Electrochemical properties of ZrO2-doped V2O5 amorphous powders with spherical shape and fine size.

Amorphous V2O5 powders with zirconia (ZrO2) dopant are prepared by one-pot spray pyrolysis at temperatures above the melting temperature of V2O5. The powders with 7 wt % ZrO2 are completely spherical and dense with a clean surface, on which crystals of pure V2O5 powders are scarcely observed. The V2O5 powders with 7 wt % ZrO2 have uniformly distributed V and Zr components. The uniformly distributed Zr component disturbs the crystallization of V2O5 during the quenching of the melted powders. These powders also give smooth initial discharge curves with a single slope, which is typical to amorphous materials. The discharge capacities of the V2O5 powders with 7 wt % ZrO2 are 309, 269, and 222 mA h g(-1) after the first, second, and 50th cycles, respectively, even at a high current density of 294 mA g(-1). The capacity retention measured after the first cycle is 83% after 50 cycles.