Dual heteroatoms doped SBA-15 templated porous carbon for symmetric supercapacitor in dual redox additive electrolyte.

ABSTRACT

Porous carbon (PC) based materials is a proficient impetus for upgrading supercapacitor thanks to its traits of high surface area, meso, micropores, and replication morphology. Mainly, single and dual heteroatom doping in PC material is one of the amazing strategies for enhancing the supercapacitor activity due to the interaction of carbon and heteroatom material along with the excessive contribution of by functional groups. Here, we have synthesized nitrogen (N) and boron (B) dual doped PC (NBPC) with the assistance of Santa Barbara Amorphous (SBA-15) silica material and afterward investigated their doping impact of the heteroatom which is investigated for supercapacitor application. Among all, NBPC material delivered a high specific capacitance of 375 F/g at 2 A/g current density in 1 M H2SO4 electrolyte with excellent rate capability and capacitance retention. Such an attractive property of NBPC is a reflection of its high specific surface area (809 m2/g) rendered by N and B functional groups. In addition, the introduction of dual redox additive materials to the electrolyte synergistically enhanced the specific capacity of the symmetric supercapacitor cell. An unprecedented high specific capacity of 929 C/g at 3 A/g current density is observed and a 56% of initial specific capacity was retained when current density increased to 20 A/g. The fabricated symmetric cell using NBPC electrode in 1 M H2SO4 + 0.01 M ammonium metavanadate + Ferrous (II) sulfate dual redox additive electrolyte delivered an energy density of 48.4 W h/kg which is five folds higher than the bare electrolyte (10.1 W h/kg). Similarly, the NBPC electrode delivered a power density of 15 kW/kg in the redox additive electrolyte which is three folds higher than the bare electrolyte (5 kW/kg).