Defect chemistry in cubic Li6.25Al0.25La3Zr2O12 solid electrolyte: A density functional theory study

Moradabadi, Ashkan; Kaghazchi, Payam

doi:10.1016/j.ssi.2019.04.023

Cited by 24 publications

(19 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the region close to the Li metal anode (under the reducing environment), the LLZO bulk shows the lower Ef of Li i × compared to other defects, which is consistent with the previous study on the Al-doped LLZO. 45 This result implies the high concentration of Li i × and the tendency of Li enrichment in LLZO near the Li metal, which has already been found in the observation using EELS analysis. 50 Moreover, the calculated reduced Ef of Li i × in the GB region indicates the accumulation of Li at some specific GBs [e.g.…”

Section: Resultssupporting

confidence: 69%

See 1 more Smart Citation

Revealing Atomic-Scale Ionic Stability and Transport around Grain Boundaries of Garnet Li7La3Zr2O12 Solid Electrolyte

Gao

Jalem

Tian

et al. 2021

Preprint

View full text Add to dashboard Cite

For real application to the all-solid-state batteries, understanding and control of the grain boundaries (GBs) are essential. However, the in-depth insight into the atomic-scale defect stabilities and transports of ions around the GBs is still far from understood. Here, the first-principles investigation on the promising garnet Li7La3Zr2O12 solid electrolyte GBs has been carried out. Our study reveals a GB-dependent behavior for the Li-ion transport correlated to the diffusion network. Especially, the Σ3(112) tilt GB model exhibits a quite high Li-ion conductivity comparable to that in bulk, and a fast intergranular diffusion contrary to the former concepts. Moreover, the preference of the electron accumulation at the Σ3(112) GB was uncovered in terms of the lower Li interstitial formation energies. This phenomenon is further enhanced by the presence of the Schottky-like defect, leading to the increase in the electronic conductivity at GBs, which plays a key role in the Li dendrite growth.

show abstract

Section: Resultssupporting

confidence: 69%

“…3d), considering the strong electrostatic interactions between Li and O, the neighboring Li and O vacancies have been considered. 45 The calculated Ef for the representative defects in bulk is 1.5-1.8 eV. Similar to the V O × , parts of defects at the 1(110) and 3(112) GBs show remarkably lower Ef values.…”

Section: Resultsmentioning

confidence: 74%

Revealing Atomic-Scale Ionic Stability and Transport around Grain Boundaries of Garnet Li7La3Zr2O12 Solid Electrolyte

Gao

Jalem

Tian

et al. 2021

Preprint

View full text Add to dashboard Cite

show abstract

“…For the native defects, we find a rich family of defect species, including lithium and oxygen vacancies and interstitials, which have been discussed previously, [36][37][38][39] and cation anti-sites; such as Li La , La Zr , Li Zr , and Zr Li ; which are often neglected when considering the defect chemistry of lithium-garnets. Under all conditions except extremely O-poor (reducing) conditions, cation anti-site defects are the highest concentration defect species after V Li .…”

Section: Summary and Discussionmentioning

confidence: 71%

Native Defects and Their Doping Response in the Lithium Solid Electrolyte Li₇La₃Zr₂O₁₂

2019

View full text Add to dashboard Cite

The Li-stuffed garnets LixM2M 3 O12 are promising Li-ion solid electrolytes with potential use in solid-state batteries. One strategy for optimising ionic conductivities in these materials is to tune lithium stoichiometries through aliovalent doping, which is often assumed to produce proportionate numbers of charge-compensating Li vacancies. The native defect chemistry of the Li-stuffed garnets, and their response to doping, however, are not well understood, and it is unknown to what degree a simple vacancy-compensation model is valid. Here, we report hybrid density-functional-theory calculations of a broad range of native defects in the prototypical Li-garnet Li7La3Zr2O12. We calculate equilibrium defect concentrations as a function of synthesis conditions, and model the response of these defect populations to extrinsic doping. We predict a rich defect chemistry that includes Li and O vacancies and interstitials, and significant numbers of cation-antisite defects. Under reducing conditions, O vacancies act as colour-centres by trapping electrons. We find that supervalent (donor) doping does not produce charge compensating Li vacancies under all synthesis conditions; under Li-rich / Zr-poor conditions the dominant compensating defects are LiZr antisites, and Li stoichiometries strongly deviate from those predicted by simple "vacancy compensation" models.

show abstract

“…the removal of Li 2 O through a Schottkylike, or partial Schottky process) is also a relatively low energy process compared to other Schottky reactions in LLZO. DFT simulation performed by Moradabadi et al 38 on Al-doped cubic LLZO shows that Li 2 O Schottky-like defect comprising of a cluster of 2 Li + and O 2− vacancies is the second most favourable defect process under poor O condition though the most favourable defect type is ZrLi 2 O-Schottky-like defect under poor Zr condition. Simulation studies indicates that the loss of Li 2 O seems to be a common feature in pristine and doped-LLZO.…”

Section: Resultsmentioning

confidence: 99%

Self-diffusion in garnet-type Li7La3Zr2O12 solid electrolytes

Kuganathan

Rushton

Grimes

et al. 2021

Sci Rep

View full text Add to dashboard Cite

Tetragonal garnet-type Li7La3Zr2O12 is an important candidate solid electrolyte for all-solid-state lithium ion batteries because of its high ionic conductivity and large electrochemical potential window. Here we employ atomistic simulation methods to show that the most favourable disorder process in Li7La3Zr2O12 involves loss of Li2O resulting in lithium and oxygen vacancies, which promote vacancy mediated self-diffusion. The activation energy for lithium migration (0.45 eV) is much lower than that for oxygen (1.65 eV). Furthermore, the oxygen migration activation energy reveals that the oxygen diffusion in this material can be facilitated at higher temperatures once oxygen vacancies form.

show abstract

Defect chemistry in cubic Li6.25Al0.25La3Zr2O12 solid electrolyte: A density functional theory study

Cited by 24 publications

References 54 publications

Revealing Atomic-Scale Ionic Stability and Transport around Grain Boundaries of Garnet Li7La3Zr2O12 Solid Electrolyte

Revealing Atomic-Scale Ionic Stability and Transport around Grain Boundaries of Garnet Li7La3Zr2O12 Solid Electrolyte

Native Defects and Their Doping Response in the Lithium Solid Electrolyte Li₇La₃Zr₂O₁₂

Self-diffusion in garnet-type Li7La3Zr2O12 solid electrolytes

Contact Info

Product

Resources

About

Defect chemistry in cubic Li6.25Al0.25La3Zr2O12 solid electrolyte: A density functional theory study

Cited by 24 publications

References 54 publications

Revealing Atomic-Scale Ionic Stability and Transport around Grain Boundaries of Garnet Li7La3Zr2O12 Solid Electrolyte

Revealing Atomic-Scale Ionic Stability and Transport around Grain Boundaries of Garnet Li7La3Zr2O12 Solid Electrolyte

Native Defects and Their Doping Response in the Lithium Solid Electrolyte Li7La3Zr2O12

Self-diffusion in garnet-type Li7La3Zr2O12 solid electrolytes

Contact Info

Product

Resources

About

Native Defects and Their Doping Response in the Lithium Solid Electrolyte Li₇La₃Zr₂O₁₂