Rational Design of F-Modified Polyester Electrolytes for Sustainable All-Solid-State Lithium Metal Batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Chemistry

Background:

• Solid polymer electrolytes (SPEs) offer flexibility and low cost for solid-state batteries.
• Current SPEs face limitations in lithium-ion (Li+) conductivity and electrochemical stability.
• Understanding the structure-property relationship is crucial for advancing SPE performance.

Purpose of the Study:

• To investigate the impact of molecular structure on Li+ conductivity in fluorinated linear polyesters.
• To establish design principles for high-performance SPEs.
• To develop sustainable and cost-effective solid-state battery materials.

Main Methods:

• Synthesized 23 fluorinated linear polyesters by modifying coordination units, flexible segments, and passivation groups.
• Analyzed the correlation between molecular asymmetry, interchain aggregation, and Li+ conductivity.
• Evaluated the electrochemical stability and recyclability of the developed SPEs.

Main Results:

• Identified molecular asymmetry and interchain aggregation as critical factors for Li+ conductivity.
• Achieved a tenfold increase in Li+ conductivity by optimizing molecular asymmetry and coordination.
• Demonstrated a room-temperature Li+ conductivity of 0.59 × 10^-4 S cm^-1 with solvent-free poly(pentanediol adipate).
• Enhanced antioxidation capability through oxalate-Li+ chelation and electron delocalization.
• Achieved 90% recycling of LiTFSI and 86% regeneration of polyesters, reducing costs.

Conclusions:

• Elucidated the structure-property relationship in polyester-based SPEs.
• Provided key design principles for developing advanced SPEs.
• Showcased a viable pathway for creating sustainable and high-performance solid-state batteries.