Three-dimensional zanthoxylum Leaves-Derived nitrogen-Doped porous carbon frameworks for aqueous supercapacitor with high specific energy

A unique three-dimensional zanthoxylum leaves-derived nitrogen-doped porous carbon frameworks (ZLPC) with hollow nanostructures have been developed by one-step carbonization and mixed metal salts-assisted co-activation process. Compared with the traditional template carbonization or two-step carbonization strategy, the presented method can combine carbonization, activation and heteroatom doping to improve the synthesis efficiency. Based on the unique three-dimensional framework structure, large specific surface area, high graphitization degree and effective nitrogen doping, the ZLPC exhibits satisfactory electrochemical performance. In particular, the symmetric supercapacitor based on ZLPC electrode material possesses high specific energy of 18.68 Wh kg(-1) at a specific power of 225 W kg(-1) operated in the voltage of 1.8 V in Na2SO4 aqueous electrolyte and excellent cycle stability (92% after 20,000 charge cycle). These results provide a clear, simple and feasible synthesis strategy for large-scale converting sustainable biomass waste to porous carbon materials for energy storage and conversion applications.