Abstract:
The limited available energy sources and their improper use require efficient
energy storage devices. Therefore, supercapacitors are more attractive due to light
weight, low cost and high specific capacitance. Graphene oxide (GO) based metal
sulfides have huge potential for electrochemical applications due to large specific
surface area and electrical conductivity. In this study, various GO based metal sulfides
were hydrothermally synthesized on nickel foam substrate for supercapacitor
applications. The structural phases were observed using X-ray diffraction. The surface
morphology of aluminum, strontium, nickel and zinc based sulfides exhibited
nanowall, nanorod, nanoplate and nanoweb like structures, respectively. The metal
sulfides showed good electrochemical performance, which was depicted using both
three and two electrodes systems.
The specific capacitance and energy density determined using three electrodes
galvanostatic charge discharge for GO based sulfides of aluminum, strontium, nickel
and zinc were 2373.51, 1824.14, 2368.833, 2400.30 Fg-1 and 118.68, 91.56, 118.44,
120 WhKg-1, respectively. Similarly, the power densities and specific capacitance
retention up to 1000 cycles were measured as 2663.58, 4356.64, 1010.00, 4407.73
WKg-1 and 57, 67, 42.20, 95.90 %, respectively.
Furthermore, an excellent two electrodes symmetric behavior was revealed for
GO based sulfides of aluminum nanowalls, strontium nanorods, nickel nanoplates and
zinc nanoweb, because high energy densities 20.55, 10.55, 15.72, 20.29 WhKg-1 and
power densities 585.50, 294.35, 848.50, 485.30 WKg-1, respectively, were observed.
Hence, the excellent electrochemical behavior exhibited by the fabricated
nanostructures suggested supercapacitor applications.
