Regensburg 2019 – wissenschaftliches Programm
MM 22.10: Vortrag
Mittwoch, 3. April 2019, 12:45–13:00, H43
A first-principles based LATP force-field for grain-boundary simulations — Simon Rittmeyer1, Karsten Reuter1, Rüdiger Eichel2, and •Christoph Scheurer1 — 1Theoretische Chemie, TU München — 2IEK-9, FZ Jülich
Superionic lithium-ion conductors of NASICON structure are promising solid-state electrolytes (SSE) for all solid-state batteries (ASSB). A detailed multi-modal experimental analysis of carefully sintered Li1+xAlxTi2−x(PO4)3 (LATP, x=0.3) has yielded interesting structural insights and a surprisingly lower ionic conductivity in the amorphous grain boundary interphase than in the grain bulk. Combined with high cycling stability observed in a LATP-based phosphate-backbone ASSB, these findings call for a detailed microscopic understanding. We have constructed a first-principles based force-field which covers stoichiometries x=0… 0.3 and sampled surface slab models representing possible LATP mixed occupancies. DFT computations on large surface models yield first insights into the mechanisms behind the peculiar properties of this material.
 A. Mertens, S. Yu, N. Schön, D. Guenduez, H. Tempel, R. Schierholz, F. Hausen, H. Kungl, J. Granwehr, and R. Eichel, Solid state ionics 309 (2017), 180.