A Vanadium-doped CuxO Nanorod Array with Modulated Electronic Structure for Enhanced Aqueous Energy Storage

The poor intrinsic electronic conductivity of copper-based oxides materials limits their development for aqueous electrochemical energy storage devices (AEESDs). Herein, we develop a self-supporting vanadium-doped CuxO nanorod array AEESD via in-situ transformation using a template precursor and modification with vanadium. Theoretical and experimental analysis illustrate that partial vanadium isomorphic substitution on copper sites can successfully modulate the electronic and lattice structure of the pristine materials, then drive electron transfer, resulting in enhanced electrical conductivity and reaction kinetics for energy storage. An AEESD constructed with a V-CuxO nanorod array negative electrode shows desirable electrochemical performance, with high energy density of 1.26 mWh·cm-2 at power density of 8.50 mW·cm-2 and 0.71 mWh·cm-2 at 85 mW·cm-2. The AEESD can effectively power LED lighting. This work provides novel insights into how the modulation of the crystal structure of copper-based oxides can enhance their electrochemical performance.