Carbon bi-metallic molybdenum tungsten oxide composite as a potential electrode for high-performance asymmetric supercapacitor

Molybdenum tungsten oxide (MTO) bi-metallic structure was synthesized using Pechini method. Asymmetric supercapacitor (SC) was constructed using MTO/ active carbon (AC) and H2SO4 electrolyte. Different AC: MTO weight ratios proved a high impact on composite electrochemical performance. Galvanostatic charge-discharge tests demonstrated a capacitance of 336.75 F/g, with 37.11 % capacitance shrinking upon increasing the applied current to 5 A/g (50-fold) from 0.1 A/g. Such high-rate capabilities were attributed to lattice spacing induced by inserting tungsten (W) into the MO lattice. The optimized ratio of MTO/AC possesses a high specific energy and power of similar to 120 Wh/kg and 256 kW/kg at 0.1 and 80 A/g, respectively. Moreover, the composite is showing similar to 100 % retention values after 20k cycling at a high current of 80 A/g. Unlike many reports of using first-class transition metal oxides for energy storage devices, bi-heavy metal composite functionalization in SC applications is scarce. This potential composite between porous carbon and bi-heavy metal oxide suggested talented electrode materials for energy storage systems.