Eutectic-Based Polymer Electrolyte with the Enhanced Lithium Salt Dissociation for High-Performance Lithium Metal...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Solid-state batteries with lithium metal anodes promise high energy density.
• Current polymer electrolytes face challenges like low ionic conductivity and poor interface stability.
• Developing advanced polymer electrolytes is crucial for practical lithium metal battery applications.

Purpose of the Study:

• To develop a novel eutectic-based polymer electrolyte for solid-state lithium metal batteries.
• To overcome the limitations of conventional polymer electrolytes.
• To enhance ionic conductivity and interface stability for improved battery performance.

Main Methods:

• Synthesis of a eutectic-based polymer electrolyte from succinonitrile (SN) and poly(ethylene glycol) methyl ether acrylate (PEGMEA).
• Characterization of ionic conductivity, electrochemical window, and interface stability with lithium anode.
• Fabrication and testing of Li/Li symmetric cells and Li/LiFePO4 and Li/LiNi0.6Co0.2Mn0.2O2 pouch cells.

Main Results:

• The PAN1.2-SPE (PEGMEA: SN = 1:1.2 mass ratio) exhibited high ionic conductivity (1.30 mS cm−1 at 30°C) and superior interface stability.
• Li/Li symmetric cells demonstrated stable long-term plating/stripping.
• Li/LiFePO4 cells achieved 80.3% capacity retention after 1500 cycles, with excellent performance in pouch cells.

Conclusions:

• The novel eutectic-based polymer electrolyte significantly enhances ionic conductivity and interface stability.
• This material enables stable cycling of lithium metal anodes in solid-state batteries.
• The study offers a new strategy for designing high-performance polymer electrolytes for advanced lithium metal batteries.