Lithium (Li) metal is a promising anode for next-generation batteries due to its high capacity, low redox potential, and low density. However, dendrite growth and interfacial instability limit its use. In this study, an artificial solid electrolyte interphase layer of LiF and Li-Sn (LiF@Li-Sn) was fabricated by spray-coating SnF2 onto Li. The LiF@Li-Sn anode exhibited improved air stability and electrochemical performance. Electrochemical impedance spectroscopy indicated a charge transfer resistance of 25.2 Ω after the first cycle. In symmetric cells, it maintained a low overpotential of 27 mV after 250 cycles at 2 mA/cm2, outperforming bare Li. In situ microscopy confirmed dendrite suppression during plating. Full cells with NMC622 cathodes and LiF@Li-Sn anodes delivered 130.8 mAh/g with 79.4% retention after 300 cycles at 1 C and 98.8% coulombic efficiency. This coating effectively stabilized the interface and suppressed dendrites, with promising implications for practical lithium metal batteries.

1. Introduction
2. Experimental Section
    2.1 Preparation of composite coating layer on lithium metal
    2.2 Electrochemical measurements
    2.3 Materials characterization
3. Results and Discussion
4. Conclusion
Funding
Conflict of Interest
Data Availability Statement
Author Information and Contribution
Acknowledgments
References

• Yeong Hoon Jeon(Department of Hydrogen Energy, Dankook University, Cheonan 31116, Republic of Korea)
• Seul Ki Choi(Department of Hydrogen Energy, Dankook University, Cheonan 31116, Republic of Korea)
• Minho Yang(Department of Hydrogen Energy, Dankook University, Cheonan 31116, Republic of Korea, Department of Energy Engineering, Dankook University, Cheonan 31116, Republic of Korea, Energy and Environmental Research Center (E2RC), Dankook University, Cheonan 31116, Republic of Korea) Corresponding author
• Yun Seung Nah(Department of Energy Engineering, Dankook University, Cheonan 31116, Republic of Korea)
• Wonil Shin(Department of Materials Science and Chemical Engineering, Hanyang University, Ansan, 15588, Republic of Korea)
• Yong-Ho Choa(Department of Materials Science and Chemical Engineering, Hanyang University, Ansan, 15588, Republic of Korea) Corresponding author