Li2OHCl Crystalline Electrolyte for Stable Metallic Lithium Anodes

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Chemistry

Background:

• Solid electrolytes are crucial for safe and efficient batteries.
• Current solid oxide electrolytes require high processing temperatures (>1600 °C).
• Developing stable solid electrolytes for lithium metal anodes remains a challenge.

Purpose of the Study:

• To investigate the formation of a stable solid electrolyte interphase (SEI) with lithium metal.
• To explore the low-temperature synthesis and properties of Li2OHCl solid electrolytes.
• To evaluate the electrochemical stability of Li2OHCl against lithium metal.

Main Methods:

• Simple mixing of lithium hydroxide (LiOH) and lithium chloride (LiCl) precursors.
• Processing at mild temperatures (<400 °C).
• Characterization of ionic conductivity and Arrhenius activation energy.

Main Results:

• Li2OHCl solid electrolyte membranes fabricated at <400 °C.
• Li2OHCl with increased crystal defects exhibited highest ionic conductivity.
• Stable SEI layer formation observed between Li2OHCl and lithium metal anode.
• Demonstrated stability even above lithium metal's melting point.

Conclusions:

• Li2OHCl is a promising solid electrolyte for lithium metal batteries.
• Low-temperature processing significantly reduces manufacturing costs.
• SEI layer formation is key to interfacial stability, enabling safer battery operation.