Lithium Metal Batteries with a Bone-Inspired Solid-Sol Electrolyte Based on Natural CaF₂

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Mammalian bone inspires strategies for integrating structure and function in advanced materials.
• Lithium metal batteries require stable and conductive electrolytes to improve performance and safety.

Purpose of the Study:

• To develop a high-performance solid-sol electrolyte for lithium metal batteries.
• To utilize abundant calcium fluoride (CaF2) as a robust inorganic matrix.
• To enhance ionic conductivity and interfacial stability.

Main Methods:

• A solid-sol electrolyte was fabricated using calcium fluoride (CaF2) as the inorganic matrix and a small amount of organic solvent.
• Nonbonding interactions between CaF2 and the organic solvent established a continuous ion transport network.
• In situ reactions formed a protective solid-electrolyte interphase (SEI) layer.

Main Results:

• The solid-sol electrolyte achieved a wide electrochemical window (5.26 V) and high ionic conductivity.
• It demonstrated suppressed lithium dendrite growth and enhanced interfacial kinetics.
• Batteries with LiFePO4 cathodes showed stable cycling over 200 cycles at 100 °C.
• The electrolyte exhibited flame-retardant properties.

Conclusions:

• The CaF2-based solid-sol electrolyte offers a promising strategy for high-performance and safe lithium metal batteries.
• The approach is versatile and adaptable to various liquid electrolytes for property tuning.
• This work highlights the potential of bio-inspired materials design in energy storage solutions.