Electrochemical Performance Enhancement Zinc Cobaltite-Reduced Graphene Oxide for Next Generation Energy Storage Applications

Abstract Recently, metal oxide decorated reduced graphene oxide based nanosheets have gained much attention because of their widespread applications in electrochemical energy storage devices, particularly in supercapacitors. Motivated by this, in the present study, zinc cobaltite-reduced graphene oxide ZnCo 2 O 4 -rGO (reduced graphene) nanoporous arrays were developed directly on a Ni foam piece by using a specific hydrothermal method, which is simple, cost-effective, and facile and followed by a process for annealing purpose. The nanocomposite of the as-prepared ZnCo 2 O 4 -rGO involves ZnCo 2 O 4 wrapped in conducting rGO sheets in order to maintain short distance for the ion diffusion process, stable structural integrity, and pathways for percolating electron conducting. As a result, this nanocomposites displays an impressive overall electrochemical performance, such as a promising capacitance (1242 F g-1 )at a current density of 2 A g-1) and remarkable cycling stability (92% capacitance retention after 10000 charge-discharge cycles at 2 A g-1). The device showed highest energy density of ∼32W h kg−1 at a power density of 1252 W kg−1The feasible design presented in this paper delivers a good synergism between the ZnCo 2 O 4 and rGO that providing superior electrochemical performance.