Innovative Separator Engineering: Hydrogen Bond-Driven Layer-By-Layer Assembly for Enhanced Stability and Efficiency...

Area of Science:

• Materials Science
• Electrochemistry
• Chemical Engineering

Background:

• Lithium metal batteries (LMBs) are crucial for next-generation energy storage.
• Conventional separators suffer from poor interfacial compatibility, leading to lithium dendrite growth and uneven ion flux.
• These issues significantly limit LMB safety and cycle life.

Purpose of the Study:

• To develop advanced functional separators for lithium metal batteries.
• To address challenges of lithium dendrite growth and inhomogeneous ion flux.
• To enhance the interfacial compatibility of battery separators.

Main Methods:

• Utilized a hydrogen bond-driven layer-by-layer (LbL) assembly strategy.
• Engineered functional separators using poly(vinyl alcohol) (PVA) and tannic acid (TA).
• Optimized the poly(propylene) (PP)/(TA/PVA)₁₅ separator structure for enhanced properties.

Main Results:

• Achieved enhanced lithiophilicity and uniform Li⁺ flux through a robust hydrogen-bonded network.
• Demonstrated stable Li//Li symmetric cell operation for 800 hours.
• Li//LiFePO₄ half cells retained 73.8% capacity after 1000 cycles at 5C.
• Obtained high ionic conductivity (0.94 mS cm^-1) and Li⁺ transference number (0.63).

Conclusions:

• The developed separator significantly improves LMB electrochemical performance and safety.
• The hydrogen-bonding strategy offers a scalable, eco-friendly approach for advanced separator engineering.
• This work presents a universal interface chemistry paradigm for next-generation lithium metal batteries.