Nanocomposite having hierarchical architecture of MXene-WO3 nanorod@rGOsponge and porous carbon for cathode and anode materials for high-performance flexible all-solid-state asymmetric supercapacitor device

Though MXenes have immense potential to be used as active electrode material in energy storage, the irreversible stacking of its layers adversely affects its electrochemical performance. To address this issue, we have adopted a strategy to prepare nanocomposite composed of Ti3C2Tx and WO3, where the insertion of nanorod-shaped WO3 in between the layers of Ti3C2Tx prevents the restacking of the layers. To take leverage of the extensive charge storage capacity of the reduced graphene oxide, we have mixed an optimum wt% of rGO sponge with the Ti3C2Tx-WO3 nanocomposite (MXene-WO3@rGOsp). Separately, we have also synthesized porous carbon (PC) derived from a bio-mass. We assembled an asymmetric supercapacitor device using MXene-WO3@rGOsp and PC as active cathode and anode materials, respectively with a polymeric gel electrolyte. The ASC device showed its ability to deliver the energy density of 34 W h kg−1 at a power density of 1450 W kg−1 and retained ∼ 86 % of specific capacitance even after 3000 cycles of charging-discharging. The real-life application of the constructed ASC device was demonstrated by illuminating a panel of 16 LED lights. These results suggest that MXene-WO3@rGOsp and PC possess excellent electrochemical properties, which can be exploited to develop high-performance asymmetric all-solid-state flexible supercapacitor devices.