Sustainable and cost effective Industrial Biomass-Based Coin Cell Supercapacitor for Powering Up Electronic Devices

Abstract

Transforming industrial waste into an energy storage device addresses two key challenges: reducing industry waste and providing a sustainable, low-cost material to meet global energy demands. In this study, the electrolyte material optimized to create a high-performance supercapacitor using biomass by sol-gel method. The prepared material exhibits a mesoporous structure with a specific surface area of 83.75 m 2 /g and used for supercapacitor electrode material. Prior to the supercapacitor fabrication, selecting an optimal electrolyte is crucial for performance enhancement. The electrodes are electrochemically characterized with potassium hydroxide (KOH) and sodium hydroxide (NaOH) electrolytes. The 3.0M KOH electrolyte is well-suited for electrochemical studies, exhibiting a low contact angle of 13° and high conductivity of 146.2 mScm -1 with the Nickel foam current collector. The electrode material achieved a high specific capacitance of 1590 Fg -1 at a current density of 3 Ag -1 using the 3.0M KOH electrolyte. Additionally, the material is tested for real-time coin cell supercapacitor device which showed an excellent capacitance retention of 93% after 5000 cycles. The coin cell device demonstrated a high energy density of 10.66 Whkg -1 and power density of 660 Wkg - 1 , enabling two cells in series to power a red-light emitting diode, digital watch, and an electronic calculator.