Nanoporous Cu/Co alloy based Cu2O/CoO nanoneedle arrays hybrid as a binder-free electrode for supercapacitors

Abstract

In this paper, Cu2O/CoO nanoneedle arrays (Cu2O/CoO-NNAs) are vertically grown on nanoporous Cu/Co (NPs-Co/Cu) conductive substrate through a facile dealloying and oxidation method. Benefiting from their intriguing structural features, the NPs-Cu/Co alloy based Cu2O/CoO-NNAs hybrid possesses fascinating electrochemical performance as an integrated binder-free electrode for symmetric supercapacitors (SSCs). High areal capacitances of 0.21 F cm−2 can be achieved at a current densities of 5 mA cm−2. Moreover, electrode has an excellent long-term cycling stability with 100% capacitance retention after 10000 cycles. A maximum of volumetric energy density (0.81 mW h cm−3) and volumetric power density (3 W cm−3) were achieved for the as-fabricated SSCs device. Therefore, the present work holds a great promise for future design and large-scale production of high volumetric energy density and volumetric energy density electrodes by dealloying and oxidation method for energy storage devices.