Negative electrode with high compaction, excellent high-temperature performance and high energy density and preparation method thereof

A high energy density, negative electrode material technology, applied in battery electrodes, electrical components, electrochemical generators, etc., can solve problems such as poor solid performance, inability to repair internal defects of natural graphite, cycle performance attenuation, etc., to achieve high temperature cycle performance Poor, excellent high temperature cycle performance, the effect of high temperature cycle performance improvement

Inactive Publication Date: 2019-05-17
HUNAN SHINZOOM TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the surface layer of natural spherical graphite is coated with soft / hard carbon, and the compaction decreases, and the soft and hard carbon coating only improves the surface defects of natural graphite, but cannot repair the internal defects of natural graphite, and the core-shell structure collapses under the condition of high compaction density. The cycle performance decays quickly, and the high temperature performance is poor
[0004] In view of the current situation that soft and hard carbon coating cannot repair the internal defects of natural spherical graphite and thus has poor high-temperature and high-pressure compaction performance, people use impregnation to repair the internal defects of spherical graphite
For example, Chinese Patent Application No. CN107814382A discloses a long-life modified natural graphite negative electrode material, using a hot isostatic press to impregnate natural spherical graphite powder and pitch, which can completely ensure that the pitch is filled with graphite particles under high temperature and high pressure At the same time, a pitch carbon coating is formed on the surface of graphite, but this high pressure is easy to cause secondary damage to graphite, affecting cycle performance

Method used

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  • Negative electrode with high compaction, excellent high-temperature performance and high energy density and preparation method thereof
  • Negative electrode with high compaction, excellent high-temperature performance and high energy density and preparation method thereof
  • Negative electrode with high compaction, excellent high-temperature performance and high energy density and preparation method thereof

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] (1) Put the spherical natural graphite with an average particle size of 10 μm in the rotary furnace, adjust the rotating speed of the rotary furnace to 5r / min, fill it with nitrogen protective gas, raise the temperature to 900°C at 5.0°C / min, and then fill it with n-hexane and nitrogen The mixed gas, the volume of n-hexane accounts for 20% of the total gas volume, the gas flow rate is 2L / min, heat preservation for 2.0h, and natural cooling to room temperature to obtain the intermediate product of internal defect repair and surface deposition of pyrolytic carbon;

[0031] (2) The asphalt particles with a softening point of 120°C are pulverized by a jet mill until the average particle size is about 2 μm, and then the intermediate product and the asphalt particles are mixed at a mass ratio of 95:5, dispersed at high speed by VC, and then placed in a box Fill the furnace with nitrogen, raise the temperature to 1000.0°C at a heating rate of 5.0°C / min, keep the temperature for...

Embodiment 2

[0034] (1) Put the spherical natural graphite with an average particle size of 15 μm in the rotary furnace, adjust the rotating speed of the rotary furnace to 10r / min, fill it with argon protective gas, raise the temperature to 950 °C at 8.0 °C / min, and then fill it with cyclohexane The mixed gas with argon, cyclohexane accounts for 15% of the total gas volume, the flow rate is 2L / min, heat preservation for 3.0h, and naturally cooled to room temperature to obtain the intermediate product of internal defect repair and surface deposition of pyrolytic carbon;

[0035] (2) The intermediate product is crushed with a jet mill until the 150°C asphalt particles with an average particle size of about 3 μm are mixed at a mass ratio of 90:10, dispersed at high speed by VC, then placed in a box furnace, filled with nitrogen, and heated at 7.0 ℃ / min heating rate to 1200.0 ℃, heat preservation 8.0h, natural cooling to room temperature;

[0036] (3) Screening and demagnetization to obtain a ...

Embodiment 3

[0038] (1) Put the spherical natural graphite with an average particle size of 20 μm in the rotary furnace, adjust the rotating speed of the rotary furnace to 20r / min, fill in the nitrogen protection gas and raise the temperature to 1100°C at 10.0°C / min, and then fill in the mixture of methane and nitrogen Gas, methane accounts for 5% of the total gas volume, the flow rate is 5L / min, heat preservation for 5.0h, and naturally cool to room temperature to obtain the intermediate product of internal defect repair and surface deposition of pyrolytic carbon;

[0039] (2) Mix the intermediate product with the jet mill until the asphalt particles with an average particle size of about 5 μm and a softening point of 200°C are mixed at a mass ratio of 85:15, then dispersed at a high speed by VC, and then placed in a box furnace, fully charged Inject nitrogen, heat up to 1300.0°C at a heating rate of 10.0°C / min, keep warm for 10.0h, and cool down to room temperature naturally;

[0040] (3...

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Abstract

The invention provides a preparation method of a negative electrode with high compaction, excellent high-temperature performance and high energy density. Carbon is deposited in holes and a surface ofnatural spherical graphite by pyrolysis of organic alkane, the defects in the natural spherical graphite and on the surface of the natural spherical graphite are recovered, high-speed stirring and uniform dispersing are performed after mixing with asphalt, and the negative electrode material with high compaction and high energy density is obtained by carbonization. The negative electrode materialprepared by the method has excellent high-temperature cycle performance, and the problem of poor high-temperature cycle property in the prior art is solved.

Description

technical field [0001] The invention relates to the technical field of preparation of negative electrode materials for lithium batteries, in particular to a high-energy-density negative electrode material with excellent high-pressure compaction and high-temperature performance and a preparation method thereof. Background technique [0002] With the improvement of production demand and environmental protection awareness, new energy vehicles have developed rapidly, and the demand for power batteries has increased accordingly. Lithium-ion secondary batteries with high energy density have attracted much attention in the field of energy storage, which requires Electrode materials are continuously improved and innovated, among which the improvement and innovation of anode materials is one of the first choices. [0003] At present, commercial anode materials are mainly graphite anodes, which include natural graphite anodes, artificial graphite anodes and modified graphite anodes. ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/36H01M4/583H01M4/62H01M10/0525C01B32/20
CPCY02E60/10
Inventor 佘英奇胡孔明王志勇皮涛贺志远邵浩明余梦泽
Owner HUNAN SHINZOOM TECH
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