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Graphene‐Polymer//Graphene‐Manganese Oxide Nanocomposites‐Based Asymmetric High Energy Supercapacitor with 1.8 V Cell Voltage in Aqueous Solution
Author(s) -
Amutha Balasubramanian,
Subramani Kaipannan,
Reddy Pula Nagesh,
Sathish Marappan
Publication year - 2017
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201701979
Subject(s) - supercapacitor , graphene , materials science , pedot:pss , nanocomposite , electrode , oxide , electrolyte , chemical engineering , cyclic voltammetry , electrochemistry , nanotechnology , polymer , composite material , chemistry , metallurgy , engineering
Asymmetric supercapacitor is fabricated using reduced graphene oxide‐polymer (RGO‐PEDOT.PSS) and reduced graphene‐manganese oxide (RGO‐CNF‐MnO 2 ) nanocomposites as negative and positive electrodes, respectively. Both the RGO‐PEDOT.PSS and RGO‐CNF‐MnO 2 (GCM) nanocomposite electrode were studied systematically with three electrode and asymmetric device configuration. The cyclic voltammetry (CV) and galvanostatic charge‐discharge (CD) studies revealed a maximum specific capacitance of 247 F/g at 1 A/g between −0.9 to 0.1 V ( vs . SCE) for RGO‐PEDOT.PSS electrode. While the GCM nanocomposite electrode showed 145 F/g at 1 A/g between −0.1 to 0.9 V ( vs . SCE). The X‐ray diffraction (XRD) studies of GCM positive electrode revealed the formation of crystalline Akhtenskite MnO 2 hexagonal structure and the XRD of RGO‐PEDOT.PSS confirms the complete reduction of graphene oxide (GO). The microscopic images of GCM demonstrate the MnO 2 nanowhiskers growth over the carbon support. The fabricated asymmetric supercapacitor device showed a cell voltage of 1.8 V in 1 M Na 2 SO 4 electrolyte. The CD profile of RGO‐PEDOT.PSS//RGO‐CNF‐MnO 2 shows the device capacitance of 47 F/g with a high energy density of 21 Wh/kg while the symmetric device shows 5 and 5.6 Wh/kg for negative and positive electrodes respectively. The high energy density and electrochemical stability of the prepared asymmetric device is promising for electrochemical energy storage in aqueous electrolyte.