Preparation of Hydrogel-Based Electrolytes for Flexible Supercapacitor Electrodes

Abstract

Energy plays a crucial part in every aspect of modern life, because of the traditional energy storage devices as well as the problem regarding endurance, the small and flexible energy storage devices are more widely used in recent times. Supercapacitor is an energy storage device with advanced applications, like specific capacitance, environmental friendliness, charging and discharging properties, extensive life-span power and energy densities. Conventional SCs used liquid electrolytes which were toxic and cause leakage in SCs. Researchers choose safer options by using hydrogel electrolytes. Hydrogels are three-dimensional network of polymer with incorporation of liquid molecules, hydrogels are leakage proof, electrochemically stable, less toxic and highly biocompatible. The performance of SCs was enhanced using gelatin and polyvinyl alcohol and ratios of polyphenols from green tea extract and potassium hydroxide. Hydrothermal method was used to prepare electrode material of core shell (ZIF8/ZIF67). Synthesis of hydrogel electrolytes was done by incorporating borate crosslinkers with polyvinyl alcohol and gelatine. Series of hydrogel electrolytes were synthesized, with different quantities of polyphenols. FTIR, contact angle and XRD techniques were performed to study hydrogel electrolytes. Then, by incorporating two electrodes and an electrolyte, a supercapacitor device was fabricated. To analyze the efficiency of the supercapacitor, GCD, CV, and EIS were performed.