Battery cell, battery and electric device

Abstract

The present application belongs to the technical field of batteries. Provided are a battery cell, a battery and an electric device. The battery cell comprises a battery electrode sheet. The battery electrode sheet comprises a current collector, an active layer, a first insulating layer and a second insulating layer, wherein a connecting surface is formed on the current collector; the active layer covers part of the connecting surface, and a first edge is formed on the connecting surface; the first insulating layer covers part of the connecting surface, and the first insulating layer is arranged to extend along the first edge; and the second insulating layer covers the first insulating layer. The present application aims to reduce the risk of burr exposure during electrode sheet die-cutting, thereby reducing the risk of short circuits in battery cells.

Description

Battery cells, batteries and electrical devices

[0001] This application claims priority to Chinese Patent Application No. 2024105028539, filed on April 25, 2024, entitled "Battery Cell, Battery and Electrical Device", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of battery technology, and in particular to a method for assembling a battery cell, a battery, and an electrical device. Background Technology

[0003] A battery cell typically includes a positive electrode, a negative electrode, a separator, and a casing. The positive electrode, negative electrode, and separator are assembled into an electrode assembly by winding or stacking. The electrode assembly is then placed into the casing and injected with electrolyte to form a battery cell.

[0004] In the manufacturing process of battery electrodes, both the positive and negative electrodes need to be die-cut. Die-cutting of battery electrodes refers to the process of cutting or slicing the battery electrodes from the raw material into the required size and shape, such as cutting out tabs. Die-cutting is one of the key steps in the manufacturing process of a battery cell, and its quality and precision directly affect the performance and stability of the battery cell.

[0005] In related technologies, during the die-cutting of the electrode sheet, burrs are easily generated at the cut edges. These burrs can easily pierce the separator, causing the positive and negative electrode sheets to conduct electricity. This cannot guarantee the insulation between the positive and negative electrode sheets, leading to a short circuit risk.

[0006] Summary of the Invention

[0007] The purpose of this application is to provide an assembly method for a battery cell, a battery, and an electrical device, which aims to solve the technical problem that burrs are easily generated during the electrode die-cutting process, leading to a risk of short circuit in the battery cell. Technical solutions

[0008] The technical solution adopted in the embodiments of this application is:

[0009] In a first aspect, this application provides a battery cell, including battery electrodes, wherein the battery electrodes include:

[0010] The current collector has a connecting surface;

[0011] An active layer covers a portion of the connecting surface and forms a first edge on the connecting surface;

[0012] A first insulating layer covers a portion of the connecting surface, and the first insulating layer extends along the first edge;

[0013] A second insulating layer covers the first insulating layer.

[0014] In this example, a first insulating layer and a second insulating layer are applied and covered at the die-cutting position of the current collector, respectively. The first insulating layer is directly connected to the current collector, and it can insulate the current collector, thereby reducing the risk of short circuits and leakage between the electrodes during winding. The second insulating layer covers the first insulating layer, thereby increasing the overall thickness of the insulating layer. During die-cutting, the current collector, the first insulating layer, and the second insulating layer are cut simultaneously, so that the first insulating layer and the second insulating layer form a thicker wrap around the cut position of the current collector, making it less likely for burrs to be exposed, reducing the risk of burr exposure, and thus reducing the risk of short circuits in individual battery cells.

[0015] In one embodiment, the second insulating layer has a second edge disposed near the first edge, the second edge being spaced apart from the first edge.

[0016] In this example, by setting the second insulating layer and the active layer alternately, the second insulating layer can be made of a material with relatively low cost and relatively low thermal stability, which helps to reduce the production cost of the battery electrode. In addition, setting the space between the electrodes helps to close the tabs and reduces the risk of the battery electrode bulging.

[0017] In one embodiment, the first insulating layer has a third edge disposed near the first edge, the third edge being connected to or spaced apart from the first edge.

[0018] In this example, the first insulating layer and the active layer are spaced apart, which can further increase the space, which is conducive to the closing of the tabs and further reduces the risk of the battery electrode bulging. In addition, it reduces the risk of fusion and penetration between the first insulating layer and the active layer. When the first insulating layer is connected to the active layer, the first insulating layer can be made of a material with higher thermal stability than the second insulating layer, which is beneficial to improving the thermal stability of the entire electrode.

[0019] In one embodiment, a first gap space is formed between the second edge and the first edge, and the first gap space has a first gap distance along a direction parallel to the connecting surface, the first gap distance being greater than 0 mm and less than or equal to 3 mm.

[0020] In this example, setting the first interval distance to be greater than 0 mm and less than or equal to 3 mm helps to ensure that the tabs have sufficient space to retract, reduces the risk of battery electrode bulging, and is less likely to cause energy density loss in the battery, thus helping to ensure stable battery performance.

[0021] In one embodiment, the second insulating layer further has a fourth edge disposed away from the active layer, the fourth edge being disposed opposite to the second edge and extending to the surface of the current collector.

[0022] In this example, the fourth edge extends to the surface of the current collector, allowing the second insulating layer to directly connect and adhere to the connection surface of the current collector, thereby enhancing the connection strength between the second insulating layer and the connection surface and reducing the risk of the first and second insulating layers detaching from the connection surface of the current collector.

[0023] In one embodiment, where the third edge is spaced apart from the first edge, the second edge extends to the surface of the current collector.

[0024] In this example, the second edge extends to the surface of the current collector, allowing the second insulating layer to directly connect and adhere to the connection surface of the current collector, thereby enhancing the connection strength between the second insulating layer and the connection surface and reducing the risk of the first and second insulating layers detaching from the connection surface of the current collector.

[0025] In one embodiment, the second insulating layer has a second edge disposed near the first edge, the second edge being in contact with the first edge.

[0026] In this example, the second insulating layer covers the upper part of the first insulating layer, so that the second insulating layer is directly connected to the active layer. This improves the overall consistency between the active layer and the second insulating layer on the connection surface of the current collector, and enhances the connection strength between the second insulating layer and the active layer, thereby strengthening the overall stability of the electrode.

[0027] In one embodiment, the second insulating layer has a fourth edge disposed away from the first edge, the fourth edge being disposed opposite to the second edge, and the fourth edge extending to the surface of the current collector.

[0028] In this example, the edge of the second insulating layer on the side away from the active layer extends to the surface of the current collector, allowing the second insulating layer to directly connect and adsorb with the connection surface of the current collector. This enhances the connection strength between the second insulating layer and the connection surface, which helps reduce the risk of the first and second insulating layers detaching from the connection surface of the current collector, improves the connection strength between the first and second insulating layers and the connection surface of the current collector, and enhances the reliability of the battery electrode.

[0029] In one embodiment, the second edge extends onto the surface of the active layer away from the current collector.

[0030] In this example, the second insulating layer forms a wrapping area or overlaps the entire first edge of the active layer, resulting in a smooth transition at the connection between the second insulating layer and the active layer. This prevents the formation of obvious steps at the connection between the second insulating layer and the active layer, which helps suppress lithium plating in lithium-ion batteries and enables them to have excellent cycle performance.

[0031] In one embodiment, the first insulating layer has a first width in a direction parallel to the connection surface and in a direction away from the active layer, and the second insulating layer has a second width, the second width being less than or equal to the first width.

[0032] In this example, by controlling the relative size of the first width of the first insulating layer and the second width of the second insulating layer, the relative position of the second insulating layer with respect to the first insulating layer can be flexibly adjusted, thereby reducing the risk of battery bulging and the risk of insulating layer detachment.

[0033] In one embodiment, the first insulating layer has a first width in a direction parallel to the connection surface and in a direction away from the active layer, and the second insulating layer has a second width greater than the first width, such that the second insulating layer extends to connect with the connection surface.

[0034] In this example, by controlling the relative size of the first width of the first insulating layer and the second width of the second insulating layer, the relative position of the second insulating layer with respect to the first insulating layer can be flexibly adjusted, thereby reducing the risk of the insulating layer falling off.

[0035] In one embodiment, the first width is 1mm-20mm; and / or

[0036] The second width is 1mm-20mm.

[0037] In this example, the width design of the first and second insulating layers is adapted to the type of battery, using a width design of 1mm-20mm, which helps to reduce production costs while ensuring insulation performance requirements.

[0038] In one embodiment, the first insulating layer has a first thickness, the second insulating layer has a second thickness, and the active layer has a third thickness, wherein the sum of the first and second thicknesses is less than the third thickness; or, the second thickness is less than the third thickness.

[0039] In this example, increasing the thickness of the active layer helps to provide sufficient energy storage capacity and electrochemical reaction active surface area. Making the sum of the thicknesses of the first insulating layer and the second insulating layer less than the thickness of the active layer helps to reduce the manufacturing cost of the battery and improve the energy density of the battery.

[0040] In one embodiment, the second thickness is 3μm-50μm.

[0041] In this example, by controlling the thickness of the second insulating layer, the electron and ion transport paths inside the battery can be adjusted, optimizing the battery's charge and discharge performance, cycle life, and safety performance. It can also make greater use of space and increase the loading of active materials, thereby increasing the battery's energy density and power density.

[0042] In one embodiment, the second thickness is 10μm-30μm.

[0043] In this example, controlling the thickness of the second insulating layer between 10μm and 30μm can better regulate the electron and ion transport paths inside the battery, optimize the battery's charge and discharge performance, cycle life, and safety performance, and help improve the internal thermal conductivity of the battery, which helps to dissipate heat better, reduce heat accumulation, and thus improve the battery's safety and stability.

[0044] In one embodiment, the first insulating layer includes a first solvent, the second insulating layer includes a second solvent, the active layer includes a third solvent, the third solvent being either an aqueous solvent or an oil-based solvent, and the first solvent and / or the second solvent being either an aqueous solvent or an oil-based solvent.

[0045] In this example, since there is a risk of fusion and penetration between the active layer and the first and second insulating layers, when the active layer is in contact with the first or second insulating layer, the third solvent of the active layer can be made to be an incompatible solvent with the first and second solvents, thereby making it less likely for the active layer to penetrate between the first and second insulating layers.

[0046] In one embodiment, both the third solvent and the second solvent are oil-based solvents, and the first solvent is an aqueous solvent.

[0047] In this example, when manufacturing the electrode, a first insulating layer can be coated on the connection surface first. The first solvent is an aqueous solvent, which has a faster drying rate. Aqueous solvents have stronger adhesion, which can form a stronger bond with the current collector. They are also environmentally friendly and low in cost. The second and third solvents are both oil-based solvents, so the second insulating wire and the active layer can be coated at the same time. Oil-based solvents have a better film-forming effect, which can improve the density and uniformity of the electrode surface.

[0048] Secondly, this application provides a battery that includes the battery cell described in the above embodiments.

[0049] Thirdly, this application provides an electrical device that includes the battery cell or battery described in the above embodiments, wherein the battery is used to provide electrical energy.

[0050] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0051] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0052] Figure 1 is a structural schematic diagram of a vehicle provided in some embodiments of this application;

[0053] Figure 2 is an exploded structural diagram of a battery provided in some embodiments of this application;

[0054] Figure 3 is a schematic diagram of the exploded structure of a battery provided in some embodiments of this application;

[0055] Figure 4 is a schematic diagram of the structure on the connection surface of the battery electrode in a battery cell provided in some embodiments of this application;

[0056] Figure 5 is a schematic diagram of the structure of a battery cell after the current collector in the battery electrode is coated with a first insulating layer according to some embodiments of this application;

[0057] Figure 6 is a schematic diagram of the structure of the current collector in the battery electrode of a battery cell after being coated with a first insulating layer and an active layer according to some embodiments of this application;

[0058] Figure 7 is a schematic diagram of the current collector in the battery electrode of a battery cell after die cutting, according to some embodiments of this application.

[0059] Figure 8 is AA view one of Figure 4;

[0060] Figure 9 is the second view of AA in Figure 4;

[0061] Figure 10 is the third view of Figure 4 (AA).

[0062] Figure 11 is the fourth view of Figure 4 (AA).

[0063] Figure 12 is view AA of Figure 4;

[0064] Figure 13 is AA view six of Figure 4;

[0065] Figure 14 is AA view seven of Figure 4;

[0066] Figure 15 is the AA view of Figure 4 (8);

[0067] Figure 16 is AA view nine of Figure 4;

[0068] Figure 17 is the AA view of Figure 4.

[0069] Explanation of reference numerals in the attached drawings: 1000, vehicle; 1100, battery; 1110, housing; 1111, first part; 1112, second part; 1113, accommodating space; 1120, battery cell; 1121, battery electrode; 11211, current collector; 112111, connection surface; 11212, active layer; 112121, first edge; 11213, first insulating layer; 112131, third edge; 11214, second insulating layer; 112141, second edge; 112142, fourth edge; 11215, tab; B1, first thickness; B2, second thickness; B3, third thickness; D1, first spacing distance; D2, second spacing distance; L1, first width; L2, second width; 1200, controller; 1300, motor. Detailed Implementation

[0070] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0071] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0072] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0073] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0074] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0075] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0076] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0077] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0078] A battery cell typically includes a positive electrode, a negative electrode, a separator, and a casing. The positive electrode, negative electrode, and separator are assembled into an electrode assembly by winding or stacking. The electrode assembly can be understood as a cell. The electrode assembly is installed in the casing and injected with electrolyte to form a battery cell.

[0079] In the manufacturing process of battery electrodes, both the positive and negative electrodes need to be die-cut. Die-cutting of battery electrodes refers to the process of cutting or slicing the battery electrodes from the raw material into the required size and shape, such as cutting out tabs. Die-cutting is one of the key steps in the manufacturing process of a battery cell. The die-cutting operation is usually carried out using a die-cutting machine or cutting tool. By placing the current collector in the appropriate position and then applying appropriate force or pressure, the current collector is cut into the required shape and size. The quality and precision of the cut directly affect the performance and stability of the battery cell.

[0080] In related technologies, burrs are easily generated at the cut edges of the electrode sheets during die-cutting. These burrs can easily puncture the separator, causing the positive and negative electrode sheets to conduct electricity. This cannot guarantee the insulation of the positive and negative electrode sheets and can easily lead to short circuit risks.

[0081] Therefore, this application provides a battery cell 1120, which includes a battery electrode 1121. The battery electrode 1121 enables the current collector 11211 to have reliable insulation and can effectively wrap the burrs generated during die cutting, reducing the risk of burr leakage. Since the burrs are wrapped, the risk of burrs piercing the separator is reduced when the positive electrode, negative electrode and separator are wound, thereby reducing the risk of short circuit in the electrode assembly and improving the reliability of the battery cell 1120.

[0082] Specifically, referring to Figures 2 and 3, this application embodiment provides an exploded structural diagram of a battery 1100. The battery 1100 may include a battery cell 1120. The battery 1100 disclosed in this application embodiment can be used in electrical devices that use the battery 1100 as a power source or in various energy storage systems that use the battery 1100 as an energy storage element. Electrical devices may include, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys may include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft may include airplanes, rockets, space shuttles, and spacecraft, etc.

[0083] For ease of explanation, the following embodiments will be described using a vehicle 1000 as an example of an electrical device according to an embodiment of this application.

[0084] Example 1

[0085] Please refer to Figure 1, which is a structural schematic diagram of a vehicle 1000 provided in some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery 1100 is installed inside the vehicle 1000, and the battery 1100 can be located at the bottom, front, or rear of the vehicle 1000. The battery 1100 can be used to power the vehicle 1000; for example, the battery 1100 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 1200 and a motor 1300. The controller 1200 is used to control the battery 1100 to supply power to the motor 1300, for example, to meet the power needs of the vehicle 1000 during startup, navigation, and driving.

[0086] In some embodiments of this application, the battery 1100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0087] Please refer to Figures 2 and 3, which are exploded structural diagrams of the battery 1100 provided in some embodiments of this application. The battery 1100 includes a housing 1110 and a battery cell 1120, with the battery cell 1120 housed within the housing 1110. The housing 1110 provides a accommodating space 1113 for the battery cell 1120, and the housing 1110 can adopt various structures. In some embodiments, the housing 1110 may include a first portion 1111 and a second portion 1112, which overlap each other, and together define the accommodating space 1113 for accommodating the battery cell 1120. The second part 1112 can be a hollow structure with one end open, and the first part 1111 can be a plate-like structure. The first part 1111 covers the open side of the second part 1112, so that the first part 1111 and the second part 1112 together define the accommodating space 1113. Alternatively, the first part 1111 and the second part 1112 can both be hollow structures with one side open, and the open side of the first part 1111 covers the open side of the second part 1112. Of course, the box 1110 formed by the first part 1111 and the second part 1112 can be of various shapes, such as a cylinder, a cuboid, etc.

[0088] The battery 1100 can be a module composed of multiple battery cells 1120 connected in series, parallel, or in a mixed configuration. These battery modules can then be connected in series, parallel, or in a mixed configuration to form a single unit. For example, the multiple battery cells 1120 within a battery module can be arranged in an array and housed within a casing 1110. The battery 1100 may also include other structures; for instance, it may include a busbar component for electrical connection between the multiple battery cells 1120.

[0089] A battery cell 1120 refers to the smallest unit that makes up a battery 1100. Each battery cell 1120 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited to these. The battery cell 1120 can be cylindrical, flat, cuboid, or other shapes.

[0090] The positive and negative electrodes in the battery cell 1120 are the two poles of the battery 1100, playing a crucial role within the battery 1100. The positive electrode is typically composed of one or more positive electrode active materials, such as oxides or phosphates. Its function is to accept electrons and release positive ions during battery discharge. These positive ions pass through the electrolyte, generating current in the battery cell 1120. During charging, the positive electrode absorbs electrons, storing the positive ions. Similarly, the negative electrode is typically composed of one or more negative electrode active materials, such as carbon or lithium. Its function is to release electrons and absorb positive ions during battery discharge. During charging, the negative electrode absorbs positive ions and releases electrons. The positive and negative electrode plates play complementary roles in the battery cell 1120. Through chemical reactions during the charging and discharging process, the battery cell 1120 is able to store and release energy. This chemical reaction is the basis for the operation of the battery cell 1120 and the principle by which the battery 1100 can provide electrical energy.

[0091] According to some embodiments of this application, as shown in Figures 4-7, this application provides a battery cell 1120, which includes a battery electrode 1121. The battery electrode 1121 includes a current collector 11211, an active layer 11212, a first insulating layer 11213, and a second insulating layer 11214. The current collector 11211 has a connecting surface 112111. The active layer 11212 covers a portion of the connecting surface 112111 and forms a first edge 112121 on the connecting surface 112111. The first insulating layer 11213 covers a portion of the connecting surface 112111 and extends along the first edge 112121. The second insulating layer 11214 covers the first insulating layer 11213.

[0092] The battery electrode 1121 can be either a positive or negative electrode. The positive and negative electrodes are wound or stacked to form a battery cell. The battery cell is one of the core components of the battery 1100, converting chemical energy into electrical energy. The basic structure of the battery cell includes a positive electrode, a negative electrode, an electrolyte, a separator, and tabs 11215. Tabs 11215 include a positive tab connected to the positive electrode and a negative tab connected to the negative electrode. The positive and negative electrodes are separated by the electrolyte and the separator. During discharge, the positive and negative electrodes undergo a redox reaction, generating current. Battery cell types include lithium-ion cells (Li-ion), nickel-metal hydride cells (NiMH), and nickel-cadmium cells (NiCd). Lithium-ion cells are characterized by high energy density and lightweight design.

[0093] Specifically, the current collector 11211 can be considered as the substrate layer of the battery electrode 1121. In the battery cell 1120, the current collector 11211 mainly acts as a conductor and carrier for the active material (i.e., the active layer 11212), collecting and outputting the current generated by the active material or inputting the electrode current to the active material, thus promoting the conversion between chemical energy and electrical energy. The main function of the current collector 11211 is to collect the current generated by the active material in the battery cell 1120 to form a larger current for external output.

[0094] The current collector 11211 adopts a sheet structure. The current collector 11211 is generally made of metal foil, including copper foil, aluminum foil, etc. For example, the positive electrode of the lithium battery 1100 can be made of aluminum foil, and the negative electrode can be made of copper foil. Both copper foil and aluminum foil have a certain degree of flexibility, which can meet the requirements of the winding process of cell manufacturing. In addition, the thinness of copper foil and aluminum foil can improve the energy density of the lithium-ion battery 1100.

[0095] The current collector 11211 has a sheet-like structure, therefore it is known that the current collector 11211 has two back-to-back surfaces, and these are relatively large surfaces. The connecting surface 112111 can be either of the two surfaces of the current collector 11211, meaning that either surface of the current collector 11211 is covered with the active layer 11212. Of course, there can be two connecting surfaces 112111, meaning that the two back-to-back surfaces of the current collector 11211 are two connecting surfaces 112111, and both connecting surfaces 112111 are covered with the active layer 11212. The connecting surface 112111 can be planar or curved.

[0096] For the connecting surface 112111 of the current collector 11211, the connecting surface 112111 can be divided into a first connecting surface and a second connecting surface. It should be noted that the division of these two regions is for the purpose of subsequently defining the positions of the active layer 11212 and the first insulating layer 11213. The first connecting surface and the second connecting surface are virtual definitions and do not represent an actual division of the connecting surface 112111. The first connecting surface and the second connecting surface can be two adjacent regions, or they can be two regions spaced apart on the connecting surface 112111.

[0097] An active layer 11212 covers the first connecting surface, and the active layer 11212 has a first edge 112121 formed on the first connecting surface. The first edge 112121 refers to the boundary position of the active layer 11212 coated on the first connecting surface. The first edge 112121 is the edge of the active layer 11212 corresponding to the first insulating layer 11213. The first insulating layer 11213 covers the second connecting surface, and the first insulating layer 11213 is coated along the extension direction of the first edge 112121, so that the first insulating layer 11213 can extend horizontally parallel to the first edge 112121 of the active layer 11212.

[0098] The active layer 11212 is a layer of material located on the connection surface 112111 of the current collector 11211. The active layer 11212 participates in the electrochemical reaction of the battery cell 1120 and undergoes lithium ion adsorption and release during charging and discharging. The presence of the active layer 11212 increases the effective surface area of ​​the battery electrode 1121, thereby improving the performance and energy density of the battery cell 1120.

[0099] For example, in a lithium-ion battery cell 1120, the active layer 11212 of the positive electrode can be made of lithium-ion compound, and correspondingly, the active layer 11212 of the negative electrode can be made of carbon material. The negative electrode absorbs lithium ions during charging and releases lithium ions after charging is completed, thus realizing the charging and discharging process of the battery cell 1120.

[0100] For the positive electrode, the active layer 11212 typically includes lithium-ion compounds, such as cobalt oxide, nickel manganese cobalt oxide, etc. Specifically, the active layer 11212 can be coated with lithium cobalt oxide, lithium iron phosphate, lithium manganese oxide, etc. The above compounds can absorb lithium ions during charging to form lithium compounds and release lithium ions after charging is completed.

[0101] For the negative electrode, the active layer 11212 of the negative electrode usually includes carbon materials, such as graphite. Carbon materials have good conductivity and stability, and can effectively adsorb and release lithium ions to realize the charging and discharging process of the battery 1100.

[0102] The active layer 11212 is connected to the connecting surface 112111 of the current collector 11211 and covers part of the connecting surface 112111 (specifically the first connecting surface). The active layer 11212 can be connected to the current collector 11211 by coating. The active layer 11212 covers the connecting surface 112111, and the edge of the active layer 11212 forms the first edge 112121. That is, the first edge 112121 is the boundary of the active layer 11212 formed on the current collector 11211. The first edge 112121 can have a certain shape. For example, the first edge 112121 can extend in a line. For example, the line includes a straight line, a curve, or an irregular combination of curves.

[0103] The first insulating layer 11213 may be made of polymer film (e.g., polypropylene, polyethylene, polyimide, etc.), ceramic material (e.g., alumina, etc.), composite material or glass fiber material, etc. Specifically, for example, the first insulating layer 11213 may be made of one or more of boehmite, calcium oxide, magnesium oxide and calcium carbonate.

[0104] The first insulating layer 11213 is connected to the connection surface 112111 of the current collector 11211, and covers a portion of the connection surface 112111 (specifically the second connection surface). The first insulating layer 11213 serves as insulation on the current collector 11211, reducing the risk of short circuits and leakage in the battery 1100. The first insulating layer 11213 on the current collector 11211 effectively reduces the risk of direct contact between the positive and negative electrode plates, thereby reducing the probability of short circuits or leakage in the battery cell 1120. Furthermore, the first insulating layer 11213 can... The insulation performance of the battery cell 1120 is effectively improved, the current conduction between the electrode and the external environment is reduced, and the electrical contact between the battery 1100 and the external environment is reduced, so that the battery cell 1120 can work normally in an environment with minimal external interference. Furthermore, the first insulating layer 11213 can also protect the current collector 11211. The first insulating layer 11213 can reduce the erosion and damage of the current collector 11211 by the external environment. Especially in high temperature, high humidity and corrosive environments, the first insulating layer 11213 forms a protective layer on the surface of the current collector 11211, which is beneficial to extending the service life of the electrode.

[0105] During the manufacturing process of battery 1100, a portion of the connecting surface 112111 of the current collector 11211 is used to coat the active layer 11212, while the remaining portion of the connecting surface 112111 can be considered a blank area. This portion of the connecting surface 112111 is used to coat the first insulating layer 11213, extending along the first edge 112121 of the active layer 11212, thereby protecting the first edge 112121 of the active layer 11212. The first insulating layer 11213 may be in contact with the first edge 112121 of the active layer 11212, or it may be spaced apart from the first edge 112121 of the active layer 11212.

[0106] As for the second insulating layer 11214, the second insulating layer 11214 also has the properties and functions of insulation. The second insulating layer 11214 can also be made of polymer film (e.g., polypropylene, polyethylene, polyimide, etc.), ceramic material (e.g., alumina, etc.), composite material or glass fiber material, etc. Specifically, for example, the first insulating layer 11213 can be made of one or more of boehmite, calcium oxide, magnesium oxide and calcium carbonate.

[0107] The second insulating layer 11214 is connected to the first insulating layer 11213 and is located on the side of the first insulating layer 11213 that is away from the current collector 11211. For example, when the current collector 11211 is placed horizontally, the first insulating layer 11213 can be considered to be above the current collector 11211 and the second insulating layer 11214 is above the first insulating layer 11213.

[0108] In the specific process of manufacturing the battery electrode 1121, a current collector 11211 is first prepared, and then an active layer 11212 is coated on a portion of the connecting surface 112111 of the current collector 11211. The active layer 11212 forms a first edge 112121 on the current collector 11211. Then, a first insulating layer 11213 is coated on a portion of the connecting surface 112111 along the edge of the active layer 11212. The first insulating layer 11213 extends along the first edge 112121 of the active layer 11212. Then, a second insulating layer 11214 is coated on the side of the first insulating layer 11213 that is away from the current collector 11211. After the above coating process is completed, the current collector 11211 can be die-cut. The die-cutting position is the overlapping position of the second insulating layer 11214 and the first insulating layer 11213.

[0109] The overlapping position of the second insulating layer 11214 and the first insulating layer 11213 is the die-cutting position (or cutting position) of the battery electrode 1121. That is to say, the die-cutting blade of the die-cutting device simultaneously cuts the current collector 11211, the first insulating layer 11213, and the second insulating layer 11214. The second insulating layer 11214 is coated on the first insulating layer 11213 to increase the overall thickness of the insulating layer. The current collector 11211 is die-cut, as shown in Figure 7, and can be directly die-cut. During die-cutting of the tab 11215, the second insulating layer 11214 and the first insulating layer 11213 can form a thicker and more complete wrapping around the burrs formed on the cutting edge of the current collector 11211, thereby reducing the risk of burr exposure. Furthermore, by stacking the second insulating layer 11214 and the first insulating layer 11213, a composite insulating coating is formed, making the overall fabrication of the insulating layer more flexible. Moreover, when applying the insulating layer, the first insulating layer 11214 is applied first. 13. The thickness of the first insulating layer 11213 can be appropriately reduced, which helps to reduce the space occupied on the surface of the current collector 11211, saving more space and making it easier to form sufficient space for the tab 11215 position when the electrode is wound, thereby helping to reduce the risk of the battery electrode 1121 bulging. In addition, coating the first insulating layer 11213 first allows the first insulating layer 11213 to dry more quickly, and then the second insulating layer 11214 can be coated on the first insulating layer 11213. The two-coating method is more conducive to the rapid drying of the insulating layer. Compared with the case of coating a thicker insulating layer at once, coating a thicker insulating layer at once will increase the performance requirements of the coating equipment. On the other hand, since the drying problem needs to be considered, the coating thickness of a thicker coating will reduce the coating rate. Therefore, the two-coating method adopted in this application is more conducive to improving the drying efficiency, thereby improving the coating efficiency of the insulating layer and thus improving the production efficiency of the electrode.

[0110] In this example, a first insulating layer 11213 and a second insulating layer 11214 are coated and covered at the die-cut position of the current collector 11211, respectively. The first insulating layer 11213 is directly connected to the current collector 11211, and the first insulating layer 11213 can insulate the current collector 11211, thereby reducing the risk of short circuits and leakage between the electrodes during winding. The second insulating layer 11214 covers the first insulating layer 11213, thereby increasing the overall thickness of the insulating layer. During die-cutting, the current collector 11211, the first insulating layer 11213, and the second insulating layer 11214 are cut simultaneously, so that the first insulating layer 11213 and the second insulating layer 11214 form a thicker wrap around the cut position of the current collector 11211, making it less likely for burrs to be exposed, reducing the risk of burr exposure, and thus reducing the risk of short circuit of the battery cell 1120.

[0111] In some examples, as shown with reference to FIG8-13, the second insulating layer 11214 has a second edge 112141 disposed near the first edge 112121 of the active layer 11212, and the second edge 112141 is disposed at a distance from the first edge 112121.

[0112] The thermal stability of insulating layer materials varies. The higher the thermal stability of a material, the higher its cost. When manufacturing electrode sheets, it is necessary to consider the production cost and make an appropriate selection of insulating layer materials.

[0113] When the thermal stability of the insulating layer material is low, the internal temperature of the battery 1100 rises during use, making the thermal stability of the insulating layer susceptible to damage. This can lead to fusion and penetration between the insulating layer and the active layer 11212, resulting in an unclear boundary between the active layer 11212 and the insulating layer. This poses several risks to the use of the battery 1100. For example, an unclear boundary between the active layer 11212 and the insulating layer may cause a decrease in the performance of the battery 1100, as the main function of the insulating layer is to prevent direct contact between the active layer 11212 and the electrolyte, thereby reducing the risk of short circuits. If the boundary is unclear, it may increase the likelihood of short circuits, leading to unstable performance of the battery 1100. Furthermore, an unclear boundary may cause unnecessary chemical reactions during charging and discharging, increasing the risk of overheating or even fire. Additionally, an unclear boundary between the active layer 11212 and the insulating layer may cause excessive diffusion of the active material in the active layer 11212 during charging and discharging, accelerating battery aging and shortening its lifespan, among other things.

[0114] Therefore, the relative position design of the insulating layer and the active layer 11212 needs to consider factors such as the performance and cost of the battery 1100. Specifically, in this application, considering that the first insulating layer 11213 mainly serves as insulation, making it difficult for the active layer 11212 to come into contact with the electrolyte and other electrodes, and the second insulating layer 11214 covers the upper part of the first insulating layer 11213 to increase the overall thickness of the insulating layer, especially the thickness at the die-cut position, and that the second insulating layer 11214, while serving as insulation, also serves to wrap burrs, the coating thickness of the first insulating layer 11213 can be appropriately reduced to save costs. Since the thickness of the first insulating layer 11213 is relatively small, considering the overall cost, the first insulating layer 11213 can be made of a material with higher thermal stability, while the second insulating layer 11214 can be made of a material with relatively lower cost and relatively lower thermal stability than the first insulating layer 11213, and the second insulating layer 11214 and the active layer 11212 are spaced apart.

[0115] Specifically, the second insulating layer 11214 and the active layer 11212 are spaced apart, that is, the second insulating layer 11214 does not contact the active layer 11212, thereby reducing the risk of fusion and penetration between the second insulating layer 11214 and the active layer 11212, which is beneficial to improving the reliability of the battery 1100 during use.

[0116] Furthermore, the second insulating layer 11214 and the active layer 11212 are spaced apart, which helps to increase the space and facilitates the gathering of the tabs 11215, thereby reducing the risk of bulging during winding.

[0117] In this example, the second insulating layer 11214 and the active layer 11212 are spaced apart. The second insulating layer 11214 can be made of a material with relatively low cost and relatively low thermal stability, which helps to reduce the production cost of the battery electrode 1121. In addition, the spaced interval helps the tab 11215 to be gathered, reducing the risk of the battery electrode 1121 bulging.

[0118] In some examples, as shown with reference to FIG8-13, the first insulating layer 11213 has a third edge 112131 disposed near the first edge 112121, the third edge 112131 being connected to or spaced apart from the first edge 112121.

[0119] Specifically, the first insulating layer 11213 and the active layer 11212 are both coated on the connection surface 112111 of the current collector 11211. Therefore, the first insulating layer 11213 and the active layer 11212 can be connected or spaced apart. The spaced arrangement of the first insulating layer 11213 and the active layer 11212 can further increase the space, which is beneficial for the tab 11215 to be retracted, and further reduces the risk of the battery electrode 1121 bulging.

[0120] Furthermore, under the premise of further reducing production costs, the first insulating layer 11213 can also be made of the same material as the second insulating layer 11214, and the first insulating layer 11213 and the active layer 11212 can be spaced apart, so that the first insulating layer 11213 does not contact the active layer 11212. This reduces the risk of fusion and penetration between the first insulating layer 11213 and the active layer 11212, which is beneficial to improving the reliability of the battery 1100 during use and achieving the goal of reducing production costs.

[0121] When the first insulating layer 11213 is connected to the active layer 11212, the first insulating layer 11213 can be made of a material with higher thermal stability than the second insulating layer 11214. Since the coating thickness of the first insulating layer 11213 is relatively thin, it will not significantly increase the production cost, but it can improve the thermal stability of the entire electrode.

[0122] In some examples, as shown in Figures 8-13, a first gap space is formed between the second edge 112141 and the first edge 112121 of the active layer 11212. Along the direction parallel to the connecting surface 112111, the first gap space has a first gap distance D1, which is greater than 0 mm and less than or equal to 3 mm.

[0123] Specifically, since the active layer 11212 and the first insulating layer 11213 are both coated on the connecting surface 112111 of the current collector 11211, and the second insulating layer 11214 is coated on the first insulating layer 11213, the edge (or boundary line) of the second insulating layer 11214 near the active layer 11212 is defined as the second edge 112141. Therefore, it can be understood that a first gap space is formed between the second edge 112141 and the first edge 112121 of the active layer 11212. This gap space can be considered to be a space parallel to the connecting surface 11212. In the direction of 111, the distance between the second edge 112141 and the first edge 112121 (boundary line) of the active layer 11212 is the first spacing distance D1. Or, more specifically, the distance between the projection line of the boundary line (second edge 112141) of the edge of the second insulating layer 11214 near the active layer 11212 on the connecting surface 112111 and the projection line of the first edge 112121 (boundary line) of the active layer 11212 on the connecting surface 112111 is the first spacing distance D1.

[0124] The value of the first spacing distance D1 directly affects the closing space of the tab 11215 of the battery electrode 1121 and the energy density of the battery 1100. Increasing the value of the first spacing distance D1 is beneficial to increasing the closing space of the tab 11215, making it easier for the tab 11215 to close and reducing the risk of bulging of the battery electrode 1121. However, when the first spacing distance D1 is too large, for example, greater than 3mm, it will cause a loss of energy density of the battery 1100. Therefore, in practical applications, it is advisable to set the first spacing distance D1 to be greater than 0mm and less than or equal to 3mm. For example, the first spacing distance D1 can be 0.5mm, 1.0mm, 1.5mm, 2.0mm, 2.5mm, 3.0mm, etc.

[0125] In the case where the third edge 112131 and the first edge 112121 of the active layer 11212 are spaced apart, a second gap space is formed between the third edge 112131 and the first edge 112121 of the active layer 11212. Along the direction parallel to the connecting surface 112111, the second gap space has a second gap distance D2. The range of the second gap distance D2 can be greater than or equal to the first gap distance D1, or the range of the second gap distance D2 can be less than or equal to the first gap distance D1.

[0126] In this example, setting the first interval distance D1 to be greater than 0 mm and less than or equal to 3 mm helps to ensure that the tab 11215 has sufficient space to be retracted, reduces the risk of the battery electrode 1121 bulging, and is less likely to cause energy density loss in the battery 1100, thus helping to ensure the stable performance of the battery 1100.

[0127] In some examples, referring to Figures 10 and 11, the second insulating layer 11214 also has a fourth edge 112142 disposed away from the active layer 11212, the fourth edge 112142 being disposed opposite to the second edge 112141, and the fourth edge 112142 extending to the surface of the current collector 11211.

[0128] Specifically, during the fabrication of the battery electrode 1121, the first insulating layer 11213 is coated before the second insulating layer 11214. The first insulating layer 11213 is coated and connected to the surface of the current collector 11211. When coating the second insulating layer 11214, the second insulating layer 11214 can be directly coated on the surface of the first insulating layer 11213 that is away from the connection surface 112111. However, due to the increase in the overall thickness of the first insulating layer 11213 and the second insulating layer 11214 on the connection surface 112111, the stress between the first insulating layer 11213 and the connection surface 112111 changes. The thickened insulating layer makes it easy for the first insulating layer 11213 to separate from the connection surface 112111, and the stability of the connection between the first insulating layer 11213 and the second insulating layer 11214 on the battery electrode 1121 and the current collector 11211 is reduced.

[0129] Therefore, in this example, the edge of the second insulating layer 11214 away from the active layer 11212 (i.e., the fourth edge 112142) is extended to the surface of the current collector 11211, so that the second insulating layer 11214 can be connected to the connection surface 112111 of the current collector 11211 while being connected to the first insulating layer 11213. This allows the second insulating layer 11214 to form a connection and adsorption force with the connection surface 112111 of the current collector 11211. Therefore, even with the overall thickening of the insulating layer, the first insulating layer 11213 and the second insulating layer 11214 can both maintain a strong connection with the connection surface 112111, which helps to reduce the risk of the first insulating layer 11213 and the second insulating layer 11214 falling off the connection surface 112111 of the current collector 11211.

[0130] In this example, the second insulating layer 11214 is connected to the first insulating layer 11213, which can further thicken the insulating layer at the die-cut position of the electrode, thereby improving the wrapping effect on the burrs at the die-cut position and reducing the risk of burr exposure. Furthermore, the fourth edge 112142 extends to the surface of the current collector 11211, so that the second insulating layer 11214 can also directly connect and adsorb to the connection surface 112111 of the current collector 11211, thereby enhancing the connection strength between the second insulating layer 11214 and the connection surface 112111. This helps to reduce the risk of the first insulating layer 11213 and the second insulating layer 11214 detaching from the connection surface 112111 of the current collector 11211, improving the connection strength between the first insulating layer 11213 and the second insulating layer 11214 and the connection surface 112111 of the current collector 11211, and improving the reliability of the battery electrode 1121.

[0131] In some examples, as shown with reference to Figures 12 and 13, when the third edge 112131 is spaced apart from the first edge 112121, the second edge 112141 extends to the surface of the current collector 11211.

[0132] Specifically, the third edge 112131 is the edge of the first insulating layer 11213 near the active layer 11212. When the third edge 112131 and the first edge 112121 of the active layer 11212 are spaced apart, that is, the first insulating layer 11213 and the active layer 11212 do not contact each other, and a second gap space is formed between the first insulating layer 11213 and the active layer 11212. The second gap space has a second gap distance D2, which can be considered as the edge of the first insulating layer 11213 near the active layer 11212. The distance between the projection line of the boundary line of the edge (third edge 112131) near the active layer 11212 on the connecting surface 112111 and the projection line of the boundary line of the first edge 112121 of the active layer 11212 on the connecting surface 112111 is such that the second distance D2 is greater than the first distance D1. Therefore, it can be seen that the edge of the second insulating layer 11214 near the active layer 11212 is closer to the active layer 11212 than the edge of the first insulating layer 11213 near the active layer 11212.

[0133] A second space is formed between the first insulating layer 11213 and the active layer 11212, which reduces the risk of direct contact between the active layer 11212 and the electrolyte, limits the interaction between the active layer 11212 and the electrolyte, and thus reduces the risk of short circuit in the battery 1100, which helps maintain the stability of the battery 1100. Other coatings can also be added within this second space to meet the characteristic requirements of the battery 1100. For example, an insulating layer can be added within the second space to enhance the isolation effect between the active layer 11212 and the electrolyte, which helps extend the service life of the battery 1100.

[0134] Extending the second insulating layer 11214 to the surface of the current collector 11211 near the active layer 11212 serves two purposes: firstly, it helps to limit the interaction between the active layer 11212 and the electrolyte, enhancing insulation performance; secondly, extending the second insulating layer 11214 towards the second spacer, i.e., extending away from the tab 11215 and connecting to the connection surface 112111, allows for more space at the tab 11215 position, ensuring sufficient room for the tab 11215 to close and reducing the risk of bulging of the battery electrode 1121; and thirdly, it makes the second insulating layer... While connecting to the first insulating layer 11213, 11214 can also connect to the connection surface 112111 of the current collector 11211. This allows the second insulating layer 11214 to form a connection and adsorption force with the connection surface 112111 of the current collector 11211. Therefore, even with the overall thickening of the insulating layer, both the first insulating layer 11213 and the second insulating layer 11214 can maintain a strong connection with the connection surface 112111, which helps to reduce the risk of the first insulating layer 11213 and the second insulating layer 11214 falling off the connection surface 112111 of the current collector 11211.

[0135] In this example, extending the second edge 112141 to the surface of the current collector 11211 and connecting the second insulating layer 11214 to the first insulating layer 11213 further thickens the insulating layer at the die-cutting position of the electrode, thereby improving the wrapping effect on burrs at the die-cutting position and reducing the risk of burr exposure. Furthermore, extending the second edge 112141 to the surface of the current collector 11211 also allows the second insulating layer 11214 to directly connect and adhere to the connection surface 112111 of the current collector 11211, thereby increasing... Strengthening the connection between the second insulating layer 11214 and the connection surface 112111 helps reduce the risk of the first insulating layer 11213 and the second insulating layer 11214 separating from the connection surface 112111 of the current collector 11211, thereby improving the connection strength between the first insulating layer 11213 and the second insulating layer 11214 and the connection surface 112111 of the current collector 11211, and enhancing the reliability of the battery electrode 1121. In addition, it also helps to limit the interaction between the active layer 11212 and the electrolyte, thereby enhancing the insulation performance.

[0136] In some examples, referring to Figures 4 and 8, in a direction parallel to the connection surface 112111 and in a direction away from the active layer 11212, the first insulating layer 11213 has a first width L1, and the second insulating layer 11214 has a second width L2, the second width L2 being less than or equal to the first width L1.

[0137] Specifically, the width refers to the distance that the first insulating layer 11213 and the second insulating layer 11214 extend from the side closest to the active layer 11212 in a direction parallel to the connecting surface 112111, moving away from the active layer 11212. When die-cutting the battery electrode 1121, the die-cutting direction must be perpendicular to the width direction of the first insulating layer 11213 and the second insulating layer 11214. Considering the existence of processing errors, this perpendicularity can have an error range of ±10°.

[0138] If the second width L2 is less than or equal to the first width L1, then in one case, the second insulating layer 11214 can be entirely located on the side of the first insulating layer 11213 facing away from the current collector 11211, so that the second insulating layer 11214 does not contact the connecting surface 112111 of the current collector 11211. This allows for more space to be formed on the electrode, which is beneficial for increasing the gathering space of the electrode tab 11215 and thus reducing the bulging problem during the electrode winding process. In another case, one side of the second insulating layer 11214 extends to the current collector. On the connection surface 112111 of the fluid 11211, the second insulating layer 11214 can form a connection and adsorption force with the connection surface 112111 of the current collector 11211. With the overall thickness of the insulating layer, the first insulating layer 11213 and the second insulating layer 11214 can also maintain a firm connection force with the connection surface 112111, which helps to reduce the risk of the first insulating layer 11213 and the second insulating layer 11214 falling off the connection surface 112111 of the current collector 11211.

[0139] In this example, by controlling the relative size of the first width L1 of the first insulating layer 11213 and the second width L2 of the second insulating layer 11214, the relative position of the second insulating layer 11214 with respect to the first insulating layer 11213 can be flexibly adjusted, thereby reducing the risk of battery 1100 bulging and the risk of insulating layer detachment.

[0140] In some examples, referring to Figures 13 and 16, in a direction parallel to the connection surface 112111 and in a direction away from the active layer 11212, the first insulating layer 11213 has a first width L1, and the second insulating layer 11214 has a second width L2, the second width L2 being greater than the first width L1, so that the second insulating layer 11214 extends to connect with the connection surface 112111.

[0141] Specifically, if the second width L2 is greater than the first width L1, then in one case, one side of the second insulating layer 11214 extends to the connecting surface 112111 of the current collector 11211, allowing the second insulating layer 11214 to form a connection and adsorption force with the connecting surface 112111 of the current collector 11211. With the overall thickness of the insulating layer, both the first insulating layer 11213 and the second insulating layer 11214 can maintain a strong connection with the connecting surface 112111, which helps reduce the risk of the first insulating layer 11213 and the second insulating layer 11214 detaching from the connecting surface 112111 of the current collector 11211. In another case, the second... Both sides of the insulating layer 11214 extend to the connection surface 112111 of the current collector 11211. The second insulating layer 11214 wraps around the first insulating layer 11213 outside the first insulating layer 11213, so that the second insulating layer 11214 can form a greater connection force with the connection surface 112111 of the current collector 11211. With the overall thickness of the insulating layer, the first insulating layer 11213 and the second insulating layer 11214 can also maintain a firm connection force with the connection surface 112111, which helps to reduce the risk of the first insulating layer 11213 and the second insulating layer 11214 falling off the connection surface 112111 of the current collector 11211.

[0142] In this example, by controlling the relative size of the first width L1 of the first insulating layer 11213 and the second width L2 of the second insulating layer 11214, the relative position of the second insulating layer 11214 with respect to the first insulating layer 11213 can be flexibly adjusted, thereby reducing the risk of insulation layer detachment.

[0143] In some examples, the first width L1 is 1mm-20mm.

[0144] Specifically, the width of the first insulating layer 11213 is 1mm-20mm, and the first width L1 can be any value between 1mm and 20mm. For example, the first width L1 can be 5mm, 10mm, 15mm, etc.

[0145] In this example, the width of the first insulating layer 11213 is designed to be adaptive according to the type of battery 1100, and a width of 1mm-20mm is adopted, which helps to reduce production costs while ensuring insulation performance requirements.

[0146] In some examples, the second width L2 is 1mm-20mm.

[0147] Specifically, the width of the second insulating layer 11214 is 1mm-20mm, and the second width L2 can be any value between 1mm and 20mm. For example, the second width L2 can be 5mm, 10mm, 15mm, etc.

[0148] In this example, the width design of the second insulating layer 11214 is adapted to the type of battery 1100, and a width design of 1mm-20mm is adopted, which helps to reduce production costs while ensuring the insulation performance requirements.

[0149] In some examples, referring to Figures 8-16, the first insulating layer 11213 has a first thickness B1, the second insulating layer 11214 has a second thickness B2, and the active layer 11212 has a third thickness B3. The sum of the first thickness B1 and the second thickness B2 is less than the third thickness B3; or, the second thickness B2 is less than the third thickness B3. It can be seen that the first thickness B1 is less than the third thickness B3, and the second thickness B2 is less than the third thickness B3.

[0150] Specifically, the third thickness B3 and the first thickness B1 refer to the distance or height by which the material extends from the connecting surface 112111 of the current collector 11211 in a direction perpendicular to the connecting surface 112111 and in a direction away from the connecting surface 112111. Referring to Figures 8, 9, and 14, when the second insulating layer 11214 is only connected to the first insulating layer 11213, the second thickness B2 can be defined as the distance or height by which the surface connected to the first insulating layer 11213 extends in a direction perpendicular to that surface and in a direction away from that surface. In this case, the sum of the first thickness B1 and the second thickness B2 is less than the third thickness B3. That is, the first insulating layer 11213 and the second insulating layer 11211... The sum of the thicknesses of 4 is less than the thickness of the active layer 11212; as shown in Figures 10-13, 15 and 16, when the second insulating layer 11214 is still in contact with the connecting surface 112111, the thickness of the second insulating layer 11214 can be defined as the distance or height extending from the connecting surface 112111 of the current collector 11211 in a direction perpendicular to the connecting surface 112111 and in a direction away from the connecting surface 112111. In this case, the second thickness B2 is less than the third thickness B3; that is, when the current collector 11211 is placed horizontally, the upper surface of the second insulating layer 11214 away from the current collector 11211 is located below the upper surface of the active layer 11212.

[0151] The active layer 11212 is the main electrochemical active part of the battery electrode 1121. It needs to provide sufficient conductivity to support the transport of electrons and ions. Therefore, the active layer 11212 is usually thick to ensure sufficient active material mass and surface area. As for the first insulating layer 11213 and the second insulating layer 11214, they mainly serve as the isolation layer of the battery 1100 to reduce the risk of short circuits between different components inside the battery 1100. Therefore, the thickness of the first insulating layer 11213 and the second insulating layer 11214 can be thinner than the thickness of the active layer 11212.

[0152] Furthermore, the internal space of the battery 1100 is a limited resource that needs to be utilized as efficiently as possible. Therefore, the first insulating layer 11213 and the second insulating layer 11214 are designed to be thinner than the active layer 11212. This maximizes the use of space and increases the loading of active materials in the active layer 11212, thereby increasing the energy density and power density of the battery 1100.

[0153] In addition, by controlling the thickness of the first insulating layer 11213 and the second insulating layer 11214, the electron and ion transport paths inside the battery 1100 can be adjusted, thereby optimizing the charge and discharge performance, cycle life, and safety performance of the battery 1100.

[0154] Furthermore, the design of a thinner first insulating layer 11213 and a thinner second insulating layer 11214 means less material consumption and a simpler manufacturing process, which helps to reduce the manufacturing cost of battery 1100 and improve the manufacturing efficiency of battery electrode 1121.

[0155] In this example, increasing the thickness of the active layer 11212 helps to provide sufficient energy storage capacity and electrochemical reaction active surface area, making the sum of the first thickness B1 and the second thickness B2 less than the third thickness B3, which is beneficial to reducing the manufacturing cost of the battery 1100 and helps to improve the energy density of the battery 1100.

[0156] In some examples, the thickness of the second thickness B2 is 3μm-50μm.

[0157] The thickness of the second insulating layer 11214 is 3μm-50μm, and the thickness of the active layer 11212 is greater than the thickness of the second insulating layer 11214. The thickness of the active layer 11212 can be 30μm-100μm. By controlling the thickness of the second insulating layer 11214 to be between 3μm and 50μm, in this example, by controlling the thickness of the second insulating layer 11214, the electron and ion transport paths inside the battery 1100 can be adjusted, the charge and discharge performance, cycle life and safety performance of the battery 1100 can be optimized, and space can be utilized to a greater extent to increase the loading of active materials, thereby increasing the energy density and power density of the battery 1100.

[0158] In some examples, the thickness of the second thickness B2 is 10μm-30μm.

[0159] In this example, the thickness of the second insulating layer 11214 is further controlled between 10μm and 30μm, which can better adjust the electron and ion transport paths inside the battery 1100, optimize the charge and discharge performance, cycle life and safety performance of the battery 1100, and help improve the thermal conductivity efficiency inside the battery 1100, which helps to dissipate heat better, reduce heat accumulation, and thus improve the safety and stability of the battery 1100.

[0160] In some examples, the first insulating layer 11213 includes a first solvent, the second insulating layer 11214 includes a second solvent, and the active layer 11212 includes a third solvent, which is either an aqueous solvent or an oil-based solvent, and the first solvent and / or the second solvent is either an aqueous solvent or an oil-based solvent.

[0161] Specifically, there is a risk of fusion and interpenetration between the active layer 11212 and the first insulating layer 11213 and the second insulating layer 11214. Therefore, when manufacturing the electrode, in addition to considering the relative positions, thicknesses, and widths of the active layer 11212 and the first insulating layer 11213 and the second insulating layer 11214, the fusion and interpenetration of the solvents in the active layer 11212, the first insulating layer 11213, and the second insulating layer 11214 should also be considered to reduce the problem of unclear interfaces between the active layer 11212 and the first insulating layer 11213 and the second insulating layer 11214 due to solvent interpenetration.

[0162] In this example, both the first insulating layer 11213 and the second insulating layer 11214 may include boehmite, calcium carbonate, paraffin, etc. The first insulating layer 11213 also includes a first solvent, which can be an aqueous solvent or an oil-based solvent. Correspondingly, the second solvent can also be an aqueous solvent or an oil-based solvent. The first solvent and the second solvent can be the same solvent or different solvents. The compatibility of the third solvent with the first solvent or the second solvent is not completely the same. For example, when the third solvent is an aqueous solvent, the first solvent and the second solvent can both be oil-based solvents, or, of the first solvent and the second solvent, one is an aqueous solvent and the other is an oil-based solvent.

[0163] Water-based solvents are solvents with water as the main component. They are highly environmentally friendly and typically have a faster drying speed, which is beneficial for coating the current collector 11211 and facilitates rapid drying. Oil-based solvents refer to solvents with organic solvents as the main component.

[0164] In this example, since there is a risk of fusion and penetration between the active layer 11212 and the first insulating layer 11213 and the second insulating layer 11214, when the active layer 11212 is in contact with the first insulating layer 11213 or the second insulating layer 11214, the third solvent of the active layer 11212 can be selected to be an incompatible solvent with the first solvent and the second solvent, thereby making it less likely for the active layer 11212 to penetrate between the active layer 11212 and the first insulating layer 11213 and the second insulating layer 11214.

[0165] In some examples, the third solvent and the second solvent are both oil-based solvents, and the first solvent is an aqueous solvent.

[0166] Specifically, the first solvent in the first insulating layer 11213 and the third solvent in the active layer 11212 are prepared using materials that do not fuse or permeate with each other. The active layer 11212 uses an oil-based formulation, and the third solvent uses an oil-based solvent, such as an oil-based adhesive, like polyacrylic acid. The first insulating layer 11213 uses an aqueous formulation, such as an aqueous adhesive, like polyvinylidene fluoride, as the first solvent. Therefore, the risk of fusion and permeation between the first insulating layer 11213 and the active layer 11212 is relatively small.

[0167] Under specific operating conditions, the second insulating layer 11214 needs to be made of a material with similar compatibility to the active layer 11212. In this case, the second insulating layer 11214 also adopts an oil-based formulation, and the second solvent is an oil-based solvent, such as an oil-based adhesive, like polyacrylic acid. In this case, the second insulating layer 11214 and the active layer 11212 need to be spaced apart to reduce the risk of mutual penetration between them.

[0168] In this example, when manufacturing the electrode, the first insulating layer 11213 can be coated on the connecting surface 112111 first. The first solvent is an aqueous solvent, which has a faster drying rate. The aqueous solvent has stronger adhesion and can be more firmly connected with the current collector 11211. It is also environmentally friendly and low in cost. The second solvent and the third solvent are both oil-based solvents. The second insulating wire and the active layer 11212 can be coated at the same time. The oil-based solvent has a better film-forming effect and can improve the density and uniformity of the electrode surface.

[0169] In a specific embodiment, referring to Figures 4-13, the battery cell 1120 includes a battery electrode 1121, which includes a current collector 11211, an active layer 11212, a first insulating layer 11213, and a second insulating layer 11214. The current collector 11211 has a connecting surface 112111, the active layer 11212 covers a portion of the connecting surface 112111, and a first edge 112121 is formed on the connecting surface 112111. The first insulating layer 11213 covers a portion of the connecting surface 112111 and extends along the first edge 112121. The second insulating layer 11214 covers the first insulating layer 11211. On layer 11213; the second insulating layer 11214 has a second edge 112141 disposed near the first edge 112121, the second edge 112141 being spaced apart from the first edge 112121; the first insulating layer 11213 has a third edge 112131 disposed near the first edge 112121, the third edge 112131 being connected to or spaced apart from the first edge 112121; a first gap space is formed between the second edge 112141 and the first edge 112121, and along a direction parallel to the connecting surface 112111, the first gap space has a first gap distance D1, the first gap distance D1 being greater than 0 mm and less than or equal to 3 mm; The second insulating layer 11214 also has a fourth edge 112142 disposed away from the active layer 11212, the fourth edge 112142 being disposed opposite to the second edge 112141, and the fourth edge 112142 extending to the surface of the current collector 11211; when the third edge 112131 is disposed spaced apart from the first edge 112121, the second edge 112141 extends to the surface of the current collector 11211; the thickness of the second insulating layer 11214 is 10μm-30μm; the first insulating layer 11213 includes a first solvent, the second insulating layer 11214 includes a second solvent, the active layer 11212 includes a third solvent, the third solvent being one of an aqueous solvent and an oily solvent, and the first solvent and / or the second solvent being the other of an aqueous solvent and an oily solvent; the third solvent and the second solvent are both oily solvents, and the first solvent is an aqueous solvent.

[0170] Based on the aforementioned battery cell 1120, this application also proposes an example of a battery 1100. Referring to Figures 2 and 3, the battery 1100 includes the battery cell 1120 as described in any of the above examples.

[0171] In this example, the battery 1100 includes a housing 1110 and battery cells 1120, with the battery cells 1120 installed inside the housing 1110. The battery 1100 may include one battery cell 1120 or multiple battery cells 1120. When the battery 1100 contains multiple battery cells 1120, the multiple battery cells 1120 can be arranged according to a preset pattern. The multiple battery cells 1120 can be arranged in a row-multiple-column or multi-row-multiple-column configuration. The multiple battery cells 1120 can be connected in series, in parallel, or in a mixed series-parallel connection.

[0172] It is understood that this example only describes the battery 1100, which includes the aforementioned battery cell 1120. The battery 1100 may also include other functional components, which will not be described in detail here.

[0173] The example of battery 1100 in this application is based on the example of battery cell 1120 described above. The example of battery 1100 includes all the technical effects of the example of battery cell 1120 described above, and will not be repeated here.

[0174] In some examples, referring to FIG1, an example of an electrical device is disclosed, which includes a battery cell 1120 as described in any of the above examples, or a battery 1100 as described in any of the above examples.

[0175] The electrical devices in this example include, but are not limited to: mobile phones, portable devices, laptops, electric vehicles, electric cars, ships, spacecraft, electric toys, and power tools, etc. The electrical devices may be equipped with the battery cell 1120 described in any of the above examples, or the battery 1100 described above may be installed in the electrical devices.

[0176] The examples of electrical devices in this application are based on the examples of the battery cell 1120 or battery 1100 described above. The examples of electrical devices include all the technical effects of the examples of the battery cell 1120 or battery 1100 described above, and will not be repeated here.

[0177] Example 2

[0178] Unlike Embodiment 1, in some examples, as shown with reference to FIG14-17, the second insulating layer 11214 has a second edge 112141 disposed near the first edge 112121, and the second edge 112141 is disposed in contact with the first edge 112121 of the active layer 11212.

[0179] Specifically, for the battery 1100 with high thermal stability requirements, the second insulating layer 11214 can be directly made of a material with high thermal stability. When the internal temperature of the battery 1100 rises, the thermal stability of the second insulating layer 11214 is not easily damaged. The second insulating layer 11214 and the active layer 11212 are not prone to fusion and penetration. Therefore, the second insulating layer 11214 can be in direct contact with the active layer 11212. With the width of the second insulating layer 11214 determined, the direct contact between the second insulating layer 11214 and the active layer 11212 creates a larger space on the side of the second insulating layer 11214 away from the active layer 11212. The side of the second insulating layer 11214 away from the active layer 11212 is used to form or connect the tab 11215. Therefore, the position of the tab 11215 creates a larger space, increasing the folding space of the tab 11215, which helps to reduce the bulging problem during the electrode winding process.

[0180] For the first insulating layer 11213, it can be in contact with the first edge 112121 of the active layer 11212, or it can be spaced apart from the first edge 112121 of the active layer 11212. When the first insulating layer 11213 is in contact with the active layer 11212, any two of the first insulating layer 11213, the second insulating layer 11214 and the active layer 11212 are connected, thereby making the integrity of the first insulating layer 11213, the second insulating layer 11214 and the active layer 11212 stronger, and the connection between the whole formed by the three and the connection surface 112111 of the current collector 11211 more reliable. The overall structure of the electrode sheet is more compact and the resistance to damage is enhanced.

[0181] When the first insulating layer 11213 and the active layer 11212 are spaced apart, a third gap space is formed between the edge of the first insulating layer 11213 near the active layer 11212 (i.e., the third edge 112131) and the first edge 112121 of the active layer 11212. The third gap space has a third gap distance in the direction parallel to the connecting surface 112111. The side of the second insulating layer 11214 near the active layer 11212 (the second edge 112141) extends into the third gap space and contacts and connects with the connecting surface 112111 of the current collector 11211. This allows the second insulating layer 11214 to connect with both the active layer 11212 and the connecting surface 112111 simultaneously. The connection strength between the second insulating layer 11214 and the current collector 11211 is enhanced, thereby improving the structural stability of the second insulating layer 11214.

[0182] When the first insulating layer 11213 and the active layer 11212 are spaced apart, the first insulating layer 11213 can be made of a material with lower thermal stability than the second insulating layer 11214. This further reduces the manufacturing cost of the electrode while ensuring that the first insulating layer 11213 and the active layer 11212 are spaced apart so that they are less likely to fuse and permeate.

[0183] In this example, the second insulating layer 11214 covers the upper part of the first insulating layer 11213, and the second insulating layer 11214 is directly connected to the active layer 11212. This improves the overall consistency between the active layer 11212 and the second insulating layer 11214 on the connection surface 112111 of the current collector 11211, and enhances the connection strength between the second insulating layer 11214 and the active layer 11212, thereby strengthening the overall stability of the electrode.

[0184] In some examples, as shown with reference to FIG16, the second edge 112141 is disposed in contact with the first edge 112121 of the active layer 11212, and the second insulating layer 11214 has a fourth edge 112142 disposed away from the first edge 112121, the fourth edge 112142 is disposed opposite to the second edge 112141, and the fourth edge 112142 extends to the surface of the current collector 11211.

[0185] Similarly, during the fabrication of the battery electrode 1121, the first insulating layer 11213 is coated before the second insulating layer 11214. The first insulating layer 11213 is coated and connected to the surface of the current collector 11211. When the second insulating layer 11214 is coated, it is directly coated on the surface of the first insulating layer 11213 away from the connection surface 112111. However, due to the increase in the overall thickness of the first insulating layer 11213 and the second insulating layer 11214 on the connection surface 112111, the stress between the first insulating layer 11213 and the connection surface 112111 changes. The thickened insulating layer makes it easy for the first insulating layer 11213 to separate from the connection surface 112111, and the stability of the connection between the first insulating layer 11213 and the second insulating layer 11214 on the battery electrode 1121 and the current collector 11211 decreases.

[0186] Therefore, in this example, the fourth edge 112142 is extended to the surface of the current collector 11211, so that the second insulating layer 11214 can be connected to the connection surface 112111 of the current collector 11211 while being connected to the first insulating layer 11213 and the active layer 11212. This allows the second insulating layer 11214 to form a connection and adsorption force with the connection surface 112111 of the current collector 11211. Thus, even with the overall thickening of the insulating layer, the first insulating layer 11213 and the second insulating layer 11214 can maintain a strong connection with the connection surface 112111, which helps to reduce the risk of the first insulating layer 11213 and the second insulating layer 11214 falling off the connection surface 112111 of the current collector 11211.

[0187] In this example, the fourth edge 112142 extends to the surface of the current collector 11211, allowing the second insulating layer 11214 to directly connect and adhere to the connection surface 112111 of the current collector 11211. This enhances the connection strength between the second insulating layer 11214 and the connection surface 112111, reducing the risk of the first insulating layer 11213 and the second insulating layer 11214 detaching from the connection surface 112111 of the current collector 11211. This improves the connection strength between the first insulating layer 11213 and the second insulating layer 11214 and the connection surface 112111 of the current collector 11211, thereby enhancing the reliability of the battery electrode 1121.

[0188] In some examples, as shown with reference to FIG17, the second edge 112141 extends onto the surface of the active layer 11212 on the side away from the current collector 11211.

[0189] Specifically, the second edge 112141 not only contacts the active layer 11212, but also extends along the surface of the first edge 112121 to the surface of the active layer 11212 on the side away from the current collector 11211. For example, when the current collector 11211 is horizontally arranged, the surface of the active layer 11212 on the side away from the current collector 11211 is the upper surface of the active layer 11212.

[0190] In this example, the second insulating layer 11214 extends to the upper surface of the active layer 11212, so that the second insulating layer 11214 forms a wrapping area or an overlapping cover over the entire first edge 112121 of the active layer 11212. The connection between the second insulating layer 11214 and the active layer 11212 forms a smooth transition, so that the connection between the second insulating layer 11214 and the active layer 11212 is less likely to form obvious steps. For the lithium-ion battery 1100, this is beneficial to suppressing lithium plating and can enable the lithium-ion battery 1100 to have excellent cycle performance.

[0191] The above are merely preferred embodiments of this application, and only specifically describe the technical principles of this application. These descriptions are only for explaining the principles of this application and should not be construed as limiting the scope of protection of this application in any way. Based on this explanation, any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application, as well as other specific embodiments of this application that can be conceived by those skilled in the art without creative effort, should be included within the scope of protection of this application.

Claims

1. A battery cell, characterized in that, Includes battery electrode sheets, said battery electrode sheets comprising: The current collector has a connecting surface; An active layer covers a portion of the connecting surface and forms a first edge on the connecting surface; A first insulating layer covers a portion of the connecting surface, and the first insulating layer extends along the first edge; A second insulating layer covers the first insulating layer.

2. The battery cell as described in claim 1, characterized in that, The second insulating layer has a second edge disposed close to the first edge, and the second edge is spaced apart from the first edge.

3. The battery cell as described in claim 1 or 2, characterized in that, The first insulating layer has a third edge disposed near the first edge, the third edge being connected to or spaced apart from the first edge.

4. The battery cell as described in claim 2, characterized in that, A first gap space is formed between the second edge and the first edge. Along the direction parallel to the connecting surface, the first gap space has a first gap distance, which is greater than 0 mm and less than or equal to 3 mm.

5. The battery cell as described in claim 2, characterized in that, The second insulating layer also has a fourth edge disposed away from the active layer, the fourth edge being disposed opposite to the second edge and extending to the surface of the current collector.

6. The battery cell as described in claim 2, characterized in that, The second edge extends to the surface of the current collector.

7. The battery cell as described in claim 1, characterized in that, The second insulating layer has a second edge disposed near the first edge, and the second edge is in contact with the first edge.

8. The battery cell as described in claim 7, characterized in that, The second insulating layer has a fourth edge disposed away from the first edge, the fourth edge being disposed opposite to the second edge, and the fourth edge extending to the surface of the current collector.

9. The battery cell as described in claim 7, characterized in that, The second edge extends onto the surface of the active layer on the side away from the current collector.

10. The battery cell as described in claim 1, characterized in that, In a direction parallel to the connection surface, the first insulating layer has a first width, and the second insulating layer has a second width, the second width being less than or equal to the first width.

11. The battery cell as described in claim 1, characterized in that, In a direction parallel to the connection surface, the first insulating layer has a first width, and the second insulating layer has a second width, the second width being greater than the first width.

12. The battery cell as described in claim 10 or 11, characterized in that, The first width is 1mm-20mm; and / or The second width is 1mm-20mm.

13. The battery cell according to any one of claims 1-9, characterized in that, The first insulating layer has a first thickness, the second insulating layer has a second thickness, and the active layer has a third thickness, wherein the sum of the first thickness and the second thickness is less than the third thickness; or, the second thickness is less than the third thickness.

14. The battery cell as described in claim 13, characterized in that, The second thickness is 3μm-50μm.

15. The battery cell according to any one of claims 1-9, characterized in that, The first insulating layer includes a first solvent, the second insulating layer includes a second solvent, and the active layer includes a third solvent, wherein the third solvent is either an aqueous solvent or an oil-based solvent, and the first solvent and / or the second solvent is either an aqueous solvent or an oil-based solvent.

16. The battery cell as described in claim 15, characterized in that, Both the third solvent and the second solvent are oil-based solvents, while the first solvent is an aqueous solvent.

17. A battery, characterized in that, The battery comprises a battery cell as described in any one of claims 1-16.

18. An electrical appliance, characterized in that, Includes the battery cell as described in any one of claims 1-16, or includes the battery as described in claim 17.

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