Multiscale Engineering of PEO Electrolytes for High-Voltage and Ultrastable Solid-State Lithium Batteries With...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Poly(ethylene oxide) (PEO) electrolytes are promising for flexible solid-state batteries.
• Current PEO electrolytes suffer from slow ion transport and poor interfacial stability.
• These limitations hinder the practical application of solid-state lithium batteries.

Purpose of the Study:

• To improve ion transport kinetics and interfacial stability in PEO-based solid-state electrolytes.
• To enable stable operation of lithium metal batteries at near-room temperature.
• To develop a scalable strategy for commercializing polymer electrolytes for solid-state batteries.

Main Methods:

• Multiscale engineering of polymer architectures and solvation configurations.
• Incorporation of poly(ethylene oxide)-poly(2-dimethylaminoethyl methacrylate) nitrate (PEG-PDMAEMAH⁺·NO₃ ^-) additives.
• Analysis of PEO crystallinity, segmental motion, and ion solvation structures.

Main Results:

• Additives disrupted PEO crystallinity, enhanced segmental motion, and improved nitrate solubility.
• Nitrate ions competitively coordinated with Li⁺, boosting bulk Li⁺ mobility.
• Engineered electrolytes formed robust inorganic-rich interlayers, enhancing interfacial kinetics and high-voltage tolerance.

Conclusions:

• The multiscale engineering strategy successfully overcomes limitations in PEO electrolytes.
• The modified electrolytes enable stable operation of lithium metal batteries at 30°C without liquid plasticizers.
• Demonstrated stable cycling performance in 4.3 V LiNi_0.8Co_0.1Mn_0.1O₂ and LiFePO₄ cells, paving the way for commercialization.