High graphitization three-dimensional carbon nanotube graphene composite material and preparation method and application thereof

Abstract

The invention provides a high graphitization three-dimensional carbon nanotube graphene composite material and a preparation method and an application thereof. The preparation method comprises the steps of performing mixing on carbon nanotubes and graphene, and adding ethyl alcohol and performing ultrasonic uniform dispersion, and putting the mixture into a drying oven to be dried at 50 DEG C to obtain a compound of carbon nanotubes and graphene; and putting the compound into a high-temperature graphitization furnace, and under high-purity argon protection, heating to 2,850 DEG C by a programheating method and continuing for 2h to obtain the high graphitization three-dimensional carbon nanotube graphene composite material. The preparation method is simple and large-scale production can berealized easily; meanwhile, by virtue of high temperature graphitization processing, the surface defect structure of the carbon material can be repaired effectively, and the oxygen-containing functional groups can be removed from the surface, so that electrical conductivity and thermal conductivity of the material are greatly improved; and a sulfur-bearing positive electrode obtained by using thehigh-temperature material shows extremely high advantage in the charging-discharging circulation at a high-rate high current, and diaphragm completeness can be protected effectively.

Description

technical field [0001] The invention mainly relates to the field of carbon nanomaterials, especially the highly graphitized three-dimensional carbon nanotube graphene composite material and its preparation and application. Background technique [0002] Lithium-sulfur battery due to high energy density, 1675mAhg -1 The theoretical capacity and cheap cost have become one of the most promising rechargeable battery systems in the field of large-scale energy storage. However, the non-conductivity of sulfur and the shuttling effect of polysulfides have been the shortcomings of lithium-sulfur batteries. [0003] In response to these shortcomings in lithium-sulfur batteries, people began to explore their solutions in the 1960s, and proposed to combine insulating sulfur with carbon nanotubes, graphene, porous carbon and other conductive carbon materials as the core of lithium-sulfur batteries. However, these methods are complex, cumbersome and ineffective in improving the shuttling...

AI Technical Summary

Problems solved by technology

However, the non-conductivity of sulfur and the shuttling effect of polysulfides have been the shortcomings of lithium-sulfur batteries.

[0003] In response to these shortcomings in lithium-sulfur batteries, people began to explore their solutions in the 1960s, and proposed to combine insulating sulfur with carbon nanotubes, graphene, porous carbon and other conductive carbon materials as the core of lithium-sulfur batteries. positive electrode materials, but these methods are complex, cumbersome and ineffective in improving the shuttle effect of polysulfides

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