Rice husk-derived mesoporous carbons via pore-tailoring as high-performance electrode materials of zinc-ion hybrid supercapacitors

Biomass-derived carbon is a promising electrode material for aqueous zinc-ion hybrid supercapacitors (ZHSCs) due to its eco-friendliness and high-efficiency in energy storage. Previous studies mainly focus on the enhancement of specific surface area; however, the optimization of pore structure is also important for energy storage performance of biomass-based carbon materials, which is always ignored. Herein, a combination method of hydrothermal treatment and high-temperature activation is reported to synthesize rice husk-derived carbon, used as a high-performance cathode for aqueous ZHSC. Relying on natural SiO2template and regulation of activation temperature, pore structure of rice husk-derived carbon got effectively tailored, exhibiting a honeycomb-like structure with abundant mesopores and large micropores. The ZHSC with the rice husk-derived mesoporous carbon as the cathode exhibits both high specific capacitance and energy density, achieving 172.5 F g-1 at a current density of 0.5 A g-1 and 77.61 W h kg-1 at a power density of 449.8 W kg-1 . Additionally, the assembled ZHSC shows a capacitance retention rate of 97.7 % after 12,000 charge-discharge cycles at 5 A g-1. This work successfully developed a rice husk-derived mesoporous carbon with pore-tailoring strategy, which offers an effective approach for transforming waste biomass into high-performance ZHSC electrode materials.