CN114497451A - Negative plate and preparation method and application thereof - Google Patents
Negative plate and preparation method and application thereof Download PDFInfo
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- CN114497451A CN114497451A CN202210104227.5A CN202210104227A CN114497451A CN 114497451 A CN114497451 A CN 114497451A CN 202210104227 A CN202210104227 A CN 202210104227A CN 114497451 A CN114497451 A CN 114497451A
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- negative electrode
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- 238000002360 preparation method Methods 0.000 title claims abstract description 26
- 239000007773 negative electrode material Substances 0.000 claims abstract description 73
- 239000003575 carbonaceous material Substances 0.000 claims abstract description 54
- 239000011230 binding agent Substances 0.000 claims abstract description 41
- 125000005842 heteroatom Chemical group 0.000 claims abstract description 33
- 229910021385 hard carbon Inorganic materials 0.000 claims abstract description 25
- 239000006258 conductive agent Substances 0.000 claims abstract description 19
- 239000011159 matrix material Substances 0.000 claims abstract description 16
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims abstract description 14
- 229910052796 boron Inorganic materials 0.000 claims abstract description 14
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 14
- 239000010703 silicon Substances 0.000 claims abstract description 14
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 14
- 229910052717 sulfur Inorganic materials 0.000 claims abstract description 14
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 7
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 4
- 239000010410 layer Substances 0.000 claims description 75
- 239000000463 material Substances 0.000 claims description 72
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 56
- 238000010438 heat treatment Methods 0.000 claims description 38
- 239000006183 anode active material Substances 0.000 claims description 31
- OBNDGIHQAIXEAO-UHFFFAOYSA-N [O].[Si] Chemical compound [O].[Si] OBNDGIHQAIXEAO-UHFFFAOYSA-N 0.000 claims description 30
- 229910052799 carbon Inorganic materials 0.000 claims description 30
- 239000002245 particle Substances 0.000 claims description 28
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 26
- 238000001035 drying Methods 0.000 claims description 20
- 239000002243 precursor Substances 0.000 claims description 20
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 claims description 19
- 239000000126 substance Substances 0.000 claims description 19
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- 238000004321 preservation Methods 0.000 claims description 13
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- 238000000034 method Methods 0.000 claims description 11
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- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims description 10
- 238000000151 deposition Methods 0.000 claims description 10
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- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims description 10
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- MNNHAPBLZZVQHP-UHFFFAOYSA-N diammonium hydrogen phosphate Chemical compound [NH4+].[NH4+].OP([O-])([O-])=O MNNHAPBLZZVQHP-UHFFFAOYSA-N 0.000 claims description 4
- 229910000388 diammonium phosphate Inorganic materials 0.000 claims description 4
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- 125000002534 ethynyl group Chemical group [H]C#C* 0.000 claims description 4
- JDSHMPZPIAZGSV-UHFFFAOYSA-N melamine Chemical compound NC1=NC(N)=NC(N)=N1 JDSHMPZPIAZGSV-UHFFFAOYSA-N 0.000 claims description 4
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- 229920003048 styrene butadiene rubber Polymers 0.000 claims description 4
- IXPNQXFRVYWDDI-UHFFFAOYSA-N 1-methyl-2,4-dioxo-1,3-diazinane-5-carboximidamide Chemical compound CN1CC(C(N)=N)C(=O)NC1=O IXPNQXFRVYWDDI-UHFFFAOYSA-N 0.000 claims description 3
- 229920000049 Carbon (fiber) Polymers 0.000 claims description 3
- 229920001661 Chitosan Polymers 0.000 claims description 3
- 239000005696 Diammonium phosphate Substances 0.000 claims description 3
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 claims description 3
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- 239000004372 Polyvinyl alcohol Substances 0.000 claims description 3
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims description 3
- HMDDXIMCDZRSNE-UHFFFAOYSA-N [C].[Si] Chemical compound [C].[Si] HMDDXIMCDZRSNE-UHFFFAOYSA-N 0.000 claims description 3
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- 239000006256 anode slurry Substances 0.000 claims description 3
- 239000007864 aqueous solution Substances 0.000 claims description 3
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- 125000002057 carboxymethyl group Chemical group [H]OC(=O)C([H])([H])[*] 0.000 claims description 3
- 239000011247 coating layer Substances 0.000 claims description 3
- JKWMSGQKBLHBQQ-UHFFFAOYSA-N diboron trioxide Chemical compound O=BOB=O JKWMSGQKBLHBQQ-UHFFFAOYSA-N 0.000 claims description 3
- BNIILDVGGAEEIG-UHFFFAOYSA-L disodium hydrogen phosphate Chemical compound [Na+].[Na+].OP([O-])([O-])=O BNIILDVGGAEEIG-UHFFFAOYSA-L 0.000 claims description 3
- 229910000397 disodium phosphate Inorganic materials 0.000 claims description 3
- 235000019800 disodium phosphate Nutrition 0.000 claims description 3
- 239000001866 hydroxypropyl methyl cellulose Substances 0.000 claims description 3
- 235000010979 hydroxypropyl methyl cellulose Nutrition 0.000 claims description 3
- 229920003088 hydroxypropyl methyl cellulose Polymers 0.000 claims description 3
- UFVKGYZPFZQRLF-UHFFFAOYSA-N hydroxypropyl methyl cellulose Chemical compound OC1C(O)C(OC)OC(CO)C1OC1C(O)C(O)C(OC2C(C(O)C(OC3C(C(O)C(O)C(CO)O3)O)C(CO)O2)O)C(CO)O1 UFVKGYZPFZQRLF-UHFFFAOYSA-N 0.000 claims description 3
- 239000005543 nano-size silicon particle Substances 0.000 claims description 3
- 235000011007 phosphoric acid Nutrition 0.000 claims description 3
- 229920002239 polyacrylonitrile Polymers 0.000 claims description 3
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- 239000001294 propane Substances 0.000 claims description 3
- 229910052814 silicon oxide Inorganic materials 0.000 claims description 3
- 239000002002 slurry Substances 0.000 claims description 3
- 239000011734 sodium Substances 0.000 claims description 3
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- 229940005550 sodium alginate Drugs 0.000 claims description 3
- 239000001488 sodium phosphate Substances 0.000 claims description 3
- 239000013589 supplement Substances 0.000 claims description 3
- YUKQRDCYNOVPGJ-UHFFFAOYSA-N thioacetamide Chemical compound CC(N)=S YUKQRDCYNOVPGJ-UHFFFAOYSA-N 0.000 claims description 3
- DLFVBJFMPXGRIB-UHFFFAOYSA-N thioacetamide Natural products CC(N)=O DLFVBJFMPXGRIB-UHFFFAOYSA-N 0.000 claims description 3
- 125000004429 atom Chemical group 0.000 abstract 1
- 239000011149 active material Substances 0.000 description 12
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 9
- 229910001416 lithium ion Inorganic materials 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 8
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- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 3
- 239000010405 anode material Substances 0.000 description 3
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
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Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M4/628—Inhibitors, e.g. gassing inhibitors, corrosion inhibitors
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/04—Construction or manufacture in general
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/133—Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/362—Composites
- H01M4/366—Composites as layered products
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
- H01M4/386—Silicon or alloys based on silicon
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
Abstract
The invention relates to the technical field of batteries, in particular to a negative plate and a preparation method and application thereof. A negative plate comprises a negative current collector, a first negative active layer and a second negative active layer; the negative current collector comprises a negative current collector matrix and a carbon material layer arranged on the surface of at least one side of the negative current collector matrix, a first negative active layer is arranged on the surface of the carbon material layer far away from the negative current collector matrix, and a second negative active layer is arranged on the surface of the first negative active layer far away from the negative current collector; the first negative electrode active layer comprises a first negative electrode active material, a first binder and a first conductive agent, and the first negative electrode active material comprises a silicon-based negative electrode material doped with hetero atoms; the second negative electrode active layer includes a second negative electrode active material including a hard carbon material doped with hetero atoms and a second binder; the atoms include at least one of P, N, S, B and O. The negative plate has excellent quick charge performance.
Description
Technical Field
The invention relates to the technical field of batteries, in particular to a negative plate and a preparation method and application thereof.
Background
In recent years, the sales volume of new energy automobiles is gradually increased, and lithium ion batteries as power sources are required to have higher and higher performance in all aspects, wherein in order to solve the problem of "endurance and charging anxiety" of products, the new lithium ion batteries need to have higher energy density and faster charging time. Graphite is used as the most mature negative active material applied in the current industry, the actual exertion capacity of the graphite is basically close to the theoretical capacity, and the high energy density index is difficult to meet. Based on the existing anode main material and battery formula system, the graphite mixed silicon-based cathode is beneficial to further improving the energy density of the lithium ion battery, and can effectively solve the disadvantage of short endurance mileage of a new energy automobile. However, the inherent semiconductor property of the silicon material limits the quick charging capability of the battery, and the difference of the electron transfer efficiency of the two materials in the charging and discharging process causes the current distribution in the negative plate to be uneven, so that the potential of a local area easily breaks through the lower limit of 0V, lithium deposition is generated, the quick charging performance of the power battery is reduced, and the safety is affected.
The silicon-doped graphite negative pole piece has different adsorption capacities on conductive carbon and a binder due to different surface tensions of two material particles, and the conditions of uneven distribution of the conductive carbon and unstable network of the binder are easy to occur in the mixed homogenate coating, so that the multiplying power performance of the battery is not ideal; because the electrochemical lithium deintercalation potentials of the graphite material and the silicon material are different, the problem of successive lithium deintercalation of two different active material materials occurs, the current distribution in the negative plate is quite uneven, local metal lithium deposition is easy to occur, and the safety of the battery is further influenced; therefore, how to obtain a pole piece with high rate characteristics by using two different active materials as main materials becomes a technical problem to be solved urgently.
In view of the above, the present invention is particularly proposed.
Disclosure of Invention
One object of the present invention is to provide a negative electrode sheet, which can improve the quick charging performance of the sheet by arranging a specific negative electrode current collector, a first negative electrode active layer and a second negative electrode active layer.
The invention also aims to provide a preparation method of the negative plate, which is simple and feasible.
Another object of the present invention is to provide a battery having excellent cycle performance and rate performance.
In order to achieve the above purpose of the present invention, the following technical solutions are adopted:
a negative plate comprises a negative current collector, a first negative active layer and a second negative active layer; the negative current collector comprises a negative current collector matrix and a carbon material layer arranged on the surface of at least one side of the negative current collector matrix, the surface of the carbon material layer, which is far away from the negative current collector matrix, is provided with the first negative active layer, and the surface of the first negative active layer, which is far away from the negative current collector, is provided with the second negative active layer;
the first negative electrode active layer comprises a first negative electrode active material, a first binder and a first conductive agent, the first negative electrode active material comprises a silicon-based negative electrode material, and a first hetero atom is doped in the silicon-based negative electrode material;
the second anode active layer includes a second anode active material and a second binder, the second anode active material includes a hard carbon material, and the hard carbon material is doped with a second hetero atom;
the first and second heteroatoms include at least one of P, N, S, B and O, respectively.
Preferably, the silicon-based negative electrode material comprises a silicon-oxygen composite material and a carbon coating layer coated on at least part of the surface of the silicon-oxygen composite material, wherein the silicon-oxygen composite material comprises Si and SiOxWherein x is more than or equal to 0.8 and less than or equal to 1.2;
preferably, in the first anode active material, the doping amount of the first hetero atom is 3 at% to 8 at%;
preferably, in the second anode active material, the doping amount of the second hetero atom is 2 at% to 5 at%;
preferably, the mass ratio of the first negative electrode active material to the second negative electrode active material is (5% to 30%): (70% to 95%).
Preferably, the silicon-based anode material comprises at least one of a nano silicon carbon material, a silicon oxygen material and a lithium-supplement silicon oxygen material;
preferably, the particle size D50 of the first negative electrode active material is 1-20 μm, preferably 3-10 μm;
preferably, the ratio of the particle diameter D90 to the particle diameter D50 of the first negative electrode active material is (1.7-3.5): 1;
preferably, the mass ratio of the first negative electrode active material, the first binder, and the first conductive agent is (95% to 98%): (1-3%): (1-2%);
preferably, the first binder comprises at least one of sodium carboxymethylcellulose, polyacrylic acid, sodium alginate, carboxymethyl chitosan, polyacrylonitrile and polyvinyl alcohol;
preferably, the first conductive agent includes at least one of conductive graphite, conductive carbon black, carbon nanotubes, carbon fibers, and graphene.
Preferably, the particle size D50 of the second negative electrode active material is 10-25 μm, preferably 15-20 μm;
preferably, the ratio of the particle size D50 of the second negative electrode active material to the particle size D50 of the first negative electrode active material is (1.5-6): 1;
preferably, the mass ratio of the second anode active material to the second binder is (95% to 98%): (2% -5%);
preferably, the second binder includes at least one of styrene-butadiene rubber, sodium carboxymethyl cellulose, and hydroxypropyl methyl cellulose.
Preferably, the roughness of the negative current collector is more than or equal to 0.1 mu m;
preferably, the carbon material layer includes at least one of graphite and graphene;
preferably, the thickness of the first negative electrode active layer is 20-60 μm;
preferably, the thickness of the second negative electrode active layer is 120-160 μm;
preferably, the thickness of the carbon material layer is 2-5 μm.
The preparation method of the negative plate comprises the following steps:
coating carbon material slurry on at least one side surface of the negative current collector matrix, and drying to obtain a negative current collector with a carbon material layer; coating first negative electrode slurry on the surface of the carbon material layer, which is far away from the negative electrode current collector substrate, and drying to obtain a first negative electrode active layer; coating a second negative electrode slurry on the surface of the first negative electrode active layer, which is far away from the negative electrode current collector substrate, and drying to obtain a second negative electrode active layer;
the first negative electrode slurry includes the first negative electrode active material, a first binder, a first conductive agent, and a first solvent;
the second anode slurry includes the second anode active material, a second binder, and a second solvent.
The first solvent and the second solvent of the present invention each comprise N-methylpyrrolidone.
Preferably, the method for preparing the first anode active material includes the steps of:
carrying out first heat treatment on a silicon-oxygen material under the condition of protective gas to obtain a silicon-oxygen composite substrate, and depositing a carbon source on the surface of the silicon-oxygen composite substrate in a gas phase deposition manner to form a carbon-coated silicon-oxygen material; drying the mixture of the carbon-coated silica material, the first heteroatom precursor material and water, and carrying out second heat treatment on the dried material under the protective gas condition;
preferably, the first heteroatomic precursor material includes at least one of a nitrogen-containing species, a phosphorous-containing species, a sulfur-containing species, and a boron-containing species;
preferably, the nitrogen-containing species comprises at least one of melamine and urea;
preferably, the phosphorus-containing material comprises at least one of diammonium phosphate, disodium phosphate, and phosphoric acid;
preferably, the sulfur-containing material comprises sulfuric acid, Na2At least one of an aqueous solution of S and thioacetamide;
preferably, the boron-containing substance comprises at least one of boric acid and boron oxide;
preferably, the mass ratio of the carbon-coated silica material to the nitrogen-containing substance is 1: (2-4);
preferably, the carbon source comprises at least one of methane, acetylene, propane, and ethylene;
preferably, the temperature of the first heat treatment is 350-450 ℃, and the heat preservation time of the first heat treatment is 55-65 min;
preferably, the vapor deposition temperature is 600-1000 ℃, and the time is 25-40 min;
preferably, the temperature of the second heat treatment is 550-750 ℃, and the heat preservation time of the second heat treatment is 90-150 min.
Preferably, the method for preparing the second anode active material includes the steps of:
and drying the mixture of the hard carbon material, the second heteroatom precursor material and water, and carrying out third heat treatment on the dried material.
Preferably, the second heteroatomic precursor material includes at least one of a nitrogen-containing species, a phosphorous-containing species, a sulfur-containing species, and a boron-containing species;
preferably, the mass ratio of the hard carbon material to the second hetero-atomic precursor material is 1: (4-10);
preferably, the temperature of the third heat treatment is 60-90 ℃, and the heat preservation time of the third heat treatment is 60-120 min.
A battery comprises the negative plate.
Compared with the prior art, the invention has the following beneficial effects:
(1) according to the invention, by carrying out hetero-atom doping on two negative electrode active materials, the diffusion coefficients of lithium ions in the two materials are closer, the local metal lithium deposition phenomenon formed by nonuniform current distribution in the pole piece is inhibited to a certain extent, and the quick charge characteristic of the pole piece is improved; compared with the traditional current collector, the compatibility between the undercoated current collector and the second layer of negative active material is better, the migration efficiency of electrons at the interface is promoted, the polarization is reduced, and the fast charging characteristic of the pole piece is improved.
(2) The cathode plate adopts a multilayer structure, and the silicon-based material and the hard carbon material are respectively used as active material layers, so that the common competition of conductive carbon adsorption is avoided, the conductive carbon adsorption and the hard carbon adsorption are cooperatively exerted, and the overall electrical property of the battery is improved.
(3) The preparation method of the negative plate is simple and easy to implement.
(4) The battery of the invention has excellent cycle performance and rate performance.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
Fig. 1 is a schematic structural view of a negative electrode sheet in example 1 of the present invention;
FIG. 2 is a graph comparing capacity retention rates of batteries;
fig. 3 is a graph comparing the rate charging performance of a battery.
Detailed Description
Embodiments of the present invention will be described in detail below with reference to examples, but it will be understood by those skilled in the art that the following examples are only illustrative of the present invention and should not be construed as limiting the scope of the present invention. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available.
According to one aspect of the present invention, the present invention relates to a negative electrode sheet including a negative electrode current collector, a first negative electrode active layer, and a second negative electrode active layer; the negative current collector comprises a negative current collector matrix and a carbon material layer arranged on the surface of at least one side of the negative current collector matrix, the surface of the carbon material layer, which is far away from the negative current collector matrix, is provided with the first negative active layer, and the surface of the first negative active layer, which is far away from the negative current collector, is provided with the second negative active layer;
the first negative electrode active layer comprises a first negative electrode active material, a first binder and a first conductive agent, the first negative electrode active material comprises a silicon-based negative electrode material, and a first hetero atom is doped in the silicon-based negative electrode material;
the second anode active layer includes a second anode active material and a second binder, the second anode active material includes a hard carbon material, and the hard carbon material is doped with a second hetero atom;
the first and second heteroatoms include at least one of P, N, S, B and O, respectively.
In the invention, hetero atoms are introduced into the two active materials to form a disordered structure defect on the surfaces of the two active materials, and the defects obviously improve the wettability of the two active materials with the surface of the electrolyte and enhance the conductivity; promoting Li at the same time+Absorption, diffusion and transport, reducing interfacial polarization between the active material and the active material, and between the active material and the current collector.
In one embodiment, a carbon material layer, a first negative electrode active layer, and a second negative electrode active layer are stacked in this order on one surface of a negative electrode current collector substrate.
In one embodiment, a carbon material layer, a first negative electrode active layer, and a second negative electrode active layer are sequentially stacked on both side surfaces of a negative electrode current collector substrate, respectively.
In one embodiment, the roughness of the negative current collector is 0.1 μm or more. For example, it may be 0.15. mu.m, 0.2. mu.m, 0.25. mu.m, 0.3. mu.m, 0.35. mu.m, 0.4. mu.m, or the like. For example, the thickness may be 0.1 to 0.5 μm.
In one embodiment, the carbon material layer includes at least one of graphite and graphene.
In one embodiment, the negative current collector matrix comprises copper foil. The bottom-coating copper foil is used, so that the adhesive force between the negative active material layer and the current collector can be remarkably improved, and the quick-charging use stability of the pole piece is enhanced; in one embodiment of the invention, the carbon material is a graphene material, and compared with the traditional current collector, the graphene coating has more contact sites for the adhesion of the second layer of negative active material, so that the cohesion of the pole piece is improved; in addition, the graphene material can improve the compatibility between the second layer of negative active material and the current collector, promote the migration efficiency of electrons at the interface, reduce polarization and further improve the fast charge characteristic of the pole piece.
The thickness of the first negative electrode active layer and the thickness of the second negative electrode active layer can be adjusted according to actual requirements.
In one embodiment, the first negative electrode active layer has a thickness of 20 to 60 μm.
In one embodiment, the second negative active layer has a thickness of 120 to 160 μm.
In one embodiment, the thickness of the carbon material layer is 2 to 5 μm.
In one embodiment, the silicon-based anode material comprises a silicon-oxygen material and a carbon coating layer coated on at least part of the surface of the silicon-oxygen material, wherein the silicon-oxygen material comprises Si and SiOxWherein x is more than or equal to 0.8 and less than or equal to 1.2.
In one embodiment, the doping amount of the first hetero atom in the first anode active material is 3 at% to 8 at%. For example, 3 at%, 3.2 at%, 3.5 at%, 3.7 at%, 4 at%, 4.5 at%, 5 at%, 6 at%, 7 at% may be included.
In one embodiment, the doping amount of the second hetero atom in the second anode active material is 2 at% to 5 at%. In one embodiment, the doping amount of the second hetero atom includes, but is not limited to, 2.2 at%, 2.5 at%, 2.7 at%, 3 at%, 3.2 at%, 3.5 at%, 3.7 at%, 4 at%, 4.2 at%, 4.5 at%, 4.7 at%, or 5 at%. The conductivity of the negative plate, the wettability of the negative plate and the surface of the electrolyte and the cycle performance of the battery are improved better by regulating and controlling the doping amount of the hetero atoms. When the doping amount of the hetero atoms is low, the formation of defects in the hard carbon material is less, the binding force of chemical bonds is insufficient, the number of active sites of generated lithium ions is insufficient, and the effect of improving the lithium storage capacity is limited; when the doping amount of the hetero atoms is too high, a large number of defects are formed in the hard carbon material, and the shuttle resistance of lithium ions in the material is large, so that the overall multiplying power performance of the material is influenced;
in one embodiment, the mass ratio of the first anode active material to the second anode active material is (5% to 30%): (70% to 95%). In one embodiment, the mass ratio of the first negative electrode active material to the second negative electrode active material includes, but is not limited to, 5%: 95% and 10%: 90%, 12%: 88% and 15%: 85%, 20%: 80% and 25%: 75% and 30%: 70 percent.
In one embodiment, the silicon-based anode material comprises at least one of a nano silicon carbon material, a silicon oxygen material and a lithium-supplement type silicon oxygen material.
In one embodiment, the particle diameter D50 of the first negative electrode active material is 1 to 20 μm, preferably 3 to 10 μm. In one embodiment, the particle size D50 of the first negative electrode active material includes, but is not limited to, 2 μm, 3 μm, 5 μm, 6 μm, 8 μm, 10 μm, 12 μm, 15 μm, 16 μm, 18 μm, or 19 μm.
In one embodiment, the ratio of the particle diameter D90 to the particle diameter D50 of the first negative electrode active material is (1.7-3.5): 1. in one embodiment, the ratio of the particle size D90 to the particle size D50 of the first negative electrode active material includes, but is not limited to, 1.8: 1. 2: 1. 2.2: 1. 2.5:1, 2.7:1, 3:1 or 3.5: 1.
In one embodiment, the mass ratio of the first negative electrode active material, the first binder, and the first conductive agent is (95% to 98%): (1-3%): (1% to 2%). In one embodiment, the mass ratio of the first negative electrode active material, the first binder, and the first conductive agent includes, but is not limited to, 95%: 2%: 2% and 96%: 3%: 1% or 97%: 2%: 1 percent. The electrical property and the mechanical property of the negative plate can be better improved by adopting the proper dosage ratio.
In one embodiment, the first binder comprises at least one of sodium carboxymethylcellulose, polyacrylic acid, sodium alginate, carboxymethyl chitosan, polyacrylonitrile, and polyvinyl alcohol.
In one embodiment, the first conductive agent includes at least one of conductive graphite, conductive carbon black, carbon nanotubes, carbon fibers (VGCF), and graphene.
In one embodiment, the particle diameter D50 of the second negative electrode active material is 10 to 25 μm, preferably 15 to 20 μm. In one embodiment, the particle size D50 of the second anode active material includes, but is not limited to, 12 μm, 15 μm, 17 μm, 19 μm, 20 μm, 22 μm, or 25 μm.
In one embodiment, the ratio of the particle size D50 of the second negative electrode active material to the particle size D50 of the first negative electrode active material is (1.5-6): 1. In one embodiment, the ratio of the particle diameter D50 of the second anode active material to the particle diameter D50 of the first anode active material includes, but is not limited to, 2.2:1, 2.5:1, 2.7:1, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, or 5.5: 1.
In one embodiment, the mass ratio of the second anode active material to the second binder is (95% to 98%): (2% to 5%). In one embodiment, the mass ratio of the second anode active material and the second binder includes, but is not limited to, 95%: 5%, 96%: 4% and 97%: 3% or 98%: 2 percent.
In one embodiment, the second binder comprises at least one of styrene butadiene rubber, sodium carboxymethyl cellulose, and hydroxypropyl methyl cellulose.
The invention uses the respectively adaptive binders for different active materials, avoids the multi-dimensional structure damage of the binders, reduces the binding power of the pole piece, and influences the stability of the pole piece.
According to another aspect of the present invention, the present invention relates to a method for preparing the negative electrode sheet, comprising the steps of:
coating carbon material slurry on at least one side surface of the negative current collector matrix, and drying to obtain a negative current collector with a carbon material layer; coating first negative electrode slurry on the surface of the carbon material layer, which is far away from the negative electrode current collector substrate, and drying to obtain a first negative electrode active layer; coating a second negative electrode slurry on the surface of the first negative electrode active layer, which is far away from the negative electrode current collector substrate, and drying to obtain a second negative electrode active layer;
the first negative electrode slurry includes the first negative electrode active material, a first binder, a first conductive agent, and a first solvent;
the second anode slurry includes the second anode active material, a second binder, and a second solvent.
The preparation method is simple and feasible.
In one embodiment, the method for preparing the first anode active material includes the steps of:
carrying out first heat treatment on a silicon-oxygen material under the condition of protective gas to obtain a silicon-oxygen composite substrate, and depositing a carbon source on the surface of the silicon-oxygen composite substrate in a gas phase deposition manner to form a carbon-coated silicon-oxygen material; and drying the mixture of the carbon-coated silica material, the first heteroatom precursor material and water, and carrying out second heat treatment on the dried material under the protective gas condition.
In one embodiment, the first heteroatomic precursor material includes at least one of a nitrogen-containing species, a phosphorous-containing species, a sulfur-containing species, a boron-containing species, and an oxygen-containing species.
In one embodiment, the first heteroatomic precursor material includes at least one of a nitrogen-containing species, a phosphorous-containing species, a sulfur-containing species, and a boron-containing species. In one embodiment, the nitrogen-containing species comprises at least one of melamine and urea. In one embodiment, the phosphorus-containing material comprises at least one of diammonium phosphate, disodium phosphate, and phosphoric acid. In one embodiment, the sulfur species comprises sulfuric acid, Na2At least one of an aqueous solution of S and thioacetamide. In one embodiment, the boron-containing species comprises at least one of boric acid and boron oxide. The oxygen element is an oxygen defect generated by the disproportionation reaction.
In one embodiment, the mass ratio of the carbon-coated silica material to the nitrogen-containing species is 1: (2-4). In one embodiment, the mass ratio of the carbon-coated silica material to the nitrogen-containing species includes, but is not limited to, 1:2.1, 1:2.5, 1:2.7, 1:3, 1:3.2, 1:3.5, or 1: 3.7.
In one embodiment, the carbon source comprises at least one of methane, acetylene, propane, and ethylene.
In one embodiment, the temperature of the first heat treatment is 350 to 450 ℃, and the heat preservation time of the first heat treatment is 55 to 65 min. In one embodiment, the temperature of the first heat treatment includes, but is not limited to, 360 ℃, 370 ℃, 380 ℃, 390 ℃, 400 ℃, 410 ℃, 420 ℃, 430 ℃, 440 ℃, or 445 ℃. The time of the incubation for the first heat treatment includes, but is not limited to, 57min, 59min, 60min, 62min, or 64 min.
In one embodiment, the vapor deposition temperature is 600-1000 ℃ and the time is 25-40 min. In one embodiment, the temperature of the vapor deposition includes, but is not limited to, 650 ℃, 700 ℃, 750 ℃, 800 ℃, 850 ℃, 900 ℃, 950 ℃, or 980 ℃. The vapor deposition time is 27min, 30min, 33min, 35min, 37min or 39 min.
In one embodiment, the temperature of the second heat treatment is 550 to 750 ℃, and the heat preservation time of the second heat treatment is 90 to 150 min. In one embodiment, the temperature of the second heat treatment includes, but is not limited to, 560 ℃, 570 ℃, 580 ℃, 600 ℃, 620 ℃, 650 ℃, 670 ℃, 700 ℃, or 720 ℃. The time of the heat preservation of the second heat treatment includes, but is not limited to, 100min, 110min, 120min, 130min, 140min, or 145 min.
In one embodiment, the method for preparing the second anode active material includes the steps of:
and drying the mixture of the hard carbon material, the precursor material of the second hetero atom and water, and carrying out third heat treatment on the dried material.
In one embodiment, the second heteroatomic precursor material includes at least one of a nitrogen-containing species, a phosphorous-containing species, a sulfur-containing species, and a boron-containing species. The second heteroatomic precursor material is the same as the first atomic precursor material.
In one embodiment, the mass ratio of the hard carbon material to the second heteroatomic precursor material is 1: (4-10). In one embodiment, the mass ratio of the hard carbon material to the second heteroatomic precursor material includes, but is not limited to, 1:4.5, 1:5, 1:5.5, 1:6, 1:7, 1: or 1: 9. The hard carbon material and the precursor material of the second hetero atom adopt a proper mass ratio, and the content of the second hetero atom is further regulated and controlled to improve the electrochemical performance of the negative plate.
In one embodiment, the temperature of the third heat treatment is 60 to 90 ℃, and the heat preservation time of the third heat treatment is 60 to 120 min. In one embodiment, the temperature of the third heat treatment includes, but is not limited to, 65 ℃, 70 ℃, 75 ℃, 80 ℃, 85 ℃, 90 ℃, 100 ℃, 110 ℃ or 120 ℃.
In one embodiment, the heteroatom is P, compared with the conventional artificial graphite, natural graphite and intermediate phase graphite, the phosphorus-doped hard carbon has higher capacity, more excellent rate performance, faster ion transmission rate and more stable cycle characteristics, and the advantages are mainly attributed to P-C bonds and P-O bonds formed after phosphorus doping, the P-O and P-C bonds can improve the adsorption effect on lithium ions, and meanwhile, the P-C bonds can participate in redox reaction to generate LixPCyThe two are used cooperatively to increase the material capacity.
According to another aspect of the invention, the invention relates to a battery, which comprises the negative plate.
The battery has excellent cycle performance and rate performance and long service life.
A person skilled in the art can prepare the lithium ion battery by combining the positive plate, the diaphragm, the electrolyte and the multilayer pole piece according to the conventional technical means. Compared with the battery before modification, the lithium ion battery prepared according to the scheme described in the application can still keep excellent capacity exertion under high rate, and the lithium precipitation window is widened by 2C.
The present invention will be further explained with reference to specific examples and comparative examples.
Fig. 1 is a schematic structural view of a negative electrode sheet in example 1 of the present invention. Fig. 2 is a graph comparing capacity retention rates of batteries. Fig. 3 is a graph comparing the rate charging performance of a battery.
Example 1
A preparation method of a negative plate comprises the following steps:
1. preparation of first and second anode active materials
Carrying out first heat treatment on SiO under the condition of protective gas to obtain a silicon-oxygen composite substrate, and then carrying out gas phase deposition on a carbon sourceDepositing on the surface of the silicon-oxygen composite substrate to form a carbon-coated silicon-oxygen material; uniformly dispersing the carbon-coated silica material and the nitrogen-containing substance by a water solvent method, and then blowing and drying the mixture in N2Carrying out second heat treatment in the atmosphere to form the N atom doped modified silicon-based negative active material; wherein the carbon source is acetylene; the temperature of the first heat treatment is 400 ℃, and the heat preservation time is 60 min; the vapor deposition temperature is 800 ℃ and the time is 30 min; the nitrogen-containing substance is melamine; the temperature of the second heat treatment is 650 ℃, and the heat preservation time is 120 min; the mass ratio of the carbon-coated silica material to the nitrogen-containing substance is 1: 3;
a method of preparing a second anode active material, comprising: uniformly dispersing a hard carbon material and a phosphorus-containing substance by a water solvent method, then carrying out blast drying, and carrying out third heat treatment under protective gas to form a phosphorus-doped modified hard carbon negative electrode active material; wherein the phosphorus-containing substance comprises diammonium hydrogen phosphate, the third heat treatment temperature is 90 ℃, the heat preservation time is 90min, and the mass ratio of the hard carbon material to the phosphorus-containing substance is 1: 7;
2. preparation of negative plate
(1) Preparing a negative current collector: coating carbon materials on the surfaces of two sides of the copper foil, wherein the carbon materials are well dispersed graphene, and drying to obtain a negative current collector with the surface roughness of 0.15 mu m;
(2) coating the first negative electrode slurry on the surface of the carbon material layer of the negative electrode current collector, and drying to obtain a first negative electrode active layer; the preparation method of the first negative electrode slurry comprises the following steps: uniformly mixing the first negative electrode active material with a first binder, a first conductive agent and a first solvent to obtain a first negative electrode slurry; the particle diameter D50 of the first negative electrode active material was 4 μm, and the particle diameter D90 was 8; the first binder is polyacrylic acid; the first conductive agent is conductive carbon black; the mass ratio of the first negative electrode active material, the first binder, and the first conductive agent is 96%: 2%: 2 percent;
(3) coating a second cathode slurry on the surface of the first cathode active layer, and drying to obtain a second cathode active layer; the preparation method of the second negative electrode slurry comprises the following steps: uniformly mixing a second negative electrode active material, a second binder and a solvent; the particle diameter D50 of the second anode active material was 12 μm; the second binder is a mixture of styrene butadiene rubber and sodium carboxymethyl cellulose; the mass ratio of the second negative electrode active material to the second binder was 97%: 3 percent;
wherein the mass ratio of the first negative electrode active material to the second negative electrode active material is 16%: 84 percent.
Example 2
A preparation method of a negative plate comprises the following steps of except for the preparation of a first negative active material, wherein the mass ratio of a carbon-coated silica material to a nitrogen-containing substance is 1: the other conditions were the same as in example 1.
Example 3
A preparation method of a negative plate comprises the following steps of except for the preparation of a first negative active material, wherein the mass ratio of a carbon-coated silica material to a nitrogen-containing substance is 1: the other conditions were the same as in example 1.
Example 4
A preparation method of a negative plate comprises the following steps of except for the preparation of a first negative active material, wherein the mass ratio of a hard carbon material to a phosphorus-containing substance is 1:4, except for; the other conditions were the same as in example 1.
Example 5
A preparation method of a negative plate comprises the following steps of except for the preparation of a first negative active material, wherein the mass ratio of a hard carbon material to a phosphorus-containing substance is 1: 10, besides; the other conditions were the same as in example 1.
Comparative example 1
A negative plate is prepared by adopting a conventional graphite blended silica negative electrode material, wherein the proportion is as follows: active material, conductive agent, binder 96:2:2, and binder PAA, wherein the active material is composed of 16% of silica material and 84% of artificial graphite, and the overall capacity is 500 mAh/g.
Examples of the experiments
Preparing batteries by respectively matching the negative plates of the examples 1-5 and the comparative example 1 with the positive plate, the diaphragm and the electrolyte; wherein, the positive electrode is prepared from active substances, a conductive agent, a binder (97: 1: 2), PVDF and NCM 811; the total capacity of the negative electrode sheets in examples 1 to 5 was 500 mAh/g. The electrical properties of the obtained soft package battery were mainly tested for the cycle life of the battery and the capacity retention rate of the battery at a large rate, as shown in table 1.
Table 1 comparison of properties of pouch cells
As can be seen from Table 1: the negative peel force in the examples was 26% greater than the comparative examples, which may indicate that the bonding effect of the multilayer negative is stronger than that of the single layer pole piece, probably due to two points, first: the modified current collector has better compatibility with the second layer of negative active material; secondly, the method comprises the following steps: the two layers of negative active materials are both adhesives matched with the active main material, so that the degree of combination with the surface functional groups of the active main material is tighter, and the conclusion can be verified according to the BOL full charge pole piece rebound data of the battery.
Fig. 2 shows that the batteries obtained by using the multilayer negative electrode sheet of the present invention have stronger cycle stability, 90% retention rate at the end and 500cls cycle life, compared with the comparative example, which is 200cls more, when the batteries are subjected to 1C/1C cycle at 25 ℃ in example 1 and comparative example 1.
Fig. 3 is a graph of the rate charging performance of the battery comprising the pole pieces in example 1 and the comparative example, after the current density of 2C, the capacity retention rate of the battery in the comparative example is significantly lower than that of the battery in example 1, the retention rates of the two batteries at 4C are 87.40% and 40.77%, respectively, and after modification, the quick charging capability of the pole pieces is greatly increased.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.
Claims (10)
1. The negative plate is characterized by comprising a negative current collector, a first negative active layer and a second negative active layer; the negative current collector comprises a negative current collector matrix and a carbon material layer arranged on the surface of at least one side of the negative current collector matrix, the surface of the carbon material layer, which is far away from the negative current collector matrix, is provided with the first negative active layer, and the surface of the first negative active layer, which is far away from the negative current collector, is provided with the second negative active layer;
the first negative electrode active layer comprises a first negative electrode active material, a first binder and a first conductive agent, the first negative electrode active material comprises a silicon-based negative electrode material, and a first hetero atom is doped in the silicon-based negative electrode material;
the second anode active layer includes a second anode active material and a second binder, the second anode active material includes a hard carbon material, and the hard carbon material is doped with a second hetero atom;
the first heteroatom and the second heteroatom comprise at least one of P, N, S, B and O, respectively.
2. The negative electrode sheet of claim 1, wherein the silicon-based negative electrode material comprises a silicon-oxygen composite material and a carbon coating layer coated on at least a part of the surface of the silicon-oxygen composite material, and the silicon-oxygen composite material comprises Si and SiOxWherein x is more than or equal to 0.8 and less than or equal to 1.2;
preferably, in the first anode active material, the doping amount of the first hetero atom is 3 at% to 8 at%;
preferably, in the second anode active material, the doping amount of the second hetero atom is 2 at% to 5 at%;
preferably, the mass ratio of the first negative electrode active material to the second negative electrode active material is (5% to 30%): (70% -95%).
3. The negative plate as claimed in claim 1, wherein the silicon-based negative electrode material comprises at least one of nano silicon carbon material, silicon oxygen material and lithium-supplement silicon oxygen material;
preferably, the particle diameter D50 of the first negative electrode active material is 1-20 μm, preferably 3-10 μm;
preferably, the ratio of the particle diameter D90 to the particle diameter D50 of the first negative electrode active material is (1.7-3.5): 1;
preferably, the mass ratio of the first negative electrode active material, the first binder, and the first conductive agent is (95% to 98%): (1-3%): (1-2%);
preferably, the first binder comprises at least one of sodium carboxymethylcellulose, polyacrylic acid, sodium alginate, carboxymethyl chitosan, polyacrylonitrile and polyvinyl alcohol;
preferably, the first conductive agent includes at least one of conductive graphite, conductive carbon black, carbon nanotubes, carbon fibers, and graphene.
4. The negative electrode sheet according to claim 1, wherein the particle diameter D50 of the second negative electrode active material is 10 to 25 μm, preferably 15 to 20 μm;
preferably, the ratio of the particle size D50 of the second negative electrode active material to the particle size D50 of the first negative electrode active material is (1.5-6): 1;
preferably, the mass ratio of the second anode active material to the second binder is (95% to 98%): (2% -5%);
preferably, the second binder includes at least one of styrene-butadiene rubber, sodium carboxymethyl cellulose, and hydroxypropyl methyl cellulose.
5. The negative plate according to claim 1, wherein the roughness of the negative current collector is greater than or equal to 0.1 μm;
preferably, the carbon material layer includes at least one of graphite and graphene;
preferably, the thickness of the first negative electrode active layer is 20-60 μm;
preferably, the thickness of the second negative active layer is 120-160 μm;
preferably, the thickness of the carbon material layer is 2-5 μm.
6. The method for preparing the negative electrode sheet according to any one of claims 1 to 5, comprising the steps of:
coating carbon material slurry on at least one side surface of the negative current collector matrix, and drying to obtain a negative current collector with a carbon material layer; coating first negative electrode slurry on the surface of the carbon material layer, which is far away from the negative electrode current collector substrate, and drying to obtain a first negative electrode active layer; coating a second negative electrode slurry on the surface of the first negative electrode active layer, which is far away from the negative electrode current collector substrate, and drying to obtain a second negative electrode active layer;
the first negative electrode slurry includes the first negative electrode active material, a first binder, a first conductive agent, and a first solvent;
the second anode slurry includes the second anode active material, a second binder, and a second solvent.
7. The negative electrode sheet preparation method according to claim 6, wherein the first negative electrode active material preparation method comprises the steps of:
carrying out first heat treatment on a silicon-oxygen material under the condition of protective gas to obtain a silicon-oxygen composite substrate, and depositing a carbon source on the surface of the silicon-oxygen composite substrate in a gas phase deposition manner to form a carbon-coated silicon-oxygen material; drying the mixture of the carbon-coated silica material, the first heteroatom precursor material and water, and carrying out second heat treatment on the dried material under the protective gas condition;
preferably, the first heteroatomic precursor material includes at least one of a nitrogen-containing species, a phosphorous-containing species, a sulfur-containing species, and a boron-containing species;
preferably, the nitrogen-containing species comprises at least one of melamine and urea;
preferably, the phosphorus-containing material comprises at least one of diammonium phosphate, disodium phosphate, and phosphoric acid;
preferably, the sulfur-containing material comprises sulfuric acid, Na2At least one of an aqueous solution of S and thioacetamide;
preferably, the boron-containing substance comprises at least one of boric acid and boron oxide;
preferably, the mass ratio of the carbon-coated silica material to the nitrogen-containing substance is 1: (2-4);
preferably, the carbon source comprises at least one of methane, acetylene, propane, and ethylene;
preferably, the temperature of the first heat treatment is 350-450 ℃, and the heat preservation time of the first heat treatment is 55-65 min;
preferably, the vapor deposition temperature is 600-1000 ℃, and the time is 25-40 min;
preferably, the temperature of the second heat treatment is 550-750 ℃, and the heat preservation time of the second heat treatment is 90-150 min.
8. The negative electrode sheet preparation method according to claim 6, wherein the second negative electrode active material preparation method comprises the steps of:
and drying the mixture of the hard carbon material, the precursor material of the second hetero atom and water, and carrying out third heat treatment on the dried material.
9. The negative electrode sheet preparation method of claim 8, wherein the second heteroatomic precursor material includes at least one of a nitrogen-containing substance, a phosphorus-containing substance, a sulfur-containing substance, and a boron-containing substance;
preferably, the mass ratio of the hard carbon material to the second heteroatomic precursor material is 1: (4-10);
preferably, the temperature of the third heat treatment is 60-90 ℃, and the heat preservation time of the third heat treatment is 60-120 min.
10. A battery comprising the negative electrode sheet according to any one of claims 1 to 5.
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| CN111900356A (en) * | 2020-08-13 | 2020-11-06 | 珠海冠宇电池股份有限公司 | Negative plate and lithium ion battery comprising same |
| CN112838197A (en) * | 2019-11-25 | 2021-05-25 | 华为技术有限公司 | Negative electrode material, preparation method thereof, battery and terminal |
| CN113471440A (en) * | 2021-07-09 | 2021-10-01 | 惠州亿纬锂能股份有限公司 | Silica material, preparation method and application thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107195893A (en) * | 2017-07-01 | 2017-09-22 | 合肥国轩高科动力能源有限公司 | A kind of lithium ion battery boron-doping silicon base negative material |
| CN107946576A (en) * | 2017-11-21 | 2018-04-20 | 中航锂电（洛阳）有限公司 | A kind of high magnification graphite cathode material and preparation method thereof, lithium ion battery |
| CN108878893A (en) * | 2018-06-29 | 2018-11-23 | 桑顿新能源科技有限公司 | A kind of fast charge negative electrode of lithium ion battery modified collector and preparation method thereof |
| CN109888266A (en) * | 2019-02-28 | 2019-06-14 | 东莞塔菲尔新能源科技有限公司 | A kind of silicon-based anode piece and preparation method thereof and lithium ion battery |
| CN112838197A (en) * | 2019-11-25 | 2021-05-25 | 华为技术有限公司 | Negative electrode material, preparation method thereof, battery and terminal |
| CN111540882A (en) * | 2020-06-04 | 2020-08-14 | 湖北亿纬动力有限公司 | Negative pole piece, preparation method and application thereof |
| CN111900356A (en) * | 2020-08-13 | 2020-11-06 | 珠海冠宇电池股份有限公司 | Negative plate and lithium ion battery comprising same |
| CN113471440A (en) * | 2021-07-09 | 2021-10-01 | 惠州亿纬锂能股份有限公司 | Silica material, preparation method and application thereof |
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