MnOX-modified corrugated carton-derived hierarchical porous carbon with ultrafast kinetics behaviour for high-performance symmetric supercapacitors

摘要

Conventional MnOx nanostructure/hierarchical porous carbon (HPC) composites meet two problems: non-optimized mass loading and poor rate capability. Here we present a judicious design of MnOX-modified corrugated carton-derived HPCs by depositing MnOX nanostructures in the mesopores of HPCs. Using a synergy of gas pore formation and KOH etching, mesopore-rich HPCs with a high aspect ratio suitable for the efficient loading of MnOX are synthesized. The Mn catalysis-induced graphitization process achieved by hydrothermal carbonization yields the MnOX-modified corrugated carton-derived HPCs (CBPC-2-800@MnOX) with ultrafast kinetics behaviour. Even at an extremely low loading of MnOx, the CBPC-2-800@MnOX electrodes exhibit a higher gravimetric capacitance (302 F g(-1) at 0.05 A g(-1)), better rate performance (capacitance retention of 87.4% from 0.05 to 5 A g(-1)), higher energy/power density (8.4 W h kg(-1) at 1000 W kg(-1)) and longer cycle life (98.8% capacitance retained after 5000 charge/discharge cycles at 2.5 A g(-1)) than those of pure HPC electrodes. The novel MnOX-modified biomass-derived HPCs with efficient mass loading and outstanding rate capability are concluded to be promising electrode materials for high-performance symmetric supercapacitors. (C) 2020 Elsevier B.V. All rights reserved.