“…To date, carbonaceous materials (activated carbon, graphene oxide, carbon nanotubes, etc. ) − have been used as supercapacitor electrode materials due to their good cyclic stability, however, they have not excelled because of their low specific capacitance, which diminished the energy density of the fabricated supercapacitors. To meet ever-increasing energy demands, various inorganic metal oxides/hydroxides, such as MnO 2 , RuO 2 , CuO, NiO, V 2 O 5 , WO 3 , Co(OH) 2 , Ni(OH) 2 , etc., − have been used as electrode materials in electrochemical energy storage.…”