CN113921771A - Preparation method of lithium manganate battery adopting graphite microchip composite positive electrode material - Google Patents

Preparation method of lithium manganate battery adopting graphite microchip composite positive electrode material Download PDF

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CN113921771A
CN113921771A CN202010645693.5A CN202010645693A CN113921771A CN 113921771 A CN113921771 A CN 113921771A CN 202010645693 A CN202010645693 A CN 202010645693A CN 113921771 A CN113921771 A CN 113921771A
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lithium manganate
positive electrode
preparing
graphite
battery
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林楷睿
许志
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Xifeng 2d Fujian Material Technology Co ltd
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
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    • 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
    • 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
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • 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
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/4235—Safety or regulating additives or arrangements in electrodes, separators or electrolyte
    • 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
    • H01M4/04—Processes of manufacture in general
    • H01M4/0402—Methods of deposition of the material
    • H01M4/0404—Methods of deposition of the material by coating on electrode collectors
    • 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
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
    • H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
    • 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
    • H01M4/621—Binders
    • 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
    • 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
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • H01M4/661—Metal or alloys, e.g. alloy coatings
    • 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
    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/028—Positive electrodes
    • 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
    • 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
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Abstract

The invention discloses a preparation method of a lithium manganate battery adopting a graphite microchip composite positive electrode material, which comprises the following steps of preparing the graphite microchip/lithium manganate composite positive electrode material; adding conductive agent and binder into the composite anode material, mixing and pulping to obtain the composite anode materialA positive electrode slurry; coating the positive electrode slurry on a current collector, and rolling to obtain a lithium manganate battery positive electrode piece; preparing an electrolyte; preparing a battery cathode; the cell assembly was completed in a glove box under argon atmosphere. According to the invention, the graphite microchip is added to the positive electrode, because the graphite microchip is provided with various organic dangling bonds, the groups are perfectly combined with an organic solvent in the electrolyte to form a high-quality external SEI film, so that the battery is effectively protected, the ultra-long cycle life of the battery is realized, and the existence of the graphite microchip can more fully excite Li in lithium manganate+Reduction of Li+The discharge efficiency is increased due to irreversible charge and discharge, and the prepared battery has super-good circulation stability, good low-temperature performance and high voltage platform.

Description

Preparation method of lithium manganate battery adopting graphite microchip composite positive electrode material
Technical Field
The invention relates to the technical field of lithium batteries, in particular to a preparation method of a lithium manganate battery adopting a graphite microchip composite positive electrode material.
Background
The lithium manganate has the outstanding advantages of abundant resources and no pollution, and is one of the more promising lithium ion anode materials. The lithium manganate mainly comprises spinel lithium manganate and lithium manganate with a layered structure, wherein the spinel lithium manganate belongs to a cubic crystal system, and lithium ions can be reversibly deintercalated from spinel crystal lattices due to the three-dimensional tunnel structure without collapse of the structure, so that the lithium manganate battery has excellent rate performance and stability. The lithium manganate used as the positive electrode material of the lithium battery has the advantages of good low-temperature performance, high compacted density and the like, but the industrialization of the lithium manganate is greatly limited by poor cycle performance.
In order to improve the cycle life performance of a lithium manganate battery, a lithium manganate battery anode is modified (the invention is based on self-developed graphite micro-sheets AND U.S. patent numbers of GRAPHENE STRUCTURES WITH ENHANCED STABILITY AND COMPOSITE MATERIALS FORMED THEREFROM: US8, 926, 853B2) -I know a special dispersion process, AND the graphite micro-sheets with excellent dispersion performance are uniformly dispersed on the surface of lithium manganate, so that a COMPOSITE anode material is prepared, the lithium manganate battery with ultra-long service life is further prepared, AND the cycle performance of the lithium manganate battery is greatly improved.
Lithium batteries with good cycle life require high quality positive and negative electrodes with compact SEI films, and only Li can be allowed+The SEI film is penetrated into the positive electrode and the negative electrode, and the positive electrode layered structure and the negative electrode graphite layered structure are inserted without damaging the original layered structures of the positive electrode and the negative electrode. Li+Small in volume, and Li+Or (Li)2 +、CH3 +、NH2 +、Li+-COOH-) And other organic groups, the volume of the composite ions is too large, and when the composite ions are inserted into the positive electrode or the negative electrode, the volume of the laminated structure expands to crack, so that the laminated structure is irreversibly damaged.
Disclosure of Invention
Aiming at the problems, the invention provides a self-developed graphite microchip with good dispersion performance, and a preparation method for a lithium manganate battery with super-long service life, wherein the graphite microchip is uniformly dispersed on the surface of lithium manganate by using a special dispersion process to form a composite positive electrode material, and then the composite positive electrode material is used as a positive electrode plate.
In order to solve the technical problems, the technical scheme adopted by the invention is as follows: a preparation method of a lithium manganate battery adopting a graphite microchip composite anode material comprises the following steps:
preparing a graphite microchip/lithium manganate composite positive electrode material;
adding a conductive agent and a binder into the composite anode material, and mixing and pulping to obtain anode slurry;
coating the positive electrode slurry on a current collector, and rolling to obtain a lithium manganate battery positive electrode piece;
preparing an electrolyte;
preparing a battery cathode;
the cell assembly was completed in a glove box under argon atmosphere.
Further, the method for preparing the graphite microchip/lithium manganate composite positive electrode material is characterized in that graphite microchips accounting for 4% of the total mass are uniformly dispersed on the surface of 96% of lithium manganate through a ball milling dispersion process.
Further, the lithium manganate is spinel lithium manganate LiMn2O4。
Further, the conductive agent is one of SP, acetylene black, CNTS and graphene, and the positive electrode binder is PVDF.
Furthermore, N-methyl pyridine is used as a solvent for mixing the positive electrode slurry, and the viscosity range of the positive electrode slurry is 6000-10000 mPa & s.
Further, the current collector is an aluminum foil current collector, and the rolled compaction density is 2.7-3.0 g/cm3。
Further, the method for preparing the electrolyte is to mix lithium hexafluorophosphate (LiPF)6) Ethylene Carbonate (EC), dimethyl carbonate (DMC), methyl ethyl carbonate (EMC) are mixed uniformly according to the proportion, wherein, the ethylene carbonate: carbonic acid dimethyl ester: the volume ratio of ethyl methyl carbonate is 3: 2: 5, the molar concentration of lithium hexafluorophosphate is 0.9-1.2mol/L, the electrolyte additive fluoroethylene carbonate accounts for 3% of the weight of the electrolyte, and ethylene carbonate accounts for 2% of the weight of the electrolyte.
Further, the material for preparing the battery negative electrode is one or the combination of natural graphite, artificial graphite, hard carbon and soft carbon.
From the above description of the structure of the present invention, compared with the prior art, the present invention has the following advantages:
1. according to the invention, the graphite microchip is added to the positive electrode, because the graphite microchip is provided with various organic dangling bonds such as hydroxyl, carboxyl and the like, and the groups are perfectly combined with an organic solvent in the electrolyte, a high-quality outer SEI film is formed, the battery is effectively protected, and the ultra-long cycle life of the battery is realized;
2. the existence of graphite micro-sheets can more fully excite Li in lithium manganate+The battery prepared from the graphite microchip/lithium manganate composite positive electrode material has super-good cycle stability and can prolong the cycle life, namely, the battery is cycled 2900 times at 3 ℃, the average attenuation rate per circle is only about 0.7 ten-thousandth, the battery has good low-temperature performance, the temperature of minus 30 ℃, the charging at 0.1C and the discharging at 3C can reach 93 percent of the normal-temperature capacity, the voltage platform is high, and the median voltage reaches 3.85V and is far higher than that of the lithium manganate positive electrode material.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention.
In the drawings:
FIG. 1 is a flow chart of a method for preparing a lithium manganate battery using a graphite microchip composite positive electrode material according to the present invention;
FIG. 2 is an SEM image of the graphite platelet/lithium manganate positive electrode composite material of the present invention;
FIG. 3 is a CV diagram of a battery made of the graphite microchip/lithium manganate composite positive electrode material of the present invention;
FIG. 4 is a battery cycle curve diagram of the graphite microchip/lithium manganate composite positive electrode material of the invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Referring to fig. 1, a method for preparing a lithium manganate battery using a graphite microchip composite positive electrode material, the method comprising the steps of:
s01, preparing a graphite microchip/lithium manganate composite positive electrode material; the method for preparing the graphite microchip/lithium manganate composite positive electrode material comprises the steps of preparing high-dispersity graphite microchips by a gas phase deposition method, and then compounding 0.1-6% of the graphite microchips with 94-99.9% of a lithium manganate material to obtain the composite positive electrode material, wherein the lithium manganate is spinel lithium manganate LiMn2O4。
S02, adding a conductive agent and a binder into the composite positive electrode material, and mixing and pulping to obtain positive electrode slurry; the conductive agent is one of SP, acetylene black, CNTS and graphene, the positive binder is PVDF, N-methyl pyridine ketone is used as a solvent for mixing the positive slurry, and the viscosity range of the positive slurry is 6000-10000 mPa.
S03, coating the positive electrode slurry on a current collector, and rolling to obtain a lithium manganate battery positive electrode sheet; the current collector is an aluminum foil current collector, and the rolled compaction density is 2.9-3.0 g/cm 3.
S04, preparing electrolyte; the method for preparing the electrolyte comprises the step of adding lithium hexafluorophosphate (LiPF)6) Ethylene Carbonate (EC), dimethyl carbonate (DMC), methyl ethyl carbonate (EMC) are mixed uniformly according to the proportion, wherein, the ethylene carbonate: dimethyl carbonate: the volume ratio of ethyl methyl carbonate is 3: 2: 5, the molar concentration of lithium hexafluorophosphate is 0.9-1.2mol/L, the electrolyte additive fluoroethylene carbonate accounts for 3% of the weight of the electrolyte, and ethylene carbonate accounts for 2% of the weight of the electrolyte.
S05, preparing a battery cathode; the material for preparing the battery negative electrode is one or the combination of natural graphite, artificial graphite, hard carbon and soft carbon.
S06, in argon atmosphere (H)2O<0.5ppm，O2<0.5ppm) was added to the glove box to complete the assembly of the cell.
Examples
Referring to fig. 1, a method for preparing a lithium manganate battery using a graphite microchip composite positive electrode material, the method comprising the steps of:
s01, preparing a graphite microchip/lithium manganate composite positive electrode material; highly dispersed graphite nanoplatelets are produced by vapor deposition, a metallic copper substrate is loaded into a chemical vapor deposition tube furnace and hydrogen gas is introduced at a rate of 20sccm while the substrate is heated to 1000 ℃ for 10 minutes. Methane was next introduced into the cvd tube furnace at a flow rate of 1000sccm at a pressure of 500torr while the flow rate of hydrogen was reduced to less than 10 sccm. Single or multiple layers of graphite nanoplatelets are synthesized on a metal substrate within 0.001 to 10 minutes after methane introduction. Because the contact place of the metal particles and the metal particles is not contacted with the deposited carbon source gas, the surface of the single metal particle is not completely covered by the graphene layer, the metal etching solution (ammonium persulfate) is directly contacted with the metal material through the position where the metal particles do not cover the graphite microchip and generates chemical reaction to completely corrode the metal particles, then acetone, absolute ethyl alcohol and water are used for washing in sequence to remove residues, and finally the hollow graphite microchip structure is obtained through drying (spray pyrolysis). Thus, the graphite micro-sheet with the diameter of 1um and the thickness of about 5-50 layers and the aggregation resistance is prepared. And uniformly dispersing the graphite micro-sheets accounting for 4% of the total mass on the surface of 96% of lithium manganate by a ball-milling dispersion process, thereby preparing the graphite micro-sheet/lithium manganate composite cathode material.
S02, adding a conductive agent and a binder into the composite positive electrode material, and mixing and pulping to obtain positive electrode slurry; the conductive agent is one of SP, acetylene black, CNTS and graphene, the positive binder is PVDF, N-methyl pyridine ketone is used as a solvent for mixing the positive slurry, and the viscosity range of the positive slurry is 6000-10000 mPa.
S03, coating the positive electrode slurry on a current collector, and rolling to obtain a lithium manganate battery positive electrode sheet; the current collector is an aluminum foil current collector, and the rolled compaction density is 3.0g/cm 3.
S04, preparing electrolyte; the method for preparing the electrolyte comprises the step of adding lithium hexafluorophosphate (LiPF)6) Ethylene Carbonate (EC), dimethyl carbonate (DMC), methyl ethyl carbonate (EMC) are mixed uniformly according to the proportion, wherein, the ethylene carbonate: dimethyl carbonate: the volume ratio of ethyl methyl carbonate is 3: 2: 5, the molar concentration of lithium hexafluorophosphate is 1.2mol/L, the electrolyte additive fluoroethylene carbonate accounts for 3 percent of the weight of the electrolyte, and ethylene carbonate accounts for 2 percent of the weight of the electrolyte.
S05, preparing a battery cathode; the material for preparing the battery cathode adopts artificial graphite.
S06, in argon atmosphere (H)2O<0.5ppm，O2<0.5ppm) was added to the glove box to complete the assembly of the cell.
As can be seen from FIG. 2, the graphite micro-sheets are well distributed on the surface of the lithium manganate material. It can be seen from the CV curve of fig. 2 that the median voltage of the battery prepared from the composite material is as high as 3.8V, and the voltage plateau is high. From the battery cycle curve chart of fig. 3, it can be seen that the battery prepared from the composite material has an average attenuation rate of about 0.7 ten-thousandth per cycle after being cycled 2900 times at 3C, and the battery has stable cycle performance, which indicates that the added graphite microchip can well improve the performance of the battery.
According to the research of the national laboratories of the northwest pacific of the united states, it was demonstrated that SEI has an inner layer (mainly inorganic) and an outer layer (mainly organic). Both good SEI and ultra long cycle life require high quality of both films, especially the outer layer (which is relatively thick). The self-developed graphite micro-sheets added to the positive electrode of the invention are provided with various organic dangling bonds, such as hydroxyl, carboxyl and the like, and the groups are perfectly combined with an organic solvent in the electrolyte, so that a high-quality external SEI film is formed, and the negative electrode of the battery is effectively protected. Meanwhile, a similar double-layer SEI film is possibly formed on the anode, and the high-quality SEI film layer effectively protects the anode and the cathode and prevents various impurities generated by repeated charge and discharge in the electrolyte from polluting and damaging the anode and the cathode, so that the ultra-long cycle life of the battery is realized. I have used diaphragms with different pore diameters, even ordinary filter paper for tests, and under the condition of large pores, the battery has long cycle life and basically does not change, so that the existence of an SEI film and high compactness of the SEI film are verified.
In addition, F in the electrolyte-The negative effect of the ions on the SEI is caused, but lithium hexafluorophosphate is used as the electrolyte in the industry because only lithium hexafluorophosphate can resist higher voltage (the withstanding voltage of the LiTSF electrolyte is not more than 3.6 volts), and a small amount of moisture in the air enters the electrolyte during the manufacturing process of the battery, so that the lithium hexafluorophosphate is decomposed to generate F-Ions. The hydroxyl and carboxyl carried by the graphite microchip developed by the inventor are univalent anions which can be similar to F which is the univalent anion in the electrolyte-Generates competition, thereby greatly reducing F-Ions enter the SEI to achieve prevention of F-The purpose of breaking the SEI film.
In addition, the positive electrode material of the lithium ion battery is a composite material with graphite micro-sheets uniformly dispersed on the surface of lithium manganate, and the negative electrode is carbon. When charging the battery, the positive electrode of the battery has Li+Generated Li+Moves to the negative electrode through the electrolyte. Because the graphite micro-sheets are uniformly dispersed on the surface of the lithium manganate, the uniform graphite micro-sheets are between the lithium manganate and the electrolyte, the graphite micro-sheets have a layered structure and play a role of a bridge, and Li+Can pass through more smoothly and quickly. Carbon as a negative electrode also has a layered structure having many micropores, and Li reaching the negative electrode+Are embedded in the micropores of the carbon layer, the embedded Li+The more, the higher the charge capacity. Similarly, Li embedded in the negative carbon layer when the battery is discharged+And the lithium ions are removed and move back to the electrolyte, the graphite micro-sheets can completely and quickly return to the positive electrode, and the more the lithium ions return to the positive electrode, the higher the discharge capacity is. The existence of graphite micro-sheets can more fully excite Li in lithium manganate+So that the irreversible change is reduced in the process of charging and discharging, and the discharging efficiency is increased.
The invention adds graphite particles to the anodeThe graphite microchip is provided with various organic dangling bonds such as hydroxyl, carboxyl and the like, and the groups are perfectly combined with an organic solvent in the electrolyte to form a high-quality outer SEI film, so that the battery is effectively protected, and the ultra-long cycle life of the battery is realized; the existence of graphite micro-sheets can more fully excite Li in lithium manganate+The battery prepared from the graphite microchip/lithium manganate composite positive electrode material has super-good cycle stability and can prolong the cycle life, namely, the battery is cycled 2900 times at 3 ℃, the average attenuation rate per circle is only about 0.7 ten-thousandth, the battery has good low-temperature performance, the temperature of minus 30 ℃, the charging at 0.1C and the discharging at 3C can reach 93 percent of the normal-temperature capacity, the voltage platform is high, and the median voltage reaches 3.85V and is far higher than that of the lithium manganate positive electrode material.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims (8)

1. A preparation method of a lithium manganate battery adopting a graphite microchip composite anode material is characterized by comprising the following steps: the method comprises the following steps:
preparing a graphite microchip/lithium manganate composite positive electrode material;
adding a conductive agent and a binder into the composite anode material, and mixing and pulping to obtain anode slurry;
coating the positive electrode slurry on a current collector, and rolling to obtain a lithium manganate battery positive electrode piece;
preparing an electrolyte;
preparing a battery cathode;
the cell assembly was completed in a glove box under argon atmosphere.
2. The method for preparing the lithium manganate battery adopting the graphite microchip composite anode material according to claim 1, characterized in that: the method for preparing the graphite microchip/lithium manganate composite positive electrode material comprises the steps of preparing the graphite microchip with high dispersibility by using a gas phase deposition method, and then compounding 0.1-6% of the graphite microchip and 94-99.9% of the lithium manganate material to obtain the composite positive electrode material.
3. The method for preparing the lithium manganate battery adopting the graphite microchip composite cathode material according to claim 2, characterized in that: the lithium manganate is spinel lithium manganate LiMn2O4。
4. The method for preparing the lithium manganate battery adopting the graphite microchip composite anode material according to claim 1, characterized in that: the conductive agent is one of SP, acetylene black, CNTS and graphene, and the positive electrode binder is PVDF.
5. The method for preparing the lithium manganate battery adopting the graphite microchip composite anode material according to claim 1, characterized in that: the positive electrode slurry mixing adopts N-methyl pyridine as a solvent, and the viscosity range of the positive electrode slurry is 6000-10000 mPa.
6. The method for preparing the lithium manganate battery adopting the graphite microchip composite anode material according to claim 1, characterized in that: the current collector is an aluminum foil current collector, and the rolled compaction density is 2.7-3.0 g/cm3。
7. The method for preparing the lithium manganate battery adopting the graphite microchip composite anode material according to claim 1, characterized in that: the method for preparing the electrolyte comprises the steps of uniformly mixing lithium hexafluorophosphate, ethylene carbonate, dimethyl carbonate and methyl ethyl carbonate according to the proportion, wherein the ethylene carbonate: dimethyl carbonate: the volume ratio of ethyl methyl carbonate is 3: 2: 5, the molar concentration of lithium hexafluorophosphate is 0.9-1.2mol/L, the electrolyte additive fluoroethylene carbonate accounts for 3% of the weight of the electrolyte, and ethylene carbonate accounts for 2% of the weight of the electrolyte.
8. The method for preparing the lithium manganate battery adopting the graphite microchip composite anode material according to claim 1, characterized in that: the material for preparing the battery negative electrode is one or the combination of natural graphite, artificial graphite, hard carbon and soft carbon.
CN202010645693.5A 2020-07-07 2020-07-07 Preparation method of lithium manganate battery adopting graphite microchip composite positive electrode material Pending CN113921771A (en)

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