Integration of MnO2 and ZIF-Derived nanoporous carbon on nickel foam as an electrode for high-performance supercapacitors

Abstract

MnO2 has the highest potential as a supercapacitor electrode; however, its disadvantage in electronic conductivity hinders its widespread use. This study reports the excellent electrochemical performance of MnMC/NF (MnO2 and ZIF-derived nanoporous carbon on nickel foam) composites. MnMC/NF composites are produced when leaf-like Co-ZIF is annealed on nickel foam, followed by potassium permanganate treatment. When the annealing temperature reaches 700 °C, the maximum specific capacitance of 531 F/g is achieved at 1 A/g (456 F/g at 20 A/g) with a rate capability of 85.5%. MnMC/NF700 has a long cyclic stability, and the capacitance retention was 82% after 5000 cycles. The energy density of an assembled device using MnMC/NF700 composite as positive electrodes can reach 38.8 Wh/kg. This is due to the combined effect of nickel substrate's 3D porous structure and the excellent electronic conductivity of ZIF-derived nanoporous carbon. The unique configuration of MnMC/NF composites may provide a referable design for energy storage systems, including materials that have the highest potential for use as supercapacitor electrodes.