| 초록 |
In this work, we developed porous 3D structures using graphene obtained via electrochemical exfoliation and explored their application as supercapacitor electrodes. By adjusting the content of the electrolyte in the exfoliation process, the aspect ratio of graphene sheets and the porosity of the graphene network can be optimized. Furthermore, the freezing temperature in the freeze drying step was also found to play a critical role in the resulting pore size distributions of the porous networks. The optimized conditions lead to meso- and macro-porous graphene aerogels with high surface area, extremely low densities and superior electrical properties. As a result, we have found that the graphene aerogel supercapacitors exhibit a specific capacitance of 325 F/g at 1 A/g and an energy density of 45 Wh/kg in 0.5 M H2SO4 aqueous electrolyte with high electrochemical stability required for the practical usage. |
