Asymmetric Supercapacitor Assembly of Ti3c2-Ppy Nanocomposite//Activated Carbon Electrodes for Superior Energy Density

High performing polypyrrole based MXene nanocomposite electrode has been prepared by intercalating PPy into the layered Ti3C2Tx by a harmonious electrodeposition technique and the enhanced energy storage performance of Ti3C2-PPy is compared to pristine Ti3C2Tx both experimentally and by using the first-principles methods. The nanotubular ash guard flower-like morphology effectively prevents Ti3C2 stacking, resulting in enhanced interlamellar spacing. Ti3C2-PPy delivers excellent specific capacitance of 474 Fg-1 in 1 M H2SO4 at a current density of 1 Ag-1 with a remarkable rate performance of 98 % across 10000 cycles. The asymmetric supercapacitor is effectively fabricated using coin cell-CR2032 that establishes a large gravimetric capacitance of 243 F g-1 with 97% retention. To realise better energy storage and safety standards for commercial applications, the quasi-solid-state supercapacitors were also fabricated with gel polymer electrolyte. They demonstrate stable, safer, and high energy density performance of 54.4 Wh kg−1 at an enhanced operating potential window (~2V), which is the widest potential window reported to date for MXene based polymeric supercapacitors. Furthermore, the variation of quantum capacitance with electrode potential for Ti3C2-PPy composites in comparison with pristine Ti3C2 is calculated theoretically and found that the  follows the experimental trend with a high value of 2104 µF/cm2 for the PPy adsorbed Ti3C2 at 1.7 V. Thus, it provides a qualitative justification for the enhanced super capacitance nature of the PPy-Ti3C2 hybrid structure and the enhanced conductivity of Ti3C2-PPy may be attributed to the presence of a higher density of states near the Fermi level.