Carbon-Coated ZnS-FeS2 Heterostructure as an Anode Material for Lithium-Ion Battery Applications.

ABSTRACT

The construction of carbon-coated heterostructures of bimetallic sulfide is an effective technique to improve the electrochemical activity of anode materials in lithium-ion batteries. In this work, the carbon-coated heterostructured ZnS-FeS2 is prepared by a two-step hydrothermal method. The crystallinity and nature of carbon-coating are confirmed by the investigation of XRD and Raman spectroscopy techniques. The nanoparticle morphology of ZnS and plate-like morphology of FeS2 is established by TEM images. The chemical composition of heterostructure ZnS-FeS2@C is discovered by an XPS study. The CV results have disclosed the charge storage mechanism, which depends on the capacitive and diffusion process. The BET surface area (37.95 m2g-1) and lower Rct value (137 Ω) of ZnS-FeS2@C are beneficial to attain higher lithium-ion storage performance. It delivered a discharge capacity of 821 mAh g-1 in the 500th continuous cycle @ A g-1, with a coulombic efficiency of around 100%, which is higher than the ZnS-FeS2 heterostructure (512 mAh g-1). The proposed strategy can improve the electrochemical performance and stability of lithium-ion batteries, and can be helpful in finding highly effective anode materials for energy storage devices.