A novel soft template strategy to fabricate mesoporous carbon/graphene composites as high-performance supercapacitor electrodes

Abstract

A novel soft template method is developed to synthesize a mesoporous carbon/graphene (MCG) composite. The resulting MCG composite exhibits a outstanding capacitance as high as 242 F g⁻¹ in 6 M KOH electrolyte at the current density of 0.5 A g⁻¹, which is much higher than mesoporous carbon, graphene and a sample made by mechanical mixing of mesoporous carbon with graphene. A series of experimental results show that the thickness, BET surface area and carbonized temperatures seriously affect the structure and energy storage performance of the as-prepared MCG composite. Remarkably, the synthesized MCG composite displays good cyclic stability, and the final capacitance was up to 105% compared to the initial capacitance after 2000 cycles of the composite. The mesoporous carbon in the MCG composite is beneficial to the accessibility and rapid diffusion of the electrolyte, and the graphene in MCG can facilitate the transport of electrons during the processes of charging and discharging owing to its high conductivity, which leads to an excellent energy storage performance.