Triple-Layered Noncombustible PEO-Based Solid Electrolyte for Highly Safe Lithium-Metal Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-metal batteries offer high energy density but face safety and conductivity challenges.
• Solid polymer electrolytes, like polyethylene oxide (PEO), provide safety and design flexibility but require improvements.
• Existing electrolytes have fire safety and ionic conductivity concerns.

Purpose of the Study:

• To develop a novel noncombustible solid polymer electrolyte with superior ionic conductivity for lithium-metal batteries.
• To enhance mechanical strength and electrode interface interactions using a triple-layer structure.
• To address fire safety and ionic conductivity limitations in current solid polymer electrolytes.

Main Methods:

• Incorporation of decabromodiphenyl ethane and zeolite as additives.
• Development of a triple-layer electrolyte structure with self-extinguishing properties.
• Optimization of LiTFSI concentration to influence PEO crystallinity and ionic conductivity.

Main Results:

• Achieved ionic conductivity of 1.5 mS cm^-1 at 60 °C with flame retardancy.
• Demonstrated anodic stability up to 4.8 V and reduced LiF formation with 60% LiTFSI addition.
• Exhibited excellent battery performance: 153 mAh g^-1 initial capacity, 87.9% retention over 1000 cycles, and 99.6% Coulombic efficiency.

Conclusions:

• The novel triple-layered electrolyte enhances safety and ionic conductivity in lithium-metal batteries.
• Optimized LiTFSI concentration improves PEO electrolyte properties and anode stability.
• The developed electrolyte enables high-performance and stable lithium-metal battery operation.