Journal Article

IMPULSE-2026-00016

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png The origin of enhanced conductivity and structure change in defective Li$_{4}$Ti$_{5}$O$_{12}$: a study combining theoretical and experimental perspectives

Chan, Y.-T. (Corresponding author) ; Grosu, C. ; Kick, M. ; Jakes, P. ; Gigl, T. ; Seidlmayer, S. ; Egger, W.MLZ* ; Eichel, R.-A. ; Granwehr, J. ; Hugenschmidt, C.MLZ* ; Scheurer, C.

2025
RSC London ˜[u.a.]œ

Please use a persistent id in citations: doi:10.1039/D5TA02110C

Abstract: The spinel Li$_{4}$Ti$_{5}$O$_{12}$ (LTO) has emerged as a promising anode material for the next generation of all-solid-state Li-ion batteries (ASSB), primarily due to its characteristic “zero strain” charge/discharge behavior and exceptional cycling stability, which significantly prolongs battery lifespan. Pristine LTO, however, is hindered by poor ionic and electronic conductivity. By employing tailored sintering protocols that create oxygen vacancies, a high-performing, blue LTO material is achieved. It has been proposed that the increased electronic conductivity could stem from vacancy-induced polarons. Yet, detailed insights into polaron stability, distribution, and dynamics within both the LTO bulk and surface have remained elusive due to limited information on structural changes. Utilizing Positron Annihilation Lifetime Spectroscopy (PALS) and Coincidence Doppler Broadening Spectroscopy (CDBS), in conjunction with Two Component Density Functional Theory (TCDFT) with the on-site Hubbard U correction, enables us to probe the depth profile of defect species introduced by sintering in a reductive environment. Our research provides direct evidence of oxygen vacancy formation within the subsurface region, an inference drawn from the observation of Ti3+. Our investigation into Li16d vacancy formation within the bulk region uncovers the interactions between mobile species, namely Li-ions and polarons. Furthermore, we delve into the polaron stability on the LTO surface, offering an explanation for the superior performance of the (100) facet exposed LTO nanoparticle, as compared to its (111) exposed counterpart.

Keyword(s): Chemical Reactions and Advanced Materials (1st) ; Condensed Matter Physics (2nd) ; Materials Science (2nd)

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Contributing Institute(s):

1. NEPOMUC (NEPOMUC)

Experiment(s):

1. NEPOMUC: Neutron induced positron source munich (SR11)

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Database coverage:
; Clarivate Analytics Master Journal List ; Current Contents - Engineering, Computing and Technology ; Current Contents - Physical, Chemical and Earth Sciences ; Essential Science Indicators ; IF >= 10 ; JCR ; National-Konsortium ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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