CN112886008A - Carbon-coated graphite negative electrode material and preparation method thereof - Google Patents

Carbon-coated graphite negative electrode material and preparation method thereof Download PDF

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CN112886008A
CN112886008A CN202110071486.8A CN202110071486A CN112886008A CN 112886008 A CN112886008 A CN 112886008A CN 202110071486 A CN202110071486 A CN 202110071486A CN 112886008 A CN112886008 A CN 112886008A
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graphite
carbon
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graphene
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彭飞
仰永军
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Qinghai Kaijin New Energy Materials Co ltd
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    • 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
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • H01M4/587—Carbonaceous material, e.g. graphite-intercalation compounds or CFx for inserting or intercalating light metals
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/05—Preparation or purification of carbon not covered by groups C01B32/15, C01B32/20, C01B32/25, C01B32/30
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/15—Nano-sized carbon materials
    • C01B32/182—Graphene
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/15—Nano-sized carbon materials
    • C01B32/182—Graphene
    • C01B32/194—After-treatment
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/20—Graphite
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/20—Graphite
    • C01B32/21—After-treatment
    • 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
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • 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
    • H01M4/624—Electric conductive fillers
    • H01M4/625—Carbon or graphite
    • 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
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Abstract

The invention relates to the technical field of battery materials, in particular to a carbon-coated graphite cathode material and a preparation method thereof, wherein the carbon-coated graphite cathode material comprises graphite, a graphene layer coated on the periphery of the graphite and a carbon layer coated on the graphene layer, the graphene layer is prepared from graphene oxide dispersion liquid, the carbon layer is prepared from carbon precursor cracking carbon, the carbon precursor is an organic matter, and the mass contents of the graphite, the graphene layer and the carbon layer are respectively as follows: 70-80% of graphite, 5-10% of graphene and 12-25% of a carbon layer. The carbon-coated graphite cathode material has the characteristics of long cycle life, high specific capacity and long service life.

Description

Carbon-coated graphite negative electrode material and preparation method thereof
Technical Field
The invention relates to the technical field of battery materials, in particular to a carbon-coated graphite negative electrode material and a preparation method thereof.
Background
Because the lithium ion battery has the important advantages of high voltage and high capacity, long cycle life and good safety performance, the lithium ion battery has wide application prospects in various aspects such as portable electronic equipment, electric automobiles, energy storage, space technology, biomedical engineering, national defense industry and the like, and becomes a research and new energy industry development hotspot which is widely concerned in the last decade and a long time in the future.
At present, most of lithium ion battery negative electrode materials in practical application are carbon materials, such as natural graphite, graphitized mesocarbon microbeads and the like. The natural graphite is a crystal material with a developed layered structure, and has the characteristics of high capacity, high compaction, good conductivity and excellent low-temperature performance when used as a lithium ion battery cathode material. However, natural graphite also has significant drawbacks when used as a negative electrode material for lithium ion batteries: the electrolyte and lithium ions form a solvent, and then are co-inserted into the graphite to perform a reduction reaction, and the gas generated by the reaction can cause graphite crystals to be pulverized and lose efficacy, which can damage the service life of the battery.
Disclosure of Invention
Based on the carbon-coated graphite cathode material, the carbon-coated graphite cathode material has the characteristics of long cycle life, high specific capacity and long service life.
The utility model provides a carbon cladding graphite anode material, includes graphite, cladding in the graphite peripheral graphite alkene layer and cladding in the carbonaceous layer on graphite alkene layer, graphite alkene layer adopts the oxidation graphite alkene dispersion liquid to make, and carbonaceous layer adopts carbon precursor schizolysis carbon to make, and the carbon precursor is the organic matter, and the mass content on graphite, graphite alkene layer and carbonaceous layer is respectively: 70-80% of graphite, 5-10% of graphene and 12-25% of a carbon layer.
In one embodiment, the graphite is natural graphite, artificial graphite or expanded graphite, and the particle size D50 of the graphite is 5-100 μm.
In one embodiment, the graphite is a porous structure.
In one embodiment, the carbon precursor is a mixture of polyvinylpyrrolidone and tannic acid.
In one embodiment, the mass ratio of the polyvinylpyrrolidone to the tannic acid is 1-2: 0.5 to 1.
The invention also provides a preparation method of the carbon-coated graphite negative electrode material, which comprises the following steps:
dispersing graphite in a solvent, uniformly mixing, adding a graphene oxide dispersion liquid, performing ultrasonic treatment for 20-60 min, then dropwise adding polyacrylamide to allow the graphene oxide dispersion liquid to be subjected to coagulation, and taking a precipitate;
heating and reducing the precipitate at high temperature to graphene, and cooling to obtain a graphene layer coated graphite material;
dispersing the graphite material coated with the graphene layer in a carbon precursor, uniformly mixing, and carrying out carbon coating treatment to form a carbon-coated graphite cathode material crude product;
and carbonizing the crude product of the carbon-coated graphite cathode material to obtain the carbon-coated graphite cathode material.
In one embodiment, the solvent is ethylene glycol or ethanol.
In one embodiment, in the step of heating and reducing the precipitate to graphene at a high temperature, and cooling to obtain the graphene layer coated graphite material, the operation of reducing the precipitate is as follows: and (3) placing the precipitate in a tubular furnace at the temperature of 810-900 ℃, preserving heat for 2-3 h, and reducing the graphene oxide into graphene.
In one embodiment, the carbon coating process comprises the steps of:
the graphite material and the carbon precursor coated with the graphene layer are prepared according to the following steps of: mixing the raw materials in a mass ratio of 0.5-1, stirring for 30-60 min, performing ultrasonic dispersion for 30-60 min, and drying to obtain a carbon-coated graphite cathode material crude product.
In one embodiment, the carbonization process comprises the steps of:
putting the carbon-coated graphite cathode material crude product into a heating device, and introducing protective gas;
raising the temperature of the heating device to 180-250 ℃, and keeping the temperature for 50-100 min;
and raising the temperature of the heating device to 1000-1500 ℃, preserving the heat for 120-360 min, and cooling to room temperature to obtain the carbon-coated graphite cathode material.
Compared with the prior art, the invention has the following beneficial effects:
1. the outer surface of the graphite is coated, and the graphene layer and the carbon layer are coated in a double-layer manner, so that the direct contact between the electrolyte and the graphite is cut off, the situation that the electrolyte is co-embedded into the graphite to generate a reduction reaction after forming a solvent with lithium ions is prevented, and the risks of graphite crystal pulverization failure, battery electrical property damage and service life damage are reduced; the graphene layer and the carbon layer have good conductivity and excellent low-temperature performance, and the conductivity of the graphene layer, the carbon layer and the graphite is mutually promoted, so that the specific capacity and the cycle performance of the graphite cathode material are improved, and the low-temperature performance of the carbon-coated graphite cathode is also improved;
2. from the raw material perspective, the process has the advantages of low production cost, environment-friendly processing technology, short processing period and good industrial popularization significance.
Detailed Description
In order that the invention may be more fully understood, reference will now be made to the following description. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.
The invention provides a carbon-coated graphite negative electrode material, which comprises graphite, a graphene layer coated on the periphery of the graphite and a carbon layer coated on the graphene layer, wherein the graphene layer is prepared from graphene oxide dispersion liquid, the carbon layer is prepared from carbon precursor cracking carbon, the carbon precursor is an organic matter, and the mass contents of the graphite, the graphene layer and the carbon layer are respectively as follows: 70-80% of graphite, 5-10% of graphene and 12-25% of a carbon layer.
In one embodiment, the graphite is natural graphite, artificial graphite or expanded graphite, and the particle size D50 of the graphite is 5-100 μm.
Preferably, the graphite is porous.
In one embodiment, the carbon precursor is a mixture of polyvinylpyrrolidone and tannic acid, and preferably, the mass ratio of polyvinylpyrrolidone to tannic acid is 1-2: 0.5 to 1.
The preparation method of the carbon-coated graphite negative electrode material comprises the following steps:
s100: dispersing graphite in a solvent, uniformly mixing, adding a graphene oxide dispersion liquid, performing ultrasonic treatment for 20-60 min, then dropwise adding polyacrylamide to enable the graphene oxide dispersion liquid to be subjected to coagulation, taking a precipitate, and drying the precipitate for later use.
The solvent may be ethylene glycol or ethanol, which may provide a good dispersion environment and does not prevent the graphene oxide dispersion from coating the graphite.
S200: and heating and reducing the precipitate to graphene at high temperature, and cooling to obtain the graphene layer coated graphite material.
In one embodiment, in the step of heating and reducing the precipitate to graphene at a high temperature, and cooling to obtain the graphene layer coated graphite material, the operation of reducing the precipitate is as follows: and (3) placing the precipitate in a tubular furnace at the temperature of 810-900 ℃, preserving heat for 2-3 h, and reducing the graphene oxide into graphene.
S300: and dispersing the graphite material coated with the graphene layer in a carbon precursor, uniformly mixing, and carrying out carbon coating treatment to form a carbon-coated graphite cathode material crude product.
The carbon coating treatment comprises the following steps:
the graphite material and the carbon precursor coated with the graphene layer are prepared according to the following steps of: mixing the raw materials in a mass ratio of 0.5-1, stirring for 30-60 min, performing ultrasonic dispersion for 30-60 min, and drying to obtain a carbon-coated graphite cathode material crude product.
S400: and carbonizing the crude product of the carbon-coated graphite cathode material to obtain the carbon-coated graphite cathode material.
The carbonization treatment comprises the following steps:
putting the carbon-coated graphite cathode material crude product into a heating device, and introducing protective gas;
raising the temperature of the heating device to 180-250 ℃, and keeping the temperature for 50-100 min;
and raising the temperature of the heating device to 1000-1500 ℃, preserving the heat for 120-360 min, and cooling to room temperature to obtain the carbon-coated graphite cathode material.
Compared with the prior art, the invention has the following beneficial effects:
1. the outer surface of the graphite is coated, and the graphene layer and the carbon layer are coated in a double-layer manner, so that the direct contact between the electrolyte and the graphite is cut off, the situation that the electrolyte is co-embedded into the graphite to generate a reduction reaction after forming a solvent with lithium ions is prevented, and the risks of graphite crystal pulverization failure, battery electrical property damage and service life damage are reduced; the graphene layer and the carbon layer have good conductivity and excellent low-temperature performance, and the conductivity of the graphene layer, the carbon layer and the graphite is mutually promoted, so that the specific capacity and the cycle performance of the graphite cathode material are improved, and the low-temperature performance of the carbon-coated graphite cathode is also improved;
2. from the raw material perspective, the process has the advantages of low production cost, environment-friendly processing technology, short processing period and good industrial popularization significance.
The following are descriptions of specific embodiments.
Example 1
The carbon-coated graphite anode material of this embodiment includes graphite, cladding in graphite peripheral graphite alkene layer and cladding in the carbonaceous layer on graphite alkene layer, and graphite alkene layer adopts the oxidation graphite alkene dispersion liquid to make, and the carbonaceous layer adopts carbon precursor schizolysis carbon to make, and the carbon precursor is the organic matter, and the mass content on graphite, graphite alkene layer and carbonaceous layer is respectively: 70% of graphite, 6% of graphene and 24% of a carbonaceous layer.
The graphite is natural graphite with a porous structure, and the particle size D50 of the graphite is 5-20 mu m.
The carbon precursor is prepared from the following components in a mass ratio of 1: 0.5 of a mixture of polyvinylpyrrolidone and tannic acid.
The preparation method of the carbon-coated graphite negative electrode material comprises the following steps:
s100: dispersing graphite in a solvent ethylene glycol, uniformly mixing, adding a graphene oxide dispersion liquid, performing ultrasonic treatment for 40min, then dropwise adding polyacrylamide to enable the graphene oxide dispersion liquid to be subjected to coagulation, taking a precipitate, and drying the precipitate for later use.
S200: and (3) placing the precipitate in a tube furnace at 900 ℃, preserving heat for 2h, reducing the graphene oxide into graphene, and cooling to room temperature to obtain the graphene layer-coated graphite material.
S300: dispersing the graphite material coated with the graphene layer in a carbon precursor, uniformly mixing, and mixing the graphite material coated with the graphene layer and the carbon precursor according to the ratio of 7: 1, stirring for 50min, performing ultrasonic dispersion for 30min, and drying to form a carbon-coated graphite cathode material crude product.
S400: putting the carbon-coated graphite cathode material crude product into a heating device, and introducing protective gas argon;
raising the temperature of the heating device to 180 ℃, and keeping the temperature for 80 min;
and (3) raising the temperature of the heating device to 1000 ℃, preserving the heat for 360min, and cooling to room temperature to obtain the carbon-coated graphite cathode material.
Example 2
The carbon-coated graphite anode material of this embodiment includes graphite, cladding in graphite peripheral graphite alkene layer and cladding in the carbonaceous layer on graphite alkene layer, and graphite alkene layer adopts the oxidation graphite alkene dispersion liquid to make, and the carbonaceous layer adopts carbon precursor schizolysis carbon to make, and the carbon precursor is the organic matter, and the mass content on graphite, graphite alkene layer and carbonaceous layer is respectively: 74% of graphite, 10% of graphene and 16% of a carbonaceous layer.
The graphite is natural graphite with a porous structure, and the particle size D50 of the graphite is 5-100 mu m.
The carbon precursor is prepared from the following components in percentage by mass: 0.8 of a mixture of polyvinylpyrrolidone and tannic acid.
The preparation method of the carbon-coated graphite negative electrode material comprises the following steps:
s100: dispersing graphite in a solvent ethylene glycol, uniformly mixing, adding a graphene oxide dispersion liquid, performing ultrasonic treatment for 20min, then dropwise adding polyacrylamide to enable the graphene oxide dispersion liquid to be subjected to coagulation, taking a precipitate, and drying the precipitate for later use.
S200: and (3) placing the precipitate in a tube furnace at 860 ℃, preserving heat for 2.5h, reducing the graphene oxide into graphene, and cooling to room temperature to obtain the graphene layer-coated graphite material.
S300: dispersing the graphite material coated with the graphene layer in a carbon precursor, uniformly mixing, and mixing the graphite material coated with the graphene layer and the carbon precursor according to the ratio of 7.5: 1, stirring for 30min, performing ultrasonic dispersion for 40min, and drying to form a carbon-coated graphite cathode material crude product.
S400: putting the carbon-coated graphite cathode material crude product into a heating device, and introducing protective gas nitrogen;
raising the temperature of the heating device to 180 ℃, and keeping the temperature for 100 min;
and raising the temperature of the heating device to 1200 ℃, preserving the heat for 240min, and cooling to room temperature to obtain the carbon-coated graphite cathode material.
Example 3
The carbon-coated graphite anode material of this embodiment includes graphite, cladding in graphite peripheral graphite alkene layer and cladding in the carbonaceous layer on graphite alkene layer, and graphite alkene layer adopts the oxidation graphite alkene dispersion liquid to make, and the carbonaceous layer adopts carbon precursor schizolysis carbon to make, and the carbon precursor is the organic matter, and the mass content on graphite, graphite alkene layer and carbonaceous layer is respectively: 76% of graphite, 7% of graphene and 17% of a carbonaceous layer.
The graphite is natural graphite, artificial graphite or expanded graphite, the particle size D50 of the graphite is 60-100 mu m, and the graphite is in a porous structure.
The carbon precursor is a mixture of polyvinylpyrrolidone and tannic acid, and the mass ratio of the polyvinylpyrrolidone to the tannic acid is 2: 1.
the preparation method of the carbon-coated graphite negative electrode material comprises the following steps:
s100: dispersing graphite in solvent ethanol, mixing uniformly, adding graphene oxide dispersion liquid, performing ultrasonic treatment for 20min, then dropwise adding polyacrylamide to enable the graphene oxide dispersion liquid to be subjected to coagulation, taking a precipitate, and drying the precipitate for later use.
S200: and (3) placing the precipitate in a tube furnace at 850 ℃, preserving heat for 2h, reducing the graphene oxide into graphene, and cooling to obtain the graphene layer-coated graphite material.
S300: dispersing the graphite material coated with the graphene layer in a carbon precursor, uniformly mixing, and mixing the graphite material coated with the graphene layer and the carbon precursor according to the ratio of 7.5: mixing the raw materials according to a mass ratio of 0.8, stirring for 30-60 min, performing ultrasonic dispersion for 30-60 min, and drying to form a carbon-coated graphite cathode material crude product.
S400: putting the carbon-coated graphite cathode material crude product into a heating device, and introducing protective gas argon or nitrogen;
raising the temperature of the heating device to 200 ℃, and keeping the temperature for 90 min;
and raising the temperature of the heating device to 1500 ℃, preserving the heat for 120min, and cooling to room temperature to obtain the carbon-coated graphite cathode material.
Example 4
The carbon-coated graphite anode material of this embodiment includes graphite, cladding in graphite peripheral graphite alkene layer and cladding in the carbonaceous layer on graphite alkene layer, and graphite alkene layer adopts the oxidation graphite alkene dispersion liquid to make, and the carbonaceous layer adopts carbon precursor schizolysis carbon to make, and the carbon precursor is the organic matter, and the mass content on graphite, graphite alkene layer and carbonaceous layer is respectively: 75% of graphite, 5% of graphene and 20% of a carbonaceous layer.
The graphite is natural graphite with a porous structure, and the particle size D50 of the graphite is 20-80 mu m.
The carbon precursor is prepared from the following components in percentage by mass: 0.5 of a mixture of polyvinylpyrrolidone and tannic acid.
The preparation method of the carbon-coated graphite negative electrode material comprises the following steps:
s100: dispersing graphite in solvent ethanol, mixing uniformly, adding graphene oxide dispersion liquid, performing ultrasonic treatment for 40min, then dropwise adding polyacrylamide to enable the graphene oxide dispersion liquid to be subjected to coagulation, taking a precipitate, and drying the precipitate for later use.
S200: and (3) placing the precipitate in a tube furnace at 820 ℃, preserving heat for 2h, reducing the graphene oxide into graphene, and cooling to obtain the graphene layer coated graphite material.
S300: dispersing the graphite material coated with the graphene layer in a carbon precursor, uniformly mixing, and mixing the graphite material coated with the graphene layer and the carbon precursor according to the ratio of 8: 1, stirring for 30min, performing ultrasonic dispersion for 60min, and drying to form a carbon-coated graphite cathode material crude product.
S400: putting the carbon-coated graphite cathode material crude product into a heating device, and introducing protective gas argon or nitrogen;
raising the temperature of the heating device to 200 ℃, and keeping the temperature for 90 min;
and raising the temperature of the heating device to 1200 ℃, preserving the heat for 150min, and cooling to room temperature to obtain the carbon-coated graphite cathode material.
Example 5
The carbon-coated graphite anode material of this embodiment includes graphite, cladding in graphite peripheral graphite alkene layer and cladding in the carbonaceous layer on graphite alkene layer, and graphite alkene layer adopts the oxidation graphite alkene dispersion liquid to make, and the carbonaceous layer adopts carbon precursor schizolysis carbon to make, and the carbon precursor is the organic matter, and the mass content on graphite, graphite alkene layer and carbonaceous layer is respectively: 81% of graphite, 8% of graphene and 11% of a carbonaceous layer.
The graphite is natural graphite with a porous structure, and the particle size D50 of the graphite is 5-60 mu m.
The carbon precursor is prepared from the following raw materials in a mass ratio of 1-2: 0.5 to 1 parts of a mixture of polyvinylpyrrolidone and tannic acid.
The preparation method of the carbon-coated graphite negative electrode material comprises the following steps:
s100: dispersing graphite in solvent ethanol, mixing uniformly, adding graphene oxide dispersion liquid, performing ultrasonic treatment for 60min, then dropwise adding polyacrylamide to enable the graphene oxide dispersion liquid to be subjected to coagulation, taking a precipitate, and drying the precipitate for later use.
S200: and (3) placing the precipitate in a tube furnace at 900 ℃, preserving heat for 2h, reducing the graphene oxide into graphene, and cooling to obtain the graphene layer-coated graphite material.
S300: dispersing the graphite material coated with the graphene layer in a carbon precursor, uniformly mixing, and mixing the graphite material coated with the graphene layer and the carbon precursor according to the ratio of 8: mixing the raw materials in a mass ratio of 0.5, stirring for 60min, performing ultrasonic dispersion for 50min, and drying to form a carbon-coated graphite cathode material crude product.
S400: putting the carbon-coated graphite cathode material crude product into a heating device, and introducing protective gas argon or nitrogen;
raising the temperature of the heating device to 190 ℃, and keeping the temperature for 100 min;
and (3) raising the temperature of the heating device to 1300 ℃, preserving the heat for 200min, and cooling to room temperature to obtain the carbon-coated graphite cathode material.
Comparative example 1
This comparative example prepared a carbon-coated graphite negative electrode material in substantially the same manner as in example 4, except that: the graphite periphery only coats the carbonaceous layer, and the quality content of graphite and carbonaceous layer is respectively: 75% of graphite and 25% of a carbonaceous layer.
Electrochemical Performance test
The carbon-coated graphite negative electrode materials prepared in examples 1 to 5 and comparative example 1 and a commercially available ordinary carbon-coated graphite negative electrode material were prepared into negative electrode sheets, and then half-cells were prepared and tested for relevant electrochemical properties, with the results shown in table 1.
The half-cell takes active material as the positive pole, and the lithium piece is assembled into a button cell as the negative pole, and the electrolyte is LiPF 6/EC: DEC (volume ratio 1: 1). The electrochemical test is carried out at room temperature, the cut-off charge-discharge voltage is 0.02-1.5V, and the charge-discharge current density is 0.2mA/cm2The first reversible specific capacity is tested under the state of 0.1C, and the cycle efficiency is tested for 50 times under the state of 0.2C.
TABLE 1
Figure BDA0002905956340000101
Figure BDA0002905956340000111
As can be seen from the test results in table 1, the electrochemical performance of the carbon-coated graphite anode materials in examples 1 to 6 is much better than that of the carbon-coated graphite anode material in comparative example 1 and commercially available, and the carbon-coated graphite anode material prepared by coating graphite on a graphene layer and a carbonaceous layer and prepared by the preparation method of the present invention has good cycling stability, good conductivity and high specific capacity.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (10)

1. The utility model provides a carbon cladding graphite anode material, its characterized in that, including graphite, cladding in graphite peripheral graphite alkene layer and cladding in the carbonaceous layer of graphite alkene layer, graphite alkene layer adopts the oxidation graphite alkene dispersion to make, carbonaceous layer adopts carbon precursor schizolysis carbon to make, the carbon precursor is the organic matter, the mass content on graphite, graphite alkene layer and carbonaceous layer is respectively: 70-80% of graphite, 5-10% of graphene and 12-25% of a carbon layer.
2. The carbon-coated graphite negative electrode material according to claim 1, wherein the graphite is natural graphite, artificial graphite or expanded graphite, and the graphite particle size D50 is 5 to 100 μm.
3. The carbon-coated graphite anode material according to claim 1 or 2, wherein the graphite has a porous structure.
4. The carbon-coated graphite anode material of claim 1, wherein the carbon precursor is a mixture of polyvinylpyrrolidone and tannic acid.
5. The carbon-coated graphite negative electrode material as claimed in claim 4, wherein the mass ratio of the polyvinylpyrrolidone to the tannin is 1-2: 0.5 to 1.
6. The method for producing the carbon-coated graphite anode material according to any one of claims 1 to 5, characterized by comprising the steps of:
dispersing graphite in a solvent, uniformly mixing, adding a graphene oxide dispersion liquid, performing ultrasonic treatment for 20-60 min, then dropwise adding polyacrylamide to perform coagulation on the graphene oxide dispersion liquid, and taking a precipitate;
heating and reducing the precipitate at high temperature to graphene, and cooling to obtain a graphene layer coated graphite material;
dispersing the graphite material coated with the graphene layer in a carbon precursor, uniformly mixing, and carrying out carbon coating treatment to form a carbon-coated graphite cathode material crude product;
and carbonizing the crude product of the carbon-coated graphite cathode material to obtain the carbon-coated graphite cathode material.
7. The method for preparing the carbon-coated graphite anode material according to claim 6, wherein the solvent is ethylene glycol or ethanol.
8. The method for preparing the carbon-coated graphite anode material according to claim 6, wherein in the step of heating and reducing the precipitate to graphene at a high temperature, and cooling the graphene layer-coated graphite material, the operation of reducing the precipitate is as follows: and (3) placing the precipitate in a tubular furnace at the temperature of 810-900 ℃, preserving heat for 2-3 h, and reducing the graphene oxide into graphene.
9. The method for preparing the carbon-coated graphite anode material according to claim 6, wherein the carbon coating treatment comprises the steps of:
the graphite material and the carbon precursor coated with the graphene layer are prepared according to the following steps of: mixing the raw materials in a mass ratio of 0.5-1, stirring for 30-60 min, performing ultrasonic dispersion for 30-60 min, and drying to obtain a carbon-coated graphite cathode material crude product.
10. The method for producing a carbon-coated graphite anode material according to claim 6, wherein the carbonization treatment comprises the steps of:
putting the carbon-coated graphite cathode material crude product into a heating device, and introducing protective gas;
raising the temperature of the heating device to 180-250 ℃, and keeping the temperature for 50-100 min;
and raising the temperature of the heating device to 1000-1500 ℃, preserving the heat for 120-360 min, and cooling to room temperature to obtain the carbon-coated graphite cathode material.
CN202110071486.8A 2021-01-19 2021-01-19 Carbon-coated graphite negative electrode material and preparation method thereof Pending CN112886008A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113571684A (en) * 2021-09-26 2021-10-29 河南电池研究院有限公司 Aluminum-carbon double-coated natural graphite negative electrode material for lithium ion battery and preparation method thereof
CN113659143A (en) * 2021-08-06 2021-11-16 东莞市创明电池技术有限公司 Preparation method of negative electrode material of sodium ion battery, negative electrode material and sodium ion battery

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104393262A (en) * 2014-10-22 2015-03-04 深圳市贝特瑞新能源材料股份有限公司 Carbon composite anode material and preparation method thereof, as well as lithium ion battery containing same
CN104868106A (en) * 2015-04-21 2015-08-26 常州第六元素材料科技股份有限公司 Method for coating graphite anode material of lithium ion battery with graphene and application thereof
CN104934603A (en) * 2015-05-22 2015-09-23 田东 Preparation method of graphene-dopedand carbon-coated modified graphite anode material
CN105591109A (en) * 2014-11-14 2016-05-18 青岛灵科新能源有限公司 Carbon material, preparation method thereof, and lithium ion battery

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104393262A (en) * 2014-10-22 2015-03-04 深圳市贝特瑞新能源材料股份有限公司 Carbon composite anode material and preparation method thereof, as well as lithium ion battery containing same
CN105591109A (en) * 2014-11-14 2016-05-18 青岛灵科新能源有限公司 Carbon material, preparation method thereof, and lithium ion battery
CN104868106A (en) * 2015-04-21 2015-08-26 常州第六元素材料科技股份有限公司 Method for coating graphite anode material of lithium ion battery with graphene and application thereof
CN104934603A (en) * 2015-05-22 2015-09-23 田东 Preparation method of graphene-dopedand carbon-coated modified graphite anode material

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113659143A (en) * 2021-08-06 2021-11-16 东莞市创明电池技术有限公司 Preparation method of negative electrode material of sodium ion battery, negative electrode material and sodium ion battery
CN113571684A (en) * 2021-09-26 2021-10-29 河南电池研究院有限公司 Aluminum-carbon double-coated natural graphite negative electrode material for lithium ion battery and preparation method thereof

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