Interconnected NiCo2O4 nanosheet arrays grown on carbon cloth as a host, adsorber and catalyst for sulfur species enabling high-performance Li–S batteries

Abstract

Li–S batteries are a promising next-generation electrochemical energy-storage system due to their high energy density, as well as the abundance and low cost of sulfur. However, the low conductivity of sulfur and Li₂S/Li₂S₂, as well as the dissolution and shuttling of intermediate lithium polysulfides, is a great challenge for high-performance Li–S batteries. Herein, interconnected NiCo₂O₄ nanosheet arrays grown on carbon cloth (CC) are applied as the cathode (S/NiCo₂O₄/CC) in Li–S batteries for accommodating sulfur. The obtained cathode shows high conductivity, high dispersion of sulfur species and excellent polysulfide adsorption and catalytic properties. As a result, significantly higher specific capacity (1480 vs. 1048 mA h g⁻¹ at 0.1C) and greatly enhanced rate performance (624 vs. 215 mA h g⁻¹ at 2C) are obtained for the S/NiCo₂O₄/CC cathode in comparison to S/CC. Further, the S/NiCo₂O₄/CC cathode demonstrates a low capacity decay of 0.060% per cycle over 400 cycles at 0.5C.