Regensburg 2019 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 56: Focus: Computational Methods for the Energy Transition: Paving the Road to Future Materials and Storage Systems - organized by Stephan Kramer and Jochen Zausch
CPP 56.7: Vortrag
Donnerstag, 4. April 2019, 17:30–17:45, H14
Computational Analysis of Composition-Structure-Property-Relationships in NZP-type Materials for Li-Ion Batteries — •Daniel Mutter1,2, Daniel F. Urban1, and Christian Elsässer1,2 — 1Fraunhofer IWM, Wöhlerstraße 11, 79108 Freiburg — 2Freiburger Materialforschungszentrum FMF, Stefan-Meier-Str. 21, 79104 Freiburg
Compounds crystallizing in the structure of NaZr2(PO4)3 (NZP) are considered as promising materials for solid state electrolytes in Li-ion batteries. Using density functional theory (DFT), a systematic computational screening of 18 NZP compounds, namely LiX2(LO4)3 with X = Ti, V, Fe, Zr, Nb, Ru, Hf, Ta, Os, and L = P, Mn is performed with respect to their activation energies for vacancy-mediated Li migration. It is shown how the different ionic radii of the cationic substitutions influence structural characteristics such as the octahedron volumes around Li ions on the initial and transition state sites, which affect the activation energies (”composition-structure-property”-relationships). The prevalent assumption that structural bottlenecks formed by triangularly arranged oxygen atoms at a certain location along the migration path determine the energy barriers for Li migration is not supported by the DFT results. Instead, the ionic neighborhood of the migrating ion in the initial and in the transition state need to be taken into consideration to relate the structure to the activation energies. This conclusion applies to Na containing NZP compounds as well.