Battery cell, battery device and electric device

Abstract

The utility model discloses a battery monomer, a battery device and a power utilization device. Each battery monomer comprises a positive pole piece, a negative pole piece, a first isolating membrane and a second isolating membrane; the positive pole piece and the negative pole piece are arranged in a winding manner, the first isolating membrane is arranged between the convex surface of the positive pole piece and the concave surface of the negative pole piece, and the first isolating membrane comprises a first base membrane layer and a first inorganic bonding layer arranged on the first base membrane layer; the second isolating membrane is arranged on the convex surface of the negative pole piece; the second isolating membrane comprises a second base membrane layer and a second inorganic bonding layer arranged on the second base membrane layer; wherein the thickness of the first isolating membrane is smaller than that of the second isolating membrane. According to the invention, the lithium precipitation phenomenon of the battery monomer in the corner area is reduced.

Description

Technical Field

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

[0002] In recent years, with the rapid development of new energy technologies, new energy vehicles have become increasingly popular, gradually replacing traditional fuel vehicles and becoming one of the mainstream modes of transportation. As the power source of new energy vehicles, power batteries are one of their core components, making their safety performance a key concern.

[0003] In the development of battery technology, how to reduce the lithium plating phenomenon of battery cells is a research direction in battery technology. Utility Model Content

[0004] Embodiments of the present application provide a battery cell, a battery device, and an electrical device, which can reduce lithium plating in the battery cell.

[0005] In a first aspect, an embodiment of the present application provides a battery cell, which includes a positive electrode sheet, a negative electrode sheet, a first isolation membrane and a second isolation membrane; the positive electrode sheet and the negative electrode sheet are arranged in a wound manner, the first isolation membrane is arranged between the convex surface of the positive electrode sheet and the concave surface of the negative electrode sheet, the first isolation membrane includes a first base film layer and a first inorganic adhesive layer arranged on the first base film layer; the second isolation membrane is arranged on the convex surface of the negative electrode sheet, the second isolation membrane includes a second base film layer and a second inorganic adhesive layer arranged on the second base film layer; wherein the thickness of the first isolation membrane is less than the thickness of the second isolation membrane.

[0006] In the above scheme, the first and second inorganic adhesive layers can improve the mechanical strength of the positive and negative electrode sheets, reduce the expansion of the positive and negative electrode sheets, and thus reduce lithium deposition. Setting the thickness of the second separator on the convex side of the negative electrode sheet to a larger thickness increases the expansion space corresponding to the convex surface of the negative electrode sheet, reducing the risk of electrolyte being squeezed out and difficult to reabsorb due to insufficient clearance on the convex surface of the negative electrode sheet in the later stage, thereby reducing lithium deposition in the corner areas of the battery cells.

[0007] In some embodiments, the first isolation film further includes a first organic adhesive layer, and the first organic adhesive layer is disposed on a side of the first inorganic adhesive layer away from the first base film layer.

[0008] In the above solution, the first organic adhesive layer can improve the adhesion performance with the first isolation film and the electrode.

[0009] In some embodiments, the convex surface and the concave surface of the first isolation film are both provided with a first organic adhesive layer, which can simultaneously enhance the adhesion performance of the first isolation film to the positive electrode sheet and the negative electrode sheet.

[0010] In some embodiments, the second isolation film further includes a second organic adhesive layer, and the second organic adhesive layer is disposed on a side of the second inorganic adhesive layer away from the second base film layer.

[0011] In the above solution, the second organic adhesive layer can improve the bonding performance between the second isolation film and the electrode.

[0012] In some embodiments, the first base film layer and the second base film layer have the same thickness, the first inorganic adhesive layer and the second inorganic adhesive layer have the same thickness, and the first organic adhesive layer has a thickness less than that of the second organic adhesive layer.

[0013] In the above solution, by controlling the thickness of other film layers to be the same, only the thickness of the first organic adhesive layer and the second organic adhesive layer needs to be adjusted to achieve different thicknesses of the first isolation film and the second isolation film, which facilitates process preparation and reduces costs.

[0014] In some embodiments, the convex surface and the concave surface of the second isolation film are both provided with a second organic adhesive layer, which can simultaneously enhance the adhesion performance of the second isolation film to the positive electrode sheet and the negative electrode sheet.

[0015] In some embodiments, the thickness of the first base film layer is equal to the thickness of the second base film layer, and the thickness of the first inorganic adhesive layer is less than the thickness of the second inorganic adhesive layer, which facilitates process preparation and reduces costs.

[0016] In some embodiments, the thickness of the first isolation film is D1, the thickness of the second isolation film is D2, and D1 and D2 satisfy: 0<D2-D1≤0.5D2.

[0017] In the above solution, the thickness difference between the first isolation film and the second isolation film is moderate, which can not only reduce the lithium plating phenomenon, but also ensure the energy density of the battery cell to a certain extent.

[0018] In some embodiments, D1 and D2 satisfy: 0.05D2≤D2-D1≤0.1D2, further reducing the lithium plating phenomenon and further ensuring the energy density of the battery cell.

[0019] In a second aspect, an embodiment of the present application further provides a battery device comprising a battery cell according to any of the above embodiments.

[0020] In a third aspect, an embodiment of the present application further provides an electrical device, comprising the above-mentioned battery device, which is used to provide electrical energy.

[0021] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 A schematic structural diagram of a vehicle according to some embodiments of the present application;

[0024] Figure 2 An exploded view of a battery device according to some embodiments of the present application;

[0025] Figure 3 This is a schematic structural diagram of a battery module according to some embodiments of the present application;

[0026] Figure 4 This is a schematic diagram of the exploded structure of a battery cell according to some embodiments of the present application;

[0027] Figure 5 is a partial structural schematic diagram of an electrode assembly in some embodiments of the present application;

[0028] Figure 6 is a schematic structural diagram of a first isolation membrane in some embodiments of the present application;

[0029] Figure 7 is a schematic structural diagram of a second isolation membrane in some embodiments of the present application;

[0030] Figure 8 is a schematic diagram of the winding of an electrode assembly in some embodiments of the present application;

[0031] Figure 9 is a schematic structural diagram of a first isolation membrane in some other embodiments of the present application;

[0032] Figure 10 is a schematic structural diagram of a first isolation membrane according to some other embodiments of the present application;

[0033] Figure 11 is a schematic structural diagram of a second isolation membrane in some other embodiments of the present application;

[0034] Figure 12 Schematic diagram of the structure of the second isolation membrane of some other embodiments of the present application.

[0035] Description of reference numerals:

[0036] 1000, vehicle; 100, battery device; 200, controller; 300, motor; 10, upper cover; 30, housing; 400, battery module; 20, battery cell; 22, housing; 21, end cap; 23, electrode assembly; 40, positive electrode plate; 50, negative electrode plate; 60, first isolation film; 61, first base film layer; 62, first inorganic bonding layer; 63, first organic bonding layer; 70, second isolation film; 71, second base film layer; 72, second inorganic bonding layer; 73, second organic bonding layer; SS1, inner circle area; SS2, outer circle area. DETAILED DESCRIPTION

[0037] The following detailed description of the embodiments of the present application is provided in conjunction with the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of the present application, but are not intended to limit the scope of the present application, that is, the present application is not limited to the described embodiments.

[0038] In the description of this application, it should be noted that, unless otherwise specified, "multiple" means more than two; the terms "upper", "lower", "left", "right", "inside", "outside", etc., indicating directions or positional relationships, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on this application. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not strictly perpendicular, but is within the allowable error range. "Parallel" is not strictly parallel, but is within the allowable error range.

[0039] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0040] The directional words appearing in the following description are all directions shown in the figures, and do not limit the specific structure of this application. In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0041] In this application, battery cells may include lithium-ion secondary battery cells, lithium-ion primary battery cells, lithium-sulfur battery cells, sodium-lithium-ion battery cells, sodium-ion battery cells, or magnesium-ion battery cells, etc., and the embodiments of this application do not limit this. Battery cells may be cylindrical, flat, rectangular, or other shapes, etc., and the embodiments of this application do not limit this. Battery cells are generally divided into three types according to the packaging method: cylindrical battery cells, square battery cells, and soft-pack battery cells, and the embodiments of this application do not limit this.

[0042] The battery device mentioned in the embodiments of the present application may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include multiple battery cells, which are connected in series, parallel, or hybrid via a busbar.

[0043] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells. For example, the battery cell assembly may be a battery module, which is formed by arranging and securing multiple battery cells to form a single module. For example, a battery module may be formed by bundling multiple battery cells using cable ties.

[0044] In some embodiments, the battery device may be a battery pack, which includes a case and one or more battery cell assemblies, wherein the battery cell assemblies are housed in the case.

[0045] As an example, the battery cell assembly may be a battery module, and the battery cell assembly may be accommodated in the box by fixing the battery module in the box.

[0046] As an example, the battery cell assembly may also be housed in the box by directly fixing the plurality of battery cells to the box.

[0047] The present invention provides an electric device that uses a battery as a power source. The electric device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery-powered vehicle, an electric car, a ship, a spacecraft, etc. The electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc. The spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0048] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device according to an embodiment of the present application.

[0049] Please refer to Figure 1 , Figure 1Schematic diagram of the structure of the vehicle provided for some embodiments of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery device 100 is provided inside the vehicle 1000, and the battery device 100 can be provided at the bottom, head or tail of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000. For example, the battery device 100 can serve as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0050] In some embodiments of the present application, the battery device 100 can serve not only as an operating power source for the vehicle 1000 , but also as a driving power source for the vehicle 1000 , replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000 .

[0051] Please refer to Figure 2 , Figure 2 Exploded diagram of the device provided in some embodiments of the present application. The battery device 100 includes a battery case and a battery cell 20. In some embodiments, the battery case may include an upper cover 10 and a case 30, the upper cover 10 and the case 30 covering each other, and the upper cover 10 and the case 30 jointly define a receiving cavity for accommodating the battery cell 20. The case 30 may be a hollow structure with one end open, and the upper cover 10 may be a plate-like structure, the upper cover 10 covering the open side of the case 30, so that the upper cover 10 and the case 30 jointly define a receiving cavity; the upper cover 10 and the case 30 may also be hollow structures with one side open, the open side of the upper cover 10 covering the open side of the case 30. Of course, the battery case formed by the upper cover 10 and the case 30 may be in various shapes, such as a cylinder, a cuboid, etc.

[0052] Figure 3 This is a schematic diagram of the structure of the battery module of some embodiments of the present application. In the battery device 100, there can be multiple battery cells 20, and the multiple battery cells 20 can be connected in series, in parallel, or in mixed connection. Mixed connection means that the multiple battery cells 20 are both connected in series and in parallel. The multiple battery cells 20 can be directly connected in series, in parallel, or in mixed connection, and then the whole formed by the multiple battery cells 20 is accommodated in the box; of course, the battery device 100 can also be a battery module formed by connecting multiple battery cells 20 in series, in parallel, or in mixed connection, and then the multiple battery modules are connected in series, in parallel, or in mixed connection to form a whole, and accommodated in the box. The battery device 100 can also include other structures. For example, the battery device 100 can also include a busbar component for realizing electrical connection between the multiple battery cells 20.

[0053] Each battery cell 20 may be a secondary battery cell or a primary battery cell; it may also be a lithium-sulfur battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell, but is not limited thereto. The battery cell 20 may be cylindrical, flat, rectangular, or in other shapes.

[0054] Please refer to Figure 4 , Figure 4 Schematic diagram of the exploded structure of a battery cell provided in some embodiments of the present application. A battery cell 20 is the smallest unit that makes up a battery. A battery cell 20 includes an end cap 21, a housing 22, an electrode assembly 23, and other functional components.

[0055] The end cap 21 is a component that covers the opening of the housing 22 to isolate the internal environment of the battery cell 20 from the external environment. The shape of the end cap 21 can be adapted to the shape of the housing 22 to fit the housing 22. Optionally, the end cap 21 can be made of a material with a certain hardness and strength (such as an aluminum alloy). This prevents the end cap 21 from deforming when subjected to compression or collision, thereby providing the battery cell 20 with greater structural strength and improved safety. Functional components such as electrode terminals 26 can be provided on the end cap 21. The electrode terminals 26 can be used to electrically connect to the electrode assembly 23 to output or input electrical energy to the battery cell 20. In some embodiments, the end cap 21 can also be provided with a pressure relief mechanism for relieving internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold. The end cap 21 can also be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this embodiment of the present application does not impose any specific limitations on this. In some embodiments, an insulating member may be provided inside the end cap 21 to isolate the electrical connection components in the housing 22 from the end cap 21 to reduce the risk of short circuit. For example, the insulating member may be made of plastic, rubber, or the like.

[0056] The electrolyte is an important component of the battery cell. The electrolyte is generally injected into the shell through the injection hole on the end cap, so that the electrolyte infiltrates into the electrode, participates in the chemical reaction, and realizes the conversion of chemical energy into electrical energy. As the battery cell cycles, the expansion of the negative electrode is greater than that of the positive electrode, resulting in insufficient gap between the convex surface of the negative electrode and the concave surface of the positive electrode. The electrode in the corner area is subject to high stress, and the electrolyte here is squeezed out and difficult to be absorbed back, which makes lithium deposition easy to occur. The lithium deposition layer will continue to form and peel off during the battery charge and discharge cycle, resulting in instability of the internal structure of the battery, increasing battery loss and life decay rate.

[0057] In order to solve the above technical problems, an embodiment of the present application provides a battery cell, which includes a positive electrode sheet, a negative electrode sheet, a first isolation membrane and a second isolation membrane; the positive electrode sheet and the negative electrode sheet are arranged in a wound manner, and the first isolation membrane is arranged between the convex surface of the positive electrode sheet and the concave surface of the negative electrode sheet, and the first isolation membrane includes a first base film layer and a first inorganic adhesive layer arranged on the first base film layer; the second isolation membrane is arranged on the convex surface of the negative electrode sheet, and the second isolation membrane includes a second base film layer and a second inorganic adhesive layer arranged on the second base film layer; wherein, the thickness of the first isolation membrane is less than the thickness of the second isolation membrane.

[0058] In the above scheme, the first and second inorganic adhesive layers can improve the mechanical strength of the positive and negative electrode sheets, reduce the expansion of the positive and negative electrode sheets, and thus reduce lithium deposition. Setting the thickness of the second separator on the convex side of the negative electrode sheet to a larger thickness increases the expansion space corresponding to the convex surface of the negative electrode sheet, reducing the risk of electrolyte being squeezed out and difficult to reabsorb due to insufficient clearance on the convex surface of the negative electrode sheet in the later stage, thereby reducing lithium deposition in the corner areas of the battery cells.

[0059] Figure 5 is a partial structural schematic diagram of an electrode assembly in some embodiments of the present application; Figure 6 is a schematic structural diagram of a first isolation membrane in some embodiments of the present application; Figure 7 is a schematic structural diagram of a second isolation membrane in some embodiments of the present application; Figure 8 This is a schematic diagram of the winding of the electrode assembly of some embodiments of the present application.

[0060] Please refer to Figure 5-Figure 8 In the first aspect, an embodiment of the present application provides a battery cell 20, which includes a positive electrode sheet 40, a negative electrode sheet 50, a first isolation film 60 and a second isolation film 70; the positive electrode sheet 40 and the negative electrode sheet 50 are arranged in a wound manner, and the first isolation film 60 is arranged between the convex surface of the positive electrode sheet 40 and the concave surface of the negative electrode sheet 50, and the first isolation film 60 includes a first base film layer 61 and a first inorganic adhesive layer 62 arranged on the first base film layer 61; the second isolation film 70 is arranged on the convex surface of the negative electrode sheet 50, and the second isolation film 70 includes a second base film layer 71 and a second inorganic adhesive layer 72 arranged on the second base film layer 71; wherein the thickness of the first isolation film 60 is less than the thickness of the second isolation film 70.

[0061] The primary function of the first and second separators 60 and 70 is to prevent direct electron flow between the two electrodes while allowing particle transport. The first and second separators 60 and 70 are thin films that prevent short circuits between the positive and negative electrodes, ensuring the proper operation of the battery. Specifically, the first and second separators 60 and 70 act as electronic insulators, blocking direct electron flow between the positive and negative electrodes of the battery. This prevents internal short circuits, direct energy dissipation, and premature battery failure. Although the first and second separators 60 and 70 block the flow of electrons, they allow ions to travel between the positive and negative electrodes. This is because the working principle of a battery involves the movement of ions in an electrolyte, from the positive electrode through the electrolyte to the negative electrode, completing the electrochemical reaction. The first and second separators 60 and 70 provide a pathway for ions to travel between the positive and negative electrodes, facilitating the battery's charge and discharge processes.

[0062] The positive electrode sheet 40, first separator 60, negative electrode sheet 50, and second separator 70 can be stacked sequentially and then wound to form a wound electrode assembly 23. The wound structure is a multi-turn structure, with the innermost turns representing the inner region SS1 and the outermost turns representing the outer region SS2. It should be noted that the convex surface is oriented toward the outer region SS2, while the concave surface is oriented toward the inner region SS1.

[0063] The first base film layer 61 of the first isolation film 60 and the second base film layer 71 of the second isolation film 70 are insulating film layers, which can be made of the same material, or different materials can be used. The first inorganic bonding layer 62 of the first isolation film 60 and the second inorganic bonding layer 72 of the second isolation film 70 can be ceramic bonding layers (CCS, Ceramic Coated Separator), and the solid particles contained therein are ceramic particles, which can improve the mechanical strength and heat resistance of the first isolation film 60 and the second isolation film 70. Of course, the first inorganic bonding layer 62 and the second inorganic bonding layer 72 can also be prepared and formed by inorganic materials such as aluminum oxide and silicon nitride. The first inorganic bonding layer 62 and the second inorganic bonding layer 72 can be made of the same material, or different materials can be used.

[0064] The first inorganic adhesive layer 62 may be provided on the convex surface or the concave surface of the first base film layer 61, or may be provided on both the convex surface and the concave surface of the first base film layer 61. The second inorganic adhesive layer 72 may be provided on the convex surface or the concave surface of the second base film layer 71, or may be provided on both the convex surface and the concave surface of the second base film layer 71.

[0065] The thickness of the first isolation film 60 is smaller than that of the second isolation film 70. This can be achieved by controlling the thickness of the first base film layer 61 and the second base film layer 71 to be the same, and the thickness of the first inorganic adhesive layer 62 to be smaller than the thickness of the second inorganic adhesive layer 72. Alternatively, the thickness of the first inorganic adhesive layer 62 and the second inorganic adhesive layer 72 can be controlled, and the thickness of the first base film layer 61 can be smaller than the thickness of the second base film layer 71. Alternatively, the thickness of the first base film layer 61 can be smaller than the thickness of the second base film layer 71, and the thickness of the first inorganic adhesive layer 62 can also be smaller than the thickness of the second inorganic adhesive layer 72.

[0066] In the above solution, the first inorganic adhesive layer 62 and the second inorganic adhesive layer 72 can improve the mechanical strength of the positive electrode sheet 40 and the negative electrode sheet 50, reduce the expansion of the positive electrode sheet 40 and the negative electrode sheet 50, and thus reduce the phenomenon of lithium deposition. The thickness of the second separator 70 on the convex side of the negative electrode sheet 50 is set to be larger, which increases the expansion space corresponding to the convex surface of the negative electrode sheet 50, reduces the risk of electrolyte being squeezed out and difficult to reabsorb due to insufficient clearance on the convex surface of the negative electrode sheet 50 in the later stage, and thus reduces the phenomenon of lithium deposition in the corner area of ​​the battery cell 20.

[0067] Figure 9 It is a schematic structural diagram of the first isolation membrane of other embodiments of the present application.

[0068] like Figure 9 As shown, in some embodiments, the first isolation film 60 further includes a first organic bonding layer 63 , and the first organic bonding layer 63 is disposed on a side of the first inorganic bonding layer 62 away from the first base film layer 61 .

[0069] The first organic adhesive layer 63 may be a polymer adhesive layer (PCS), that is, the first organic adhesive layer 63 includes an organic polymer. Alternatively, the material of the first organic adhesive layer 63 may also be silicone, hot melt adhesive, etc.

[0070] The first organic bonding layer 63 may be provided on only one side of the first base membrane layer 61, or may be provided on both the convex and concave surfaces of the first base membrane layer 61. In other embodiments, the first organic bonding layer 63 and the first inorganic bonding layer 62 may be located on different sides of the first base membrane layer 61.

[0071] In the above solution, the first organic adhesive layer 63 can improve the adhesion performance between the first isolation film 60 and the electrode.

[0072] Figure 10 Schematic diagram of the structure of the first isolation membrane of some other embodiments of the present application.

[0073] like Figure 10As shown, in some embodiments, the convex surface and the concave surface of the first isolation film 60 are both provided with a first organic bonding layer 63 , which can simultaneously improve the bonding performance of the first isolation film 60 with the positive electrode sheet 40 and the negative electrode sheet 50 .

[0074] Figure 11 It is a schematic structural diagram of the second isolation membrane in other embodiments of the present application.

[0075] like Figure 11 As shown, in some embodiments, the second isolation film 70 further includes a second organic bonding layer 73 , and the second organic bonding layer 73 is disposed on a side of the second inorganic bonding layer 72 away from the second base film layer 71 .

[0076] The second organic adhesive layer 73 may be a polymer adhesive layer (PCS), that is, the second organic adhesive layer 73 includes an organic polymer. Alternatively, the second organic adhesive layer 73 may be made of silicone, hot melt adhesive, or the like.

[0077] The second organic bonding layer 73 may be provided on only one side of the second base membrane layer 71, or may be provided on both the convex and concave surfaces of the second base membrane layer 71. In other embodiments, the second organic bonding layer 73 and the second inorganic bonding layer 72 may be located on different sides of the second base membrane layer 71.

[0078] The second organic bonding layer 73 and the first organic bonding layer 63 may be made of the same material, or may be made of different materials.

[0079] In the above solution, the second organic adhesive layer 73 can improve the adhesion performance between the second isolation film 70 and the electrode.

[0080] Figure 12 Schematic diagram of the structure of the second isolation membrane in some other embodiments of the present application.

[0081] like Figure 12 As shown, in some embodiments, the thickness of the first base membrane layer 61 is the same as that of the second base membrane layer 71, the thickness of the first inorganic bonding layer 62 is the same as that of the second inorganic bonding layer 72, and the thickness of the first organic bonding layer 63 is less than that of the second organic bonding layer 73.

[0082] In the above solution, by controlling the thickness of other film layers to be the same, only the thickness of the first organic bonding layer 63 and the second organic bonding layer 73 need to be adjusted to achieve different thicknesses of the first isolation film 60 and the second isolation film 70, which facilitates process preparation and reduces costs.

[0083] In some embodiments, the second organic bonding layer 73 is provided on both the convex surface and the concave surface of the second isolation film 70 , which can simultaneously improve the bonding performance between the second isolation film 70 and the positive electrode sheet 40 and the negative electrode sheet 50 .

[0084] In some embodiments, the thickness of the first base film layer 61 is equal to the thickness of the second base film layer 71, and the thickness of the first inorganic adhesive layer 62 is less than the thickness of the second inorganic adhesive layer 72, which facilitates process preparation and reduces costs.

[0085] In some embodiments, the thickness of the first isolation film 60 is D1 , the thickness of the second isolation film 70 is D2 , and D1 and D2 satisfy: 0<D2−D1≤0.5D2.

[0086] Wherein, (D2-D1) / D2 can be any value between 0 and 0.5. For example, (D2-D1) / D2 can be 0.05, 0.07, 0.13, 0.2, 0.4, 0.5, etc.

[0087] In the above solution, the thickness difference between the first isolation film 60 and the second isolation film 70 is moderate, which can reduce the lithium plating phenomenon and ensure the energy density of the battery cell 20 to a certain extent.

[0088] In some embodiments, D1 and D2 satisfy: 0.05D2≤D2-D1≤0.1D2.

[0089] Wherein, (D2-D1) / D2 can be any value between 0.05 and 0.1. For example, (D2-D1) / D2 can be 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, etc. The embodiment of the present application further reduces the lithium plating phenomenon and further ensures the energy density of the battery cell 20.

[0090] In a second aspect, an embodiment of the present application further provides a battery device 100 , comprising a battery cell 20 according to any of the above embodiments.

[0091] In a third aspect, an embodiment of the present application further provides an electrical device, comprising the above-mentioned battery device 100, wherein the battery device 100 is used to provide electrical energy.

[0092] According to some embodiments of the present application, a battery cell 20 is provided. The battery cell 20 includes a positive electrode sheet 40, a negative electrode sheet 50, a first separator 60, and a second separator 70. The positive electrode sheet 40 and the negative electrode sheet 50 are arranged in a wound manner. The first separator 60 is arranged between the convex surface of the positive electrode sheet 40 and the concave surface of the negative electrode sheet 50. The first separator 60 includes a first base film layer 61 and a first inorganic adhesive layer 62 arranged on the first base film layer 61. The second separator 70 is arranged on the convex surface of the negative electrode sheet 50. The second separator 70 includes a second base film layer 71 and a second inorganic adhesive layer 72 arranged on the second base film layer 71. The thickness of the first separator 60 is less than that of the second separator 70. The first separator 60 also includes a first organic adhesive layer 63, which is arranged on the side of the first inorganic adhesive layer 62 facing away from the first base film layer 61. The second isolation film 70 further includes a second organic bonding layer 73 . The second organic bonding layer 73 is disposed on a side of the second inorganic bonding layer 72 facing away from the second base film layer 71 .

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that: include: Positive electrode; negative electrode; The positive electrode sheet and the negative electrode sheet are wound together. a first separator, disposed between the convex surface of the positive electrode sheet and the concave surface of the negative electrode sheet, the first separator comprising a first base film layer and a first inorganic adhesive layer disposed on the first base film layer; a second separator, disposed on the convex surface of the negative electrode plate, the second separator comprising a second base film layer and a second inorganic adhesive layer disposed on the second base film layer; Wherein, the thickness of the first isolation film is smaller than the thickness of the second isolation film.

2. The battery cell according to claim 1, wherein: The first isolation film further includes a first organic adhesive layer, which is arranged on a side of the first inorganic adhesive layer away from the first base film layer.

3. The battery cell according to claim 2, characterized in that: The first organic adhesive layer is provided on both the convex surface and the concave surface of the first isolation film.

4. The battery cell according to claim 2, characterized in that: The second isolation film further includes a second organic adhesive layer, which is arranged on a side of the second inorganic adhesive layer away from the second base film layer.

5. The battery cell according to claim 4, characterized in that The first base film layer and the second base film layer have the same thickness, the first inorganic adhesive layer and the second inorganic adhesive layer have the same thickness, and the first organic adhesive layer has a thickness less than that of the second organic adhesive layer.

6. The battery cell according to claim 4, characterized in that The second organic adhesive layer is provided on both the convex surface and the concave surface of the second isolation film.

7. The battery cell according to claim 1, characterized in that The thickness of the first base film layer is equal to the thickness of the second base film layer, and the thickness of the first inorganic adhesive layer is less than the thickness of the second inorganic adhesive layer.

8. The battery cell according to claim 1, wherein: The thickness of the first isolation film is D1, the thickness of the second isolation film is D2, and D1 and D2 satisfy: 0<D2-D1≤0.5D2.

9. The battery cell according to claim 8, characterized in that The D1 and D2 satisfy: 0.05D2≤D2-D1≤0.1D2.

10. A battery device, characterized in that: The invention comprises a battery cell according to any one of claims 1 to 9.

11. An electrical device, characterized in that: The battery device according to claim 10 is included, and the battery device is used to provide electrical energy.

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