Dataset Information

Fast Li-Ion-Conducting Garnet-Related Li_7-3x Fe _x La₃Zr₂O₁₂ with Uncommon I43d Structure.

ABSTRACT: Fast Li-ion-conducting Li oxide garnets receive a great deal of attention as they are suitable candidates for solid-state Li electrolytes. It was recently shown that Ga-stabilized Li₇La₃Zr₂O₁₂ crystallizes in the acentric cubic space group I4?3d. This structure can be derived by a symmetry reduction of the garnet-type Ia3?d structure, which is the most commonly found space group of Li oxide garnets and garnets in general. In this study, single-crystal X-ray diffraction confirms the presence of space group I4?3d also for Li_7-3x Fe _x La₃Zr₂O₁₂. The crystal structure was characterized by X-ray powder diffraction, single-crystal X-ray diffraction, neutron powder diffraction, and Mößbauer spectroscopy. The crystal-chemical behavior of Fe³⁺ in Li₇La₃Zr₂O₁₂ is very similar to that of Ga³⁺. The symmetry reduction seems to be initiated by the ordering of Fe³⁺ onto the tetrahedral Li1 (12a) site of space group I4?3d. Electrochemical impedance spectroscopy measurements showed a Li-ion bulk conductivity of up to 1.38 × 10^-3 S cm^-1 at room temperature, which is among the highest values reported for this group of materials.

SUBMITTER: Wagner R

PROVIDER: S-EPMC4997531 | biostudies-literature | 2016 Aug

REPOSITORIES: biostudies-literature

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Fast Li-Ion-Conducting Garnet-Related Li7-3x Fe x La3Zr2O12 with Uncommon I4̅3d Structure.

Wagner Reinhard R Redhammer Günther J GJ Rettenwander Daniel D Tippelt Gerold G Welzl Andreas A Taibl Stefanie S Fleig Jürgen J Franz Alexandra A Lottermoser Werner W Amthauer Georg G

Chemistry of materials : a publication of the American Chemical Society 20160728 16

Fast Li-ion-conducting Li oxide garnets receive a great deal of attention as they are suitable candidates for solid-state Li electrolytes. It was recently shown that Ga-stabilized Li7La3Zr2O12 crystallizes in the acentric cubic space group I4̅3d. This structure can be derived by a symmetry reduction of the garnet-type Ia3̅d structure, which is the most commonly found space group of Li oxide garnets and garnets in general. In ...[more]

PMID: 27570369

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Project description:Several "Beyond Li-Ion Battery" concepts such as all solid-state batteries and hybrid liquid/solid systems envision the use of a solid electrolyte to protect Li-metal anodes. These configurations are very attractive due to the possibility of exceptionally high energy densities and high (dis)charge rates, but they are far from being realized practically due to a number of issues including high interfacial resistance and difficulties associated with fabrication. One of the most promising solid electrolyte systems for these applications is Al or Ga stabilized Li7La3Zr2O12 (LLZO) based on high ionic conductivities and apparent stability against reduction by Li metal. Nevertheless, the fabrication of dense LLZO membranes with high ionic conductivity and low interfacial resistances remains challenging; it definitely requires a better understanding of the structural and electrochemical properties. In this study, the phase transition from garnet (Ia3̅d, No. 230) to "non-garnet" (I4̅3d, No. 220) space group as a function of composition and the different sintering behavior of Ga and Al stabilized LLZO are identified as important factors in determining the electrochemical properties. The phase transition was located at an Al:Ga substitution ratio of 0.05:0.15 and is accompanied by a significant lowering of the activation energy for Li-ion transport to 0.26 eV. The phase transition combined with microstructural changes concomitant with an increase of the Ga/Al ratio continuously improves the Li-ion conductivity from 2.6 × 10-4 S cm-1 to 1.2 × 10-3 S cm-1, which is close to the calculated maximum for garnet-type materials. The increase in Ga content is also associated with better densification and smaller grains and is accompanied by a change in the area specific resistance (ASR) from 78 to 24 Ω cm2, the lowest reported value for LLZO so far. These results illustrate that understanding the structure-properties relationships in this class of materials allows practical obstacles to its utilization to be readily overcome.

Dataset Information

Fast Li-Ion-Conducting Garnet-Related Li_7-3x Fe _x La₃Zr₂O₁₂ with Uncommon I43d Structure.

Publications

Fast Li-Ion-Conducting Garnet-Related Li<sub>7-3<i>x</i></sub> Fe <sub><i>x</i></sub> La<sub>3</sub>Zr<sub>2</sub>O<sub>12</sub> with Uncommon <i>I</i>4̅3<i>d</i> Structure.

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Dataset Information

Fast Li-Ion-Conducting Garnet-Related Li7-3x Fe x La3Zr2O12 with Uncommon I43d Structure.

Publications

Fast Li-Ion-Conducting Garnet-Related Li<sub>7-3<i>x</i></sub> Fe <sub><i>x</i></sub> La<sub>3</sub>Zr<sub>2</sub>O<sub>12</sub> with Uncommon <i>I</i>4̅3<i>d</i> Structure.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

Fast Li-Ion-Conducting Garnet-Related Li_7-3x Fe _x La₃Zr₂O₁₂ with Uncommon I43d Structure.