Direct synthesis of highly crumpled nitrogen-rich porous carbon nanosheets with a mesopore-dominant for high performance supercapacitors

Abstract

Direct synthesis of porous carbon nanosheets without adding any chemical activators or templates remains a great challenge. In this work, we present a novel and simple method to synthesize highly crumpled nitrogen-rich porous carbon nanosheets (HCNPCNS) by one-step procedure based on the direct carbonization of polyethylene and melamine. HCNPCNS consist of interconnected crumpled porous carbon nanosheets with a nanoscale thickness, an ultrahigh nitrogen content (10.3 at.%) and a mesopore-dominant, which thus ensure much more available surface area. As a result, the unique structures of HCNPCNS exhibit a high specific capacitance of 257.2 F g−1 in 6 M KOH and 265 F g−1 in 1 M H2SO4, high rate capability both in 6 M KOH and 1 M H2SO4, and long cycling stability of 96.7 % in 6 M KOH and 100 % in 1 M H2SO4 when act as supercapacitor electrodes. Moreover, the HCNPCNS//HCNPCNS based supercapacitor in ionic liquid can deliver an excellent power density of 175 kW kg−1 and an energy density of 58.8 W h kg−1. This strategy opens up a new avenue towards preparing porous carbon nanosheets without complicated procedure and particular chemical activators or templates for high performance supercapacitors.