The importance of electrolyte environment during in situ self-transformation for synthesizing V2O5·nH2O.

ABSTRACT

V2O5·nH2O is a promising cathode material for zinc-ion batteries. One of the synthesis methods of V2O5·nH2O is in situ self-transformation. In this communication, we focus on the influence of the electrolyte environment during in situ self-transformation (from VO2 to V2O5·nH2O). 2 M ZnSO4 and 2 M Zn(OTf)2 were used as different electrolytes to produce VOH-1 and VOH-2. VOH-1 expands in volume along the electric field to form a porous surface structure and shows low crystallinity along the (0 0 1) plane, while VOH-2 exhibits the opposite. These advantages enable the assembled batteries with VOH-1 to maintain excellent cycling performance at a rate of 2 A g-1 with a capacity of 500 mA h g-1 and stable cycling for 1800 cycles.