Positive electrode framework structure of metal/metal oxide lithium-sulfur battery

Abstract

The invention provides a metal / metal oxide lithium-sulfur battery positive electrode skeleton structure, which utilizes a synergistic effect between a two-dimensional (2D) core-shell heterostructure and oxygen vacancies (OVs), that is, a porous core-shell structure and an oxygen vacancies combined CC (at) Co / CoO1-x nanosheet array are grown on carbon cloth (CC) to serve as the positive electrode skeleton structure, so that the electrochemical performance of a lithium-sulfur battery is improved. The unique 2D porous structure enables the CoO < 1-x > nanosheet to have high active sites, and the CoO < 1-x > nanosheet has strong chemical interaction with LiPS, so that the fracture of S-S bonds in LiPS is promoted. In addition, the Co core at the bottom of the nanosheet and the carbon cloth form a continuous integrated conductive frame, so that rapid charge transfer can be realized, and further the conversion of the fixed LiPS is accelerated. Due to the synergistic effect between the CoO < 1-x > sulfur-loving shell and the Co conductive core, the CC (at) Co / CoO < 1-x > serving as a lithium-sulfur battery positive electrode material framework has excellent rate capability and long cycle stability, after 400 cycles under the current density of 3.35 A g <-1 >, the coulombic efficiency is as high as 99.8%, and the capacity fading rate per week is only 0.023%.

Description

technical field [0001] The invention relates to a positive electrode skeleton structure of a lithium-sulfur battery, in particular to a CC@Co / CoO with a two-dimensional porous core-shell structure and oxygen vacancy combination 1-x Skeleton structure of nanosheet arrays for lithium-sulfur batteries. Background technique [0002] The lithium-sulfur battery has a theoretical specific capacity (1675mAh g -1 ), low cost, good environmental compatibility and other advantages, it is considered to be a very promising next-generation energy storage system, and has received extensive attention from global research institutions. However, the poor electrical conductivity of sulfur, the shuttle effect of polysulfides (LiPS) and their poor reaction kinetics seriously hinder the practical application of Li-S batteries. [0003] Carbon materials are considered as ideal sulfur storage materials due to their strong electrical conductivity, low mass density and large specific surface area. ...

AI Technical Summary

Problems solved by technology

However, due to the low electrical conductivity of metal oxides, their electrocatalytic activity is often unsatisfactory, severely limiting their catalytic activity for LiPS conversion.

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