Orange Peel Derived Activated Carbon for Fabrication of High-Energy and High-Rate Supercapacitors

Owing to our inevitable energy necessity, alternate energy resources have to be implemented in our energy storage systems to enervate the energy demands. On the consideration of the above statement, activated high surface area three-dimensional (3D) nanoporous carbon derived from the orange peel bio-waste has been studied for symmetric flexible and bendable solid state supercapacitor (SSC) with high energy density. The nitrogen adsorption/desorption isotherms revealed that the activated nano-porous carbon exhibits a high specific surface area and average pore volume of 2160 m²/g and 0.779 cc/g with the uniform meso and microporous network. The fabricated symmetric cell using the activated porous carbon in aqueous electrolyte exhibits a high specific capacitance of 460 F/g at 1 A/g with an excellent electrochemical stability of 98% for 10000 cycles and virtuous rate performance at higher current densities. The fabricated aqueous symmetric device exhibits a high energy density and power density of 12 Wh/kg and 32.8 kW/kg, respectively. Similarly, the symmetric device in ionic liquid electrolyte shows a high cell voltage of 3 V and high energy and power density of 43 Wh/kg and 1185 W/kg, respectively. Also, fabricated all-solid-state flexible supercapacitor device exhibits a high energy and power density of 11.4 Wh/kg and 6.6 kW/kg, respectively. The flexible supercapacitor device was shown to light up a red light emitting diode (LED) for more than three minutes.