Preparation and Evaluation of the Supercapacitive Performance of MnO2/3D-reduced Graphene Oxide Aerogel Composite Electrode Through In Situ Electrochemical Deposition

Composite supercapacitive materials can combine two different kinds of electrode materials with different energy storage mechanisms, as well as present enhanced supercapacitive performance. In this paper, a reduced graphene oxide aerogel (GA) was prepared with an adjustable pore structure and used as a matrix for loading of secondary active material (MnO2) through an electrochemical deposition method. The influences of the deposition time and deposition voltage on the electrochemical behaviors and specific capacitances of MnO2/GA composites were studied. The unique three-dimensional porous structure of GA can act as a good matrix for MnO2. The results show that when the deposition time is 30 s and deposition voltage is 1.0 V, the MnO2/GA composite has the highest specific capacitance of 664 F/g at a current density of 1 A/g. Compared with neat GA, the specific capacitance of the MnO2/GA composite is enhanced by 190%, which can be assigned to the co-contribution of two kinds of active materials, a facile ion diffusion path through the porous structure, and good electron conductivity of the GA.