Symmetric Supercapacitors with layer-by-layer Molybdenum disulfide - reduced graphene oxide structures and poly(3,4-ethylenedioxythiophene) nanoparticles nanohybrid electrode

Abstract

Fabrication of electrode material with stable cycling performances, enhanced surface area, improved electrode/ electrolyte interactions and interfaces is expected in order to reach supercapacitor goal and worth exploring for ternary nanocomposites of PEDOT nanoparticles (PEDOTNP) with 2D-2D MoS2-rGO heterostructures. Herein, layer-by-layer structures of MoS2-rGO have been prepared availing the opposite surface charges of GO nanosheets and MoS2 nanosheets (self-assembly method) followed by reduction, confirmation of which have been understood from the co-existence of MoS2 layers and rGO layers at hetero-interfaces from HR-TEM analysis. Ternary MoS2-rGO/ PEDOTNP based nanocomposites were fabricated by in-situ reduction of GO in presence of pre-synthesized PEDOTNP. Mesoporous and hydrophilic ternary MoS2-rGO/PEDOTNP/NF electrode exhibits specific capacitance of 1143.7 F g−1 at 1-fold of current density and retains 73.3% (840 F g−1) of capacitance at 9-fold of current density with 97.7% of cycle life after repeated 3000 GCD cycles. MoS2-rGO/PEDOTNP // MoS2-rGO/PEDOTNP symmetric supercapacitor (SSC) delivers specific capacitance of 289.25 F g−1 at 1-fold of current density, 49% of rate capability at 20-fold of current density, and excellent cycling stability of 93.17% after 10,000 GCD cycles at 20-fold of current density. Moreover, MoS2-rGO/PEDOTNP // MoS2-rGO/PEDOTNP SSC exhibits specific energy of 33.56 W h kg−1 at specific power of 450.03 W kg−1 based on the total mass at 1-fold of current density.