A highly stable solid-state supercapacitor device based on robust layer-by-layer electrodeposited poly-(3, 4-ethylenedioxythiophene)-re-duced graphene oxide-molybdenum disulfide nanocomposite electrode

A ternary nanocomposite film of PEDOT-rGO-MoS2 for a symmetrical solid-state supercapacitor device has been fabricated via in-situ interconversions by employing efficient electrochemical approach. The higher porosity offered by popcorn like microstructures of PEDOT has enabled better stacking within PEDOT-rGO-MoS2 com-posite resulting in superior supercapacitive performance. The obtained electrode exhibits good volumetric capacitance (887.6 F cm-3) and high volumetric energy density (123 mWh cm-3) with high-power density (2930 mW cm-3). The efficiency in the supercapacitor performance originates from the synergy of the trio forming a well-integrated optimized energy storage system. Assembly of composite films into a solid-state symmetrical device with PVA-KCl gel-electrolyte has resulted in excellent cyclic stability, good capacitive retention of 98.3 % and coulombic efficiency of 100.2 % over 10,000 cycles. The obtained symmetrical device offered high areal energy density (1.1 mu Wh cm-2) has been successfully evaluated for its practical utility in the configuration of four devices connected in series with an output of 25 min to illuminate green LED. The findings pave a promising way for the development of energy efficient microelectronics by using the present device structure in future energy storage applications.

Automated summary

A ternary nanocomposite film of PEDOT-rGO-MoS2 has been fabricated using an efficient electrochemical approach for a symmetrical solid-state supercapacitor device, showing excellent electrochemical performance. The assembly of the composite film into a solid-state symmetrical device has significantly improved its cyclic stability and coulombic efficiency.