Spray-dried V2O5 As Cathode Material for High-Performance Aqueous Zinc-Ion Batteries

Rechargeable aqueous zinc-ion batteries (ZIBs) have recently received increasing attention due to their high safety, low cost, and material abundance. Nevertheless, finding a suitable cathode material with a high capac-ity and good stability remains a challenge. To solve this problem, we prepared vanadium pentoxide micro-spheres with high performance through a one-step spray-drying process. As confirmed by SEM and laser granulometry, microspheres in the range of 1-10 mu m are obtained and result from the agglomeration of com-mercial nanoparticles. A comparative study with commercial V2O5 is realized and shows the benefit of the architecture design of vanadium pentoxide on the electrochemical performance of ZIBs. Spray-dried V2O5 delivers remarkably high capacities of 495 mAh g-1 and 240 mAh g-1 at low (0.1 A g-1) and high current density (5 A g-1) respectively, excellent rate capability, and good stability. Excellent capacity retention of 93 % is observed after 1000 cycles at high current density. The experimental results suggest a promising poten-tial for V2O5 microspheres as cathode material in aqueous zinc-ion batteries.