Microenvironment Regulation Unlocks High Li⁺ Conduction in Polyether Electrolytes for High-Performance...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Chemistry

Background:

• Polyether electrolytes (PEs) are crucial for high-performance lithium metal batteries (LMBs).
• Traditional PEs suffer from low lithium-ion (Li⁺) conductivity due to strong Li⁺-polymer interactions.
• Existing modification strategies face limitations due to polymer constraints and process complexity.

Purpose of the Study:

• To develop a novel and straightforward strategy to enhance Li⁺ conductivity in PEs.
• To reduce Li⁺-polymer interactions and increase free Li⁺ concentration.
• To introduce ion-channels by regulating the PE microenvironment.

Main Methods:

• Introducing Ge⁴⁺ sites with weak Lewis acidity during in situ polymerization.
• Regulating the microenvironment of polyether electrolytes.
• In situ polymerization for electrolyte synthesis.

Main Results:

• Achieved high ionic conductivity (1.83 mS cm⁻¹ at 25 °C) and Li⁺ transference number (0.8).
• Demonstrated extraordinary cycling stability (>2000 h) in Li||Li symmetric cells with dendrite-free Li deposition.
• Achieved impressive capacity retention (92.1%) and Coulombic efficiency (≈100%) over 2190 cycles in Li||LiFePO₄ cells at 5 C.

Conclusions:

• Microenvironment regulation via Ge⁴⁺ sites is an effective strategy for designing advanced polymer electrolytes.
• The developed electrolyte shows significant potential for high-performance and stable lithium metal batteries.
• This approach offers new insights into overcoming limitations in current polyether electrolyte research.