Heterostructure VO2@VS2 tailored by one-step hydrothermal synthesis for stable and highly efficient Zn-ion storage

Abstract

The increasing demand for advanced energy storage solutions has driven extensive research into Zn-ion batteries due to their safety, cost-effectiveness, and environmental compatibility. This study presents a synthesis and evaluation of VO _2 @VS _2 hollow nanospheres as a novel cathode material for Zn-ion batteries. The VO _2 @VS _2 composite, synthesized via a one-step hydrothermal method, demonstrates a significant improvement in electrochemical performance. The material exhibits a reversible capacity of 468 mAh g ^−1 at 0.1 A g ^−1 and maintains a high capacity of 237 mAh g ^−1 at 1.0 A g ^−1 over 1000 cycles with a retention rate of 85%. Electrochemical analyses reveal enhanced charge transfer and Zn-ion storage, attributed to the synergistic effect and built-in electric field of the VO _2 and VS _2 heterostructure. Additionally, the composite shows superior electrochemical kinetics, facilitating rapid ion transport and charge transfer. In-situ Raman analysis confirms the reversible Zn-ion storage mechanism, further validating the composite’s structural stability during cycling. Density functional theory calculations further support these findings, indicating the composite’s potential for high-rate capability and long-term cycling stability. This research highlights the promise of VO _2 @VS _2 hollow nanospheres in advancing the performance of aqueous Zn-ion batteries.

Keywords

• Zn-ion batteries
• vanadium-based cathode
• hollow nanospheres
• heterostructure
• pseudocapacitive