Groundnut shell–derived porous carbon-based supercapacitor with high areal mass loading using carbon cloth as current collector

The present study demonstrates fabrication, characterization, and electrochemical performances of bio-waste-based groundnut shell–derived activated porous carbon as supercapacitor electrodes by using carbon cloth as a current collector with high-level mass loading of 9–10 mg cm−2. The higher mass loading on the electrode is mainly attributed to interconnected porous network of carbon cloth, which helps to accommodate more active materials per unit volume as compared with that of other metallic current collectors. The obtained activated porous carbon possesses a very high specific surface area of 1700 m2 g−1 and a total pore volume of 0.82 cm3 g−1. The electrochemical performances of the supercapacitor electrodes are systematically investigated by using two different aqueous electrolytes such as 6 M KOH and 0.5 M Na2SO4 in two-electrode systems. The obtained results revealed that the supercapacitor electrodes exhibited a higher energy density of about 16.92 Wh kg−1 in 0.5 M Na2SO4 as compared with 6 M KOH electrolyte due to its low potential window of 1 V. Furthermore, the electrode is having more advantages like high packing density (0.73 g cm−3) and high volumetric performances with long durability. It is also found that the supercapacitor exhibits excellent durability upon 12,000 charge-discharge cycles with 99% of capacitance retention and also 99% of Coulombic efficiency. This study unveils an eco-friendly, cost-effective, and facile route to fabricate the activated porous carbon, and it is explored as a potential electrode for high volumetric supercapacitor applications.