Defect-Mediated Faceted Lithium Nucleation on Carbon Composite Substrates

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Uniform, nondendritic seed formation is critical for dense lithium metal anodes and long-life batteries.
• Current methods face challenges in achieving uniform lithium deposition, impacting battery performance and safety.

Purpose of the Study:

• To discover a method for growing uniform, faceted lithium seeds on a scalable substrate.
• To understand the role of carbon defects in facilitating uniform lithium nucleation and deposition.
• To demonstrate the performance benefits of such lithium anodes in full battery cells.

Main Methods:

• Growth of hexagonal lithium seeds on carbon-polymer composite films.
• Characterization of carbon defects using Raman spectroscopy.
• Electrochemical cycling of full cells with LiNi_0.8Mn_0.1Co_0.1O₂ cathodes and engineered lithium anodes.

Main Results:

• Uniform, faceted hexagonal lithium seeds were successfully grown on carbon-polymer composite films.
• Carbon defects were identified as crucial nucleation sites for uniform lithium seed formation.
• Full cells demonstrated a 313% improvement in cycle life at a 1 C rate due to reduced lithium pulverization.

Conclusions:

• Defect-engineered carbon composite films provide a scalable and low-cost substrate for uniform lithium seed growth.
• This approach enables low-porosity lithium deposition, enhancing fast-charging capabilities and cycle life of lithium metal batteries.
• The developed method offers a promising pathway towards high-energy-density and high-rate lithium metal batteries.