S-Doped Carbon-Coated FeS2/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.

Automated summary

In this study, S-doped carbon-coated rod-like FeS2/C@C was fabricated as an anode material for potassium-ion batteries, demonstrating excellent rate performance and stable cycle performance. The unique structure of FeS2/C@C is associated with its superior performance, making it a potential anode material for PIBs.