Copper oxide/cuprous oxide/hierarchical porous biomass-derived carbon hybrid composites for high-performance supercapacitor electrode

Low cost and high-performance electrode materials are essential for supercapacitor development and applications. Herein, this paper reports a cost-effective and easy-operation method to prepare hierarchical structural heteroatoms-doped carbon/copper oxide/cuprous oxide (CuOx@C) nanocomposites using a calcination process and a hydrothermal treatment. When waste bamboo leaves are converted into carbon materials, the unique hierarchical structures and inherent heteroatoms could be maintained. The hierarchical porous structures allow a short diffusion and facile ion-transfer of electrolyte ions to the active materials during the electrochemical reaction. The copper oxide/cuprous oxide nanoparticles are introduced by hydrolysis of copper ions. By controlling the reaction condition, copper oxide/cuprous oxide nanoparticles are dispersed in the carbon. The hybridization of carbon and metal oxide results in a combination of electrical double-layer capacitance and battery-like capacitance. The obtained CuOx@C composite exhibits an excellent specific capacitance of capacity of 147 F g⁻¹ and a long cyclic life of 93% after 10000 cycles of charge-discharge when it is applied as a material for supercapacitor. This work provides a new approach for fabrication of metal oxide/carbon nanocomposites for application in energy storage.