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Preparation method of graphene in-situ modified graphite carbon electrode material

An in-situ modification and electrode material technology, applied in the direction of graphene, active material electrodes, negative electrodes, etc., can solve the problems of low coulombic efficiency of the first charge and discharge, no obvious voltage platform, and fast cycle attenuation, etc. Clear platform, improved Coulombic efficiency, and simplified process flow

Inactive Publication Date: 2019-03-05
成都昂多生物技术有限责任公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, at present, when graphene is used as the negative electrode material of lithium-ion batteries, there are the following shortcomings: the first charge and discharge coulombic efficiency is low, the charge voltage hysteresis is obvious, there is no obvious voltage plateau and the cycle decays too fast and other defects, these are the obvious defects of hard carbon materials. feature

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] The main steps of the preparation of graphene in situ modified graphite carbon electrode material are as follows:

[0021] (1) Low-temperature reaction, in a 500 ml beaker, add 1 g of raw graphite, 90 ml of concentrated sulfuric acid and 25 ml of concentrated nitric acid in an ice-water bath, stir for 15 minutes, then slowly add 3 g of potassium permanganate, stir, and place in an ice-water bath Medium reaction 60 min;

[0022] (2) Medium-temperature reaction, slowly raise the temperature of the solution in step (1) to 35°C, and react for 30 minutes;

[0023] (3) High-temperature reaction, slowly add 350 ml of distilled water to the solution in step (2), and at the same time raise the temperature to 90 °C for 30 min to obtain an oxidized intercalated graphite carbon material;

[0024] (4) Wash and filter with suction, after the solution in step (3) is cooled to room temperature, add 18 ml of 30% hydrogen peroxide to react for 10 min. Wash with distilled water subseque...

Embodiment 2

[0028] Use the LAND CT2001A type charge and discharge instrument to test the charge and discharge performance of the sample prepared in Example 1. The specific steps are as follows:

[0029] (1) Mix acetylene black, binder PTFE and powdery negative electrode active material (weight ratio: 5:10:85), and make slurry-like negative electrode material after stirring evenly.

[0030] (2) Roll the prepared slurry evenly with a roller machine, press it on the copper mesh with a pressure of 20 MPa, and dry it to become the negative electrode sheet.

[0031] (3) Stack the positive electrode (lithium metal)-diaphragm-negative electrode in order from top to bottom, and inject the electrolyte (1mol / l LiPF6 EC / DMC / EMC (volume ratio 1:1:1) solution ) After that, the assembly process of the button battery is completed through processes such as buckle cover and sealing.

[0032] (4) Use the battery charge and discharge equipment LAND CT2001A to conduct a constant current charge and discharge ...

Embodiment 3

[0034] Example 3: Similar to Example 1, the difference is that it is only reacted at 90°C for 30 minutes, and then washed, dried and expanded to obtain a graphene in-situ modified graphite carbon material. The specific surface area of ​​the material obtained in this process is 200 m2 / g, the cycle life is 320 mAh / g.

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Abstract

The invention discloses a preparation method of a graphene in-situ modified graphite carbon electrode material. In an airtight reactor, graphite oxide and talc powder are subjected to pyrolysis expansion at 200-300 DEG C in a mass ratio of 10:1 to obtain a graphene in-situ modified graphite carbon material, the graphite oxide is preferably obtained by a Hummers method, and the graphene in-situ modified graphite carbon material, acetylene black and a binder are mixed and tabletted to obtain a graphene-based graphite carbon composite electrode material. Through in-situ modification of graphite carbon with grapheme, the distribution of graphene in the product is more uniform than that of physical doping; the use of the expansion technology of the airtight reactor reduces the experimental costand simplifies the process flow; the graphene in-situ modified graphite carbon composite electrode material synthesizes the respective advantages of graphene and graphite carbon, and significantly improves the lithium storage capacity, cycle life and coulomb efficiency, and the charging and discharging platform is obvious.

Description

technical field [0001] The invention relates to a preparation method of graphene in-situ modified graphite carbon electrode material, specifically, it relates to a method for preparing graphene-based graphite carbon electrode material by applying in-situ modification technology, which belongs to the preparation of graphite electrode material for lithium ion batteries technology field. Background technique [0002] As a new type of high-energy secondary power supply, lithium-ion secondary batteries have the advantages of large specific energy, stable discharge voltage, high voltage, good low-temperature performance, environmental friendliness, superior safety performance, no memory effect and long cycle life, etc. It is considered to be a high-tech industry of great significance to the national economy and people's life in the 21st century. However, with the development of battery miniaturization, the development of lithium-ion batteries with higher specific capacity and mor...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B32/225C01B32/184H01M4/587H01M10/0525
CPCC01B2204/22C01B2204/32H01M4/587H01M10/0525H01M2004/021H01M2004/027Y02E60/10
Inventor 朱康
Owner 成都昂多生物技术有限责任公司