In the current scenario going green with the clean environment is very much needed for sustainable growth and so is the need for developing structured and efficient energy storing devices. Supercapacitors are a true example that have attracted the scientists worldwide for their high durability and energy density. Supercapacitors however impart relatively low energy but the energy storage capacity can be substantially enhanced which now a days is the current area of interest. High capacitance (C) and high electrochemical potential or stability window (V) can be two key reasons that can give rise to an enhanced energy density. The two well-known mechanisms used in charge storage for supercapacitors comprises mainly: (i) electric double-layer (EDL); (ii) reversible redox reaction. The choice of taking EDL-type cathode and redox-type anode in ASCs increases the energy storage per unit volume and correspondingly the power generated per unit volume as such type of electrode combination can use different voltage ranges. The current chapter outlines a discussion on a variety of electrode materials and electrolytes available for fabrication of number of energy storage devices for their utilisation in sustainable energy applications.