Growth of large-area petal-like V2O5 thin nanosheets for superior lithium storage

There is a need for simple and rapid methods of controllably fabricating large-area V2O5 thin nanosheets for applications in high-energy Li-ion batteries (LIBs). Here, we report a novel growth-induced synthesis of two-dimensional (2D) petal-like V2O5 nanosheets with a thickness of approximately 15 nm and lateral size exceeding 5 µm. The mechanism of formation of the nanosheets is systematically investigated by studying the effects of reagent concentrations on the nanosheet morphology. The resultant V2O5 nanosheets were effective cathode materials for LIBs, giving high reversible capacities of 291.7 and 101 mAh g−1 at current densities of 0.1 and 3.0 A g−1, respectively, in the voltage window of 2.0–4.0 V. Furthermore, the cathode operated stably for 200 cycles at 1.5 A g−1, with a reversible capacity of 139.6 mAh g−1 at the 200th cycle, corresponding to a capacity fading of 0.03% per cycle. The enhanced lithium storage is attributed to the increased electrode/electrolyte contact area, the enhanced strain tolerability, and shortened charge transport path of the unique nanosheet structure. The influence of the electrochemical reaction kinetics on the performance is also discussed in detail. These findings will accelerate the development of V2O5 cathodes for next generation high-energy LIBs.