Li-rich antiperovskite superionic conductors based on cluster ions

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Chemistry

Background:

• All-solid-state batteries offer enhanced safety and energy density but require solid electrolytes with high ionic conductivity.
• Current solid electrolytes often lack the necessary conductivity (10^-2 S/cm) at room temperature for practical applications.

Purpose of the Study:

• To explore lithium-rich antiperovskites for novel solid electrolyte materials.
• To identify and characterize materials with high ionic conductivity for next-generation energy storage.

Main Methods:

• Computational exploration of lithium-rich antiperovskites.
• Synthesis and characterization of Li3SBF4 and Li3S(BF4)0.5Cl0.5.
• Measurement of ionic conductivity, activation energy, band gap, and mechanical properties.

Main Results:

• Li3SBF4 exhibits an estimated 3D room temperature conductivity of 10^-2 S/cm, low activation energy (0.210 eV), and a large band gap (8.5 eV).
• A mixed-phase material, Li3S(BF4)0.5Cl0.5, achieved a higher room temperature conductivity of 10^-1 S/cm with low activation energy (0.176 eV).
• High ionic conductivity is attributed to cluster ion vibrations and enlarged ion channels.

Conclusions:

• Lithium-rich antiperovskites, specifically Li3SBF4 and its mixed-phase variant, are promising solid electrolytes for all-solid-state batteries.
• These materials address the critical need for high ionic conductivity at room temperature.
• The findings pave the way for developing safer and more powerful next-generation energy storage devices.