Preparation and sodium storage performance of 2D bilayered V2O5?nH2O nanomaterial with Zn2+intercalation

摘要

Two-dimensional (2D) bilayered vanadium pentoxide (V2O5 center dot nH2O) nanomaterial with Zn2+ intercalation is prepared by a facile sol-gel method combined with the vacuum freeze-drying technique. The microstructure and surface morphology of the sample are analyzed by XRD, EDS, XPS, and SEM measurements. The sodium storage performance of the sample is characterized by discharge-charge, CV, and EIS tests. The results demon-strate that the Zn2+ intercalation leads to more low valance state V4+ in V2O5 center dot nH2O and induces the formation of a layer-by-layer stacked sheet-like morphology. Compared to pure V2O5 center dot nH2O sample (without Zn2+ inter-calation), the V2O5 center dot nH2O sample with Zn2+ intercalation exhibits improved rate capability, better cycling sta-bility, enhanced Na+ diffusivity, and lower electrochemical reaction resistance. At 1.0 A g-1, the V2O5 center dot nH2O sample with Zn2+ intercalation delivers a reversible specific capacity of 71.2 mAh g-1, much higher than the corresponding value (12.1 mAh g-1) of the pure V2O5 center dot nH2O sample was only. After 100 cycles at 0.1 Ag-1, the specific capacity of the V2O5 center dot nH2O sample with Zn2+ intercalation maintains at 98.9 mAh g-1, obviously higher than that (72.7 mAh g-1) of the pure-V2O5 center dot nH2O sample.

关键词