N/O co-doped micropores carbon derived from a solvent-free synthesized polymer for high-performance supercapacitor

Abstract

BackgroundHeteroatom-doped porous carbons have attracted widespread concern as promising electrode materials for supercapacitors. Polymers are considered as the promising carbon sources because their derived carbons possess the unique advantages of inherited uniform heteroatoms doping, high purity, and good reproducibility. While the synthesis process of polymers usually involves solvents, which will bring a pollution of the environment and increase the consumption of cost and energy. MethodsHerein, nitrogen/oxygen co-doped porous carbons (NOPCs) with predominant micropores were prepared via carbonization and activation of a solvent-free synthesized polymer using 2-aminophenol, hexamethylenetetramine as monomers. Kinetics studies and density functional theory (DFT) simulations reveal that N/O heteroatoms credibly introduces pseudocapacitance and greatly improves the chemisorption of K+, leading to an outstanding electrochemical performance. Significant findingsThe obtained NOPCs exhibit interconnected microporous structure, large specific surface area (3297 m2 g−1), narrow pore size distribution (ca. < 1 nm), suitable heteroatoms content (N: 4.13%, O: 13.06%) and high carbon yield of 48 wt%. Benefitting from these features, the optimal NOPC-800 delivers a remarkable specific capacitance of 410 F g−1 at 1 A g−1 and retains 270 F g−1 at 50 A g−1. The solid-state micro-supercapacitors fabricated from the NOPCs presents areal capacitance up to 29.7 mF cm−2 and energy density up to 0.97 μWh cm−2.