100 K cycles: Core-shell H-FeS@C based lithium-ion battery anode

Lithium ion batteries (LIBs) are still suffering from the issues of low capacity, limited lifespan and poor rate performance. To address these issues, FeS-hollow core-shell structure with ultrathin carbon coated composite (H-FeS@C) were synthesized and used for high rate LIBs. The ultra-thin carbon matrix wrapped on the surface of FeS can enhance the electric conductivity and protect the electrode, while the hollow structure can adjust large volume expansion during cycling. Benefiting from its unique structure, the H-FeS@C core-shell composite delivers high capacity, remarkable cycling stability (with reversible capacity of 100 mA h g^-1 after 100 K cycles at 80,000 mA g^-1) and high rate performance. Moreover, when charging at 200 mA g^-1 and discharging at 10,000 mA g^-1, the battery delivers a reversible capacity of 540 mA h g^-1 after 100 cycles with capacity retention of 86%. The superior electrochemical properties of H-FeS@C may provide a new method for designing new materials with high rate and long-term stability.