Carbon-coated CoS@rGO anode material with enhanced cyclic stability for sodium storage

Carbon-coated cobalt sulfide@reduced graphene oxide (CoS@rGO@C) composite was innovatively synthesized by a simple solvothermal reaction and subsequent carbon coating process for use as the anode material in sodium-ion batteries (SIBs). In this composite structure, the rGO network and extra outer carbon coating worked synergically to achieve excellent electrode architecture stability upon long-term cycling. Specifically, the CoS@rGO@C composite anode demonstrated superior reversible capacity (706 mAh·g−1 at 100 mA·g−1 at the 1st cycle), high rate capability (374 mAh·g−1 at 1.6 A·g−1), and remarkably stable cycling performance (80% capacity preservation for up to 100 cycles) based on the synergistic action of rGO and carbon coating on CoS. In addition to improving the electrochemical performance of CoS anodes, this composite material strategy can be conveniently adapted to other metal-based anode designs to improve their cycling stability and promote their application in energy storage.