MnMoS4 anchored at carbon nanofiber as a flexible electrode for solid-state asymmetric supercapacitor device

Abstract

In this investigation, self-standing core-shell manganese molybdenum sulfide/carbon nanofiber (MnMoS4@CNF) hybrid mats were fabricated and evaluated their electrochemical properties for flexible supercapacitor applications. At first, free-standing hybrid mats were prepared via electrospinning of polyacrylonitrile/Mn(acac)2/MoO2(acac)2 blend precursor solution followed by thermal stabilization and carbonization in an inert atmosphere. As-prepared Mn–Mo encapsulated CNF mat was then treated with thioacetamide using a solvothermal process to produce nanostructured MnMoS4-decorated CNF hybrid mat. This way the developed hybrid mats yielded specific capacitance of 1727.9 F g-1 at 1 A g-1 and nearly 84% of capacity retention at 10 A g-1 after 6000 cycles in 2 electrode symmetrical cell configuration with an aqueous electrolyte (3 M KOH). Given this merit, MnMoS4@CNF and pure CNF were employed as a positive and negative binder-free electrode in a solid-state asymmetry supercapacitor (ASC) device with PVA-KOH based solid gel polymer electrolyte. This exhibited outstanding electrochemical properties of energy density 73.7 Wh Kg−1 at power density of 800 W kg−1 and good cycling stability (88.3% after 6000 cycles). Thus, the nanostructured MnMoS4-decorated CNF hybrid mat with excellent electrochemical properties could be useful for fabrication of next-generation solid-state supercapacitors.