TY  - JOUR
AU  - Moradabadi, Ashkan
AU  - Kaghazchi, Payam
TI  - Effect of lattice and dopant–induced strain on the conductivity of solid electrolytes: application of the elastic dipole method
JO  - Materialia
VL  - 9
SN  - 2589-1529
CY  - Amsterdam
PB  - Elsevier
M1  - FZJ-2020-02584
SP  - 100607
PY  - 2020
AB  - Here, we studied the possibility of applying the elastic dipole method (EDM) to predict the response of defect formation and migration energy to an external strain field (ϵij) in Al-doped cubic Li6.25Al0.25La3Zr2O12 (Al-LLZO) and Li10GeP2S12 (LGPS). It is shown that EDM can quantitatively provide accurate values for Li-defect formation energy as a function of ϵij. EDM can also predict, qualitatively, how the migration barrier varies with ϵij. In both Al-LLZO and LGPS systems, the formation energy of Li vacancy decreases (increases) by applying a tensile (compressive) strain, which is because the lattice parameters tend to expand by formation of a Li vacancy. An opposite behavior is found for the formation energy of interstitial Li. Furthermore, we found that a compressive strain decreases the diffusion barrier in Al-LLZO, while it increases it in LGPS. The lowering of migration barrier in Al-LLZO is in spite of contraction of bottleneck width of Li diffusion in this system. This finding is in line with a recent experimental study. Analysis of EDM results shows that the lowering (rising) in the migration barrier of Li in Al-LLZO (LGPS) under a compressive strain is due to tendency of the system to contract (expand) Li–O (Li–S) bond lengths in the transition states where Li ions are at the bottlenecks of diffusion pathways. We finally show that the result of Li migration barrier as a function of strain in a non-doped solid electrolyte can be used to predict the global effect of substitution/doping on the conductivity of that system.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000537621200031
DO  - DOI:10.1016/j.mtla.2020.100607
UR  - https://juser.fz-juelich.de/record/878028
ER  -