Rose-like VS2 Self-Assembled from Nanosheets with Superior Sodium Storage Performance

Recently, sodium ion batteries (SIBs) have exhibited great application potential in the area of renewable energy storage. However, developing anodes for SIBs with excellent cycling stability and high capacity is a great challenge. In recent years, VS2 attracts more attention due to its high specific capacity. In this work, three-dimensional (3D) rose-like VS2 self-assembled from nanosheet was prepared via a solvothermal method using N-methylpyrrolidone as the solvent. The special 3D structure facilitates electron/Na+ transport and can relieve the volume change during Na+ insertion/extraction. Benefitting from the 3D self-assembled structure, VS2 exhibits outstanding cycling stability at high current density. Even when tested at 5 A g(-1), the 3D VS2 electrode can maintain a high capacity of 565 mA h g(-1) after 350 cycles. Through pseudo-capacitance contribution calculation, we speculate that the high capacitance contribution confers the superior high rate performance to the VS2. This work sheds a new light on the design and preparation 3D VS2, which can be utilized as an excellent anode for SIBs.

Automated summary

In this study, a three-dimensional rose-like VS2 structure with excellent cycling stability and high capacity was prepared via a solvothermal method. The self-assembled structure facilitates electron/Na+ transport and mitigates volume change during Na+ insertion/extraction, resulting in outstanding performance at high current densities. Benefitting from the 3D self-assembled structure, the VS2 electrode maintained a high capacity of 565 mA h g(-1) after 350 cycles at 5 A g(-1), showcasing superior high rate performance.