Executive Summary : | In this rapid growing world, energy storage devices that efficiently use energy, in particular renewable energy, are being actively pursued. Aqueous redox supercapacitors, which operate in high ionic conductivity and environmentally friendly aqueous electrolytes, storing and releasing high amounts of charges with rapid response rate and long cycling life, are emerging as a solution for energy storage applications. The proposed study is to enhance the performance of supercapacitors such as the high charging−discharging rate and long cycle life, and high energy density, approaching that of a battery. The most commercial supercapacitors are carbon based electrode materials, with specific capacitance of about (10-50) × 10-6 Fcm-2 and an energy density of 3 to 4 Wh kg-1 (at a power density of 3 to 4 kW kg-1) in both aqueous electrolyte and organic electrolyte. Although this energy density is suitable for many applications, it is far below the 30−200 Wh kg-1 of Li-ion batteries. Metal oxides such as RuO2, TiO2, Fe3O4 or MnO2, as well as electronically conducting polymers have been extensively studied in the past decades. But RuO2 is costlier, toxic and present in rare availability, whereas carbon nanotube (CNT) needs fictionalization and TiO2 possess low conductivity. Also the synthesis or coating methods are either of high time consuming or implausible to manufacture in a laboratory. To obtain a higher capacitance and energy density compared to carbon materials, transition-metal oxide/hydroxide is a good choice for use in supercapacitor applications because they can store more charges and energy via Faradic reaction. Though titania and ruthenium oxides were largely investigated towards the application of these energy-generating devices, the high cost investments for ruthenium and low conductivity of titania emphasize the need of suitable alternatives with such specific capacitance values, cyclability, energy density and power density. Thus in our proposed work, SnO2 nanostructure proposed as supporting material, are to be synthesized using simple, facile hydrothermal route along with the metal hydroxides. The self-supported SnO2 nanostructure on stainless steel foil is highly conductive which will be used as the substrates for Co3O4 or Ni(OH)2 growth in a chemical bath using chemical bath deposition technique. Moreover, the possibility of porous and wire morphology formation using the simple hydrothermal synthesis routes for the nanostructured Co and Ni(OH)2 paved the suitability as core on the AISI 316L SS foils. In addition, the Co-Ni metal hydroxides should be satisfactory materials for supercapacitor due to the low cost and high specific capacitance. Based on these aspects this proposed work is believed to place a milestone in the research with low investments and high productivity. |