Self-Assembled Nanostructured MoS₂ Quantum Dot Polyaniline Hybrid Gels for High Performance Solid State Flexible Supercapacitors

Nanostructured hybrid conductive polyaniline (PANI) hydrogels are usually applied for supple energy storage devices owing to their flexible durability, fast-rate electrochemical activity, and good electrical conductivity. Here we prepare a flexible solid-state supercapacitor (SC) by using N,N′-dibenzoyl-l-cystine (D)/MoS2 quantum dot (QD)/PANI (DMP) hydrogel via in situ polymerization of aniline monomer with the gelator D and MoS2 QDs. TEM images show MoS2 QDs embedded into a three-dimensional (3D) fibrous network structure. Raman spectra prove the existence of both MoS2 QDs and PANI, and XPS spectra confirm the formation of PANI in emeraldine salt (ES) form. The interaction between the PANI and MoS2 QDs produces a synergistic effect resulting in decent energy storage performance. The hybrid DMP gel exhibits a high specific capacitance value 791 F/g at 1.0 A/g in a three electrode system. For practical applications an all-solid-state flexible supercapacitor device is fabricated. The supercapacitor exhibits a specific capacitance value of 331 F/g at 1 A/g for hybrid DMP xerogel, an energy density 29.4 Wh/kg, and a power density 398 W kg–1. The DMP xerogel demonstrates 84.2% capacitance retention after 10 000 galvanostatic charge–discharge cycles. Four charged solid-state supercapacitors connected in series forming a tandem SC which can power red, yellow, and white colored light emitting diode bulbs for long time, representing its capability as a good storage device.