Large-Scale and Low-Cost Motivation of Nitrogen-Doped Commercial Activated Carbon for High-Energy-Density Supercapacitor

The growing requirement for high-performance energy-storage devices has spurred the development of supercapacitors, but the low energy density remains a technical hurdle. In this work, porous nitrogen-doped activated carbon (NAC) is prepared on a large scale from commercial activated carbon (AC) and inexpensive chemicals by a one-step method. The NAC material with 3.1 wt % nitrogen has a high specific surface area of 1186 m² g^-1 and shows a specific capacitance of 427 F g^-1 in a symmetric cell with an aqueous electrolyte. 98.2% of the capacity is reserved after 20 000 cycles at 20 A g^-1. The energy densities of the NAC are 17.2 and 87.8 Wh kg^-1 in acidic and organic electrolytes, respectively. Moreover, this simple process is readily scalable to address commercial demand and can be extended to the motivation of a variety of carbon-based materials with poor capacitances.