N‑Doped Hierarchically Porous Carbon Aerogels\nby Controlling the Zn–Chitosan Complex Ratio for High-Performance\nSupercapacitors

Abstract

In\nthis paper, we have successfully synthesized Zn–chitosan\naerogels by freeze drying and further obtained N-doped hierarchically\nporous carbon (NHPC) aerogels through a one-step carbonization process.\nZn ions as activators and soft templates can efficiently fabricate\nhierarchical porous structures in a carbon matrix. By adjusting the\nratio of zinc–chitosan complexes, the structure and morphology\nof NHPC can be controlled. In three-electrode systems, the optimal\nNHPC shows a superior capacity of 230 F g^–1 (0.5\nA g^–1) and excellent cycle stability. In two-electrode\nsystems, the symmetric supercapacitors deliver a high energy density\nand power density in aqueous electrolytes (4.67 W h kg^–1 and 5101 W kg^–1, respectively). Our work provides\na prospect for the efficient preparation of biomass porous carbons\nand the development of high-performance supercapacitor electrode materials.