Nitrogen self-doped carbon aerogels from chitin for supercapacitors

Abstract

Carbon aerogels with low cost and eco-friendly are considered as ideal electrode materials for supercapacitors. In this investigation, nitrogen self-doped carbon aerogels (NSCA) are prepared by microwave hydrothermal and high-temperature carbonization using chitin as carbon and nitrogen sources. Zinc chloride is used as a dehydration agent and an activator. Owing to the low boiling point of Zinc chloride, it does not require any additional steps to remove the activator. Also, due to the activation of Zinc chloride, the specific surface area of NSCA reaches 2540 m2 g−1. In the three-electrode system, NSCA-1000 exhibits specific capacitance of 249.4 and 164.9 F g−1 at current densities of 1.0 and 10 A g−1, respectively. In the two-electrode system, the NSCA-1000 based symmetrical supercapacitor demonstrates an energy density and power density of 26.15 Wh kg−1 and 0.95 kW kg−1 at 1.0 A g−1, respectively. Meanwhile, NSCA-1000 displays excellent cycling stability that the specific capacitance can maintain 98.44% after 15,000 cycles at a current density of 2.0 A g−1.