Porous MnO2 for use in a high performance supercapacitor: replication of a 3D graphene network as a reactive template

Graphene oxide hydrogel is used as a reactive template to prepare nanoporous materials with a 3D microstructure. The as-prepared porous MnO2 shows a capacitance retention of ~70.6% at a current density as high as 15 A g(-1), resulting from the 3D interconnected ion transport channel replicated from the graphene oxide hydrogel.