Mechanically and Thermally Robust Gel Electrolytes Built from A Charged Double Helical Polymer

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Chemistry

Background:

• Solid-state batteries are crucial for next-generation energy storage.
• Existing polymer electrolytes often lack the necessary properties for practical battery applications.
• Developing robust polymer electrolytes with enhanced performance is a key research area.

Purpose of the Study:

• To develop a novel rigid gel polymer electrolyte with improved properties for solid-state batteries.
• To investigate the structure-property relationships of a PBDT-based polymer electrolyte.
• To evaluate the electrochemical performance and thermal stability of the developed electrolyte in Li/LiFePO4 cells.

Main Methods:

• Synthesis and characterization of a rigid gel polymer electrolyte incorporating poly(2,2 '-disulfonyl-4,4 '-benzidine terephthalamide) (PBDT).
• Immobilization of a liquid electrolyte mixture within a PBDT matrix.
• Systematic study of ion transport mechanisms using complementary techniques.
• Electrochemical performance testing of Li/LiFePO4 cells, including long-term cycling and thermal cycling.

Main Results:

• The PBDT-based electrolyte exhibits a nanofibrillar structure due to PBDT's rigid double helical conformation.
• Enhanced mechanical properties, a wider operating temperature window, and higher battery rate capability compared to PEO-based electrolytes.
• Excellent capacity retention in Li/LiFePO4 cells over extended cycling.
• Demonstrated thermal cycling reversibility between ambient and elevated temperatures.

Conclusions:

• The rigid gel polymer electrolyte based on PBDT shows significant potential for advanced solid-state battery applications.
• The unique structure of PBDT contributes to superior electrolyte performance.
• The electrolyte is suitable for batteries requiring fast charging at high temperatures and slower discharging at ambient temperatures.