Spatially resolved stoichiometry determination of Li7La3Zr2O12 solid-state electrolytes using LA-ICP-OES. Issue 5 (8th April 2020)

• Record Type: Journal Article
• Authors: Smetaczek, Stefan; Bonta, Maximilian; Wachter-Welzl, Andreas; Taibl, Stefanie; Wagner, Reinhard; Rettenwander, Daniel; Fleig, Jürgen; Limbeck, Andreas
• Is Part Of: Journal of analytical atomic spectrometry. Volume 35:Issue 5(2020)
• Page Start: 972
• Page End: 983
• Publication Date: 2020-04-08
• Subjects: Atomic spectra -- Periodicals; Atomic absorption spectroscopy -- Periodicals; 543.0858
• DOI: 10.1039/d0ja00051e
• Languages: English
• ISSNs: 0267-9477

Abstract

Abstract : LA-ICP-OES in combination with matrix-matched calibration standards and proper signal normalization enables reliable laterally resolved stoichiometry determination of Al stabilized LLZO (Li7−3 x Al x La3 Zr2 O12 ) solid electrolytes. Abstract : Cubic Li7 La3 Zr2 O12 (LLZO) garnets are among the most promising solid-state electrolytes for next-generation Li batteries. However, despite intensive research in recent years, little effort is spent on proper chemical analysis of the material. For reliable LLZO investigation, knowledge about the exact chemical composition, especially the Li content, is of uttermost importance. Herein, we present a method for the laterally resolved stoichiometry determination of Al stabilized LLZO (Li7−3 x Al x La3 Zr2 O12 ) using LA-ICP-OES. To ensure reliable signal quantification, matrix-matched standards are prepared and carefully characterized using sample digestion and liquid ICP-OES measurement. An internal standard-independent calibration strategy based on 100 m% normalization is applied, enabling the quantification of all cations within the material. By comparing the obtained high-precision LA-ICP-OES calibrations with analog LA-ICP-MS measurements, it is shown that ICP-OES is the superior choice for the analysis of Li. The developed method is applied to record quantitative distribution images of an Al stabilized LLZO pellet, revealing macroscopic stoichiometry variations within the sample. To verify the analysis, the average stoichiometry obtained by the LA measurements is compared with the bulk composition determined via liquid ICP-OES analysis after sample fusion. The obtained values show excellent agreement, confirming the accuracy of the developed method.