Direct synthesis of vanadium pentoxide powder with carbon recombination as aqueous zinc-ion battery cathode

Abstract

Abstract Advanced energy storage technologies have been prompted by the benefits of safe, high-capacity, and stable cathode materials for aqueous Zn-ion batteries (ZIBs). Vanadium oxide has lately become a popular cathode material thanks to its advantages of a sufficient operating voltage window and a highly reversible redox reaction. However, Vanadium pentoxide has several drawbacks, including poor electrical conductivity and slow ion diffusion. To resolve these problems, orthorhombic single crystal V2O5 sheets were synthesized by a facile solution combustion synthesis method to improve their performance by adding C6H12O6. As cathode materials for the ZIBs, the V2O5/C particles with larger surfaces and higher oxygen defects concentration are obtained with C6H12O6 addition, which increases the dynamic performance of ion diffusion and the activity of the vanadium-based cathode. The synthesized V2O5/C sample exhibited the specific capacitance of 220 mAh g− 1 (V2O5 is 180 mAh g− 1) in the aqueous electrolytes at 4 A g− 1, which exhibited a high specific capacity of 85.5% after 500 cycles with nearly 100% coulomb efficiency, indicating improved specific capacitance and cyclic stability.