Additive-Driven Nanoscale Architecture of Solid Electrolyte Interphase Revealed by Cryogenic Transmission Electron
Hayoung Park1,2, Yonggoon Jeon1,2, Minhee Park2
1Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul National University, Seoul 08826, Republic of Korea.
ACS Nano
|May 6, 2024
Summary
Understanding solid electrolyte interphase (SEI) additives like lithium nitrate (LiNO3) and vinylene carbonate (VC) is crucial for stable lithium metal batteries (LMBs). Their combined action optimizes SEI properties for enhanced battery performance and longevity.
Area of Science:
- Materials Science
- Electrochemistry
- Battery Technology
Background:
- Lithium metal batteries (LMBs) offer high theoretical capacity but face challenges with reactive lithium (Li) growth.
- The solid electrolyte interphase (SEI) is critical for stable Li plating, and electrolyte additives are used to optimize SEI properties.
- The precise roles of common additives like lithium nitrate (LiNO3) and vinylene carbonate (VC) in SEI formation and battery performance remain unclear.
Purpose of the Study:
- To elucidate the distinct roles of LiNO3 and VC additives in modifying the SEI layer in localized high-concentration electrolytes for LMBs.
- To investigate how these additives influence SEI nanoscale architecture, solvation structure, and electrochemical reduction kinetics.
- To establish mechanisms for Li growth and cycling behavior based on SEI physicochemical properties.
Main Methods:
- Cryogenic transmission electron microscopy (cryo-TEM) for nanoscale SEI architecture analysis.
- Raman spectroscopy to probe chemical composition and structure.
- Molecular dynamics (MD) simulations and density functional theory (DFT) calculations for theoretical insights.
- Electrochemical measurements to assess battery performance.
Main Results:
- LiNO3 and VC exhibit distinct functions in SEI formation, solvation structure, and electrochemical reduction kinetics.
- The synergistic effect of LiNO3 and VC leads to an optimized SEI, promoting stable Li plating and prolonged cycle performance in LMBs.
- Proposed mechanisms link SEI properties (uniformity, elasticity, ionic conductivity) to Li growth and cycling behaviors.
Conclusions:
- The combined use of LiNO3 and VC is effective in creating a desirable SEI for high-performance LMBs.
- Understanding additive-SEI interactions provides critical insights for electrolyte design and chemical compatibility.
- This study offers a mechanistic understanding of SEI formation and its impact on LMB stability and cycle life.
