Co-pyrolysis of Lotus Pollen and Ammonium Nitrate to Produce Graphene-Like Porous Carbon with Charge and Mass Transfer Highways for High-Performance Supercapacitor

Biomass-derived carbon-based supercapacitors offer a promising sustainable energy storage strategy for addressing global energy and environmental challenges. Herein, we report the synthesis of a graphene-like porous carbon by co-pyrolysis of lotus pollen and ammonium nitrate. During the co-pyrolysis process, ammonium nitrate could release a large amount of heat, etch the carbon skeleton, reduce the pyrolysis temperature, and create hierarchically porous carbon networks with rich N doping. The hierarchically N-doped porous structure has an ultra-large specific surface area (3106 m(2) g(-1)) and an adapted interconnected porous structure, provides highways for charge and mass transfer, leading to a specific capacitance as high as 373.7 F g(-1) at 0.5 A g(-1) current density. The symmetric solid-state supercapacitor device exhibits a specific energy density of 53.5 Wh kg(-1) at a power density of 640 W kg(-1).