Battery monomer, battery device and electric device

Abstract

The invention discloses a battery monomer, a battery device and a power utilization device. The battery monomer comprises a negative pole piece, and the negative pole piece comprises a negative pole current collector and a negative pole film layer positioned on at least one side of the negative pole current collector; the negative electrode film layer comprises a main body region and a concave region; the thickness of the concave region is smaller than that of the main body region; and the negative electrode film layer comprises a first binder with a linear structure. The battery provided by the embodiment of the invention has relatively good dynamic performance and cycle performance.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to a battery cell, a battery device, and an electrical device. Background Technology

[0002] Batteries are widely used in electronic devices such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric car toys, electric toy ships, electric toy airplanes, and power tools.

[0003] In the development of battery cells, improving the cycle performance of battery cells is one of the urgent problems to be solved. Summary of the Invention

[0004] To address the aforementioned technical problems, this application provides a battery cell, a battery device, and an electrical device.

[0005] In a first aspect, embodiments of this application provide a battery cell including a negative electrode sheet, the negative electrode sheet including a negative current collector and a negative electrode film layer located on at least one side of the negative current collector; the negative electrode film layer includes a main region and a recessed region, the thickness of the recessed region being less than the thickness of the main region; the negative electrode film layer includes a first binder having a linear structure.

[0006] In this embodiment, a shallow recessed area is provided in the negative electrode film layer, and a first binder with a linear structure is added to the negative electrode film layer. This linear binder has strong adhesion and flexibility, and the linear structure is conducive to forming a bonding network structure in the negative electrode film layer. This can improve the bonding strength of the negative electrode film layer while improving the toughness of the negative electrode sheet. This can reduce the rupture of the negative electrode film layer when the recessed area is subjected to rolling pressure or other stresses, reduce the risk of the negative electrode film layer falling off, and thus improve the cycle performance of the battery cell.

[0007] In some embodiments, the thickness of the recessed area is H1, the thickness of the main body area is H2, and 0.2≤H1 / H2≤0.8.

[0008] In some embodiments, 0.2 ≤ H1 / H2 ≤ 0.6.

[0009] In some embodiments, the recessed region includes channels or pores formed on the negative electrode film layer.

[0010] In some embodiments, the opening shape of the recessed area includes one or more of the following: rectangle, square, circle, ellipse, rhombus, and triangle.

[0011] In some embodiments, the negative electrode film layer includes a plurality of recessed regions, and the plurality of recessed regions are spaced apart.

[0012] In some embodiments, the equivalent diameter of the recessed area is D, the distance between adjacent recessed areas is L, and 5 ≤ L / D ≤ ​​500.

[0013] In some embodiments, 40 μm ≤ D ≤ 200 μm; and / or, 200 μm ≤ L ≤ 1 × 10 5 μm.

[0014] 20. In some embodiments, the sum of the opening areas of the recessed regions is S1, and the area of ​​one side of the negative electrode film layer is S2, where 0.1% ≤ S1 / S2 ≤ 50%.

[0015] In some embodiments, 1% ≤ S1 / S2 ≤ 5%.

[0016] In some embodiments, the mass content of the first binder in the negative electrode film layer is 0.4% to 5%.

[0017] In some embodiments, the mass content of the first binder in the negative electrode film layer is 0.5% to 4%.

[0018] In some embodiments, the number-average molecular weight of the first adhesive is greater than or equal to 200,000.

[0019] In some embodiments, the first adhesive includes one or more of polyacrylic adhesives and fluorocellulose adhesives.

[0020] In some embodiments, the polyacrylic adhesive includes one or more of polyacrylic acid, polyacrylate, polyacrylonitrile, and polyacrylamide.

[0021] In some embodiments, the fluorinated fiberized binder includes one or more of polytetrafluoroethylene, polychlorotrifluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and ethylene-chlorotrifluoroethylene copolymer.

[0022] In some embodiments, the negative electrode film layer further comprises a second binder, the second binder comprising one or more of nitrile rubber, hydrated nitrile rubber, styrene-butadiene rubber, and hydrated styrene-butadiene rubber.

[0023] In some embodiments, the mass content of the second binder in the negative electrode film layer is less than or equal to 2%.

[0024] Secondly, embodiments of this application provide a battery device, including a single battery cell from the first aspect of this application.

[0025] Thirdly, embodiments of this application provide an electrical device, including a battery cell from the first aspect of this application or a battery device from the second aspect of this application. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly described below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0027] Figure 1 The diagram shows the structural features of a vehicle provided in some embodiments of this application.

[0028] Figure 2 This is an exploded schematic diagram of a battery provided for some embodiments of this application.

[0029] Figure 3 for Figure 2 The diagram shows an exploded view of the battery module.

[0030] Figure 4 This is a schematic diagram of the negative electrode sheet in some embodiments of this application.

[0031] Figure 5 for Figure 4 The diagram shows the interface of the negative electrode.

[0032] The accompanying drawings are not necessarily drawn to scale.

[0033] The reference numerals in the attached drawings are explained as follows: 1. Vehicle; 2. Battery unit; 3. Controller; 4. Motor; 5. Housing; 5a. First housing section; 5b. Second housing section; 5c. Receiving space; 6. Battery module; 7. Battery cell; 81. Negative electrode current collector; 82. Negative electrode film layer; 82a. Main body area; 82b. Recessed area. Detailed Implementation

[0034] The following detailed description, with appropriate reference to the accompanying drawings, specifically discloses embodiments of the battery cell, battery device, and power-consuming device of this application. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of practically identical structures may be omitted. This is to avoid unnecessarily lengthy descriptions and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided for those skilled in the art to fully understand this application and are not intended to limit the subject matter of the claims.

[0035] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0036] Unless otherwise specified, all embodiments and optional embodiments of this application may be combined with each other to form new technical solutions, and such technical solutions should be considered to be included in the disclosure of this application.

[0037] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions, and such technical solutions shall be deemed to be included in the disclosure of this application.

[0038] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0039] Unless otherwise specified, in this application, the terms "first," "second," etc., are used to distinguish different objects, rather than to describe a specific order or primary / secondary relationship.

[0040] In this application, the terms "multiple" or "various" refer to two or more kinds.

[0041] In the description of the embodiments of this application, unless otherwise specified, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0042] Unless otherwise stated, the terms used in this application have the common meanings as commonly understood by those skilled in the art.

[0043] Unless otherwise stated, the values ​​of the parameters mentioned in this application can be determined using various testing methods commonly used in the art, for example, according to the testing methods given in the embodiments of this application. Unless otherwise stated, the test temperature for each parameter is 25°C.

[0044] The battery device mentioned in the embodiments of this application can be a single physical module comprising one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in this application can include battery cells, battery modules, or battery packs.

[0045] A single battery cell is the smallest unit that makes up a battery, and it can independently perform the functions of charging and discharging. When there are multiple battery cells, they are connected in series, parallel, or mixed connections through a busbar.

[0046] In some embodiments, the battery device may be a battery module; when there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0047] In some embodiments, the battery device may be a battery pack, which includes a housing and individual battery cells, with the individual battery cells or battery modules housed within the housing.

[0048] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0049] In some embodiments, the battery device may be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0050] The technical solutions described in the embodiments of this application are applicable to battery devices and electrical devices that use battery devices.

[0051] Battery devices can be used as the power source for electrical devices or as energy storage units for electrical devices. Electrical devices can be, but are not limited to, mobile devices (such as mobile phones, tablets, laptops, etc.), vehicles (such as pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc.

[0052] Electrical devices can choose the type of battery device according to their usage needs, such as individual battery cells, battery modules, or battery packs.

[0053] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device.

[0054] Figure 1 The diagram shows the structural features of a vehicle provided in some embodiments of this application.

[0055] like Figure 1 As shown, a battery device 2 is installed inside the vehicle 1. The battery device 2 can be located at the bottom, front, or rear of the vehicle 1. The battery device 2 can be used to power the vehicle 1; for example, the battery device 2 can serve as the operating power source for the vehicle 1.

[0056] The vehicle 1 may also include a controller 3 and a motor 4. The controller 3 is used to control the battery device 2 to supply power to the motor 4, for example, for the power needs of the vehicle 1 during starting, navigation and driving.

[0057] In some embodiments, the battery device 2 can not only serve as the operating power source for the vehicle 1, but also as the driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0058] Figure 2 This is a schematic diagram of a battery explosion provided for some embodiments of this application. For example... Figure 2 As shown, the battery device 2 includes a housing 5 and battery cells (not shown), with the battery cells housed within the housing 5.

[0059] The housing 5 is used to house individual battery cells, and the housing 5 can have various structures. In some embodiments, the housing 5 may include a first housing portion 5a and a second housing portion 5b, which overlap each other, and together define a housing space 5c for housing the individual battery cells. The second housing portion 5b may be a hollow structure with one end open, and the first housing portion 5a may be a plate-like structure, with the first housing portion 5a covering the open side of the second housing portion 5b to form a housing 5 with the housing space 5c; alternatively, both the first housing portion 5a and the second housing portion 5b may be hollow structures with one side open, with the open side of the first housing portion 5a covering the open side of the second housing portion 5b to form a housing 5 with the housing space 5c. Of course, the first housing portion 5a and the second housing portion 5b can have various shapes, such as cylinders, cuboids, etc.

[0060] To improve the sealing performance after the first housing part 5a and the second housing part 5b are connected, a sealing element, such as sealant or sealing ring, can also be provided between the first housing part 5a and the second housing part 5b.

[0061] Assuming that the first box section 5a covers the top of the second box section 5b, the first box section 5a can also be called the upper box cover, and the second box section 5b can also be called the lower box.

[0062] In battery device 2, there can be one or more battery cells. If there are multiple battery cells, they can be connected in series, in parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells are connected in both series and parallel configurations. Multiple battery cells can be directly connected in series, in parallel, or in a mixed configuration, and then the whole assembly of multiple battery cells is housed in housing 5. Alternatively, multiple battery cells can first be connected in series, in parallel, or in a mixed configuration to form battery module 6, and then multiple battery modules 6 can be connected in series, in parallel, or in a mixed configuration to form a whole assembly, which is then housed in housing 5.

[0063] Figure 3 for Figure 2 The diagram shows an exploded view of the battery module.

[0064] like Figure 3 As shown, in some embodiments, there are multiple battery cells 7, which are first connected in series, parallel, or mixed to form a battery module 6. The multiple battery modules 6 are then connected in series, parallel, or mixed to form a whole and housed in a casing.

[0065] Multiple battery cells 7 in battery module 6 can be electrically connected through a busbar component to achieve parallel, series, or mixed connection of multiple battery cells 7 in battery module 6.

[0066] The battery cells mentioned in the embodiments of this application may include lithium-ion battery cells or sodium-ion battery cells.

[0067] The battery cell includes an electrode assembly. The electrode assembly can be a wound structure or a stacked structure, and the embodiments of this application are not limited to this.

[0068] Electrode assemblies generally include a positive electrode, a negative electrode, and a separator.

[0069] [Negative electrode plate]

[0070] In some embodiments, the negative electrode sheet includes a negative current collector 81 and a negative electrode film layer 82 located on at least one side of the negative current collector 81;

[0071] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode film layer is disposed on either or both of the two opposite surfaces of the negative electrode current collector. The negative electrode current collector can be made of materials such as metal foil, carbon-coated metal foil, or porous metal plate, and copper foil is an option.

[0072] Reference Figure 4 and Figure 5 The negative electrode film layer 82 of this application includes a main region 82a and a recessed region 82b, the thickness H1 of the recessed region 82b is less than the thickness H2 of the main region 82a; the negative electrode film layer includes a first binder with a linear structure.

[0073] In this application, the first adhesive may be present in both the main body area and the recessed area.

[0074] For example, both the main body region and the recessed region may include a negative electrode active material, a first binder, a conductive agent, and optionally other additives.

[0075] For example, the recessed region can be a void region formed on the negative electrode film layer, such as a hole, groove, or channel opened on the negative electrode film layer.

[0076] In some embodiments, the recessed area can be obtained by creating holes or laser marking. For example, after the negative electrode sheet is prepared, a certain thickness of the negative electrode film layer is removed in a certain area by creating holes or laser marking to obtain the recessed area, and the area not treated by creating holes or laser marking is the main area.

[0077] This application incorporates a recessed region in the negative electrode film layer. The thickness of this recessed region is smaller than that of the main body region, allowing the electrolyte to better wet the negative electrode film layer and enabling active ions to quickly embed into the negative electrode active material, thus improving the kinetic performance of the battery cell. However, the presence of the recessed region leads to localized thinning of the negative electrode film layer, resulting in weakened structural strength in this area. Under rolling pressure or other stresses, the negative electrode layer is prone to cracking or even detachment, leading to deterioration in the battery cell's performance. Therefore, this application incorporates a first binder with a linear structure into the negative electrode film layer. This linear binder possesses strong adhesion and flexibility, and its linear structure facilitates the formation of a bonding network structure within the negative electrode film layer. This improves both the bonding strength and the toughness of the negative electrode sheet, thereby reducing the risk of cracking in the recessed region under rolling pressure or other stresses, lowering the risk of negative electrode film detachment, and ultimately improving the cycle performance of the battery cell.

[0078] In this application, the electrolyte wettability of the negative electrode sheet can be adjusted by further adjusting the thickness of the recessed area, thereby adjusting the dynamic performance of the battery cell.

[0079] In some embodiments, the thickness of the recessed area is H1, the thickness of the main body area is H2, and 0.2 ≤ H1 / H2 ≤ 0.8. Exemplarily, the value of H1 / H2 can be 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, or any range of the above values. Optionally, 0.2 ≤ H1 / H2 ≤ 0.6.

[0080] The ratio H1 / H2, where the thickness of the recessed region is equal to the thickness of the main region, reflects the thickness difference between them, indicating the extent to which the negative electrode film material is removed from the recessed region. By controlling this ratio within the specified range, the negative electrode sheet can achieve better electrolyte wettability, improve ion transport, and enhance the kinetic performance of the battery cell. Simultaneously, the negative electrode film can maintain high structural strength, reducing the risk of film detachment during rolling, bending, and other processes. A smaller H1 / H2 value indicates a thinner recessed region, meaning more negative electrode film material is removed. This leads to reduced overall structural strength of the negative electrode film, increasing the risk of cracking or even detachment, thus affecting the battery cell's lifespan and cycle performance. Conversely, a larger H1 / H2 value indicates a thicker recessed region, meaning less negative electrode film material is removed. This has a limited effect on improving the wettability of the negative electrode sheet, resulting in a lower improvement in the battery cell's kinetic performance.

[0081] In this application, the shape of the opening in the recessed area is not limited and can be adjusted according to actual needs. For example, the opening shape of the recessed area can be one or more of the following: rectangle, square, circle, ellipse, rhombus, and triangle.

[0082] In some embodiments, the negative electrode film layer may include multiple recessed regions, and the multiple recessed regions may be spaced apart.

[0083] By spaced out multiple recessed regions on the negative electrode film layer, the overall uniformity of the negative electrode film layer is improved, resulting in a more uniform stress distribution on the negative electrode sheet. This also helps improve the uniformity of electrolyte wetting at different locations on the negative electrode sheet, further enhancing the dynamic performance of the battery cell. In the embodiments of this application, the multiple spaced-out recessed regions can be evenly distributed across the entire surface of the negative electrode film layer, or they can be distributed on a portion of the surface of the negative electrode film layer.

[0084] In some embodiments, the equivalent diameter of the recessed area is D, and the distance between adjacent recessed areas is L, then L / D can be 5 ≤ L / D ≤ ​​500. Optionally, the value of L / D can be 5, 10, 50, 30, 40, 50, 60, 70, 80, 90, 100, 150, 200, 250, 300, 350, 400, 450, 500, or any range of the above values. Optionally, 10 ≤ L / D ≤ ​​200, and more preferably, 20 ≤ L / D ≤ ​​100.

[0085] In this application, the equivalent diameter of the recessed region refers to the diameter of a circle with the same area as the opening of the recessed region, which can be calculated from the area of ​​the opening of the recessed region. For example, if the opening area of ​​the recessed region is denoted as S, then the equivalent diameter of the recessed region is... The opening area of ​​the recessed region refers to the area of ​​the opening position of the recessed region on the surface of the negative electrode film, that is, the projected area of ​​the recessed region on the surface of the negative electrode sheet. The opening area of ​​the recessed region can be determined by conventional calculation or measurement methods. The distance L between adjacent recessed regions refers to the distance between the closest edge positions of two adjacent recessed regions.

[0086] By limiting the L / D value within the aforementioned range, the negative electrode sheet can possess high electrolyte wettability, which is beneficial for improving the kinetic performance of the battery cell. Simultaneously, the negative electrode film layer exhibits high structural strength, further reducing the risk of film rupture and detachment, thus enhancing the cycle performance of the battery cell.

[0087] In some embodiments, the spacing diameter L between adjacent recessed regions can satisfy 200μm≤L≤1×10 5 μm. Optionally, 1000μm≤L≤2×10 4 μm. By limiting the spacing diameter L between adjacent recessed regions to the above range, each layer of negative electrode sheet can have at least one of the aforementioned recessed regions after the negative electrode sheet is wound to form an electrode assembly, thereby improving wettability.

[0088] As an example, if the electrode assembly is a square wound electrode assembly, the spacing diameter L between adjacent recessed areas can satisfy 200μm≤L≤1×10 5μm; if the electrode assembly is a cylindrical wound electrode assembly, the spacing diameter L between adjacent recessed areas can satisfy 200μm≤L≤2×10 4 μm, which allows for square windings to have at least one recessed area to improve wettability.

[0089] In some embodiments, the equivalent diameter D of the recessed region can satisfy 40μm≤D≤200μm. Exemplarily, the value of D can be 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 110μm, 120μm, 130μm, 140μm, 150μm, 160μm, 170μm, 180μm, 190μm, 200μm, or any range of the above values.

[0090] In some embodiments, the sum of the opening areas of the recessed regions is S1, and the area of ​​one side of the negative electrode film layer is S2, where 0.1% ≤ S1 / S2 ≤ 50%. Exemplarily, the value of S1 / S2 can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, or any range of the above values. Optionally, 1% ≤ S1 / S2 ≤ 5%.

[0091] In this application, the sum of the opening areas of the recessed regions refers to the total area of ​​the openings of all recessed regions. By limiting the ratio of the area of ​​all recessed regions to the area of ​​one side of the negative electrode film to the above range, the negative electrode sheet can have higher electrolyte wettability, improving the dynamic performance of the battery cell; at the same time, the negative electrode film can have higher structural strength, reducing the risk of negative electrode film detachment and improving the cycle performance of the battery cell.

[0092] By setting a recessed area in the negative electrode film layer and controlling the structural parameters of the recessed area within the above range, and further adjusting the content of the first binder in the negative electrode film layer, the negative electrode sheet can have improved electrolyte wettability while further enhancing the bonding strength of the negative electrode film layer and reducing the risk of the negative electrode film layer falling off.

[0093] In some embodiments, the mass content of the first binder in the negative electrode film layer can be from 0.4% to 5%. Exemplarily, the mass content of the first binder in the negative electrode film layer can be 0.4%, 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, or any range of the above values. Optionally, the mass content of the first binder in the negative electrode film layer can be from 0.5% to 4%. When the content of the first binder is within the above range, the negative electrode film layer has higher bonding strength and wettability, which is beneficial to further improving the cycle performance of the battery cell. When the binder content is low, the internal bonding force of the negative electrode film layer is insufficient, and the film layer is prone to detachment; when the binder content is high, the negative electrode sheet becomes more brittle and less tough, making it prone to brittle fracture during winding, and also leading to poor electrolyte wetting, affecting the cycle performance of the battery cell.

[0094] In some embodiments, the number-average molecular weight of the first adhesive may be greater than or equal to 200,000.

[0095] In some embodiments, the first adhesive may include one or more of acrylic adhesives and fluorocellulose adhesives.

[0096] For example, polyacrylic adhesives include one or more of polyacrylic acid, polymethacrylic acid, polyacrylate, polyacrylonitrile, and polyacrylamide.

[0097] For example, the fluorocellulose binder includes one or more of polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and ethylene-chlorotrifluoroethylene copolymer (ECTFE).

[0098] In some embodiments, the negative electrode film layer further includes a second binder, which includes one or more of styrene-butadiene rubber, water and styrene-butadiene rubber, nitrile rubber, and hydrated nitrile rubber.

[0099] In some embodiments, the mass content of the second binder in the negative electrode film layer may be less than or equal to 2%.

[0100] The negative electrode film layer includes a negative electrode active material. As an example, the negative electrode active material may include one or more of the following: artificial graphite, natural graphite, mesophase microcarbon spheres, hard carbon, soft carbon, silicon, and silicon-carbon composite materials.

[0101] Silicon-based composite materials can be prepared by methods known in the art. For example, they can be prepared by vapor deposition using graphite and silicon materials as raw materials.

[0102] In some embodiments, the negative electrode film layer may further include a negative electrode conductive agent. As an example, the negative electrode conductive agent may include, but is not limited to, one or more of superconducting carbon, conductive graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0103] In some embodiments, the negative electrode film layer may also include other additives. As an example, other additives may include thickeners, such as sodium carboxymethyl cellulose (CMC), PTC thermistor materials, etc.

[0104] In some embodiments, the negative electrode current collector may be a metal foil or a composite current collector. Examples of metal foils include copper foil, copper alloy foil, aluminum foil, and aluminum alloy foil. The composite current collector may include a polymeric material substrate and a metal material layer formed on at least one side of the polymeric material substrate. Examples of metal materials include, but are not limited to, one or more of copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. Examples of polymeric material substrates include, but are not limited to, one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene (PE).

[0105] The negative electrode sheet does not exclude other additional functional layers besides the negative electrode film layer. For example, in some embodiments, the negative electrode sheet may also include a conductive undercoat layer sandwiched between the negative electrode current collector and the negative electrode film layer and located on the surface of the negative electrode current collector, which may be composed of a conductive agent and a binder; in some embodiments, the negative electrode sheet may also include a protective layer covering the surface of the negative electrode film layer.

[0106] The negative electrode sheet can be prepared as follows: The negative electrode active material, negative electrode binder, negative electrode conductive agent, and optional other additives are dispersed in a solvent and stirred evenly to form a negative electrode slurry; the negative electrode slurry is coated onto a negative electrode current collector, and after drying, rolling, and other processes, a negative electrode sheet is formed. The solvent can be N-methylpyrrolidone (NMP) or deionized water, but is not limited to these.

[0107] [Positive electrode plate]

[0108] In some embodiments, the positive electrode active material includes one or more of lithium phosphate, layered lithium transition metal oxide, Prussian blue compounds, polyanionic compounds, and sodium transition metal oxide.

[0109] If the positive electrode active material is one or more of lithium phosphate and layered lithium transition metal oxide, then the positive electrode active material can be used in lithium-ion battery cells; if the positive electrode active material is one or more of Prussian blue compounds, polyanionic compounds, and sodium transition metal oxide, then the positive electrode material can be used in sodium-ion battery cells.

[0110] Lithium-containing phosphates may include one or more of lithium iron phosphate, lithium manganese phosphate, lithium manganese iron phosphate, and their respective modified compounds.

[0111] Examples of layered lithium-containing transition metal oxides may include one or more of lithium cobalt oxides, lithium nickel oxides, lithium manganese oxides, lithium nickel cobalt oxides, lithium manganese cobalt oxides, lithium nickel manganese oxides, lithium nickel cobalt manganese oxides, lithium nickel cobalt aluminum oxides, and their respective modified compounds.

[0112] In some embodiments, the layered lithium-containing transition metal oxide may include Ni. The molar amount of Ni may account for more than 70% of the total molar amount of transition metal elements in the layered lithium-containing transition metal oxide; optionally, the molar amount of Ni may account for more than 80% of the total molar amount of transition metal elements in the layered lithium-containing transition metal oxide; more preferably, the molar amount of Ni may account for more than 90% of the total molar amount of transition metal elements in the layered lithium-containing transition metal oxide.

[0113] The higher the Ni content in layered lithium-containing transition metal oxides, the higher the energy density of the battery cell.

[0114] In some embodiments, layered lithium-containing transition metal oxides may include Li a Ni b Co c M d O e A f Wherein, 0 < a ≤ 1.2; 0.8 ≤ b < 1; 0 < c < 1; 0 < d < 1; 1 ≤ e ≤ 2; 0 ≤ f ≤ 1; M includes, but is not limited to, one or more of Mn, Al, Zr, Zn, Cu, Cr, Mg, Fe, V, Ti, and B; A includes, but is not limited to, one or more of N, F, S, and Cl. This can further improve the energy density of individual battery cells.

[0115] In some embodiments, as an example, layered lithium-containing transition metal oxides may include, but are not limited to, LiNi. 0.8 Co 0.1 Mn 0.1 O2, LiNi 0.8 Co 0.15 Al 0.05 O2, LiNi 0.9 Co 0.06 Mn 0.04 O2, LiNi 0.92 Co 0.06 Mn 0.02 O2, LiNi 0.96 Co 0.02 Mn0.02 One or more of O2.

[0116] During the charging and discharging process of a battery cell, Li undergoes insertion / extraction and consumption, resulting in varying molar Li content at different discharge states. In the examples of positive electrode active materials in this application, the molar Li content refers to the initial state of the material, i.e., the state before feeding. After charge-discharge cycles, the molar Li content may change when the positive electrode active material is applied to the battery cell.

[0117] In some embodiments, as an example, sodium transition metal oxides may include, but are not limited to:

[0118] Na 1-x Cu h Fe k Mn l M 1 m O 2-y M 1 It is one or more of Li, Be, B, Mg, Al, K, Ca, Ti, Co, Ni, Zn, Ga, Sr, Y, Nb, Mo, In, Sn, and Ba, 0 <x≤0.33,0<h≤0.24,0≤k≤0.32,0<l≤0.68,0≤m<0.1,h+k+l+m=1,0≤y<0.2;

[0119] Na 0.67 Mn 0.7 Ni z M 2 0.3-z O2, where M 2 It is one or more of Li, Mg, Al, Ca, Ti, Fe, Cu, Zn and Ba, 0 <z≤0.1;

[0120] Na a Li b Ni c Mn d Fe e O2, of which 0.67 <a≤1,0<b<0.2,0<c<0.3,

[0121] 0.67 <d+e<0.8,b+c+d+e=1。

[0122] In some embodiments, as an example, the polyanionic compound may include, but is not limited to:

[0123] A 1 f M 3 g (PO4) i O jX 1 3-j , where A is one or more of H, Li, Na, K, and NH4, M 3 is one or more of Ti, Cr, Mn, Fe, Co, Ni, V, Cu, and Zn, X 1 is one or more of F, Cl, and Br, 0 < f ≤ 4, 0 < g ≤ 2, 1 ≤ i ≤ 3, 0 ≤ j ≤ 2;

[0124] Na n M 4 PO4X 2 , where M 4 is one or more of Mn, Fe, Co, Ni, Cu, and Zn, X 2 is one or more of F, Cl, and Br, 0 < n ≤ 2;

[0125] Na p M 5 q (SO4)3, where M 5 is one or more of Mn, Fe, Co, Ni, Cu, and Zn, 0 < p ≤ 2, 0 < q ≤ 2;

[0126] Na s Mn t Fe 3-t (PO4)2(P2O7), where 0 < s ≤ 4, 0 ≤ t ≤ 3, for example, t is 0, 1, 1.5, 2, or 3.

[0127] In some embodiments, by way of example, Prussian blue compounds may include, but are not limited to:

[0128] A u M 6 v [M 7 (CN)6] w ·xH2O, where A is H + 、NH4 + 、alkali metal cations and alkaline earth metal cations, M 6 and M 7 are each independently one or more of transition metal cations, 0 < u ≤ 2, 0 < v ≤ 1, 0 < w ≤ 1, 0 < x < 6. For example, A is H + 、Li + 、Na + 、K + 、NH4 + 、Rb + 、Cs + 、Fr + 、Be 2+ 、Mg2+ Ca 2+ 、Sr 2+ Ba 2+ and Ra 2+ One or more of them, M 6 and M 7 Each is an independently selected cation of one or more transition metal elements chosen from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sn, and W. Optionally, A is Li. + Na + and K + One or more of them, M 6 It is a cation of one or more transition metal elements selected from Mn, Fe, Co, Ni, and Cu, M 7 It is a cation of one or more transition metal elements selected from Mn, Fe, Co, Ni and Cu.

[0129] In the examples of positive electrode active materials in this application, the molar content of O is only a theoretical value. Oxygen release from the crystal lattice will cause the molar content of O to change, and the actual molar content of O will fluctuate.

[0130] The modified compounds for the above-mentioned positive electrode active materials can be obtained by doping and / or surface coating of the positive electrode active materials.

[0131] In some embodiments, the positive electrode film layer may optionally include a binder. As an example, the binder may include one or more of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), PVDF-tetrafluoroethylene-propylene terpolymer, PVDF-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorinated acrylate resins.

[0132] In some implementations, the weight percentage of the binder in the positive electrode film layer is greater than or equal to 0.5%, which is beneficial for obtaining good adhesion performance.

[0133] In some embodiments, the positive electrode film layer further includes a conductive agent. As an example, the conductive agent may include one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0134] In some embodiments, the positive current collector may be a metal foil or a composite current collector. For example, aluminum foil may be used as the metal foil. The composite current collector may include a polymer substrate and a metal layer formed on at least one surface of the polymer substrate. The composite current collector may be made by forming a metal material, such as aluminum, aluminum alloy, copper, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, on the polymer substrate. The polymer substrate may include polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), and other substrates.

[0135] In some embodiments, the thickness of the positive current collector is from 4 μm to 20 μm. It is optionally from 6 μm to 18 μm, and more preferably from 8 μm to 16 μm.

[0136] In some embodiments, the positive electrode sheet can be prepared by dispersing the above-mentioned components for preparing the positive electrode sheet, such as positive active material, conductive agent, binder and any other components, in a solvent (e.g., N-methylpyrrolidone) to form a positive electrode slurry; coating the positive electrode slurry onto the positive electrode current collector, and then obtaining the positive electrode sheet after drying, cold pressing and other processes.

[0137] [Electrolytes]

[0138] A single battery cell includes an electrolyte.

[0139] In some embodiments, the electrolyte is an electrolyte solution, which includes an electrolyte salt and an organic solvent.

[0140] In some embodiments, the electrolyte includes anion, which may include bis(fluorosulfonyl)imide anion (FSI). - ), bis(trifluoromethanesulfonyl)imide anion (TFSI) - ), dioxaborate anion (BOB) - ), difluorooxalate borate anion (DFOB) - ), difluorodioxanol phosphate anion (DFOP) - ), tetrafluorooxalate phosphate anion (TFOP) - ), difluorophosphate anion (PO2F2) - ), hexafluorophosphate anion (PF6) - ), tetrafluoroborate anion (BF4) - ), hexafluoroarsenate anion (AsF6) - ), trifluoromethanesulfonate anion (CF3SO3) - One or more of the following.

[0141] In some embodiments, the electrolyte includes cations, which may include one or more of lithium ions and sodium ions.

[0142] In some embodiments, the concentration of the electrolyte salt may be 0.3 mol / L or higher, optionally 0.7 mol / L or higher, and further optionally 4 mol / L or lower, optionally 2.5 mol / L or lower, or 1.7 mol / L or lower. When the concentration of the electrolyte salt is within the above range, the electrolyte can have a suitable ionic conductivity.

[0143] Organic solvents may include, but are not limited to, one or more of esters, ethers, sulfones, and nitriles. Esters may include, but are not limited to, one or more of carbonates, phosphate esters, carboxylic esters, sulfate esters, and sulfonates. Carbonates may include cyclic carbonates and / or chain carbonates; optionally, carbonates may include both cyclic and chain carbonates. Chain carbonates may include low-viscosity polar chain carbonates, aliphatic branched carbonates, etc.

[0144] As an example, organic solvents may include, but are not limited to, ethylene carbonate (EC), propylene carbonate (PC), butene carbonate, ethyl methyl carbonate (EMC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), butylene carbonate (BC), fluoroethylene carbonate (FEC), methyl formate (MF), methyl acetate (MA), ethyl acetate (EA), propyl acetate (PA), methyl propionate (MP), ethyl propionate (EP), propyl propionate (PP), methyl butyrate (MB), ethyl butyrate (EB), 1,4-butyrolactone (GBL), sulfolane (SF), dimethyl sulfone (MSM), methyl ethyl sulfone (EMS), diethyl sulfone (ESE), dimethyl ether tetraethylene glycol (TEGDME), ethylene glycol dimethyl ether (DME), 1,3-dioxolane (DOL), trimethyl phosphate, 3-methoxypropionitrile, H(CF2)2OCH3, C4F9O CH3, H(CF2)2OCH2CH3, H(CF2)2OCH2CF3, H(CF2)2CH2O(CF2)2H, CF3CHFCF2OCH3, CF3CHFCF2OCH2CH3, 2-trifluoromethylhexafluoropropyl methyl ether, 2-trifluoromethylhexafluoropropyl ethyl ether, 2-trifluoromethylhexafluoropropyl propyl ether, 3-trifluoromethyloctafluorobutyl methyl ether, 3-trifluoromethyloctafluorobutyl ethyl ether, 3-trifluoromethyloctafluorobutyl propyl ether, 4-trifluoromethyl One or more of the following: decafluoropentyl methyl ether, 4-trifluoromethyl decafluoropentyl ethyl ether, 4-trifluoromethyl decafluoropentyl propyl ether, 5-trifluoromethyl dodecylfluorohexyl methyl ether, 5-trifluoromethyl dodecylfluorohexyl ethyl ether, 5-trifluoromethyl dodecylfluorohexyl propyl ether, 6-trifluoromethyl tetradecafluoroheptyl methyl ether, 6-trifluoromethyl tetradecafluoroheptyl ethyl ether, 6-trifluoromethyl tetradecafluoroheptyl propyl ether, 7-trifluoromethyl hexadecylfluorooctyl methyl ether, 7-trifluoromethyl hexadecylfluorooctyl ethyl ether, and 7-trifluoromethyl hexadecylfluorooctyl propyl ether.

[0145] In some embodiments, the electrolyte may optionally include additives. For example, the additives may include negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain battery performance, such as additives that improve battery overcharge performance, additives that improve battery high-temperature performance, additives that improve battery low-temperature power performance, etc.

[0146] [Isolation Component]

[0147] In some embodiments, the electrode assembly further includes an isolator disposed between the positive and negative electrodes.

[0148] In some embodiments, the isolation chamber includes an isolation membrane. This application does not impose any particular limitation on the type of isolation membrane; any known porous membrane with good chemical and mechanical stability can be selected.

[0149] In some embodiments, the material of the separator may include at least one selected from glass fiber, nonwoven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer may be the same or different, without particular limitation. The separator may be a single component located between the positive and negative electrodes, or it may be attached to the surfaces of the positive and negative electrodes. An inorganic particle coating, an organic particle coating, or an organic / inorganic composite coating may also be applied to the surface of the separator.

[0150] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0151] Example

[0152] The following embodiments describe the disclosure of this application in more detail. These embodiments are merely illustrative, as various modifications and variations will be apparent to those skilled in the art within the scope of the disclosure of this application. Unless otherwise stated, all parts, percentages, and ratios reported in the following embodiments are based on mass, and all reagents used in the embodiments are commercially available or synthesized by conventional methods and can be used directly without further processing, and the instruments used in the embodiments are commercially available.

[0153] Example 1

[0154] Negative electrode sheet

[0155] S10, graphite (negative electrode active material), Super P (conductive agent), carboxymethyl cellulose (CMC) (thickener), polyacrylic acid (PAA, number average molecular weight 250,000) (first binder), and styrene-butadiene rubber (SBR) (second binder) are mixed evenly in deionized water at a mass ratio of 96.7:0.4:1.1:0.5:1.3 to prepare a negative electrode slurry; the solid content of the negative electrode slurry is 55%, and the viscosity is 5000 mPa·s; the negative electrode slurry is uniformly coated on the current collector copper foil, and the density of the coating on one side is 116 g / m². 2 The negative electrode film layer has a single-sided thickness H2 of 80μm. It is dried at 85℃, then cold-pressed and slit to obtain the negative electrode sheet.

[0156] S20, laser etching is performed on the negative electrode film layer on the surface of the negative electrode sheet to form multiple spaced recessed areas. The recessed areas are designed as identical grooves, the distance L between adjacent grooves is 1000μm, the thickness H1 of the recessed area is 40μm, and the equivalent diameter D of the opening of each recessed area is 100μm.

[0157] Positive electrode sheet

[0158] S20, the positive electrode active material lithium nickel cobalt manganese oxide (LiNi 0.8 Co 0.1 Mn 0.1 O2), conductive carbon black, conductive carbon nanotubes, and polyvinylidene fluoride (PVDF) binder are mixed in a mass ratio of 97.5:1.2:0.3:1 and then added to the solvent N-methylpyrrolidone (NMP) to uniformly disperse and obtain a positive electrode slurry. The positive electrode slurry is coated onto the surface of the positive electrode current collector aluminum foil, and then dried, cold-pressed, and slit to obtain the positive electrode sheet.

[0159] Separating membrane

[0160] A polyethylene (PE) film with a thickness of 7μm was selected.

[0161] electrolyte

[0162] The electrolyte solvent is a mixture of diethyl carbonate, dimethyl carbonate, and ethylene carbonate in a volume ratio of 5:2:3. The electrolyte salt is LiPF6 with a concentration of 1.2 mol / L.

[0163] battery cell

[0164] The positive electrode, negative electrode, and separator are stacked in sequence, with the separator positioned between the positive and negative electrodes and the three electrodes in close contact to form an electrode assembly. The electrode assembly is then assembled into a housing, injected with electrolyte, and subjected to a formation process to obtain a single battery cell.

[0165] Examples 2 to 14

[0166] The preparation method of the battery cell is similar to that in Example 1, except that the parameters of the negative electrode film are different. For details of the parameter adjustments, please refer to Table 1.

[0167] Comparative Example 1

[0168] The preparation method of the battery cell is similar to that in Example 1, except that no recessed area is designed in the negative electrode film layer.

[0169] Comparative Example 2

[0170] The preparation method of the battery cell is similar to that in Example 1, except that no first binder is added to the negative electrode film layer.

[0171] Table 1

[0172]

[0173] Test section

[0174] 1. Wetting test

[0175] The wound electrode assembly was vacuum heated at 105℃ for more than 6 hours to reduce the water content of the electrode sheet to less than 20ppm. The electrode assembly was then placed in a tank filled with electrolyte, with the electrolyte immersion height not less than half the height of the electrode assembly. After immersing the electrode assembly for 3 hours, it was disassembled and the electrolyte immersion height of the negative electrode sheet was observed. The lowest immersion position of the entire negative electrode sheet was recorded as the immersion height.

[0176] 2. Battery cell capacity and dynamic performance testing

[0177] At 25°C, the battery cell was charged to 4.2V at a constant current of 0.33C, then charged to 0.05C at a constant voltage of 4.2V, left to stand for 30 minutes, and then discharged to 2.5V at a constant current of 0.33C. After standing for 30 minutes, the discharge capacity was recorded as C0.

[0178] The positive electrode, negative electrode, and separator are stacked sequentially, with the separator positioned between the positive and negative electrodes and all three tightly bonded to form a stacked battery. The side of the positive electrode not facing the negative electrode is covered with adhesive tape to prevent lithium from detaching. A lithium-plated copper wire is inserted as the third electrode, positioned between the positive and negative electrodes and separated by the separator to prevent contact between the wire and the electrodes. The battery is charged from a fully discharged state to 4.2V using different charging rates (0.5C / 1C / 2C / 3C / 4C). The potential difference between the lithium-plated copper wire and the negative electrode is recorded. A potential difference of 0% represents the charging capability (xxSOC) at that rate. For example, 4C can charge to 30% SOC, 3C to 50% SOC, and 2C to 80% SOC. The time taken to charge from 0% SOC to 80% SOC is recorded as the charging time to test the fast-charging performance of the individual battery cells.

[0179] 3. Cyclic performance test

[0180] At 25°C, the battery cells were charged at their charging capacity limits: 4C0 to 30% SOC; 3C0 to 50% SOC; 2C0 to 80% SOC; 0.33C0 to 4.2V, then rested for 30 minutes; and finally discharged at a constant current of 0.5C0 to 2.5V, then rested for 30 minutes. This charge-discharge process was repeated, and the discharge capacity Cn of each cycle was recorded until the cycle capacity retention (Cn / C0*100%) fell below 80%, at which point the number of cycles was recorded.

[0181] The test results are detailed in Table 2.

[0182] Table 2

[0183] Immersion height (mm) Fast charging time (min) Number of cycles (laps) Example 1 70 20 1550 Example 2 60 20 1500 Example 3 78 22 1500 Example 4 40 20 1000 Example 5 60 20 1480 Example 6 80 21 1600 Example 7 82 25 600 Example 8 70 20 1500 Example 9 72 20 1390 Example 10 70 22 1550 Example 11 70 21 1550 Example 12 65 25 600 Example 13 72 19 1100 Example 14 70 20 1550 Comparative Example 1 30 20 200 Comparative Example 2 70 19 1200

[0184] Based on the data in Table 2, the battery cell provided in this application embodiment can improve the rate performance and cycle performance of the battery cell by setting a recessed area in the negative electrode film layer and adding a first binder with a linear structure to the negative electrode film layer.

[0185] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A battery cell, characterized in that, Includes a negative electrode sheet, the negative electrode sheet including a negative current collector and a negative electrode film layer located on at least one side of the negative current collector; The negative electrode film layer includes a main region and a recessed region, wherein the thickness of the recessed region is less than the thickness of the main region; The negative electrode film layer includes a first binder having a linear structure.

2. The battery cell according to claim 1, characterized in that, The thickness of the recessed area is H1, and the thickness of the main body area is H2, where 0.2 ≤ H1 / H2 ≤ 0.

8.

3. The battery cell according to claim 2, characterized in that, 0.2≤H1 / H2≤0.

6.

4. The battery cell according to any one of claims 1 to 3, characterized in that, The recessed area includes channels or pores formed on the negative electrode film layer.

5. The battery cell according to any one of claims 1 to 4, characterized in that, The opening shape of the recessed area includes one or more of the following: rectangle, square, circle, ellipse, rhombus, and triangle.

6. The battery cell according to any one of claims 1 to 5, characterized in that, The negative electrode film layer includes a plurality of recessed regions, and the plurality of recessed regions are spaced apart.

7. The battery cell according to claim 6, characterized in that, The equivalent diameter of the recessed area is D, and the distance between adjacent recessed areas is L, where 5 ≤ L / D ≤ ​​500.

8. The battery cell according to claim 7, characterized in that, 40μm≤D≤200μm; and / or, 200μm≤L≤1×10 5 μm.

9. The battery cell according to any one of claims 1 to 8, characterized in that, The sum of the opening areas of the recessed regions is S1, and the area of ​​one side of the negative electrode film is S2, where 0.1% ≤ S1 / S2 ≤ 50%.

10. The battery cell according to claim 9, characterized in that, 1% ≤ S1 / S2 ≤ 5%.

11. The battery cell according to any one of claims 1 to 10, characterized in that, The mass content of the first binder in the negative electrode film layer is 0.4% to 5%.

12. The battery cell according to claim 11, characterized in that, The mass content of the first binder in the negative electrode film layer is 0.5% to 4%.

13. The battery cell according to any one of claims 1 to 12, characterized in that, The number average molecular weight of the first adhesive is greater than or equal to 200,000.

14. The battery cell according to any one of claims 1 to 13, characterized in that, The first adhesive includes one or more of polyacrylic adhesives and fluorocellulose adhesives.

15. The battery cell according to claim 14, characterized in that, The polyacrylic adhesive includes one or more of polyacrylic acid, polyacrylate, polyacrylonitrile, and polyacrylamide; and / or The fluorocellulose binder includes one or more of polytetrafluoroethylene, polychlorotrifluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and ethylene-chlorotrifluoroethylene copolymer.

16. The battery cell according to any one of claims 1 to 15, characterized in that, The negative electrode film layer further includes a second binder, which includes one or more of nitrile rubber, hydrated nitrile rubber, styrene-butadiene rubber, and hydrated styrene-butadiene rubber.

17. The battery cell according to claim 16, characterized in that, The mass content of the second binder in the negative electrode film layer is less than or equal to 2%.

18. A battery device, characterized in that, Includes the battery cell according to any one of claims 1 to 17.

19. An electrical appliance, characterized in that, Includes the battery device as described in claim 18.

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