20.500.12556/RUL-168456 Transport number determination and relevance for lithium metal batteries using localized highly concentrated electrolytes The lithium transport number (t$_{Li^+}$) determination of fluorinated ether (1,2-(1,1,2,2-tetrafluoroethoxy) ethane, TFEE)-based localized highly concentrated electrolytes (LHCEs) with 1,2-dioxolane (DOL) and dimethoxyethane (DME) as solvents has been explored using molecular dynamics simulations, nuclear magnetic resonance spectroscopy, Bruce-Vincent’s method, and low-frequency electrochemical impedance spectroscopy (EIS). We showcase that the TFEE-DOL LHCE has a t$_{Li^+}$ as high as 0.65 but, on the other hand, exhibits low Coulombic efficiency (<90%) and poor stability vs Li metal anodes, i.e., in a lithium metal battery (LMB) setting. In contrast, the TFEE-DME LHCE shows high Coulombic efficiency (98.9%) and stability, despite a much lower t$_{Li^+}$ (0.25). A significant migration resistance through the porous solid electrolyte interphase (SEI) for the former is the likely explanation, as revealed by EIS and assisted by scanning electron microscopy and X-ray photoelectron spectroscopy experiments. We thus find the interfacial properties at the Li metal anode to be more crucial than the ionic transport through the bulk of the electrolyte for LMB performance. We therefore propose that the focus should be put on the full (operando) impedance spectra of Li metal anodes in contact with electrolytes, since it enables the characterization of the interphase layer(s), rather than solely determining the (bulk) t$_{Li^+}$ of the electrolytes. electrodes electrolytes ions metals surface chemistry elektrokemija litij NMR spektroskopija elektroliti SEI true false true Angleški jezik Slovenski jezik Članek v reviji 2025-04-14 10:32:56 2025-04-14 10:32:57 2025-04-15 04:06:56 0000-00-00 00:00:00 2025 0 0 Str. 2485–2495 iss. 7 Vol. 37 Apr. 8, 2025 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 544.5/.6 1520-5002 10.1021/acs.chemmater.4c03067 231531523 ishfaq-et-al-2025-transport-number-determination-and-relevance-for-lithium-metal-batteries-using-localized-highly.pdf ishfaq-et-al-2025-transport-number-determination-and-relevance-for-lithium-metal-batteries-using-localized-highly.pdf 1 DF92ACBE5744360483AF40106D04075D 99ad83e3588a255da5688454090a1a691f8058d2c29785bdbd527a956a1b6f64 5c997d37-190a-11f0-b232-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=201944 https://pubs.acs.org/doi/10.1021/acs.chemmater.4c03067 1 f4bef6a1-1909-11f0-b232-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=201943 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0