An Approach To Fabricate PDMS Encapsulated All-Solid-State Advanced Asymmetric Supercapacitor Device with Vertically Aligned Hierarchical Zn-Fe-Co Ternary Oxide Nanowire and Nitrogen Doped Graphene Nanosheet for High Power Device Applications.

We highlight the design and fabrication of a polydimethylsiloxane (PDMS) encapsulated advanced all-solid-state asymmetric supercapacitor (ASC) device consisting of hierarchical mesoporous zinc-iron-cobalt ternary oxide (ZICO) nanowire coated nickel (Ni) foam (ZICO@Ni foam) as a promising positive electrode and nitrogen doped graphene coated Ni foam (N-G@Ni foam) as negative electrode in the presence of PVA-KOH gel electrolyte. Owing to outstanding electrochemical behavior and ultrahigh specific capacitance of ZICO (≈ 2587.4 F/g at 1 A/g) and N-G (550 F/g at 1 A/g) along with their mutual synergistic outputs, the assembled all-solid-state ASC device exhibits an outstanding energy density of ≈40.5 Wh/kg accompanied by a remarkable long-term cycle stability with ≈95% specific capacitance retention even after 5000 charge-discharge cycles. The exclusive hierarchical ZICO nanowires were synthesized by a facile two-step process comprising of a hydrothermal protocol followed by an annealing treatment on a quartz substrate. While Zn gives the stability of the oxide system, Fe and Co ions provide better electronic conductivity and capacitive response under vigorous cyclic condition. The extraordinary performance of as-fabricated ASC device resembles its suitability for the construction of advanced energy storage devices in modern electronic industries.