PEDOT-PSS coated VS2 nanosheet anodes for high rate and ultrastable lithium-ion batteries

Abstract

As a typical member of transition metal dichalcogenides (TMDs), VS₂ is regarded as a promising substitute for the traditional carbon anode due to its high theoretical specific capacity. However, the practical application of VS₂ has been seriously limited by the grievous capacity decay. Herein, VS₂ nanosheets coated with PEDOT-PSS (poly(styrenesulfonate)-doped poly(3,4-ethylenedioxythiophene)) were prepared by a simple and gentle aqueous solution method. Compared with un-coated VS₂, the 5VS₂@PEDOT-PSS presents higher reversible capacity of 569.0 mA h g⁻¹ at 0.1 A g⁻¹ after 100 cycles. Even at a very high current density of 2 A g⁻¹, the composites still deliver a good reversible performance of 186.8 mA h g⁻¹ after 1000 cycles. The excellent electrochemical performance of 5VS₂@PEDOT-PSS can be attributed to the special sheet-like structure of VS₂ and the decreased charge transfer resistance of the conducting coating systems.