High-Performance Poly(ethylene Oxide)-Based Composite Solid Electrolyte with Enhanced Room-Temperature Ionic...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Poly(ethylene oxide) (PEO)-based solid-state polymer electrolytes are promising for high-energy-density lithium-metal batteries.
• Low room-temperature ionic conductivity is a major hurdle for PEO-based electrolytes.
• Developing practical solid-state electrolytes requires addressing ionic conductivity limitations.

Purpose of the Study:

• To overcome the low room-temperature ionic conductivity of PEO-based solid-state electrolytes.
• To develop a composite solid electrolyte (CSE) with enhanced performance.
• To enable practical applications of solid-state lithium-metal batteries.

Main Methods:

• Developed a composite solid electrolyte (CSE) using a "polymer-in-salt" strategy.
• Incorporated high-concentration lithium salts to disrupt PEO crystallinity and form ion channels.
• Utilized Al2O3 filler to further suppress crystallization and enhance ionic transport.

Main Results:

• Achieved ultrahigh ionic conductivity of 9.62 × 10^-4 S cm^-1 at room temperature.
• Obtained a 4.8 V electrochemical stability window.
• Demonstrated stable cycling in Li symmetric cells for 1000 hours.
• Showcased excellent capacity retention in Li//LiFePO4 coin and pouch cells.

Conclusions:

• The developed CSE effectively addresses the low ionic conductivity challenge in PEO-based solid-state electrolytes.
• The synergistic effect of high-concentration lithium salts and Al2O3 filler significantly enhances ionic conductivity and electrochemical stability.
• This work presents a new strategy for designing high-performance solid-state lithium batteries.