Halide Salt-Catalyzed Crosslinked Polyurethanes for Supercapacitor Gel Electrolyte Applications

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Chemistry

Background:

• Gel polymer electrolytes are crucial for advanced energy storage, offering improved safety and ionic conductivity.
• Polyethylene oxide (PEO) and polypropylene oxide (PPO) based materials are promising for electrolyte applications.

Purpose of the Study:

• To develop a facile synthesis of chemically crosslinked PEO-PPO polyurethanes for gel polymer electrolytes.
• To investigate the catalytic role of non-toxic salts in the gelation process.
• To evaluate the electrochemical properties of the synthesized gel polymer electrolytes.

Main Methods:

• A one-step synthesis of chemically crosslinked polyurethanes incorporating PEO and PPO segments.
• Utilized tetrabutylammonium or potassium chloride/bromide salts as catalysts for rapid gelation.
• Impregnated the synthesized polymer with a liquid electrolyte.
• Measured ionic conductivity and activation energy of the gel electrolyte.

Main Results:

• Successful synthesis of chemically crosslinked PEO-PPO polyurethanes via catalyzed polyaddition reactions.
• Demonstrated rapid gelation within minutes using common non-toxic salt catalysts.
• Achieved a practical ionic conductivity of 1.1×10^-4 S cm^-1 at 40°C.
• Observed low segmental chain motion activation energy (11 kJ mol^-1).

Conclusions:

• PEO-PPO polyurethanes are a viable and biocompatible material class for gel polymer electrolytes.
• The developed synthesis method is efficient and utilizes safe catalytic agents.
• These materials show significant potential for application in supercapacitors and other energy storage devices.