Dual-Anion Regulated SEI Formation Enabling Stable and Thin Interphases for Lithium-Metal Anodes
발표자
이제민 (경북대학교)
연구책임자
유지영 (경북대학교)
공동저자
이제민 (경북대학교), 장은빈 (경북대학교), 유지영 (경북대학교)
초록
내용
A dual-anion locally concentrated ionic liquid electrolyte (D-LCILE) using LiFSI and LiTFSI forms a thin, uniform, and LiF-rich solid electrolyte interphase (SEI), enabling stable lithium-metal batteries. Raman spectroscopy and molecular dynamics simulations show that dual-anion chemistry induces aggregate-rich Li⁺ solvation, promoting anion co-migration during charging and allowing FSI⁻ to decompose into LiF at the lithium anode. AIMD confirms rapid fluorine dissociation from FSI⁻, while weakly coordinating TFSI⁻ supports Li⁺ transport and electrolyte wettability. ToF-SIMS, XPS, and SEM analyses reveal a fluorine-rich SEI and thinner, denser lithium deposits. As a result, full cells exhibit excellent cycling stability with 99.93% capacity retention over 200 cycles. This dual-anion strategy offers an effective route to optimize solvation structure, SEI composition, and interfacial stability in lithium-metal batteries.
This research was supported by the National Research Foundation (NRF) funded by the Korean government (MSIT) (No. RS-2025-00562734).
This research was supported by Basic Science Research Program through National Research Foundation of Korea funded by Ministry of Science and ICT of Korea (No. RS-2025-02217276).