The crystallinity gradients of MoS2 controlled by glycol to boost redox kinetics for stabilization of sodium-ion batteries

Abstract

Controlling the crystallinity and microstructure of electrode materials is crucial to enhancing the sodium storage performance. Transition metal dichalcogenides, because of their high theoretical capacity, hold great promise for sodium-ion batteries. However, fundamental challenges exist in limited active sites and rapid capacity fading of crystalline transition metal dichalcogenides electrode materials. In this work, the crystallinity and microstructure of the MoS₂/rGO electrode materials are directly regulated by adjusting the volume of glycol in the solvent. It shows that the MoS₂/rGO-60 % electrode with balanced crystallinity and microstructure demonstrates remarkable cycling stability (82.2 % after 500 cycles) and outstanding rate performance. Additionally, we investigate the phase transition mechanism of MoS₂/rGO-60 % during cycling, and the transition from amorphous to crystalline is found. This discovery provides insights into the design of long-life and sustainable sodium-ion batteries.