Sponge-like 3D flower-like core-shell heterostructure CuCo2O4@CuCo2S4 as advanced electrodes for high-performance supercapacitor

Abstract

The design of nanocomposite electrode materials with reasonable core-shell heterostructures is vital to upgrade the energy density and structural stability of asymmetric supercapacitors. Herein, a unique sponge-like 3D flower-like core-shell CuCo2O4@CuCo2S4 (CCO@CCS-4) heterostructure is engineered and synthesized on a carbon cloth substrate by hydrothermal assisted electrodeposition method, which reveals that the externally interconnected CCS nanosheets as shell is uniformly anchored on the vertically aligned CCO nanoneedles, not only spatially separating the redox reaction but also improving the stability of the composite. Benefiting from its exclusive structure and the heterogeneity synergies of two components, the as-obtained CCO@CCS-4 electrode material exhibits specific capacity (1459.15 C g−1, 2.91 C cm−2), together with ascendant cycle stability of only 6.77% loss after 10,000 cycles. Moreover, the as-assembled asymmetric supercapacitor device, composed of CCO@CCS-4 as the cathode and activated carbon as the anode, provides considerable energy density (92.06 Wh kg−1 at 799.99 W kg−1). These properties indicate that there is a great potential in the application of high-performance supercapacitors.