3D hierarchical porous N, O co-doped carbon derived from the waste walnut shell via one-step carbonization for high-performance supercapacitor

Porous carbon derived from biomass is considered a promising material for supercapacitors. However, improving the wettability and electrical conductivity of porous carbon materials remains a great challenge. Herein, a bidirectional pore-creating strategy is proposed to construct N/O-doped Walnut-shells-based hierarchical porous carbon materials (WSC-N/O-900). The high specific surface area (981 m2 g-1) and heteroatom content of WSC-N/O-900 enhance the wettability and electrical conductivity. Thus, WSC-N/O-900 shows a high capacitance of 431 F g-1 at 1.0 A g-1. Additionally, the capacitance retention rate of WSC-N/O-900//WSC-N/O-900 (SSC) remains 88.4 % after 9000 cycles and achieves an energy density of 14.8 Wh kg-1 with a power density of 300 W kg-1. Overall, this work can provide an effective strategy to prepare advanced biomass derived porous carbon for electrochemical energy storage. image