Solvent-Mediated Synthesis and Characterization of Li₃InCl₆ Electrolytes for All-Solid-State Li-Ion Battery...

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Chemistry

Background:

• Superionic halides are promising solid electrolytes for high-voltage applications.
• Li3InCl6 is a notable halide with facile synthesis routes.
• The impact of synthesis solvents on Li3InCl6 properties is not well understood.

Purpose of the Study:

• To investigate the influence of different solvents (water, ethanol, water-ethanol mixture) on the synthesis and properties of Li3InCl6.
• To correlate structural differences with ionic conductivity and electrochemical performance.
• To evaluate the potential of solvent-optimized Li3InCl6 in all-solid-state lithium metal batteries.

Main Methods:

• Synthesis of Li3InCl6 using water, ethanol, and a water-ethanol mixture.
• Characterization of crystal structure, unit cell parameters, and vacancy concentration.
• Measurement of ionic conductivity at room temperature.
• Electrochemical testing of all-solid-state lithium metal batteries (ASSLMBs).

Main Results:

• Ethanol-synthesized Li3InCl6 showed larger unit cell parameters and increased vacancies.
• These structural features facilitated 3D isotropic lithium-ion migration.
• The ethanol-derived electrolyte achieved the highest ionic conductivity (1.06 mS cm⁻¹) and lowest binding energy (0.272 eV).
• ASSLMBs demonstrated a high initial discharge capacity (153.9 mA h g⁻¹) and 82.83% capacity retention after 50 cycles.

Conclusions:

• Solvent choice significantly impacts Li3InCl6 crystal structure and ionic conductivity.
• Ethanol is an optimal solvent for synthesizing high-performance Li3InCl6 electrolytes.
• This work provides a foundation for designing advanced halide electrolytes for energy storage applications.