Co9S8 nanotube wrapped with graphene oxide as sulfur hosts with ultra-high sulfur content for lithium-sulfur battery

Lithium-sulfur battery is investigated as the most promising next-generation energy storage devices owing to its high energy density and environmental friendliness. However, it is a challenge to solve the electrical insulation of sulfur and the dissolution of intermediates in the electrolyte for the lithium-sulfur battery. To solve these issues, we report a novel Co9S8@S/GO hybrid, as host for the sulfur cathode. The graphene oxide and polar hollow Co9S8 nanotube can capture polysulfides in both physical and chemical adsorption. The Co9S8@S/GO composite exhibits a discharge capacity of 1022 mAh/g after 100 cycles at 0.1C and an ultralow fade rate of 0.027% per cycle at 1C with a high sulfur content of 89.22 wt%. The obtained Co9S8@S/GO electrode exhibits better electrochemical performance.

Automated summary

The lithium-sulfur battery is a promising energy storage device with high energy density and environmental friendliness, but challenges exist in solving the electrical insulation of sulfur and the dissolution of intermediates in the electrolyte. A novel Co9S8@S/GO hybrid has been developed as a host for the sulfur cathode, which shows better electrochemical performance by capturing polysulfides through physical and chemical adsorption with graphene oxide and polar hollow Co9S8 nanotube.