Three-dimensional porous C/CoS nanocomposites for a long-life and high-rate potassium storage

The three-dimensional (3D) porous C/CoS nanocomposites were successfully synthesized using a spontaneous template method followed by a subsequent vulcanization process. As potassium ion battery anode, the 3D porous C/CoS nanocomposites exhibited a reversible capacity of 165 mAh g −1 at 5 A g −1 after 2000 cycles and superior rate performance. The excellent electrochemical performance of 3D porous C/CoS nanocomposites is ascribed to its distinctive architecture, which can alleviate the volume variation of CoS in the cyclic processes, improve electronic/ionic conductivity, and provide more chances of contact between electrode material and electrolyte. It is promising that our fabricating method can be expanded for synthesizing other 3D porous C/metal sulfides composites as high-performance PIB anodes.