High-performance supercapacitor electrode materials based on chemical co-precipitation synthesis of nickel oxide (NiO)/cobalt oxide (Co3O4)-intercalated graphene nanosheets binary nanocomposites

Graphene (Gr)/metal oxide nanocomposites, as advanced electrode materials, have drawn significant attention in supercapacitors due to their two components' synergistic cooperation, which compensates each other's drawbacks and hence perform better than individual components. In this study, graphene/metal Gr/NiO Gr/Co3O4 binaries were separately synthesized by a co-precipitation method NiO or Co3O4 interlayer spacers inserted into the graphene structure. The as-synthesized electroactive materials drop-cast on as-grown Cu(OH)2 nanowire arrays/Cu substrates fabricated drenching copper rich-alkaline solution. Three-electrode's electrochemical characterizations 6 M KOH electrolyte showed that exhibit high capacitances of 342.6 652 F g?1 at scan sweep 5 mV s?1, 278.5 667.58 current density 1 A g?1, respectively. addition, power 250 W kg?1 leads energy densities 23.17 9.7 Wh for Gr/Co3O4, with cyclic stability 95% has performance (with 83%), implying more pseudocapacitance contribution nanoparticles embedded within nanosheets efficient cooperation between these Furthermore, full Gr/NiO/Cu(OH)2/Cu||Gr/NiO/Cu(OH)2/Cu Gr/Co3O4/Cu(OH)2/Cu||Gr/Co3O4/Cu(OH)2/Cu symmetric cells organic TEA-BF4 acetonitrile potential window 2 V also assembled 10 exhibited highest specific 32.67 24.86