A Universal Self-Propagating Synthesis of Aluminum-Based Oxyhalide Solid-State Electrolytes

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Chemistry

Background:

• Inorganic solid-state electrolytes (SSEs) are crucial for high-energy all-solid-state batteries (ASSBs).
• Current SSE preparation methods, like ball milling and high-temperature annealing, are energy-intensive and not scalable for industrial applications.

Purpose of the Study:

• To develop a facile and scalable synthesis strategy for cost-effective aluminum-based oxyhalide SSEs.
• To investigate the potential of these SSEs in promoting the practical application of high-energy-density ASSBs.

Main Methods:

• A self-propagating method utilizing an exothermic reaction of raw materials for SSE synthesis.
• Characterization of synthesized SSEs for ionic conductivity and structural properties.

Main Results:

• Successful scalable synthesis of various aluminum-based oxyhalide SSEs with tunable components.
• Achieved high ionic conductivities (>10⁻³ S/cm at 25°C) for Li⁺, Na⁺, and Ag⁺ ions.
• Identified an amorphous matrix with oxidized chloroaluminate species as key for high ion mobility.

Conclusions:

• The self-propagating synthesis method offers a cost-effective and efficient route to advanced SSEs.
• Aluminum-based oxyhalide SSEs demonstrate significant potential for enhancing the performance of all-solid-state batteries.
• The developed SSEs are lightweight, easy to synthesize, and suitable for practical ASSB applications.