Oxychloride Polyanion Clustered Solid-State Electrolytes via Hydrate-Assisted Synthesis for All-Solid-State Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Chemistry

Background:

• Solid-state electrolytes (SSEs) are crucial for developing high-energy all-solid-state batteries.
• Current synthesis methods like mechanical ball milling and high-temperature annealing are not suitable for large-scale production.

Purpose of the Study:

• To develop a universal, scalable, and energy-efficient synthesis strategy for oxychloride SSEs.
• To investigate the structure-property relationships governing ion conductivity in these materials.

Main Methods:

• A hydrate-assisted synthesis strategy using alkali chlorides, AlCl3, and AlCl3·6H2O.
• Characterization of synthesized aluminum-based oxychloride SSEs, including structural analysis and ionic conductivity measurements.
• Demonstration of scalability through kilogram-scale reactions and synthesis of related oxychloride SSEs.

Main Results:

• Achieved a scalable synthesis route for aluminum-based oxychloride SSEs.
• Synthesized SSEs exhibit high Li+ conductivity (>1 mS cm-1 at 30 °C).
• The SSEs possess a heterogeneous structure with crystalline and amorphous components, where amorphous regions facilitate faster Li+ mobility.

Conclusions:

• The hydrate-assisted strategy offers a simple, scalable, and energy-efficient method for producing oxychloride SSEs.
• The unique heterogeneous structure with amorphous components enhances Li+ conductivity.
• This approach significantly advances the practical application of SSEs in all-solid-state batteries.