Research Projects

The whole research focus on supercapacitors (SCs) is to enhance their energy density (E) to the order of Li-ion batteries without losing their high power density (P). An evident choice to progress ahead with such focus would be the utilization of asymmetric/hybrid SCs, as they can be made to furnish vital energy storage properties like large potential window, specific capacitance (Cs), E, P, coulombic efficiency (ƞ), rate capability and cyclic stability, in higher magnitudes by using the harmless aqueous electrolytes. 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 used as electrode materials, but each of them suffers from some serious limitations, which reduce their energy storing properties. The main limitations of PANI and PPy are their low order cyclic stability and rate 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 and variable electrical conductivity. In addition, the PANI and PPy are facile to synthesis, inexpensive, less toxic, 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 is remarkable large, which still creates the substantial research gap to explore the PPy further. The MOs are 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 to produce efficient electrode materials for SCs (by synergistic effect). Thus, each of these aforementioned different faradic materials possess their intrinsic merits and limitations. The merits of the aforementioned materials make the material suitable for the further study, when their limitations are subside. Hence, it is a novel notion to make supercapacitive materials by integrating all the merits of them. Among different MOs available, the MnO2, V2O₅ and SnO2, are remarkable as they are with, high theoretical Cs of 3700, 2210 and 2134 F g-1 at 1.2 V respectively, multiple oxidation states, cheap and facile to synthesis. The integrity of the composite electrode is also believed to substantially deter the electrode material from undergoing structural failures and there by imparting overall stability to the device, which is expected to surpass the limitations of conventional capacitors and replace the Li-ion batteries with high E. And this replacement is the aim of the project. Hence, it is proposed to develop nanocomposite electrodes, containing PPy, PANI, MnO2, V2O₅ and SnO2 as binary and ternary composites, which combine the merits and mitigate the shortcomings of the individual components to create effective supercapacitors.