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Lithium‐Ion Transport in Li 4 Ti 5 O 12 Epitaxial Thin Films vs. State of Charge
Author(s) -
Pagani Francesco,
Döbeli Max,
Battaglia Corsin
Publication year - 2021
Publication title -
batteries and supercaps
Language(s) - English
Resource type - Journals
ISSN - 2566-6223
DOI - 10.1002/batt.202000159
Subject(s) - lithium (medication) , elastic recoil detection , materials science , analytical chemistry (journal) , ion , electrochemistry , lithium titanate , thin film , epitaxy , conductivity , diffraction , anode , electrode , lithium ion battery , chemistry , nanotechnology , optics , battery (electricity) , medicine , power (physics) , physics , organic chemistry , chromatography , endocrinology , quantum mechanics , layer (electronics)
We investigate the electrochemical lithiation of epitaxial Li 4 Ti 5 O 12 thin‐film model electrodes grown on epitaxial platinum current collectors. Structure and composition of Li 4 Ti 5 O 12 films are confirmed by out‐of‐plane and in‐plane X‐ray diffraction and elastic recoil detection analysis. Employing different cell configurations, we deconvolute electrochemical impedance spectra and extract for the first time the lithium‐ion conductivity as a function of electrochemical lithiation. Lithium‐ion conductivity increases monotonously by more than two orders of magnitude from 2.6 ⋅ 10 −9 S/cm in Li 4 Ti 5 O 12 to above 3 ⋅ 10 −7 S/cm between Li 4.5 Ti 5 O 12 and Li 6 Ti 5 O 12 and drops again to 1.3 ⋅ 10 −9 S/cm in Li 7 Ti 5 O 12 . We discuss our results in light of nuclear magnetic resonance studies and theoretical models reported previously and derive important implications for fast‐charging applications of lithium‐ion batteries with Li 4 Ti 5 O 12 anodes.