Flaky CoS2 and graphene nanocomposite anode materials for sodium-ion batteries with improved performance

Abstract

A flaky CoS₂ based reduced graphene oxide (CoS₂/rGO) composite was successfully synthesized via a solvothermal route. CoS₂ nanoparticles with sizes of 20–30 nm are uniformly anchored on the reduced graphene oxide (rGO), resulting in the flaky structure. The as-fabricated CoS₂ based rGO composite exhibits improved sodium storage capacity compared with bare CoS₂ as anode materials for sodium-ion batteries. After cycling for 1000 cycles at 1 A g⁻¹, the CoS₂ based rGO electrode still delivered a reversible capacity of 192 mA h g⁻¹. The enhanced electrochemical performances of the CoS₂ based rGO composite can be ascribed to the formation of a robust, conductive and high surface area composite.