Development of a Novel Bio‐based Redox Electrolyte using Pivalic Acid and Ascorbic Acid for the Activated Carbon‐based Supercapacitor Fabrication

Abstract Supercapacitor is considered a promising energy storage device due to its high‐power density and high specific capacitance. Electrode materials and electrolytes are major components of supercapacitors. The most used electrolytes are not biocompatible, which limits their practical applications. Bio‐electrolytes often cause low performances of supercapacitors. However, the inadequate performances of bio‐electrolytes for supercapacitor applications could be improved using redox molecules. Here, we are reporting the development of a novel redox bio‐electrolyte based on pivalic acid (PA) and ascorbic acid (AA). The salts of PA and AA served as the bio‐electrolyte and redox molecules, respectively. It is worth to note that PA which can be generated from bio‐sources and industrial wastes, is soluble in alkaline solutions. AA is found in most living organisms, including plants. The developed supercapacitor with the bio‐based redox electrolyte provides a specific capacitance of 308 Fg −1 at a current density of 1 Ag −1 and achieved an energy density of 15 Whkg −1 at a power density of 300 Wkg −1 . The supercapacitor demonstrates a good coulombic efficiency of ∼97% with capacitance retention of ∼72% after 10000 charge‐discharge cycles. This study is expected to widen the applications of bio‐based redox electrolytes for practical electrochemical energy storage applications and enables access to greener and more sustainable energy storage technology.