Self-assembled three-dimensional interpenetrating porous graphene aerogels with MnO2 coating and their application as high-performance supercapacitors

Abstract

In this work, a hybrid materials of MnO₂-wrapped graphene aerogels (GAs) were prepared using a simple in situ reduction method. The porous GAs obtained in our work not only boost ion and electron movement in electrochemical processes but can also serve as a 3D skeleton for combining with MnO₂, which allows the poor electronic conductivity of MnO₂ nanoparticles to be wired up to a current collector through the underlying GA conducting layers. As a supercapacitor electrode material, the structure exhibits a high reversible capacity of 210 F g⁻¹ at a current density of 0.5 A g⁻¹ with an excellent cycling retention of 99% after the 800th cycle at a current density of 2 A g⁻¹. These results highlight the importance of anchoring MnO₂ on GAs for maximum utilization of the electrochemical activity and retaining the good electrochemical stability of the electrode materials.