Winded cells and batteries

Abstract

This application relates to the field of battery technology, specifically to wound battery cells and batteries. The present invention involves respectively providing a first active coating and a second active coating on both sides of the current collector of the negative electrode and / or positive electrode. The first active coating is disposed on the surface of the current collector closer to the center of the coil; the second active coating is disposed on the surface of the current collector farther from the center of the coil. When the diffusion coefficient of the first active coating is less than that of the second active coating, the battery capacity for long-term cycling can be effectively maintained, the problem of easy lithium plating in the second active coating can be effectively improved, and the battery life can be extended.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to wound battery cells and batteries. Background Technology

[0002] In recent years, with the continuous emergence of consumer electronics products such as smartphones, tablets, and smart bracelets, and the rapid growth of the electric vehicle market, lithium-ion batteries, which power these products, have received increasing attention. Therefore, the lifespan of lithium-ion batteries is crucial.

[0003] For wound-type battery cells, the different circumference of each turn of the wound cell leads to an imbalance of the active materials on both sides of the surface arc near the center of the winding of the same negative electrode sheet. This results in problems such as lithium plating and long-term battery capacity decay, which seriously affects the battery's lifespan.

[0004] Therefore, a technical solution is needed to address the problems of lithium plating and long-term cycle capacity decay in wound batteries. Summary of the Invention

[0005] In view of this, the present invention provides a wound cell and a battery. This wound cell can effectively maintain battery capacity over long cycles, thereby improving the lithium plating problem and extending battery life.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] The present invention provides a wound battery cell, which includes a negative electrode and / or a positive electrode.

[0008] The negative electrode sheet includes a first negative electrode active coating, a current collector, and a second negative electrode active coating arranged sequentially; the first negative electrode active coating is disposed on the surface of the current collector near the center of the curl; the second negative electrode active coating is disposed on the surface of the current collector away from the center of the curl; the diffusion coefficient of the first negative electrode active coating is less than the diffusion coefficient of the second negative electrode active coating;

[0009] The positive electrode sheet includes a first positive electrode active coating, a current collector, and a second positive electrode active coating arranged sequentially; the first positive electrode active coating is disposed on the surface of the current collector near the center of the curl; the second positive electrode active coating is disposed on the surface of the current collector away from the center of the curl; the diffusion coefficient of the first positive electrode active coating is less than the diffusion coefficient of the second positive electrode active coating.

[0010] Preferably, the diffusion coefficient of the first negative electrode active coating is 1×10⁻⁶. ―9 ~3×10 ―8 cm 2 / s;

[0011] Preferably, the diffusion coefficient of the second negative electrode active coating is 1×10⁻⁶. ―8 ~1×10 ―7 cm 2 / s;

[0012] Preferably, the diffusion coefficient of the first positive electrode active coating is 1×10⁻⁶. ―9 ~2×10 ―8 cm 2 / s;

[0013] Preferably, the diffusion coefficient of the second positive electrode active coating is 5 × 10⁻⁶. ―8 ~1×10 ―7 cm 2 / s.

[0014] In the embodiments provided by the present invention, the diffusion coefficient of the first negative electrode active coating being less than that of the second negative electrode active coating can be controlled by at least one of the following methods:

[0015] (1) The surface density of the first negative electrode active coating is greater than that of the second negative electrode active coating;

[0016] (2) D of the active material in the first negative electrode active coating 50 D greater than that of the active material in the second negative electrode active coating 50 ;

[0017] (3) The aspect ratio of the active material in the first negative electrode active coating is smaller than that of the active material in the second negative electrode active coating;

[0018] (4) The compaction density of the first negative electrode active coating is greater than that of the second negative electrode active coating;

[0019] (5) The conductive agent content of the first negative electrode active coating is less than that of the second negative electrode active coating;

[0020] (6) The thickness of the first negative electrode active coating is less than the thickness of the second negative electrode active coating;

[0021] (7) The conductive agents of the first negative electrode active coating and the second negative electrode active coating are both tubular conductive agents, and the tube wall length of the conductive agent of the first negative electrode active coating is less than the tube wall length of the conductive agent of the second negative electrode active coating.

[0022] The diffusion coefficient of the first positive electrode active coating being less than that of the second positive electrode active coating can be controlled by at least one of the following methods:

[0023] (1) The surface density of the first positive electrode active coating is greater than that of the second positive electrode active coating;

[0024] (2) D of the active material in the first positive electrode active coating50 D greater than that of the active material in the second positive electrode active coating 50 ;

[0025] (3) The aspect ratio of the active material in the first positive electrode active coating is smaller than that of the active material in the second positive electrode active coating;

[0026] (4) The compaction density of the first positive electrode active coating is greater than that of the second positive electrode active coating;

[0027] (5) The conductive agent content of the first positive electrode active coating is less than that of the second positive electrode active coating;

[0028] (6) The thickness of the first positive electrode active coating is less than the thickness of the second positive electrode active coating;

[0029] (7) The conductive agents of the first positive electrode active coating and the second positive electrode active coating are both tubular conductive agents, and the tube wall length of the conductive agent of the first positive electrode active coating is less than the tube wall length of the conductive agent of the second positive electrode active coating.

[0030] Preferably, the components of the first negative electrode active coating or the second negative electrode active coating, by weight, include:

[0031] The negative electrode active material is 75–99.8 wt%.

[0032] Conductive agent 0.5–15 wt%;

[0033] Adhesive 0.5–15 wt%.

[0034] Preferably, in the first negative electrode active coating or the second negative electrode active coating...

[0035] The negative electrode active material is independently selected from one or more of carbon-based graphite materials, other carbon-based materials or silicon-carbon materials, and lithium titanate; the carbon-based graphite material is selected from at least one of natural graphite, artificial graphite, and mesophase carbon spheres; the other carbon-based materials are selected from at least one of hard carbon, soft carbon, and graphene.

[0036] The conductive agent is independently selected from one or more of carbon black, conductive graphite, carbon fiber, carbon nanotubes, and graphene; the carbon black is selected from at least one of SP, Ketjen black, and acetylene black.

[0037] The adhesive is independently selected from one or more of polyvinylidene fluoride, polymethyl methacrylate, polyvinyl alcohol, polytetrafluoroethylene, styrene-butadiene latex compounds, polyacrylate compounds, polyacrylonitrile, polytetrafluoroethylene, and polyethylene oxide.

[0038] Preferably, the components of the first positive electrode active coating or the second positive electrode active coating, by weight, include:

[0039] Positive electrode active material: 75–99.8 wt%;

[0040] Conductive agent 0.5–15 wt%;

[0041] Adhesive 0.5–15 wt%.

[0042] Preferably, in the first positive electrode active coating or the second positive electrode active coating...

[0043] The positive electrode active material is independently selected from one or more of lithium cobalt oxide, lithium iron phosphate, lithium manganese iron phosphate, sodium iron phosphate, lithium vanadium phosphate, sodium vanadium phosphate, lithium vanadium oxide phosphate, sodium vanadium oxide phosphate, lithium vanadium oxide, lithium manganese oxide, lithium nickel oxide, lithium nickel cobalt manganese oxide, lithium-rich manganese-based materials, or lithium nickel cobalt aluminum oxide.

[0044] The conductive agent is independently selected from one or more of the following: conductive carbon black, Ketjen black, conductive fiber, conductive polymer, acetylene black, carbon nanotubes, graphene, flake graphite, conductive oxide, and metal particles.

[0045] The adhesive is independently selected from one or more of polyvinylidene fluoride, copolymers of polyvinylidene fluoride and hexafluoropropylene, polyamide, polyacrylonitrile, polyacrylate, polyacrylic acid, polyacrylate, polyvinylpyrrolidone, polyvinyl ether, polymethyl methacrylate, polytetrafluoroethylene, polyhexafluoropropylene, and styrene-butadiene rubber.

[0046] The types of negative electrode active materials, positive electrode active materials, conductive agents, and binders mentioned above are not limited to these; all types recognized by those skilled in the art are within the scope of protection of this invention.

[0047] In this invention, the first negative electrode active coating, the second negative electrode active coating, the first positive electrode active coating, or the second positive electrode active coating may include other functional components recognized in the art, in addition to the components mentioned above.

[0048] Preferably, the thickness of the first negative electrode active coating is 20–75 μm.

[0049] Preferably, the thickness of the second negative electrode active coating is 20–75 μm.

[0050] Preferably, the thickness of the first positive electrode active coating is 20–75 μm.

[0051] Preferably, the thickness of the second positive electrode active coating is 20–75 μm.

[0052] In the embodiments provided by the present invention, the current collector used for the negative electrode is selected from one or more of copper foil, carbon-coated copper foil, and perforated copper foil.

[0053] In the embodiments provided by the present invention, the current collector used in the positive electrode is selected from one or more of aluminum foil, carbon-coated aluminum foil, and perforated aluminum foil.

[0054] In the embodiments provided by the present invention, the wound battery cell may further include one or more of the following: positive tab, negative tab, and separator.

[0055] In some embodiments, the diaphragm is selected from one or both of polyethylene and polypropylene.

[0056] In the embodiments provided by the present invention, the wound battery cell can be a conventional wound cell structure, a wound cell structure with the tabs in the middle, a wound cell structure without tabs, a wound cell structure with three tabs, a wound cell structure with multiple tabs, etc.

[0057] The present invention also provides a battery comprising the above-described wound cell.

[0058] According to an embodiment of the present invention, the battery further includes an electrolyte and / or a casing.

[0059] In some embodiments, the electrolyte is a non-aqueous electrolyte, which includes a non-aqueous organic solvent and a lithium salt.

[0060] In some embodiments, the non-aqueous organic solvent is selected from one or more of ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), fluoroethylene carbonate (FEC), dimethyl carbonate (DMC), methyl ethyl carbonate (EMC), ethylene carbonate, γ-butyrolactone, methyl propyl carbonate, and ethyl propionate.

[0061] In some embodiments, the lithium salt is selected from one or more of LiPF6, LiBF4, LiSbF6, LiClO4, LiCF3SO3, LiAlO4, LiAlCl4, Li(CF3SO2)2N, LiBOB, and LiDFOB.

[0062] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0063] This invention provides a first active coating and a second active coating on both sides of the current collector of the negative electrode and / or positive electrode, respectively. The first active coating is disposed on the surface of the current collector near the center of the curl, and the second active coating is disposed on the surface of the current collector away from the center of the curl. When the diffusion coefficient of the first active coating is less than that of the second active coating, the battery capacity for long-term cycling can be effectively maintained, the problem of easy lithium plating of the second active coating can be effectively improved, and the battery life can be extended. Attached Figure Description

[0064] Figure 1 This is a schematic diagram of the negative electrode structure;

[0065] Figure 2 This is a schematic diagram of the positive electrode structure;

[0066] Figure 3 This is a schematic diagram of a conventional core structure;

[0067] Figure 4 This is a schematic diagram of a core structure with a centrally located electrode tab.

[0068] Explanation of reference numerals in the attached figures:

[0069] 1. Negative electrode sheet; 1-1 Negative electrode current collector; 1-2 First negative electrode active coating; 1-3 Second negative electrode active coating;

[0070] 2. Positive electrode sheet; 2-1 Positive current collector; 2-2 First positive electrode active coating; 2-3 Second positive electrode active coating;

[0071] 3. Positive electrode ear;

[0072] 4. Negative electrode ear;

[0073] 5. Diaphragm. Detailed Implementation

[0074] This invention discloses a wound battery cell and a battery. Those skilled in the art can refer to the content of this document and appropriately modify the process parameters to achieve the desired result. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in this invention. The methods and applications of this invention have been described through preferred embodiments. Those skilled in the art can obviously make modifications or appropriate alterations and combinations to the methods and applications described herein without departing from the content, spirit, and scope of this invention to realize and apply the technology of this invention.

[0075] Terminology Explanation:

[0076] Ion diffusion rate refers to the extent to which lithium ions diffuse within a specific material. This lithium ion diffusion rate can be measured using galvanostatic intermittent titration (GITT) under charge / discharge conditions. For example, the lithium ion diffusion rate can be measured using GITT at a state of charge (SOC) of 50%.

[0077] Areal density: In engineering materials, it is the mass per unit area of ​​a material with a specified thickness.

[0078] Aspect ratio: refers to the ratio of the longest diameter passing through the interior of a particle to the longest diameter perpendicular to it; in this application, the aspect ratio is the ratio of the longest axis length inside the active material particle to the diameter length perpendicular to it.

[0079] Compacted density: During the manufacturing process of lithium-ion power batteries, compacted density has a significant impact on battery performance. The calculation method is: Compacted density = Areal density / Material thickness.

[0080] All chemical components or materials used in this invention are commercially available.

[0081] The present invention will be further illustrated below with reference to the embodiments:

[0082] Examples 1-9: Winded battery cells

[0083] 1. Structure and Composition

[0084] In this embodiment, the wound battery cell includes a wound negative electrode 1, a positive electrode 2, a positive electrode tab 3, a negative electrode tab 4, and a separator 5.

[0085] (1) Negative electrode sheet

[0086] Among them, such as Figure 1 As shown, the negative electrode sheet 1 includes a negative electrode current collector 1-1, a first negative electrode active coating 1-2, and a second negative electrode active coating 1-3; the first negative electrode active coating is disposed on the surface of the negative electrode current collector near the center of the curl; the second negative electrode active coating is disposed on the surface of the negative electrode current collector away from the center of the curl.

[0087] The diffusion coefficient of the first negative electrode active coating is smaller than that of the second negative electrode active coating. The diffusion coefficient of the first negative electrode active coating is 1×10⁻⁶. ―9 ~3×10 ―8 cm 2 / s, the diffusion coefficient of the second negative electrode active coating is 1×10 ―8 ~1×10 ―7 cm 2 s.

[0088] The aforementioned first negative electrode active coating comprises: 96.5 wt% active material (artificial graphite), 1.5 wt% conductive agent (conductive carbon black), and 2 wt% binder (sodium carboxymethyl cellulose). In Examples 1-9, the D of the active material in the first negative electrode active coating... 50 Its thickness is 13–16 μm, and its surface density is 0.008–0.016 g / cm³. 2 The compacted density is 1.3–2.2 g / cm³. 3 The aspect ratio is 0.6–1.5. The coating thickness is 50–60 μm, and the tube wall length is 14–16 nm.

[0089] The aforementioned second negative electrode active coating comprises: 96.5 wt% active material (artificial graphite), 2.3 wt% conductive agent (conductive carbon black), and 1.2 wt% binder (sodium carboxymethyl cellulose). In Examples 1-9, the D of the active material in the second negative electrode active coating... 50 Its thickness is 10–13 μm, and its surface density is 0.004–0.007 g / cm³. 2 The compacted density is 0.5–1.0 g / cm³.3 The aspect ratio is 4–5. The coating thickness is 70–75 μm, and the tube wall length is 22–23 nm.

[0090] (2) Positive electrode plate

[0091] Among them, such as Figure 2 As shown, the positive electrode 2 includes a positive current collector 2-1, a first positive active coating 2-2, and a second positive active coating 2-3; the first positive active coating is disposed on the surface of the positive current collector near the center of the curl; the second positive active coating is disposed on the surface of the positive current collector away from the center of the curl.

[0092] The diffusion coefficient of the first positive electrode active coating is smaller than that of the second positive electrode active coating. The diffusion coefficient of the first positive electrode active coating is 1×10⁻⁶. ―9 ~2×10 ―8 cm 2 / s; the diffusion coefficient of the second positive electrode active coating is 5×10 ―9 ~1×10 ―7 cm 2 / s.

[0093] The aforementioned first positive electrode active coating comprises: 97 wt% active material (lithium cobalt oxide material), 1 wt% conductive agent (acetylene black), and 2 wt% binder (polyvinylidene fluoride). In Examples 1-9, the D of the active material in the first positive electrode active coating... 50 Its thickness is 15–17 μm, and its surface density is 0.016–0.02 g / cm³. 2 The compacted density is 3.2–4.0 g / cm³. 3 The aspect ratio is 1 to 1.5. The coating thickness is 50 μm, and the tube wall length is 14 to 16 nm.

[0094] The aforementioned second positive electrode active coating comprises: 97 wt% active material (lithium cobalt oxide material), 1.8 wt% conductive agent (acetylene black), and 1.2 wt% binder (polyvinylidene fluoride). In Examples 1-9, the D of the active material in the second positive electrode active coating... 50 Its thickness is 14–16 μm, and its surface density is 0.012–0.016 g / cm³. 2 The compacted density is 1.8–2.5 g / cm³. 3 The aspect ratio is 3.5–5. The coating thickness is 65 μm, and the tube wall length is 22–23 nm.

[0095] 2. Preparation process

[0096] (1) Add 1 wt% acetylene black and 2 wt% polyvinylidene fluoride to 97 wt% lithium cobalt oxide, and then adjust with N-methylpyrrolidone to form positive electrode slurry A. Add acetylene black and polyvinylidene fluoride to lithium cobalt oxide, and then adjust with N-methylpyrrolidone to form positive electrode slurry B. Coat positive electrode slurries A and B onto the surface of the current collector using a coating device, and then dry, roll-slit and form into positive electrode sheets.

[0097] (2) The negative electrode active material artificial graphite, the conductive agent conductive carbon black, and the binder sodium carboxymethyl cellulose are mixed in a ratio of (96.5wt%, 1.5wt%, and 2wt%), and then deionized water is added to disperse them to prepare a negative electrode slurry A with an appropriate solid content; the negative electrode active material artificial graphite, the conductive agent conductive carbon black, and the binder sodium carboxymethyl cellulose are mixed in a ratio of (96.5wt%, 2.3wt%, and 1.2wt%), and then deionized water is added to disperse them to prepare a negative electrode slurry B with an appropriate solid content. Then, negative electrode slurries A and B are simultaneously coated on the negative electrode current collector using a coating equipment, followed by drying, rolling, slitting, and sheet forming to obtain a negative film.

[0098] like Figure 3 As shown, the wound cell in this embodiment has a conventional wound cell structure.

[0099] This technical solution is also applicable to the electrode-center wound core structure. Figure 4 (as shown) and other wound core structures formed by winding (such as infinite loop wound core structure, tri-loop wound core structure, multi-loop wound core structure, etc.).

[0100] Comparative Example 1: Winded Battery Cell

[0101] Similar to Example 1, except for: diffusion coefficient, D 50 The parameters such as aspect ratio and positive electrode formulation differ. See Table 1 for specific differences.

[0102] Comparative Example 2: Winded Battery Cell

[0103] Similar to Example 1, except for: diffusion coefficient, D 50 The parameters such as aspect ratio and positive electrode formulation differ. See Table 1 for specific differences.

[0104] Table 1-1

[0105]

[0106]

[0107] Table 1-2

[0108]

[0109]

[0110] Test Example 1 Cycle Life Test

[0111] The positive and negative electrode sheets of the battery cells in Examples 1-9 and Comparative Examples 1-2 were stacked together with the separator and wound into a core. The core was then encapsulated with an aluminum-plastic film. The battery cells were then subjected to processes such as liquid injection, aging, formation, and secondary encapsulation. Finally, the electrochemical performance of the lithium-ion battery was tested.

[0112] The preparation method of the electrolyte includes: mixing propylene carbonate, ethylene carbonate, dimethyl carbonate and ethyl methyl carbonate in a weight ratio of 1:1:0.5:1, and then adding LiPF6 to obtain the electrolyte, wherein the concentration of LiPF6 is 1 mol / L.

[0113] The cycle life and lithium plating of the lithium-ion batteries prepared above were compared using the following test methods:

[0114] ① Cycle life: The life test is performed by charging at 3C rate to 4.4V and discharging at 1C rate for 500 cycles.

[0115] ② Lithium plating test: Fully charge at 5C, discharge at 0.5C, and after 20 charge-discharge cycles, dissect the cell to check for lithium plating.

[0116] The results are shown in the table below:

[0117] Table 2

[0118]

[0119] The results showed that Examples 1-9 maintained a capacity retention of 91.25%–92.60% after 500 cycles without lithium plating. Comparative Examples 1-2 maintained capacities of 85.1% and 82.7% respectively after 500 cycles, but exhibited lithium plating. Therefore, Examples 1-9 showed a significantly improved capacity retention after 500 cycles without lithium plating.

[0120] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A wound battery cell, characterized in that, The wound battery cell includes a negative electrode and / or a positive electrode; The negative electrode sheet includes a first negative electrode active coating, a current collector, and a second negative electrode active coating arranged sequentially; the first negative electrode active coating is disposed on the surface of the current collector near the center of curling; the second negative electrode active coating is disposed on the surface of the current collector away from the center of curling; the diffusion coefficient of the first negative electrode active coating is less than the diffusion coefficient of the second negative electrode active coating; The positive electrode sheet includes a first positive electrode active coating, a current collector, and a second positive electrode active coating arranged sequentially; the first positive electrode active coating is disposed on the surface of the current collector near the center of curling; the second positive electrode active coating is disposed on the surface of the current collector away from the center of curling; the diffusion coefficient of the first positive electrode active coating is less than the diffusion coefficient of the second positive electrode active coating; The diffusion coefficient of the first negative electrode active coating is ~ ; The diffusion coefficient of the second negative electrode active coating is ~ ; The diffusion coefficient of the first positive electrode active coating is ~ ; The diffusion coefficient of the second positive electrode active coating is ~ .

2. The wound battery cell according to claim 1, characterized in that, The diffusion coefficient of the first negative electrode active coating is smaller than that of the second negative electrode active coating, and this is controlled by at least one of the following methods: (1) The surface density of the first negative electrode active coating is greater than that of the second negative electrode active coating; (2) The D of the active material in the first negative electrode active coating 50 D greater than that of the active material in the second negative electrode active coating 50 ; (3) The aspect ratio of the active material in the first negative electrode active coating is smaller than that of the active material in the second negative electrode active coating; (4) The compaction density of the first negative electrode active coating is greater than that of the second negative electrode active coating; (5) The conductive agent content of the first negative electrode active coating is less than that of the second negative electrode active coating; (6) The thickness of the first negative electrode active coating is less than the thickness of the second negative electrode active coating; (7) The conductive agents of the first negative electrode active coating and the second negative electrode active coating are both tubular conductive agents, and the tube wall length of the conductive agent of the first negative electrode active coating is less than the tube wall length of the conductive agent of the second negative electrode active coating. The diffusion coefficient of the first positive electrode active coating is smaller than that of the second positive electrode active coating, and this is controlled by at least one of the following methods: (1) The areal density of the first positive electrode active coating is greater than that of the second positive electrode active coating; (2) The D of the active material in the first positive electrode active coating 50 D greater than that of the active material in the second positive electrode active coating 50 ; (3) The aspect ratio of the active material in the first positive electrode active coating is smaller than that of the active material in the second positive electrode active coating; (4) The compaction density of the first positive electrode active coating is greater than that of the second positive electrode active coating; (5) The conductive agent content of the first positive electrode active coating is less than that of the second positive electrode active coating; (6) The thickness of the first positive electrode active coating is less than the thickness of the second positive electrode active coating; (7) The conductive agents of the first positive electrode active coating and the second positive electrode active coating are both tubular conductive agents, and the tube wall length of the conductive agent of the first positive electrode active coating is less than the tube wall length of the conductive agent of the second positive electrode active coating.

3. The wound battery cell according to claim 1, characterized in that, The components of the first negative electrode active coating or the second negative electrode active coating, by weight, include: Negative electrode active material: 75~99.8 wt%; Conductive agent 0.5~15 wt% Adhesive 0.5~15 wt%.

4. The wound battery cell according to claim 3, characterized in that, In the first negative electrode active coating or the second negative electrode active coating, The negative electrode active material is independently selected from one or more of carbon-based graphite materials, hard carbon, soft carbon, graphene, silicon carbide materials, and lithium titanate; the carbon-based graphite material is selected from at least one of natural graphite, artificial graphite, and mesophase carbon spheres. The conductive agent is independently selected from one or more of carbon black, conductive graphite, carbon fiber, carbon nanotubes, and graphene; the carbon black is selected from at least one of SP, Ketjen black, and acetylene black. The adhesive is independently selected from one or more of polyvinylidene fluoride, polymethyl methacrylate, polyvinyl alcohol, polytetrafluoroethylene, styrene-butadiene latex compounds, polyacrylate compounds, polyacrylonitrile, polytetrafluoroethylene, and polyethylene oxide.

5. The wound battery cell according to claim 1, characterized in that, By weight, the components of the first positive electrode active coating or the second positive electrode active coating include: Positive electrode active material 75~99.8wt%; Conductive agent 0.5~15 wt% Adhesive 0.5~15 wt%.

6. The wound battery cell according to claim 5, characterized in that, In the first positive electrode active coating or the second positive electrode active coating, The positive electrode active material is independently selected from one or more of lithium cobalt oxide, lithium iron phosphate, lithium manganese iron phosphate, sodium iron phosphate, lithium vanadium phosphate, sodium vanadium phosphate, lithium vanadium oxide phosphate, sodium vanadium oxide phosphate, lithium vanadium oxide, lithium manganese oxide, lithium nickel oxide, lithium nickel cobalt manganese oxide, lithium-rich manganese-based materials, or lithium nickel cobalt aluminum oxide. The conductive agent is independently selected from one or more of the following: conductive carbon black, Ketjen black, conductive fiber, conductive polymer, acetylene black, carbon nanotubes, graphene, flake graphite, conductive oxide, and metal particles. The adhesive is independently selected from one or more of the following: polyvinylidene fluoride, copolymer of polyvinylidene fluoride and hexafluoropropylene, polyamide, polyacrylonitrile, polyacrylate, polyacrylic acid, polyacrylate, polyvinylpyrrolidone, polyvinyl ether, polymethyl methacrylate, polytetrafluoroethylene, polyhexafluoropropylene, and styrene-butadiene rubber.

7. The wound battery cell according to claim 1, characterized in that, The thickness of the first negative electrode active coating, the second negative electrode active coating, the first positive electrode active coating, or the second positive electrode active coating is 20~75μm.

8. A battery, characterized in that, The battery comprises a wound cell as described in any one of claims 1-7.

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