Hybrid supercapacitor based on graphene and Ni/Ni(OH)2 nanoparticles formed by a modified electrochemical exfoliation method

Abstract

Hybrid supercapacitor combined with the merits of both the electric double layer capacitance and redox pseudocapacitance and thus have great potential. Here, hybrid materials of graphene and Ni/Ni(OH)2 nanoparticles were prepared through a modified electrochemical exfoliation method for using for supercapacitor. Large quantities of Ni/Ni(OH)2 nanoparticles with high redox pseudocapacitance were found to disperse either on the outer surface of the graphene or enclosed by the graphene with high electric double layer capacitance. The hybrid materials as-prepared show a capacitance as ultrahigh as 5715 mF/cm2 (1905 F/g) at 10 mA/cm2 and it remains 94.8% after 1000 cycles in 6 M KOH.