N-O-P co-doped porous carbon aerogel derived from low-cost biomass as electrode material for high-performance supercapacitors

Heteroatom-doped porous carbon materials have attracted great interest and are considered promising candidate electrode materials for supercapacitors. Here, a facile and effective strategy is developed for the synthesis of porous carbon aerogels from abundant renewable radishes. Based on the high oxygen content of biomass, N-O-P co-doped of the carbon aerogel was achieved by introducing NH4H2PO4 during ZnCl2 activation process. A continuous three-dimensional porous network interconnected was obtained with uniform distribution of O, N and P on the whole aerogel framework. The N-O-P co-doped functional groups improve the conductivity and wettability of the material and stimulate the additional Faraday reaction, and thus can impart a variety of beneficial effects to the electrochemical performance of the material. The N-O-P co-doped carbon aerogel exhibits a high gravimetric specific capacitance of 352 F/g at a current density of 1 A/g in the three-electrode system using 6 M KOH as the electrolyte. Besides, the material also exhibits a high specific capacitance retention rate of 78.4% by increasing the current density from 1 to 10 A/g. In 10,000 cycles of charging and discharging performance, the N-O-P co-doped aerogel exhibits excellent cycle stability with only a slight capacitance loss of less than 10%. [Display omitted] •A strategy was developed to synthesize radish N-O-P co-doped carbon aerogel.•A 3D porous network was obtained with uniform distribution of O, N and P.•The gravimetric specific capacitance reached 352 F/g at a current density of 1 A/g.•The RCA-N exhibited excellent cycle stability with capacitance loss of less than 10%.