Nickel Modified Cobalt Molybdate Nanocomposites for High‐Performance Supercapattery

ABSTRACT The urgent issue in achieving net‐zero emission and advancing clean energy storage devices is to integrate the high‐performance transition metal oxides through structural design, due to their excellent electrochemical properties. In this study, a ternary metal molybdate material using material engineering strategies via integrating the high conductive nickel‐ions with 3D cobalt molybdate (CM) nanostructures was fabricated to form NiCoMoO 4 (NCM) nanocomposite as the high‐performance super‐capattery/capacitor electrode materials. The mixed‐oxidation states of Ni, Co, and Mo in NCM help the electrode surface to have more active sites and hence, the electrode‐electrolyte diffusion pathway is enhanced, making the overall high efficiency of the device. The NCM electrodes (0.5%) exhibit a superior energy storage performance of ~714 F/g (~89.25 mAh/g) at 1 A/g and the NCM||AC ASB device delivered a Csp of ~190 F/g (~76.52 mAh/g), with an energy and power density of ~200 and ~20 880 W/kg at 1 and 10 A/g, respectively. After 25 000 cycles, the device retains ~99% of its capacitance. The remarkable electrochemical performance is attributed to the synergistic effect between CM and highly‐conducting Ni‐ions. These results have addressed an effective strategy for designing ternary metal molybdate electrodes and highlighted the potential of molybdates as high‐performance and durable electrodes for super‐capattery/capacitor, which can promote sustainable solutions for the future green energy storage.