A modified separator based on ternary mixed-oxide for stable lithium metal batteries

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Lithium metal batteries (LMBs) offer high energy density but face challenges like dendrite formation and low Coulombic efficiency.
• These issues hinder the practical application of LMBs for next-generation energy storage.

Purpose of the Study:

• To develop a functional separator that mitigates lithium dendrite growth and improves the cycling stability of LMBs.
• To investigate the role of Lewis acidity in modulating ion transport and enhancing electrolyte stability.

Main Methods:

• A functional separator coated with a Lewis acidic mixed oxide (ZrO2-SiO2-Al2O3) was synthesized.
• The separator's anion anchoring ability and ion transport modulation near the lithium anode were analyzed.
• Performance was evaluated in an anode-free cell with a high-loading LiNi0.8Co0.1Mn0.1O2 cathode.

Main Results:

• The ZrO2-SiO2-Al2O3 coating demonstrated strong Lewis acid sites, immobilizing anions and increasing the Li+ transference number to 0.88.
• This resulted in suppressed dendrite formation and improved electrolyte chemical stability.
• An anode-free cell achieved stable cycling for 150 cycles at 0.5C.

Conclusions:

• The developed functional separator effectively suppresses lithium dendrite growth and enhances the long-term operation of anode-free LMBs.
• Mixed oxides with high Lewis acidity represent a promising strategy for designing advanced separators for high-performance lithium metal batteries.