Facile synthesis and electrochemical properties of Fe2SeS for lithium ion batteries

• Pure Fe2SeS is synthesized by facile solid-state reaction.
• Electrochemical properties of Fe2SeS are investigated as an anode material.
• Only one step reaction occurs during both charge and discharge process.
• Fe2SeS has higher capacity and better cycle performance than FeS and FeSe.

Fe2SeS is successfully synthesized by facile solid-state reaction and the electrochemical investigation of Fe2SeS as anode for lithium ion batteries is reported for the first time. Fe2SeS deliverers a large initial discharge capacity of 471 mAh g−1. The initial coulombic efficiency (92.56%) is higher than most of double-anion compounds reported previously. It is unexpected to find that Fe reacts simultaneously with Li2S and Li2Se to reform Fe2SeS during charging process, which is different from most double-anion compounds.