Stackable, three dimensional carbon-metal oxide composite for high performance supercapacitors

We report a stackable all-solid-state supercapacitor based on three dimensional PPy-NiO/RGO-CNT electrodes. The electrodes were prepared by growing NiO nanowalls (NWs) on both sides of a freestanding RGO-CNT film with the hydrothermal method, followed by coating with conductive polypyrrole. The double-sided architecture of the NiO NWs on a carbon-based current collector suggests that the novel approach addresses the issue of low areal capacitance in supercapacitors. Furthermore, conductive polypyrrole renders fast electron transport through the two-dimensional structure of NiO NWs. With our 3D-designed electrodes, we successfully fabricated a stackable all-solid-state supercapacitor and thus achieved a high areal capacitance of 1948 mF cm^-2.