Heteroatom-Doped Porous Carbon Nanosheets: General Preparation and Enhanced Capacitive Properties

摘要

High-performance electrical double-layer capacitors (EDLCs) require carbon electrode materials with high specific surface area, short ion-diffusion pathways, and outstanding electrical conductivity. Herein, a general approach combing the molten-salt method and chemical activation to prepare N-doped carbon nanosheets with high surface area (654m(2)g(-1)) and adjustable porous structure is presented. Owing to their structural features, the N-doped carbon nanosheets exhibited superior capacitive performance, demonstrated by a maximum capacitance of 243Fg(-1) (area-normalized capacitance up to 37Fcm(-2)) at a current density of 0.5Ag(-1) in aqueous electrolyte, high rate capability (179Fg(-1) at 20Ag(-1)), and excellent cycle stability. This method provides a new route to prepare porous and heteroatom-doped carbon nanosheets for high-performance EDLCs, which could also be extended to other polymer precursors and even waste biomass.