On Replacing Poly(ethylene oxide) in Solid Block Copolymer Electrolytes by Poly(glycidyl methyl ether): Morphology...

Area of Science:

• Materials Science
• Polymer Chemistry
• Electrochemistry

Background:

• Poly(ethylene oxide) (PEO) is a common component in solid polymer electrolytes (SPEs) but suffers from limitations like crystallization.
• Block copolymers offer a route to engineer electrolyte properties, combining distinct polymer blocks for tailored performance.

Purpose of the Study:

• To develop and evaluate novel block copolymer electrolytes based on polystyrene (PS) and poly(glycidyl methyl ether) (PGME) or its copolymers.
• To compare the ionic conductivity and properties of these new electrolytes against established PEO-based systems.

Main Methods:

• Anionic ring-opening copolymerization was used to synthesize PS-b-P-(EO-co-GME) and PS-b-PGME block copolymers.
• The synthesized polymers were doped with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI).
• DC conductivity measurements were performed across various temperatures, including at the glass transition temperature of the polystyrene block.

Main Results:

• The synthesized block copolymers exhibited full amorphousness and narrow dispersity.
• PS-b-PGME and PS-b-P-(EO-co-GME) doped with LiTFSI showed superior dc-conductivity compared to PEO-based electrolytes.
• PS-b-PGME demonstrated higher conductivity than PS-b-P-(EO-co-GME) and other single-ion conductors.

Conclusions:

• Poly(glycidyl methyl ether) (PGME) is a promising alternative to PEO as the soft block in block copolymer SPEs.
• PGME-based electrolytes offer a favorable combination of low glass transition temperature, salt solubilization, high dielectric permittivity, and non-crystallinity.
• These findings suggest a new pathway for designing high-performance solid polymer electrolytes for advanced battery applications.