High-Performance Cellulosic Solid-State Electrolytes: Engineering the Li⁺ Transference Number and Deciphering...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Chemistry

Background:

• Solid-state electrolytes are crucial for safer and higher-performance batteries.
• Developing electrolytes with high ionic conductivity, mechanical strength, and stable interfaces remains a challenge.

Purpose of the Study:

• To develop a novel cellulose-based solid polymer electrolyte with enhanced properties.
• To investigate the ion transport mechanisms and interfacial stability of the new electrolyte.

Main Methods:

• Grafting trifluoromethanesulfonimide (-TFSI) groups onto a cellulose backbone.
• Characterization using dielectric relaxation spectroscopy, molecular dynamics simulations, and density functional theory.
• Electrochemical testing of lithium plating/stripping cycles.

Main Results:

• The cellulose-based solid polymer electrolyte (Cell-TFSI) achieved a high Li+ transference number (0.79) and ionic conductivity (1.12 × 10-4 S cm-1).
• Weakly coordinated solvation structures facilitate a hopping-decoupled ion transport mechanism.
• Stable lithium plating/stripping cycling (>1000 h) was achieved due to an in situ LiF-rich solid electrolyte interphase.

Conclusions:

• A universal design principle based on weak solvation and anion immobilization was established for high-performance solid-state polymer electrolytes.
• Cell-TFSI demonstrates potential as a sustainable and efficient electrolyte for solid-state batteries.