Enriched performance of practical device assisted asymmetric supercapacitor: NiO/Co3O4 intercalated with rGO nanocomposite electrodes

Abstract

In this present report, we developed high performance supercapacitor electrode material of NiO/Co3O4/rGO ternary nanocomposites synthesized by a hydrothermal method with a different nickel and cobalt molar proportions. The phase formation, surface morphology and elemental information studies of binary NiO/Co3O4 and ternary NiO/Co3O4/rGO nanocomposites were investigated. The electrochemical investigations of the binary and ternary nanocomposites electrodes have been examined. Compare with various molar proportions, the ternary NiO/Co3O4(1,3)/rGO nanocomposites shows an extraordinary capacitance value of 980 Fg−1 at 1 Ag−1 as well as robust cycle life (cyclic retention of 92 % over the 5000 cycles at 10 Ag−1). In 0–1.4 V, an asymmetric supercapacitor attained a specific capacitance of 87.2 Fg−1 and large power density (1396.3 W/kg) with extreme energy density (23.7 Wh/kg). Moreover, assembled device reveals a great rate capability (89 % over the 5000 cycles in the electrolyte of PVA-KOH). The ternary electrode has high capacitance, capacitance retention and large energy density due to NiO and Co3O4 nanoparticles being intercalated with the high surface of rGO, as well as the synergetic effect of NiO/Co3O4 and rGO.