S-Doped Carbon-Coated FeS_(2)/C@C Nanorods for Potassium Storage

Potassium-ion batteries(PIBs) are promising scalable energy storage system;however,one of the challenges for its potential application is the huge volume variations during cycling due to the insertion/extraction of large size potassium ions.Here,we fabricated the S-doped carbon-coated rod-like FeS2/C@C,which not only effectively alleviate the volume variations upon cycling but also can improve electrical conductivity and maintain the structural integrity.As an anode material for PIBs,the rod-like FeS2/C@C electrodes delivered excellent rate performance(175 mA h g-1 at 0.5 A g-1) and stable cycle performance(262 mA h g-1 after 100 cycles at 0.1 A g-1).The superior excellent performance is associated with the unique structure of FeS2/C@C.The as-synthesized FeS2/C@C is demonstrated to be a potential anode for PIBs.