Elaborate construction of N/S-co-doped carbon nanobowls for ultrahigh-power supercapacitors

The rational construction of carbon materials with well-designed porosity and appropriate surface functionality is of critical significance for high-performance supercapacitors. Herein, we report a design strategy for the facile synthesis of N/S-co-doped carbon nanobowls through a one-pot condensation and carbonization process. The carbon nanostructure can be changed from a nanoball to a nanobowl by elaborately controlling the capillary compression and nanoshell thickness. The N/S-co-doped carbon nanobowls greatly increase the volumetric density by eliminating hollow interiors. The unique hierarchical micro/mesoporosity and the N,S-functionalized structure enable the carbon nanobowls to utilize the high specific surface area efficiently resulting in high specific capacitance and ultrafast charge/discharge capability. The electrochemical benefits endow the symmetric supercapacitors with a high energy density of 9.6 W h kg^-1, a maximum power density of 475.5 kW kg^-1, and a long cycle lifetime over 50,000 cycles. These encouraging results demonstrate the potential of the N/S-co-doped carbon nanobowls for application in ultrahigh-power supercapacitors.