The origin of conductivity variations in Al-stabilized Li7La3Zr2O12 ceramics

Atomistic Insight into Ion Transport and Conductivity in Ga/Al-Substituted Li7La3Zr2O12 Solid Electrolytes

“…Matsuda et al 59 used impedance spectroscopy to show that decreasing the density 21 are represented by filled symbols (error bars smaller than symbols). Literature data from experiments by Rettenwander et al, 11 Bernuy-Lopez et al, 16 Wu et al, 49 Wachter-Welzl et al, 69 Suzuki et al, 70 Zhang et al, 61 Rangasamy et al, 60 Matsuda et al 59 and Yi et al 63 (0.8 mS/cm), and Bernuy-Lopez et al 16 (1.0 mS/cm).…”

Local Li-ion conductivity changes within Al stabilized Li7La3Zr2O12 and their relationship to three-dimensional variations of the bulk composition

“…For LLZO stabilized by Al, which was the rst element found to stabilize the cubic phase at room temperature, 44,45 published values for bulk conductivity cover essentially the entire range from 10 À4 S cm À1 to 10 À3 S cm À1 , whereby overall effective conductivities are oen lower than the bulk value. [46][47][48][49] A recent study on 44 nominally identical samples revealed conductivities from about 10 À5 S cm À1 to 0.8 Â 10 À3 S cm À1 for LLZO with 0.2 Al per formula unit (pfu). 46 Conductivity variations thus cannot be attributed only to the different preparation routes and degradation effects and must be caused by another (yet unknown) parameter.…”

Spatially resolved stoichiometry determination of Li7La3Zr2O12 solid-state electrolytes using LA-ICP-OES

“…In these experiments, the bulk composition of the samples (determined by ICP-OES) served as standard for signal quantication, assuming that the chemical composition is constant over the whole sample aer reaching a specic sampling depth. Since one of our previous studies revealed macroscopic inhomogeneities in Al stabilized LLZO pellets, 19 this assumption does not seem to be correct for all samples, questioning the suitability of this quantication approach. Overall, there is still need for a laterally resolved method for LLZO analysis that provides reliable quantitative information.…”

“…For example, pellets with the same nominal composition prepared at different laboratories show differences in ionic conductivity of more than an order of magnitude. 11,19 Furthermore, local conductivity variations have been reported within one and the same sample. 20 The reasons for these variations are still not completely understood, however, they probably relate to differences in sample stoichiometry.…”

“…20 The reasons for these variations are still not completely understood, however, they probably relate to differences in sample stoichiometry. 19 Since synthesis of LLZO normally involves hightemperature treatment, partial loss of Li 2 O due to evaporation cannot be avoided. 21,22 In addition, Al incorporation from the commonly used Al 2 O 3 crucibles further changes the sample composition.…”