Electrochemical performances of coal-based carbon prepared by low-temperature catalytic graphitization as anode materials for potassium-ion batteries

Potassium-ion batteries (PIBs) are promising as an attractive replacement to lithium-ion batteries (LIBs) on a wide storage energy stationary scale because of the abundance of potassium resources and easily accessible. Herein, we successfully prepared carbon anodes materials for PIBs from a cheap and abundant coal by the low-temperature graphitization with Ni(CH3COO)2.4H2O catalyst. After 100 cycles, the coal-based carbon anode delivers a specific capacity of 200 mAh g-1 at 0.2 A g-1 current density, with more than 97% coulombic efficiency. This excellent potassium storage efficiency and the low cost make coal-based carbon anodes a most promising anode candidate for PIBs.