Ferrocene-Based Artificial Interfacial Layer for High-Performance Lithium Metal Anodes: Continuous Regulation of Li⁺...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium metal anodes are crucial for high-energy-density batteries but suffer from dendrite growth, hindering performance.
• Existing hybrid artificial layers offer benefits but lack tunable control over lithium ion diffusion.
• Developing controllable artificial layers is key to stable lithium metal anode operation.

Purpose of the Study:

• To create a tunable hybrid artificial layer for lithium metal anodes.
• To investigate the effect of component ratios on lithium ion diffusion and layer properties.
• To demonstrate the performance enhancement of lithium metal anodes with the optimized artificial layer.

Main Methods:

• Synthesized hybrid artificial layers (LF layers) with varying proportions of LiClO4, PMMA, and ferrocene (Fc).
• Characterized the artificial SEI layer's ionic conductivity (Li+ transference number) and mechanical properties (Young's modulus).
• Tested Li||Li symmetric cells and pouch cells with LiFePO4 cathodes to evaluate electrochemical performance and stability.

Main Results:

• Optimized LF layer achieved a high Li+ transference number (0.66) and Young's modulus (4.8 GPa).
• Fc-based artificial SEI layer effectively suppressed lithium dendrite growth and volume changes.
• Li||Li symmetric cells showed stable cycling for 1500 hours at 10 mA cm-2.
• Pouch cells demonstrated 75% capacity retention after 250 cycles at 0.5C with a high-loading cathode.

Conclusions:

• Modulating component proportions in hybrid artificial layers enables tunable control over Li diffusion.
• The optimized Fc-based artificial SEI layer significantly improves the stability and performance of lithium metal anodes.
• This approach offers a promising strategy for developing next-generation high-performance lithium metal batteries.