Enhanced power density of a supercapacitor by introducing 3D-interfacial graphene
Developing a supercapacitor with high power density has been considered one of the important directions to facilitate its real applications. Herein, by introducing three-dimensional (3D) interfacial graphene between active materials and the Ni collector, it is demonstrated that the power density can be improved by 220% and 48%, corresponding to the supercapacitors using microwave thermally-exfoliated reduced graphene oxide and solvothermal reduced graphene oxide as the active materials, respectively. The results show that the specific capacitance shows almost no obvious change, compared with using the pure Ni collector, indicating the negligible contribution of 3D interfacial graphene to the capacitor behavior. The electrochemical impedance spectroscopy analysis showed that the enhancement of power density was caused by the smaller charge transfer resistance attributed to the good conductivity and adhesion of the 3D interfacial graphene. This study demonstrates that the 3D interfacial graphene could facilitate the charge transport and is suitable for developing energy devices with high power density.