Constructing Hierarchical Porous Carbon of High-Performance Capacitance through a Two-Step Nitrogen-Fixation Method

Abstract

Highly conductive and nitrogen-rich carbon materials have broad application prospects in energy storage, yet they are somehow contradictory because good conductivity requires high-temperature heat treatment, which decomposes most nitrogen species. Herein, a novel approach to synthesize a nitrogen-rich and highly conductive carbon material with extraordinary capacitance through a two-step nitrogen-fixation sol-gel method is reported. The process benefits from the coordination of Zn2+ with nitrogen atoms in the precursor sol and the stabilizing bonding between silicon and nitrogen during high-temperature chemical vapor deposition. The final product shows a high nitrogen content of 5.6 at%, a hierarchical porous structure with a high specific surface area (1610 m(2) g(-1)), and an extraordinary conductivity (23 S cm(-1)), which enables an impressive capacitance of 380 F g(-1). This nitrogen-fixing method starting with a composite sol-gel may offer a reliable route to the preparation of high-performance supercapacitor electrode materials.