Iron sulfide/carbon hybrid cluster as an anode for potassium-ion storage

Due to the natural abundance and low cost of potassium resource, potassium-ion batteries (KIBs) are promising alternatives in comparison to lithium-ion batteries (LIBs). Herein, we report a three-dimensional (3D) iron sulfide/carbon hybrid cluster as a novel anode material for high-performance KIBs. The iron sulfide and amorphous carbon petals overlap as a whole, forming a stable conductive structure. A high capacity of 226 mAh g⁻¹ is obtained at a current density of 0.1 A g⁻¹ over 100 cycles. The improved electrochemical performances are mainly due to the synergistic effect of the unique structure with high capacity, high conductivity and less agglomeration.