Synthesis of binder-free hydrated vanadium oxide-polyaniline electrodes via in situ polymerization for high-performance aqueous zinc-ion batteries

Abstract

Hydrated vanadium oxide, a kind of layered electrode material with high theoretical specific capacity, has great potential for developing high-performance, low-cost, and eco-friendly aqueous zinc-ion batteries. However, its characteristics of poor electronic conductivity, vanadium dissolution, and unstable structure lead to poor electrochemical performance, such as low specific capacity, poor rate performance and short cycle life. Combining PANI with layered hydrated vanadium oxide is expected to overcome the shortcomings and achieve high zinc storage performance. In this work, binder-free hydrated vanadium oxide-polyaniline inorganic–organic hybrid compounds deposited on carbon cloth (VOH-PANI/CC) are developed by combination of layer-by-layer and in-situ polymerization process. Benefiting from synergistic effect between polyaniline and hydrated vanadium pentoxide, the hybrid electrode (VOH-PANI/CC) delivers high capacities of 290 mA h/g at 0.5 A/g and 165 mA h/g at 4 A/g. In contrast, the specific capacities of VOH/CC are only 185 and 70 mA h/g at 0.5 and 4 A/g, respectively. This in-situ polymerization of aniline via layer-by-layer strategy on hydrated vanadium oxide provides a novel synthesis scheme for the use of vanadium oxide as cathode material for aqueous zinc-ion batteries.