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Preparation method of tungsten nitride/nitrogen-doped graphene/tungsten oxide composite material applied to lithium-sulfur battery positive electrode material

A nitrogen-doped graphene and composite material technology, applied in the field of material chemistry, can solve the problems of poor conductivity, low coulombic efficiency, low utilization efficiency of elemental sulfur, etc., achieve good conductivity, improve cycle performance, and suppress the effect of shuttle effect

Active Publication Date: 2020-06-30
INT ACAD OF OPTOELECTRONICS AT ZHAOQING SOUTH CHINA NORMAL UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] Aiming at the problems of poor conductivity of positive electrode materials of lithium-sulfur batteries, low utilization efficiency of elemental sulfur, and low coulombic efficiency due to shuttle effect caused by polysulfides produced in the cycle process, the present invention proposes a tungsten nitride / Preparation method of nitrogen-doped graphene / tungsten oxide composite

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  • Preparation method of tungsten nitride/nitrogen-doped graphene/tungsten oxide composite material applied to lithium-sulfur battery positive electrode material

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] The first step: prepare tungsten trioxide-graphene composite material:

[0021] Take 5g of sodium tungstate and 0.2g of graphene dissolved in 70mL of deionized water, use hydrochloric acid solution to adjust the pH to 2.8, stir evenly and transfer to the reaction kettle, the reaction temperature is 180°C, and the reaction time is 12h. After the reaction is completed, The product was collected by centrifugation, washed three times with deionized water and ethanol, and then dried to obtain a tungsten trioxide-graphene composite material.

[0022] The second step: preparation of tungsten nitride / nitrogen-doped graphene / tungsten oxide composite material:

[0023] The tungsten trioxide-graphene composite material prepared in the first step was placed in a tube furnace, and the temperature was raised to 500°C under an argon atmosphere at a rate of 2°C / min, and then the argon gas was continuously fed into the furnace. Under the conditions, start to feed ammonia gas, the ratio...

Embodiment 2

[0025] The first step: prepare tungsten trioxide-graphene composite material:

[0026] Take 10g of sodium tungstate and 1g of graphene dissolved in 100mL of deionized water, adjust the pH to 3.0 with hydrochloric acid solution, stir evenly and transfer to the reaction kettle, the reaction temperature is 200°C, and the reaction time is 24h. After the reaction is completed, centrifuge The product was collected, washed three times with deionized water and ethanol, and then dried to obtain a tungsten trioxide-graphene composite material.

[0027] The second step: preparation of tungsten nitride / nitrogen-doped graphene / tungsten oxide composite material:

[0028] The tungsten trioxide-graphene composite material prepared in the first step was placed in a tube furnace, and the temperature was raised to 600°C under an argon atmosphere at a rate of 5°C / min. Under the conditions, start to feed ammonia gas, the ratio of argon to ammonia gas is 20:1, and after 2 hours, close the ammonia ...

Embodiment 3

[0030] The first step: prepare tungsten trioxide-graphene composite material:

[0031] Take 1g of sodium tungstate and 0.1g of graphene dissolved in 50mL of deionized water, use hydrochloric acid solution to adjust the pH to 2.5, stir evenly and transfer to the reaction kettle, the reaction temperature is 150°C, and the reaction time is 12h. After the reaction is completed, The product was collected by centrifugation, washed three times with deionized water and ethanol, and then dried to obtain a tungsten trioxide-graphene composite material.

[0032] The second step: preparation of tungsten nitride / nitrogen-doped graphene / tungsten oxide composite material:

[0033] The tungsten trioxide-graphene composite material prepared in the first step was placed in a tube furnace, and the temperature was raised to 400 ° C under an argon atmosphere, and the heating rate was 1 ° C / min, and then the argon gas was kept flowing continuously. Under the conditions, start to feed ammonia gas...

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Abstract

The invention relates to a preparation method of a tungsten nitride / nitrogen-doped graphene / tungsten oxide composite material for a lithium-sulfur battery positive electrode material, and the method prepares a composite material which takes graphene as a carrier and is loaded with a tungsten oxide / tungsten nitride heterojunction structure through a simple one-step hydrothermal method and an ammonia gas calcination method. Tungsten oxide grows on the surface of the graphene through a hydrothermal method, the particle size distribution of tungsten oxide is more uniform, the dispersity is relatively good, deposition of tungsten oxide particles is avoided, polysulfide can be more effectively adsorbed, the characteristic of good conductivity of graphene can be effectively utilized, the conductivity of the whole material is improved, and the cycle performance of the lithium-sulfur battery is improved.

Description

technical field [0001] The invention relates to a preparation method of a tungsten nitride / nitrogen-doped graphene / tungsten oxide compound used as a positive electrode material of a lithium-sulfur battery, and belongs to the field of material chemistry. Background technique [0002] Since the beginning of the 20th century, the survival and development of human society have faced three major themes including energy, environment and information. Among them, the energy crisis has had a huge impact on the development and stability of the world economy. At the same time, due to the continuous intensification of industrialization, the number of automobiles has continued to increase, leading to the gradual depletion of non-renewable energy sources such as oil, coal, and natural gas, and causing serious damage to the atmospheric environment. Serious pollution has affected the living environment and physical and mental health of human beings. Therefore, it is urgent to solve the ener...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/36H01M4/485H01M4/58H01M4/62H01M10/0525
CPCH01M4/364H01M4/485H01M4/58H01M4/625H01M10/0525H01M2004/028Y02E60/10
Inventor 王新王加义
Owner INT ACAD OF OPTOELECTRONICS AT ZHAOQING SOUTH CHINA NORMAL UNIV