Engineering preparation of the nanocomposite containing CoWO4 nanodots and its high electrochemical activities

Designing hybrid composites electrodes with hierarchical nano-structural features and superb electrochemical performances sites is vital factor for engineering advanced supercapacitors. Herein, a novel nanocomposite from CoWO4 nanodots anchored on olive derived activated carbon doped with N and S (OACNS) is successfully prepared via an in-situ hydrothermal process. The well dispersion of the CoWO4 nanodots (pseudo-capacitor type) with ca. 7 nm in diameter on the OACNS nanosheets prevents their agglomerations to build hierarchical porous structure with high surface area (162.8 cm2·g−1) and various pores sizes distribution. Noteworthy, through the synergistic effect, the composite shows superb capacitance value of 152 mAh·g−1 (0.5 A·g−1) and splendid life cycle of 93.5 % (via 12,000 cycles). Interestingly, an asymmetric CoWO4@OACNS//OACNS hybrid supercapacitor provides excellent specific energy (53.6 Wh·kg−1) at maximum specific power of 650 W·kg−1. Such fascinating electrochemical performance indicates that the proposed CoWO4@OACNS hybrid composite can be exploited as cathode for next generation of energy storage devices.