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.