Eco-Friendly Synthesis of Cobalt Molybdenum Hydroxide 3d Nanostructures on Carbon Fabric Coupled with Cherry Flower Waste-Derived Activated Carbon for Quasi-Solid-State Flexible Asymmetric Supercapacitors

We report a greener, effortless, and scalable approach involving the synthesis of a self-grown nanomaterial on a flexible conductive substrate along with the synthesis of activated carbon derived from biomass waste. Contrary to the popular idea of using a variety of additives for the synthesis of nanomaterials, such as surface-activating agents, 3d metal-oxide nanoplates were synthesized on a highly hydrophobic carbon cloth substrate using no foreign elements except the metal precursors. The activated carbon was derived from biomass waste in that it was synthesized using withered cherry flower petals. The two as-synthesized materials were combined to fabricate an asymmetric supercapacitor, the design of which is presented as a greener and sustainable way to obtain an alternative energy storage unit. The three-dimensional nanoplate architecture from the positive electrode combined with the densely populated meso-/microporous structures of the negative electrode delivered an energy density of 106.3 μWh cm–2 for a power density of 657 μW cm–2, which is maintained at 57.5 μWh cm–2 even at a high power density of 5283.4 μW cm–2. Furthermore, a highly stable rate performance was achieved with high capacity retention even after charging–discharging for over 6000 cycles. The fabricated device exhibits highly satisfactory results in practice and hence presents itself as a highly capable candidate for a green energy solution.