High Voltage Asymmetric Supercapacitors Using Tungsten‐Doped Mn‐Co Spinel Ferrite Electrodes

Physicochemical properties emerging nanomaterials possessing tungsten (W) are unique and the applications could be extended over a wide spectrum as nanocomposite electrodes for effective high voltage energy storage applications. Herewith, W doped spinel ferrite nanostructures was synthesized with facile hydrothermal strategy to get MnCo 1.98 W 0.02 O 4 (MnCoW). The spectroscopic characterization studies proved spherical subunits embedded onto nanosheets formed by W doped bimetallic oxide with a crystalline phase. The resistance due to charge transfer of the electrodes was reduced which led to enhanced transfer of charge across interface of electrode and electrolyte was addressed upon W doping. Carbon based nanocomposite electrodes endowed by their unique structures and the electrochemical performance with various aqueous electrolytes were tested in an asymmetric supercapacitor application. Excellent capacitance development from 141.2 F g −1 to 203.7 F g −1 was achieved by W doping possessing an energy density of 17.9 Wh kg −1 . A superior capacitance retention of 91 % was obtained from MnCoW‐based device right after 10000 cycles (charging/discharging) at 1 A g −1 . The designed supercapacitor device employing MnCoW electrode exhibited better lifetime performance during lighting a LED under various angles.