5 (As understood by the dotted line B in FIG), the outer side surface 1215 of the first separator is configured as a bonding surface having an adhesive layer 123. The outer side surface 1215 of the first separator is oriented in the same direction as the second side surface 1213, and the second side surface 1213 is configured as a non-bonding surface. Along the winding direction A, the inner side surface 1222 and the outer side surface of the second separator are both configured as bonding surfaces having an adhesive layer 123, and the adhesive layer 123 of the inner side surface 1222 of the second separator extends from the starting end 1224 to the ending end of the second separator. Along the winding direction A, the adhesive layer 123 of the outer side surface 1223 of the second separator extends from the starting end 1224 of the second separator to at least the ending end 1225 of the second separator.

[0168] The above description of the various embodiments tends to emphasize the differences between the various embodiments. The same or similar aspects can be referenced with each other and will not be repeated herein for the sake of brevity.

[0169] 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 make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions 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: include: shell; an electrode assembly disposed in the housing, the electrode assembly comprising a pole piece and a separator, the separator being used to electrically insulate two adjacent pole pieces and to transmit ions between the two adjacent pole pieces, the pole piece and the separator being stacked and wound to form a roll having a winding start section and a winding end section, the separator comprising a first separator extending from a starting end of the winding start section to a terminating end of the winding end section along a winding direction of the pole piece and the separator, the first separator having a first separator end section, which, along a stacking direction of the pole piece and the separator, covers the outer side of the pole piece and at least partially forms an outer peripheral surface of the electrode assembly; Along the stacking direction, the side of the first insulating member tail section facing the winding starting section is the first side, and the side of the first insulating member tail section away from the winding starting section is set as the second side. The first side is set as the bonding surface with an adhesive layer, and the second side is set as the non-bonding surface without an adhesive layer.

2. The battery cell according to claim 1, wherein: Along the winding direction, from the starting end to the ending end of the first isolating member, the inner side surface of the first isolating member is configured as an adhesive surface having an adhesive layer, and the inner side surface of the first isolating member and the first side surface face the same direction.

3. The battery cell according to claim 1, wherein: Along the winding direction, from the starting end of the first isolating member to the starting end of the tail section of the first isolating member, the outer side surface of the first isolating member is configured as an adhesive surface having an adhesive layer, and the outer side surface of the first isolating member and the second side surface have the same orientation.

4. The battery cell according to claim 1, wherein: Along the winding direction, the tail section of the first isolating member at least partially exceeds the terminal end of the pole piece.

5. The battery cell according to claim 4, characterized in that Along the winding direction, the starting end of the tail section of the first isolating member exceeds the ending end of the electrode sheet, and the tail section of the first isolating member is arranged around the electrode assembly for at least one circle.

6. The battery cell according to claim 5, characterized in that The tail section of the first isolation member is arranged to wrap around the electrode assembly one to three times.

7. The battery cell according to any one of claims 1 to 6, characterized in that: The pole piece includes a first pole piece and a second pole piece with opposite polarities, the separator also includes a second separator, the first pole piece, the first separator, the second pole piece and the second separator are sequentially stacked and wound to form the roll, and the second separator has a second separator tail section; Along the stacking direction, the tail section of the first isolating member is located outside the tail section of the second isolating member, the inner side surface and the outer side surface of the second isolating member are respectively set as bonding surfaces with bonding layers, and the inner side surface and the outer side surface of the second isolating member are set oppositely along the stacking direction.

8. The battery cell according to claim 7, characterized in that Along the winding direction, the adhesive layer on the inner side surface of the second separator extends from the starting end to the ending end of the second separator; And / or, along the winding direction, the adhesive layer on the outer side surface of the second isolating member extends from the starting end of the second isolating member to at least the starting end of the tail section of the second isolating member.

9. The battery cell according to claim 7, characterized in that: Along the winding direction, the terminal end of the first insulating member tail section exceeds the terminal end of the second insulating member tail section or the terminal end of the first insulating member tail section is flush with the terminal end of the second insulating member tail section, and the starting end of the second insulating member tail section exceeds the terminal end of the first pole piece and the terminal end of the second pole piece.

10. The battery cell according to any one of claims 1 to 6, characterized in that: The area of ​​the first isolating member configured as the bonding surface is coated with an adhesive to form the bonding layer.

11. An electrode assembly, characterized in that: The electrode assembly comprises a pole piece and a separator, wherein the pole piece and the separator are stacked and wound to form a roll having a winding start section and a winding end section, wherein the separator comprises a first separator, and along the winding direction of the pole piece and the separator, the first separator extends from the starting end of the winding start section to the ending end of the winding end section, and the first separator has a first separator end section, and along the stacking direction, the first separator end section covers the outside of the pole piece and at least partially forms the outer peripheral surface of the electrode assembly; Along the stacking direction, the side of the first insulating member tail section facing the winding starting section is the first side, and the side of the first insulating member tail section away from the winding starting section is set as the second side. The first side is set as the bonding surface having an adhesive layer, and the second side is set as the non-bonding surface.

12. A battery device, characterized in that: The invention comprises a plurality of battery cells according to any one of claims 1 to 10.

13. An electrical device, characterized in that: The battery cell comprises the battery cell according to any one of claims 1 to 10 or the battery device according to claim 12, wherein the battery cell is used to store or provide electrical energy.

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