Development of 3D Urchin-Shaped Coaxial Manganese Dioxide@Polyaniline (MnO2@PANI) Composite and Self-Assembled 3D Pillared Graphene Foam for Asymmetric All-Solid-State Flexible Supercapacitor Application

We have fabricated high-energy-density all-solid-state flexible asymmetric supercapacitor by using a facile novel 3D hollow urchin-shaped coaxial manganese dioxide@polyaniline (MnO2@PANI) composite as positive electrode and 3D graphene foam (GF) as negative electrode materials with polyvinyl alcohol...

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Veröffentlicht in:ACS applied materials & interfaces 2017-05, Vol.9 (18), p.15350-15363
Hauptverfasser: Ghosh, Kalyan, Yue, Chee Yoon, Sk, Md Moniruzzaman, Jena, Rajeeb Kumar
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Sprache:eng
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Zusammenfassung:We have fabricated high-energy-density all-solid-state flexible asymmetric supercapacitor by using a facile novel 3D hollow urchin-shaped coaxial manganese dioxide@polyaniline (MnO2@PANI) composite as positive electrode and 3D graphene foam (GF) as negative electrode materials with polyvinyl alcohol (PVA)/KOH gel electrolyte. The coaxial MnO2@PANI composite was fabricated by hydrothermal route followed by oxidation without use of an external oxidant. The formation mechanism of the 3D hollow MnO2@PANI composite occurs first by nucleation and growth of the MnO2 crystal species via dissolution–recrystallization and oriented attachment mechanisms followed by the oxidation of aniline monomers on the MnO2 crystalline template. The self-assembled 3D graphene block was synthesized by hydrothermal route using vitamin C as a reducing agent. The microstructures of the composites are analyzed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. The morphology is characterized by field-emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM), which clearly showed the formation of urchin-shaped coaxial MnO2@PANI composite. The electrochemical studies are explored by cyclic voltammetry, electrochemical impedance spectrometry, and cyclic charge–discharge tests. The symmetric all-solid-state flexible MnO2@PANI//MnO2@PANI and GF//GF supercapacitors exhibit the specific capacitance of 129.2 and 82.1 F g–1 at 0.5 A/g current density, respectively. The solid-state asymmetric supercapacitor shows higher energy density (37 Wh kg–1) with respect to the solid-state symmetric supercapacitors MnO2@PANI//MnO2@PANI and GF//GF, where the obtained energy density are found to be 17.9 and 11.4 Wh kg–1, respectively, at 0.5 A/g current density. Surprisingly, the asymmetric supercapacitor shows a high energy density of 22.3 Wh kg–1 at a high current density of 5 A g–1. The solid-state asymmetric supercapacitor shows a good cyclic stability in which ∼11% capacitance loss was observed after 5000 cycles.
ISSN:1944-8244
1944-8252
DOI:10.1021/acsami.6b16406