Micro/Mesoporous Carbon Nanospheres with Homogeneously N, S, P-Tridoped Skeletons as Electrodes for High-Performance Supercapacitors

Hierarchical porous heteroatom-doped carbon materials are one of the most promising materials for supercapacitor (SC) electrodes due to their outstanding inherent characteristics. In this study, a micro/mesoporous N, P, S-tridoped carbon material (NPSC-900) is prepared using poly(cyclotriphosphazene-co-4,4′-sulfonyldiphenol) as the only precursor through a one-step synthesis strategy combining direct carbonization and in situ heteroatom doping. The obtained NPSC-900 as a SC electrode exhibits outstanding electrochemical performances, such as a high capacitance of 392 F g–1 at 2 mV s–1, superior rate capacity, and good long-term stability after 10,000 cycles with 98.5% capacitance retention. Moreover, a flexible asymmetric SC is assembled by coupling the NSPC-900/carbon cloth (CC) and NiO/CC electrodes. Its maximum energy and power densities reach 119.5 Wh kg–1 and 23.4 kW kg–1, respectively. The remarkable electrochemical properties of NSPC-900 are benefited from the adequate surface area, ultralarge pore volume, hierarchical micro/mesoporous structure, and heteroatom-doped skeleton, which provide a significant way for designing high-performance electrodes for energy storage systems.