A Two-Parameter Space to Tune Solid Electrolytes for Lithium Dendrite Constriction.

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Lithium dendrite penetration and microcrack propagation challenge stable cycling in solid-state batteries at high current densities.
• The "dynamic stability" effect, utilizing interfacial decomposition reactions, shows promise for suppressing lithium dendrite penetration.

Purpose of the Study:

• To classify electrolytes using a two-parameter space to define conditions for "dynamic stability."
• To investigate the influence of chemical composition and core-shell microstructures on electrolyte properties within this space.
• To design and validate electrolytes that achieve stable long-term cycling in solid-state batteries.

Main Methods:

• Development of a two-parameter classification space for solid electrolytes based on decomposition energy and critical mechanical modulus.
• Utilizing high-throughput computation and machine learning for predictive modeling of electrolyte behavior.
• Experimental synthesis of electrolytes with controlled chemical compositions and core-shell microstructures.

Main Results:

• Identification of a specific region in the two-parameter space critical for achieving "dynamic stability."
• Demonstration that electrolyte chemical composition and core-shell microstructures can tune electrolyte positions within this space.
• Designed electrolytes achieved stable cycling for 10,000–20,000 cycles at high current densities (8.6–30 mA/cm²).

Conclusions:

• A balance between sufficient decomposition energy and low critical mechanical modulus is crucial for "dynamic stability" in solid-state batteries.
• Computational and experimental strategies enable the design of electrolytes with optimized properties for dendrite suppression.
• The developed electrolytes significantly enhance the cycle life of solid-state batteries compared to controls exhibiting dendrite penetration.