High-performance sodium-ion anodes enabled by a low-temperature molten salt approach

Abstract

A low-temperature doping approach has been developed for fabricating nitrogen and sulfur co-doped few-layer graphene (NS-FLG) by annealing graphene oxide in KSCN molten salt at 175 °C. The as-prepared NS-FLG with a high doping level and unique few-layer structure delivers remarkable performance for sodium-ion batteries (SIBs) in terms of a high reversible capacity of 325.4 mA h g⁻¹ at 0.5 A g⁻¹, a superb rate capacity of 203.6 mA h g⁻¹ at 10 A g⁻¹, and ultra-long cyclability over 5100 cycles. This work provides a new avenue for exploring advanced graphene-based materials towards SIBs and even other electrochemical fields.