Chemically stripped multi-wall carbon nanotube-based lithium-sulfur battery positive electrode material and preparation method and application thereof

Abstract

The invention discloses a chemically stripped multi-wall carbon nanotube-based lithium-sulfur battery positive electrode material. The positive electrode material comprises chemically stripped multi-wall carbon nanotubes and sulfur nanoparticles; the chemically stripped multi-wall carbon nanotubes comprise n layers of carbon nanotubes, and sulfur nanoparticles are fixed on the surfaces of at leastone layer of the carbon nanotubes through carbon sulfur bond combination, wherein counting from the carbon nanotube on the outermost layer, the tube walls of m layers of carbon nanotubes in the chemically stripped multi-wall carbon nanotubes comprise openings, wherein n and m are both positive integers and n-m is greater than or equal to 1; and the mass ratio of the chemically stripped multi-wallcarbon nanotubes to sulfur nanoparticles is 3:7 to 1:1. The invention also discloses a preparation method and an application of the chemically stripped multi-wall carbon nanotube-based lithium-sulfurbattery positive electrode material. By fixing sulfur through the carbon sulfur bonds, the lithium-sulfur battery adopting the positive electrode material has the advantages of high cycle stability,high coulombic efficiency and the like; and in addition, the preparation method is simple and convenient, and so that wide development prospect in the lithium-sulfur battery can be achieved.

Description

technical field [0001] The invention relates to the technical field of cathode materials for lithium-sulfur batteries. More specifically, it relates to a lithium-sulfur battery cathode material based on chemical exfoliation of multi-walled carbon nanotubes, its preparation method and application. Background technique [0002] Currently, commercial rechargeable lithium-ion battery cathode materials are usually lithium transition metal oxides, such as LiCoO 2 , LiMn 2 o 4 and LiFePO 4 etc. These transition metals are relatively rare on the earth, and the theoretical specific capacity of existing lithium-ion batteries (LiCoO 2 Positive electrode 274mA·h·g -1 ) can no longer meet the needs of large electronic devices such as electric vehicles or large smart devices. Therefore, electrode materials with high specific capacity, high cost performance and environmental friendliness have become the focus of research. [0003] Sulfur is an abundant, cheap and environmentally fri...

AI Technical Summary

Problems solved by technology

The current method of chemically immobilizing sulfur is mainly to bond sulfur with organic carbon materials through anti-sulfurization, but this process is relatively complicated and the conductivity is often poor.

Carbon nanotubes have a large specific surface area, and their structure is conducive to the transport of electrons and lithium ions. They have good prospects for anode materials for lithium-sulfur batteries. There are few reports on the method of forming chemical bonds to fix sulfur based on carbon nanotubes.

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