Polyaniline‐coated V2O5 as a high‐performance cathode material for Zn‐ion batteries

Abstract

AbstractIntroductionDue to the advantages of environmental compatibility, low cost, and safety, aqueous zinc‐ion batteries (ZIBs) have stood out as the emerging energy storage devices among metal‐ion batteries. However, most cathode materials suffer from slow Zn2+ diffusion rates, resulting in poor charge–discharge rates and cycle life of state‐of‐the‐art ZIBs.Objective and MethodIn this work, a polyaniline (PANI) coating method is proposed to improve the Zn2+ diffusion kinetics and stability of the V2O5 cathode. The coating of PANI can maintain the structural stability of V2O5. Moreover, PANI is conducive to improving the electronic conductivity and increasing the intercalation/deintercalation capacity of V2O5 by promoting the diffusion process of Zn2+ ions, thereby increasing the charge–discharge capacity of ZIBs.ResultsEventually, the electrochemical performance of the PANI‐coated V2O5 electrode is significantly improved, delivering a high discharge specific capacity of 0.374 mAh cm−2 at the current density of 2 mA cm−2 and improved capacity retention of 83% after 500 cycles. This work demonstrates the positive effect of the PANI‐coating strategy on improving the electrochemical performance of V2O5 electrodes.