Facile synthesis of biomass-derived porous carbons incorporated with CuO nanoparticles as promising electrode materials for high-performance supercapacitor applications

Supercapacitors with large capacity, good stability and low cost are attractive to the development of energy storage technology. Herein, a new method for preparing biomass-derived carbon materials incorporated with CuO nanoparticles is proposed using cheap peanut shells as the carbon resource and copper acetate as the CuO precursor. The as-prepared CuO-AC sample retains a large BET surface area of 2640.55 m 2 /g with hierarchical micro-mesoporous structures. CuO nanoparticles with a particle size of 10–20 nm are formed and uniformly dispersed on the surface of the carbon skeleton. The synergetic effect of the double-layer capacitance of the porous carbon matrix and the Faraday capacitance introduced by CuO nanoparticles was successfully achieved, benefiting from which the CuO-AC electrode exhibits a high gravimetric specific capacitance up to 530 F/g at 1 A/g with prominent cycling stability of 92.5% after 10,000 cycles in the three-electrode system. CuO-AC was also used as the anode to assemble an asymmetric supercapacitor to investigate its practical application, showing that a high energy density of 11.7 W h/kg was reached at a power density of 628.73 W/kg. The large specific capacitance, high energy density and long cycle life of CuO-AC endow it a potential electrode material for supercapacitors. • A facile method is designed for the synthesis of biomass carbon/CuO composite. • A large surface area of 2640 m 2 /g is obtained with well-dispersed CuO nanoparticles. • A high capacitance of 530 F/g is achieved at 1 A/g by the CuO-AC electrode. • High capacitance retention of 92.5% is achieved after 10,000 cycles.