An activated carbon cloth anode obtained with a fast molten salt method for high-performance supercapacitors

Abstract Carbon materials are the most important anode materials used in supercapacitors. However, there are still great challenges in improving their low specific capacitance and energy density. In this study, a fast molten salt method was developed for the preparation of a super-high capacity activated carbon cloth anode. The nitrogen-activated carbon cloth electrode (NCC) showed better electrochemical performance than most of the carbon-based materials reported on previously. The maximum areal capacitance of the nitrogen-activated carbon cloth electrode was 6.72 F cm−2 at the current density of 2 mA cm−2. By employing the first-principle calculations method, it was derived that the adsorption energy of the K atoms on the graphite increased with the increase in nitrogen doping, especially on the pyridinic nitrogen (N-6). In addition, when the NCC and Ni-Co-S@CC electrodes were assembled into an asymmetric supercapacitor (ASC), the ASC demonstrated an operation in a large potential window of 1.8 V, and it achieved a high volumetric energy density of 23.51 mWh cm−3 at a power density of 1808 mW cm−3. This work showed the super high capacity of activated carbon cloth as a new anode material for high-performance supercapacitors prepared using a simple molten salt method.