Negative electrode and battery

Abstract

The present application provides a negative electrode sheet and a battery, wherein the negative electrode sheet includes a current collector, a first coating layer provided on the surface of the current collector, and a second coating layer provided on the first coating layer. The first coating layer includes a negative electrode active material, a first conductive agent, and a first binder, and the second coating layer includes a metal-organic framework compound (MOF), a second conductive agent, and a second binder. The negative electrode sheet provided by the present application solves the problem of lithium deposition on the surface of negative electrode sheets in lithium-ion batteries.

Description

Technical Field

[0001] The present application relates to the field of lithium-ion batteries, and in particular to a negative electrode sheet and a battery. Background Art

[0002] With the rapid development of lithium-ion battery technology, lithium-ion batteries are increasingly used in portable mobile electronic devices such as laptops and smart phones, and people's requirements for battery charging speed are also getting higher and higher.

[0003] At present, with the increase in charging speed, when lithium-ion batteries are charged rapidly at a high rate, lithium is easily deposited on the surface of the negative electrode of the lithium-ion battery, resulting in poor rate performance of the lithium-ion battery. Summary of the Invention

[0004] The embodiments of the present application provide a negative electrode sheet and a battery, which solve the problem of easy lithium deposition on the surface of the negative electrode sheet of a lithium-ion battery.

[0005] To achieve the above objectives, in a first aspect, an embodiment of the present application provides a negative electrode sheet, comprising a current collector, wherein a first coating is provided on a surface of the current collector, and a second coating is provided on the first coating;

[0006] The first coating layer includes a negative electrode active material, a first conductive agent and a first binder, and the second coating layer includes a metal organic framework compound MOFs, a second conductive agent and a second binder.

[0007] Optionally, the second coating layer does not include the negative electrode active material;

[0008] Alternatively, the second coating layer includes the negative electrode active material, and the content of MOFs on the side close to the current collector is less than the content of MOFs on the side away from the current collector, and the content of the negative electrode active material on the side close to the current collector is greater than the content of the negative electrode active material on the side away from the current collector.

[0009] Optionally, the content of the MOFs in the second coating layer increases in a gradient manner in a direction from the current collector to a direction away from the current collector.

[0010] Optionally, the thickness of the second coating layer ranges from 5 microns to 50 microns.

[0011] Optionally, a thickness ratio of the second coating layer to the first coating layer ranges from 0.5 to 2.

[0012] Optionally, the median particle size of the MOFs ranges from 5 microns to 20 microns.

[0013] Optionally, the metal ions in the MOFs include at least one of zinc ions, cobalt ions, copper ions, nickel ions and manganese ions; and / or,

[0014] The organic ligand in the MOFs includes at least one of 2-methylimidazole, benzimidazole, 2-aminobenzimidazole, trimesic acid, terephthalic acid and naphthalenetetracarboxylic acid.

[0015] Optionally, the negative electrode sheet further includes at least one third coating layer, and the at least one third coating layer is located between the first coating layer and the second coating layer;

[0016] Each of the third coating layers includes the MOFs, and the content of the MOFs in the at least one third coating layer and the second coating layer increases in a gradient manner in a direction away from the current collector.

[0017] Optionally, the negative electrode active material includes at least one of graphite, hard carbon, soft carbon, lithium titanate, silicon oxide and silicon carbide.

[0018] In a second aspect, an embodiment of the present application provides a battery comprising the negative electrode sheet as described in the first aspect.

[0019] In an embodiment of the present application, the negative electrode sheet includes a current collector, the surface of the current collector is provided with a first coating, and the first coating is provided with a second coating. The first coating includes a negative electrode active material, a first conductive agent and a first binder, and the second coating includes a metal organic framework compound MOFs, a second conductive agent and a second binder. By making the outermost coating on the current collector, i.e., the second coating, include MOFs, an effective liquid-phase lithium ion diffusion channel can be constructed, thereby reducing the possibility of lithium precipitation on the surface of the negative electrode sheet, thereby improving the rate performance of the battery. By providing at least two coatings and making the first coating include a negative electrode active material, the energy density of the battery can be increased while improving the rate performance of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following description is given of the drawings in the specification. Obviously, the following drawings are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the listed drawings without paying any creative work.

[0021] Figure 1 This is one of the structural diagrams of the negative electrode sheet provided in the embodiment of the present application;

[0022] Figure 2 This is the second structural schematic diagram of the negative electrode sheet provided in the embodiment of the present application. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0024] See also Figure 1 An embodiment of the present application provides a negative electrode sheet, including a current collector 11 , a first coating 21 is provided on the surface of the current collector 11 , and a second coating 22 is provided on the first coating 21 .

[0025] In specific implementation, the first coating layer 21 and the second coating layer 22 may be sequentially stacked and coated only on a single surface of the current collector 11 , or the first coating layer 21 and the second coating layer 22 may be sequentially stacked and coated on both surfaces of the current collector 11 .

[0026] As an example, in a laminated battery comprising one positive electrode sheet and one negative electrode sheet, the first surface of the current collector 11 of the negative electrode sheet can be sequentially coated with a first coating 21 and a second coating 22, while the second surface of the current collector 11 is coated only with the first coating 21. The first surface of the current collector 11 is the surface of the negative electrode sheet that faces the positive electrode sheet. This improves the battery's rate performance while also increasing its energy density.

[0027] The first coating layer 21 includes a negative electrode active material, a first conductive agent, and a first binder, and the second coating layer 22 includes a metal organic framework compound MOFs, a second conductive agent, and a second binder.

[0028] Optionally, the negative electrode active material includes at least one of graphite, hard carbon, soft carbon, lithium titanate, silicon oxide, and silicon carbide.

[0029] Optionally, the first conductive agent includes at least one of conductive carbon black, acetylene black, Ketjen black, conductive graphite, conductive carbon fiber, carbon nanotubes and metal powder.

[0030] Optionally, the first binder includes at least one of polyvinyl alcohol, sodium carboxymethyl cellulose, styrene-butadiene latex, polytetrafluoroethylene, polyethylene oxide and polyvinylidene fluoride.

[0031] Optionally, the second conductive agent includes at least one of conductive carbon black, acetylene black, Ketjen black, conductive graphite, conductive carbon fiber, carbon nanotubes and metal powder.

[0032] Optionally, the second binder includes at least one of polyvinyl alcohol, sodium carboxymethyl cellulose, styrene-butadiene latex, polytetrafluoroethylene, polyethylene oxide and polyvinylidene fluoride.

[0033] The first conductive agent and the second conductive agent may be the same or different. For example, the first conductive agent and the second conductive agent are both conductive carbon black, or the first conductive agent is Ketjen black and the second conductive agent is carbon nanotubes and metal powder.

[0034] The first binder and the second binder may be the same or different. For example, the first binder and the second binder may both be polyvinylidene fluoride, or the first binder may be polyethylene oxide and the second binder may be polyvinylidene fluoride.

[0035] Metal organic frameworks (MOFs) are a class of porous materials formed by the coordination and complexation of metal ions and organic ligands. They have advantages such as high specific surface area and porosity, good thermal stability, and a stable and ordered crystal structure. In batteries, the coating on the negative electrode sheet close to the diaphragm surface (i.e., the outermost coating on the current collector 11) has a lower potential and a greater risk of lithium plating. Therefore, adding MOFs to the outermost coating on the current collector 11, i.e., the second coating 22, can construct an effective liquid-phase lithium ion diffusion channel, thereby reducing the possibility of lithium plating on the negative electrode surface and improving the battery's rate performance.

[0036] However, MOFs have poor voltage resistance, and providing only one MOF-containing coating on the surface of the current collector 11 is not conducive to improving the battery's energy density. Therefore, in the embodiment of the present application, at least two coatings are provided on the surface of the current collector 11, and the first coating 21 includes a negative electrode active material, which can improve the battery's rate performance while also increasing the battery's energy density.

[0037] Optionally, the second coating layer 22 does not include negative electrode active material;

[0038] Alternatively, the second coating layer 22 includes a negative electrode active material, and the content of MOFs on the side close to the current collector 11 is less than the content of MOFs on the side away from the current collector 11 .

[0039] In a specific implementation, the second coating layer 22 may not include the negative electrode active material, so that the possibility of lithium deposition on the surface of the negative electrode sheet can be further reduced, thereby improving the rate performance of the battery.

[0040] The second coating layer 22 may also include a negative electrode active material, thereby improving the rate performance of the battery and the energy density of the battery.

[0041] As mentioned above, the closer the negative electrode sheet is to the surface of the diaphragm, the lower the potential of the coating (i.e., the outermost coating on the current collector 11) is, and the greater the risk of lithium plating. Therefore, when the second coating 22 includes a negative electrode active material, the content of MOFs on the side close to the current collector 11 is set to be less than the content of MOFs on the side away from the current collector 11, and the content of negative electrode active material on the side close to the current collector 11 is greater than the content of negative electrode active material on the side away from the current collector 11. It can make the position with a greater risk of lithium plating have a more effective liquid-phase lithium ion diffusion channel, and the position with a lower risk of lithium plating has more negative electrode active material while having an effective liquid-phase lithium ion diffusion channel. In this way, the energy density of the battery can be further improved while improving the rate performance of the battery.

[0042] Optionally, the content of MOFs in the second coating 22 increases in a gradient from the current collector 11 to the direction away from the current collector 11. As mentioned above, the closer the coating of the negative electrode is to the surface of the diaphragm (i.e., the outermost coating on the current collector 11), the lower the potential is, and the greater the risk of lithium deposition. Therefore, while solving the problem of easy lithium deposition on the surface of the negative electrode of the lithium-ion battery, by increasing the content of MOFs in the second coating 22 in a gradient from the current collector 11 to the direction away from the current collector 11, the use of unnecessary MOFs materials can be reduced, thereby saving materials and reducing the cost of the negative electrode.

[0043] Optionally, the thickness of the second coating layer 22 ranges from 5 micrometers to 50 micrometers.

[0044] In a specific implementation, the thickness of the second coating layer 22 can be 5 microns, 10 microns, 22 microns, 30 microns, 45 microns, 50 microns, etc. If the second coating layer 22 is too thick, it will be easily broken when the negative electrode sheet is rolled; if the second coating layer 22 is too thin, it will not effectively solve the problem of lithium deposition on the surface of the negative electrode sheet. Through experimental exploration, the inventors of this application found that when the thickness of the second coating layer 22 ranges from 5 microns to 50 microns, it can effectively solve the problem of lithium deposition on the surface of the negative electrode sheet while preventing the second coating layer 22 from breaking when the negative electrode sheet is rolled.

[0045] Optionally, the thickness of the first coating layer 21 ranges from 20 micrometers to 200 micrometers.

[0046] In a specific implementation, the thickness of the second coating 22 can be 20 micrometers, 22 micrometers, 30 micrometers, 45 micrometers, 50 micrometers, 60 micrometers, 100 micrometers, 150 micrometers, 200 micrometers, etc.

[0047] Optionally, the thickness ratio of the second coating layer 22 to the first coating layer 21 ranges from 0.5 to 2.

[0048] In a specific implementation, the thickness ratio of the second coating layer 22 to the first coating layer 21 can be 0.5, 0.7, 1.1, 1.5, 1.8, 2, etc. If the thickness ratio of the second coating layer 22 to the first coating layer 21 is too large, the energy density of the battery will be relatively low. If the thickness ratio of the second coating layer 22 to the first coating layer 21 is too small, the problem of easy lithium deposition on the surface of the negative electrode sheet cannot be solved well, that is, the rate performance of the battery cannot be improved. Through experimental exploration, the inventors of this application found that when the thickness ratio of the second coating layer 22 to the first coating layer 21 is in the range of 0.5 to 2, the energy density of the battery can be improved while improving the rate performance of the battery.

[0049] Optionally, the median particle size Dv50 of MOFs ranges from 5 microns to 20 microns.

[0050] In a specific implementation, the median particle size of MOFs can be 5 microns, 10 microns, 15 microns, or 20 microns. Through experimental exploration, the inventors of this application found that the median particle size Dv50 of MOFs ranges from 5 microns to 20 microns, which can improve the rate performance of the battery while increasing the energy density of the battery.

[0051] Optionally, the metal ions in the MOFs include at least one of zinc ions, cobalt ions, copper ions, nickel ions, and manganese ions;

[0052] And / or, the organic ligand in the MOFs includes at least one of 2-methylimidazole, benzimidazole, 2-aminobenzimidazole, trimesic acid, terephthalic acid and naphthalenetetracarboxylic acid.

[0053] In a specific implementation, at least one of a salt containing zinc ions, a salt containing cobalt ions, a salt containing copper ions, a salt containing nickel ions, and a salt containing manganese ions; an organic ligand selected from 2-methylimidazole, benzimidazole, 2-aminobenzimidazole; trimesic acid, terephthalic acid, and naphthalenetetracarboxylic acid; or at least one of other aromatic carboxylic acids; and a dispersant are added to a solvent. The solvent is selected from methanol, N,N-dimethylformamide, ethanol, N,N-diethylformamide, deionized water, or a mixture thereof in a certain proportion. The dispersant is polyvinylpyrrolidone (PVP). After uniform mixing, the mixture is washed and dried to obtain MOFs.

[0054] For example, the preparation method of Co-MOF (Co(NO3)2·6H2O metal salt, 2-methylimidazole ligand) is as follows:

[0055] Co(NO3)2·6H2O (1 part 54.6 g) was dissolved in 1.5 L of methanol to form a clear solution, which was then injected into 1.5 L of methanol containing (1 part 61.6 g) 2-methylimidazole (MeIM) and stirred ultrasonically at room temperature for 100 minutes. The solution was then transferred to a 5 L Teflon-lined autoclave and heated at 120°C for 4 hours. The resulting precipitate was centrifuged, washed several times with ethanol, and dried overnight at 70°C in a vacuum oven.

[0056] Alternatively, see Figure 2 The negative electrode sheet further includes at least one third coating layer 23 , which is located between the first coating layer 21 and the second coating layer 22 . The first coating layer 21 , the at least one third coating layer 23 , and the second coating layer 22 can be stacked in sequence.

[0057] Each third coating layer 23 includes MOFs, and the content of MOFs in at least one of the third coating layers 23 and the second coating layer 22 increases in a gradient manner in a direction away from the current collector 11 .

[0058] The third coating layer 23 may or may not include a negative electrode active material.

[0059] In the case where the second coating layer 22 does not include the negative electrode active material, the third coating layer 23 may include the negative electrode active material to improve the energy density of the battery.

[0060] In the case where the second coating layer 22 does not include the negative electrode active material, the third coating layer 23 may not include the negative electrode active material to improve the rate performance of the battery.

[0061] In the case where the second coating layer 22 includes a negative electrode active material, the third coating layer 23 may also include a negative electrode active material to improve the energy density of the battery.

[0062] In specific implementation, whether the third coating layer 23 includes the negative electrode active material can be set according to actual needs.

[0063] As mentioned above, the closer the negative electrode sheet is to the diaphragm surface, the lower the potential of the coating (i.e., the outermost coating on the current collector 11) is, and the greater the risk of lithium plating. By making the negative electrode sheet include a first coating 21, a second coating 22, and at least one third coating 23, with at least one third coating 23 located between the first coating 21 and the second coating 22, the MOFs content of each coating in the at least one third coating 23 and the second coating 22 can be more accurately set after rigorous calculations or experiments, so that the position with a greater risk of lithium plating has a liquid-phase lithium ion diffusion channel that matches the position more accurately, and the position with a lower risk of lithium plating has a liquid-phase lithium ion diffusion channel that matches the position while having more negative electrode active material. In this way, the energy density of the battery can be further improved while improving the rate performance of the battery.

[0064] The present application also provides a battery, including the negative electrode sheet provided in the present application. The structure and operating principle of the negative electrode sheet provided in the present application can be referred to in the above embodiments and will not be described in detail here. Since the battery provided in the present application includes the negative electrode sheet provided in the present application, the battery provided in the present application has all the beneficial effects of the negative electrode sheet provided in the present application.

[0065] The battery provided in the embodiments of the present application is described below in conjunction with specific experiments.

[0066] Example 1.

[0067] (1) Graphite was used as the active material 1 to prepare slurry 1: 96.8% of the negative electrode active material, 1.2% of the first conductive agent, and 2% of the second binder were mixed according to a certain mixing process. The slurry had a viscosity of 2000-5000 mPa.s and a solid content of 40%-50%.

[0068] (2) 80 wt% of Co-MOF (Co(NO3)2·6H2O, 2-methylimidazole ligand), 5 wt% of a second conductive agent (conductive carbon black) and 15 wt% of a second binder (polyvinylidene fluoride) were mixed, and N-methylpyrrolidone was added and stirred to disperse to prepare slurry 2.

[0069] (3) The negative electrode slurries prepared in (1) and (2) are simultaneously coated on the negative electrode current collector, with slurry 2 supported on slurry 1, and slurry 1 supported on the current collector. The thickness of slurry 1 is 30 μm and the thickness of slurry 2 is 30 μm. The coating work on the other side of the current collector is completed in the same manner.

[0070] (4) Prepare positive electrode slurry using the positive electrode active material: Prepare positive electrode slurry according to a specific batching process using a ratio of 96% positive electrode active material, 2.5% conductive agent, and 1.5% binder. The slurry has a viscosity of 2000-7000 mPa·s and a solids content of 70%-80%. The slurry is sieved and then coated onto the positive electrode current collector.

[0071] The positive and negative electrode sheets obtained above are rolled, die-cut and slit, and then assembled into a core by winding. After passing the short-circuit test, they are packaged with aluminum-plastic film, baked in an oven to remove moisture until the moisture standard required for liquid injection is reached, and then the electrolyte is injected. After aging for 24-48 hours, the first charge is completed by hot pressing process to obtain the activated battery cell.

[0072] Preparation method of Co-MOF (Co(NO3)2·6H2O metal salt, 2-methylimidazole ligand):

[0073] Co(NO₃)₂·6H₂O (1 portion, 54.6 g) was dissolved in 1.5 L of methanol to form a clear solution, which was then added to 1.5 L of methanol containing 2-methylimidazole (MeIM) (1 portion, 61.6 g) and stirred ultrasonically at room temperature for 100 minutes. The solution was then transferred to a 5 L Teflon-lined autoclave and heated at 120°C for 4 hours. The resulting precipitate was centrifuged, washed several times with ethanol, and dried under vacuum at 70°C overnight.

[0074] Examples 2 to 5

[0075] The difference between Examples 2 to 5 and Example 1 is that the coating thickness of the metal organic framework compound Co-MOF (Co(NO3)2·6H2O metal salt, 2-methylimidazole ligand) and graphite is different, as shown in Table 1.

[0076] Example 6

[0077] (1) Graphite was used as the active material 1 to prepare slurry 1: 96.8% of the negative electrode active material, 1.2% of the first conductive agent, and 2% of the second binder were mixed according to a certain mixing process. The slurry had a viscosity of 2000-5000 mPa.s and a solid content of 40%-50%.

[0078] (2) 60 wt% of Co-MOF (Co(NO3)2·6H2O, 2-methylimidazole ligand), 20 wt% of graphite, 5 wt% of a second conductive agent (conductive carbon black) and 15 wt% of a second binder (polyvinylidene fluoride) were mixed, and N-methylpyrrolidone was added and stirred to disperse to prepare slurry 2.

[0079] (3) The negative electrode slurries prepared in (1) and (2) are simultaneously coated on the negative electrode current collector, with slurry 2 supported on slurry 1, and slurry 1 supported on the current collector. The thickness of slurry 1 is 30 μm and the thickness of slurry 2 is 30 μm. The coating work on the other side of the current collector is completed in the same manner.

[0080] (4) Prepare positive electrode slurry using the positive electrode active material: Prepare positive electrode slurry according to a specific batching process using a ratio of 96% positive electrode active material, 2.5% conductive agent, and 1.5% binder. The slurry has a viscosity of 2000-7000 mPa·s and a solids content of 70%-80%. The slurry is sieved and then coated onto the positive electrode current collector.

[0081] The positive and negative electrode sheets obtained above are rolled, die-cut and slit, and then assembled into a core by winding. After passing the short-circuit test, they are packaged with aluminum plastic film and baked in an oven to remove moisture until the moisture standard required for injection is reached. Then, the electrolyte is injected. After aging for 24-48 hours, the first charge is completed by hot pressing process to obtain the activated battery cell.

[0082] Comparative Example 1.

[0083] (1) Prepare slurry 1 using graphite as active material 1: prepare negative electrode slurry according to a certain batching process according to the ratio of 96.8% negative electrode active material, 1.2% conductive agent, and 2% binder. The slurry viscosity is 2000-5000mPa.s and the solid content is 40%-50%.

[0084] (2) The negative electrode slurry 1 prepared above was coated on the negative electrode current collector with a slurry thickness of 60 μm. The coating work on the other side of the current collector was completed in the same way.

[0085] (3) Prepare positive electrode slurry using the positive electrode active material: Prepare positive electrode slurry according to a specific batching process using a ratio of 96% positive electrode active material, 2.5% conductive agent, and 1.5% binder. The slurry has a viscosity of 2000-7000 mPa·s and a solids content of 70%-80%. Pass the slurry through a sieve and apply it to the positive electrode current collector.

[0086] The positive and negative electrode sheets obtained above are rolled, die-cut and slit, and then assembled into a core by winding. After passing the short-circuit test, they are packaged with aluminum-plastic film, baked in an oven to remove moisture until the moisture standard required for liquid injection is reached, and then the electrolyte is injected. After aging for 24-48 hours, the first charge is completed by hot pressing process to obtain the activated battery cell.

[0087] Comparative Example 2

[0088] The difference between Comparative Example 2 and Comparative Example 1 is that only one layer of metal organic framework Co-MOF (Co(NO3)2·6H2O metal salt, 2-methylimidazole ligand) is coated on the negative electrode current collector.

[0089] The battery cells prepared in the above examples and comparative examples were fully charged at 0.5C, and the ratio of the energy E discharged at 0.5C to the battery cell volume V was the energy density ED / Wh·L-1.

[0090] The prepared battery cells were charged at a 3C rate and discharged at a 1C rate for 700 cycles to test the volume expansion rate of the battery cells.

[0091] The prepared battery cells were fully charged at 5C and discharged at 0.5C. After 20 cycles of charge and discharge, the battery cells were dissected to check for lithium plating.

[0092] The test results shown in Table 1 are obtained.

[0093]

[0094]

[0095] Table 1

[0096] As can be seen from Table 1, the batteries provided by the embodiments of the present application, such as Examples 1 to 3, can significantly improve the battery's energy density and cycle capacity retention, and improve lithium plating compared to the conventional coating method, namely Comparative Example 1. Comparing Example 1 with Examples 2 and 4, it can be seen that a smaller amount of MOFs does not significantly improve the capacity retention. Comparing Example 1 with Examples 3 and 5, it can be seen that a larger amount of MOFs can improve energy density, but the MOF material itself is not pressure-resistant. After exceeding a certain amount, the MOF material crushes, resulting in increased cycle capacity decay and worsening lithium plating.

[0097] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of this application, ordinary technicians in this field can also make many forms without departing from the purpose of this application and the scope of protection of the claims, all of which are within the protection of this application.

Claims

1. A negative electrode sheet, characterized in that: The device comprises a current collector, wherein a first coating is provided on the surface of the current collector, and a second coating is provided on the first coating; The first coating layer includes a negative electrode active material, a first conductive agent and a first binder, and the second coating layer includes a metal organic framework compound MOFs, a second conductive agent and a second binder; The second coating layer includes the negative electrode active material, and the content of MOFs on the side close to the current collector is less than the content of MOFs on the side away from the current collector, and the content of the negative electrode active material on the side close to the current collector is greater than the content of the negative electrode active material on the side away from the current collector; the content of the MOFs in the second coating layer increases gradiently in the direction from the current collector to the direction away from the current collector.

2. The negative electrode sheet according to claim 1, characterized in that: The thickness of the second coating layer ranges from 5 microns to 50 microns.

3. The negative electrode sheet according to claim 1, characterized in that: The thickness ratio of the second coating layer to the first coating layer ranges from 0.5 to 2.

4. The negative electrode sheet according to claim 1, characterized in that: The median particle size of the MOFs ranges from 5 microns to 20 microns.

5. The negative electrode sheet according to claim 1, characterized in that: The metal ions in the MOFs include at least one of zinc ions, cobalt ions, copper ions, nickel ions and manganese ions; and / or, The organic ligand in the MOFs includes at least one of 2-methylimidazole, benzimidazole, 2-aminobenzimidazole, trimesic acid, terephthalic acid and naphthalenetetracarboxylic acid.

6. The negative electrode sheet according to claim 1, characterized in that: The negative electrode sheet further includes at least one third coating layer, wherein the at least one third coating layer is located between the first coating layer and the second coating layer; Each of the third coating layers includes the MOFs, and the content of the MOFs in the at least one third coating layer and the second coating layer increases in a gradient manner in a direction away from the current collector.

7. The negative electrode sheet according to claim 1, characterized in that: The negative electrode active material includes at least one of graphite, hard carbon, soft carbon, lithium titanate, silicon oxide and silicon carbide.

8. A battery, characterized in that: The negative electrode sheet comprises the negative electrode sheet according to any one of claims 1 to 7.

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