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

Abstract

We report the stackable all-solid-state supercapacitor based on the three dimensional ppy-NiO/RGO-CNT electrodes. The electrode was prepared by growing NiO nanowalls (NWs) on both sides of a freestanding RGO-CNT film with hydrothermal method, followed by being coated with conductive polypyrrole. The double-sided architecture of NiO NWs on carbon-based current collector suggests the novel approach in addressing the issue of low areal capacitance in supercapacitor. Furthermore, conductive polypyrrole renders fast electron transport through the two-dimensional structure of NiO NWs. With our 3Ddesigned electrode, we successfully fabricated the stackable all-solid-state supercapacitor and thus achieved high areal capacitance of 1,948 mF cm -2 . PPy-coated NiO nanowalls were encapsulated with PVA-KOH gel electrolyte, producing a single electrode of all-solid-state supercapacitors. A pair of the electrochemical capacitors exhibited the areal capacitance of 664 mF cm -2 at a current density of 1 mA cm -2 . In this work, we demonstrated a prototype multilayered supercapacitors by stacking 3 pairs of

Approaching High‐Performance Supercapacitors via Enhancing Pseudocapacitive Nickel Oxide‐Based Materials

“…In addition, the CV profiles showed almost no evident variation during the bending operation (Figure 11g), indicating a promising potential application in flexible devices. Kim et al104 designed triple stack ASSSC devices using PPy‐coated NiO nanowalls on an rGO‐CNT film, and PVA‐KOH‐based alkaline gel was used as electrolyte, which showed an excellent areal capacitance of 1948 mF cm −2 at 2 mA cm −2 .…”

Nickel Oxide/Graphene Composites: Synthesis and Applications

“…i) Cycle life of the graphene/NiO material. a, b) Reproduced with permission . Copyright 2015, Royal Society of Chemistry.…”

“…Kim et al. developed a rGO–CNT film by growing NiO nanowalls on both sides (Figure a,b) . The nanowalls provided efficient transport for ions and electrons, resulting in superior electrochemical performance (1948 mF cm −2 at a current density of 1 mA cm −2 ).…”

“…[36] Various crystalline structures of NiO, including 0D (nanoparticles (NPs)), [37,38] 1D (nanowires, nanorods), [39] 2D (nanosheets, nanoflakes, nanowalls), [40,41] and 3D (mesospheres, nanoflowers), [42] have been incorporated with graphene nanostructures to develop sufficient electrochemical properties. Al arge number of synthetic strategies appliedt oN iO/graphene nanostructures have flourished in the past few decades, such as the hydrothermal method, [40,43,44] the solvothermalm ethod, [45] chemical reduction, [46,47] electrophoretic deposition, [48,49] and atomic layer deposition( ALD). [50] Yushu Liu is aB .S.…”

“…Kim et al developed ar GO-CNT film by growingN iO nanowalls on both sides (Figure 3a,b). [44] The nanowalls provided efficient transport for ions and electrons, resultingi ns uperior electrochemical performance (1948 mF cm À2 at ac urrent density of 1mAcm À2 ). Zhao et al described nickel foam (NiF)-graphene-NiO nanowalls as an electrode for SCs, [59] which provided efficient channels for ion/ electrolyte diffusion and conductiven etworks for electron collection.…”