Redox-Additive Gel Polymer Electrolyte Based on the Biodegradable Polymer Pectin for Supercapacitors with Enhanced...

Area of Science:

• Materials Science
• Electrochemistry
• Green Chemistry

Background:

• Transitioning to net-zero emissions necessitates environmentally friendly energy storage solutions.
• Biodegradable polymers offer a sustainable alternative to conventional materials in energy devices.

Purpose of the Study:

• To develop and evaluate a pectin-based gel polymer electrolyte (GPE) for supercapacitor applications.
• To enhance supercapacitor performance using redox additives (lithium chloride and potassium iodide) within the GPE.
• To investigate the electrochemical properties and stability of the GPE-based supercapacitors.

Main Methods:

• Synthesis of a pectin-based GPE incorporating lithium chloride and potassium iodide as redox additives.
• Characterization of GPE thermal stability and flame retardancy using thermogravimetric and differential scanning calorimetry.
• Electrochemical performance testing of symmetric supercapacitors utilizing activated carbon electrodes derived from melon peel waste and the optimized GPE.

Main Results:

• The optimized GPE demonstrated high ionic conductivity (43 mS cm⁻¹) and a wide stable potential window (∼2 V).
• Supercapacitors with the redox-additive GPE showed a fivefold increase in specific capacitance (∼437 F g⁻¹) and energy density (∼34 Wh kg⁻¹).
• The devices achieved stable cycling for up to 8000 cycles with high Coulombic efficiency (99-100%) and minimal capacitance fade.

Conclusions:

• Pectin-based GPEs with redox additives are effective for high-performance, sustainable supercapacitors.
• The use of waste-derived activated carbon electrodes further enhances the environmental credentials of the energy storage system.
• This approach offers a promising pathway for developing eco-friendly and efficient energy storage technologies.