Research Projects

The whole research focus on supercapacitors (SCs) is to enhance their energy density (E) to the orderof Li-ion batteries without losing their high power density (P). An evident choice to progress ahead withsuch focus would be the utilization of asymmetric/hybrid SCs, as they can be made to furnish vitalenergy storage properties like large potential window, specific capacitance (Cs), E, P, coulombicefficiency (ƞ), rate capability and cyclic stability, in higher magnitudes by using the harmless aqueouselectrolytes. Among the existing electrode materials, the metal oxides (MOs) and conducting polymers(CPs), particularly, polyaniline (PANI) and polypyrrole (PPy), are with extraordinary qualities to be usedas electrode materials, but each of them suffers from some serious limitations, which reduce theirenergy storing properties. The main limitations of PANI and PPy are their low order cyclic stability andrate capability. The merits of PANI and PPy are their ability to furnish E and P in higher magnitudes.The energy storing ability of these CPs can be further enhanced by utilizing their faradic chemistry andvariable electrical conductivity. In addition, the PANI and PPy are facile to synthesis, inexpensive, lesstoxic, eco-friendly and exhibit high theoretical Cs (PANI - 2000 F g-1 and PPy - 3400 F g-1). However,another notable limitation of PPy, is that the disparity between its theoretical and experimental Cs isremarkable large, which still creates the substantial research gap to explore the PPy further. The MOsare good providers of high E and rate capability (merits) but provide low P and cyclic stability(limitations). Therefore, it is a rational notion to add these MOs to the integrity of PANI and PPy toproduce efficient electrode materials for SCs (by synergistic effect). Thus, each of these aforementioneddifferent faradic materials possess their intrinsic merits and limitations. The merits of theaforementioned materials make the material suitable for the further study, when their limitations aresubside. Hence, it is a novel notion to make supercapacitive materials by integrating all the merits ofthem. Among different MOs available, the MnO2, V2O₅ and SnO2, are remarkable as they are with, hightheoretical Cs of 3700, 2210 and 2134 F g-1 at 1.2 V respectively, multiple oxidation states, cheap andfacile to synthesis. The integrity of the composite electrode is also believed to substantially deter theelectrode material from undergoing structural failures and there by imparting overall stability to thedevice, which is expected to surpass the limitations of conventional capacitors and replace the Li-ionbatteries with high E. And this replacement is the aim of the project. Hence, it is proposed to developnanocomposite electrodes, containing PPy, PANI, MnO2, V2O₅ and SnO2 as binary and ternarycomposites, which combine the merits and mitigate the shortcomings of the individual components tocreate effective supercapacitors.