Gel-polymer electrolytes based on polyurethane ionomers for lithium power sources

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Chemistry

Background:

• Polyurethanes offer a versatile polymer matrix for developing novel ion-conducting materials.
• Aminoethers of ortho-phosphoric acid serve as a key component in creating polymer electrolytes.
• Aliphatic polyisocyanates are utilized to tailor the properties of polyurethane-based electrolytes.

Purpose of the Study:

• To synthesize and characterize new polymer electrolytes based on functionalized polyurethanes.
• To investigate the ionic conductivity of these polymer electrolytes.
• To enhance the performance of polyurethane ionomers for energy storage applications.

Main Methods:

• Synthesis of polyurethane ionomers using aminoethers of ortho-phosphoric acid and aliphatic polyisocyanates.
• Impedance spectroscopy to measure ionic conductivity of samples immersed in LiBF4 electrolyte.
• Chemical modification of aminoethers with phthalic anhydride to introduce carboxylate ions.

Main Results:

• Polyurethane ionomer samples achieved a conductivity of 0.62 mS cm⁻¹ after immersion in a 1 M LiBF4 solution.
• Phosphate ion clusters and conducting channels were identified as the mechanism for ion transport.
• Modification with carboxylate ions increased channel size and cation mobility, raising conductivity to 2.1 mS cm⁻¹.

Conclusions:

• The developed polyurethane-based materials show potential as polymer electrolytes.
• Modification strategies, such as introducing carboxylate ions, can significantly enhance ionic conductivity.
• These findings contribute to the development of advanced electrolytes for electrochemical devices.