Amorphous C/SbSx composites from natural stibnite as low cost and high performance lithium/sodium-ion battery anodes

Abstract

Antimony sulfide is a promising anode material for lithium/sodium-ion batteries due to its high theoretical capacity, but it suffers from large volume expansion during cycling and high cost. In the present work, we synthesized low cost amorphous C/SbS_x (x ≈ 1.18) composites using natural stibnite and charcoal as raw materials by a fast microwave heating method (tens of seconds). These composites showed excellent cycling performance and rate capability as anodes for lithium/sodium-ion batteries. For instance, the C/SbS_x composite with 74 wt% SbS_x delivered a stable capacity of 686 mA h g⁻¹ after 500 cycles at a current density of 0.5 A g⁻¹ and a high rate capacity of 520 mA h g⁻¹ at a current density of 2 A g⁻¹ in lithium-ion batteries. The amorphization of SbS_x was found to be crucial for the improvement of the cycling performance of the composite, as it could suppress the volume expansion and enhance the reversibility during the electrochemical reactions. The excellent rate capability of this composite was mainly attributed to the reduced size of the active material and the combination with conductive charcoal. This work demonstrates the great potential of using natural stibnite as a raw material for low cost and high performance lithium/sodium-ion battery anodes by a fast microwave heating method.