Uniform and Anisotropic Solid Electrolyte Membrane Enables Superior Solid-State Li Metal Batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Composite solid electrolytes (CSEs) are crucial for high-performance solid-state Li metal batteries.
• Rational structure design is key to improving CSE properties like ionic conductivity and dendrite suppression.

Purpose of the Study:

• To develop a novel CSE membrane with enhanced Li-ion conductivity and dendrite suppression capabilities.
• To investigate the structure-property relationships in a garnet/polymer microfiber-based CSE.

Main Methods:

• Fabrication of a CSE membrane composed of interwoven garnet/polyethylene oxide-Li bis(trifluoromethylsulphonyl)imide (LLZO/PEO-LiTFSI) microfibers.
• Characterization of Li-ion conductivity and electrochemical performance.
• Analysis of Li dendrite suppression using electrochemical cycling.

Main Results:

• The novel CSE exhibits high Li-ion conductivity and exceptional Li dendrite suppression.
• Uniform LLZO dispersion in PEO-LiTFSI creates continuous ion pathways and enhances mechanical properties.
• Anisotropic Li-ion conduction along microfibers homogenizes the electric field, preventing flux concentration.

Conclusions:

• The interwoven LLZO/PEO-LiTFSI microfiber CSE offers a promising strategy for high-performance solid-state Li metal batteries.
• This design approach enriches CSE structural design and promotes practical applications of solid-state batteries.