Electrospun VO2/carbon fibers for aqueous zinc-ion batteries

Abstract

Aqueous zinc-ion batteries (AZIBs) have become one of the most potential energy storage devices due to their high safety and low cost. Vanadium oxide is an ideal cathode material for AZIBs because of its unique tunnel structure and multivalent nature. In this work, electrospun VO₂/carbon fibers (VO₂@CPAN) with a three-dimensional (3D) network are obtained by an electrospinning strategy combining with a controlled heat treatment. As cathode for AZIBs, the 3D network of the carbon fiber significantly improves the conductivity of VO₂, avoids the agglomeration of VO₂, and increases the stability of VO₂. Therefore, VO₂@CPAN delivers a specific capacity of 323.2 mA h g⁻¹ at 0.2 A g⁻¹, which is higher than pure VO₂. At the same time, excellent capacity retention of 76.6% is obtained at high current density of 10 A g⁻¹ after 3000 cycles.