Novel poly(epichlorohydrin)-based matrix for monolithic ionogel electrolyte membrane with high lithium storage...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Chemistry

Background:

• Monolithic ionogel electrolyte membranes (MIEMs) are crucial for energy storage but limited by functional matrix development.
• Existing MIEMs often lack optimal mechanical properties and ionic conductivity for widespread application.

Purpose of the Study:

• To introduce a novel ionized polymer matrix for enhanced MIEMs.
• To improve the balance between mechanical strength and ionic conductivity in MIEMs.
• To explore PECH-based MIEMs for efficient lithium storage.

Main Methods:

• Synthesized an ionized polymer matrix from poly (epichlorohydrin) (PECH) with quaternary ammonium side-chain ionic groups.
• Prepared flexible MIEMs using a solvent casting technique with lithium bis-(fluorosulfonyl) imide (LiFSI) and 1-ethyl-3-methylimidazolium bis-(fluorosulfonyl)-imide (EMImFSI).
• Characterized the thermal stability, ionic conductivity, and electrochemical performance of the prepared MIEMs.

Main Results:

• The developed MIEM exhibited excellent thermal stability up to approximately 250 °C.
• Achieved a high ionic conductivity of 1.21 mS cm⁻¹ at 20 °C.
• Li|LiFePO₄ coin cells demonstrated high capacity (150.0 mA h g⁻¹ at 0.2C), good cycling stability, and excellent C-rate performance.

Conclusions:

• PECH-based ionized polymer matrices offer a promising route for developing high-performance MIEMs.
• The novel MIEMs are suitable for advanced lithium storage and broader energy storage systems.
• This work provides a new strategy for functionalizing polymer matrices in ionogel electrolytes.