Electrochemical deposition of nanostructured manganese oxide on hierarchically porous graphene-carbon nanotube structure for ultrahigh-performance electrochemical capacitors

► The a-MnOx/GS-CNT is fabricated by combining the solution-assemble process and anodic deposition. ► The use of a-MnOx on the 3D GS-CNT material produces a specific capacitance of MnOx of 1200 F g−1. ► The specific energy and specific power of a-MnOx/GS-CNT are as high as 46.2 Wh kg−1 and 33.2 kW kg−1. ► This work conceptually provides new chances for designing 3D graphene-based architecture.