Studies on technologically relevant compounds for all-solid-state batteries - the garnet-type solid-state electrolyte Li6La3ZrTaO12

 

Ceramic electrolytes with high ionic conductivities are a prerequisite for the next-generation of all-solid-state lithium batteries as well as a negligible electronic conductivity to avoid self-discharge and/or formation of Li dendrites. , being currently one of the key issues hindering the development of long-lasting all-solid-state batteries. The garnet-type Li7La3Zr2O12 (LLZO) is an ideal model system for detailed studies on effects driven by extrinsic or intrinsic factors such as impurities, chemical inhomogeneities, grain boundaries, morphology and size effects. The high instrumental resolution of HEiDi allowed for comprehensive structural studies on the pure and Ta doped single crystals.

  Li6La3ZrTaO12 Copyright: © IfK

a, b) Crystal structure of Ga-containing Li6.4Ga0.2La3Zr2O12 (space group I43d (No. 220)) as determined by a combined, simultaneous refinement of both data from X-ray diffraction and neutron diffraction. The Li ions are distributed over three different crystallographic sites (12a (Li1), 12b (Li2), 48e (Li3)) in the acentric space group. Ga3 + ions share sites with Li+ located at the Li1 site, being the Wyckoff position 12a. The Li+ ions form a 3D network enabling them to quickly diffuse through the crystal structure [3].

 

Publications:

[1] Single-crystal neutron and X-ray diffraction study of garnet-type solid-state electrolyte Li6La3ZrTaO12: an in situ temperature-dependence investigation (2.5 ≤ T ≤ 873 K); G. J. Redhammer, M. Meven, S. Ganschow, G. Tippelt and D. Rettenwander; Acta Cryst. B 77, 123-130 (2021); DOI: 10.1107/S2052520620016145

[2] Wet-Environment-Induced Structural Alterations in Single- and Polycrystalline LLZTO Solid Electrolytes Studied by Diffraction Techniques; Günther J. Redhammer, Pavan Badami, Martin Meven, Steffen Ganschow, Stefan Berendts, Gerold Tippelt, and Daniel Rettenwander; ACS Appl. Mater. Interfaces, 350–359 (2021); DOI: 10.1021/acsami.0c16016

[3] The Electronic Conductivity of Single Crystalline Ga Stabilized Cubic Li7La3Zr2O12: A Technologically Relevant Parameter for All Solid State Batteries; Martin Philipp, Bernhard Gadermaier, Patrick Posch, Ilie Hanzu, Steffen Ganschow, Martin Meven, Daniel Rettenwander, Günther J. Redhammer, H. Martin R. Wilkening; Adv. Mater. Interfaces 7, 200450 (2020); DOI: 10.1002/admi.202000450