Behaviors of H, D, and Li in water-soaked LATP solid electrolytes at room temperature

The elastic recoil detection (ERD) technique was employed to measure the depth distributions of lithium (Li) and hydrogen isotopes (H and D) near the surface of NASICON-type LATP (Li1+xAlxTi1-x/2Ge1-x/2P3-yO12) solid electrolytes soaked in water (H2O and D2O) at room temperature for 1-80 days. The ERD spectra demonstrated H and D absorption on the LATP surface by H2O and D2O soaking and Li segregation to the top surface. Moreover, the field emission-scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM) images, and atomic absorption spectrophotometry (AAS) indicated the formation of numerous black substances with approximately 0.5 x 3.0 mu m2 in area and < similar to 50 nm in thickness and the dissolution of Li in water. Li migration from the bulk to the surface may occur through the reactions of H2O and D2O with Ge, subsequently leading to H and D trapping at Li substitutional sites.(c) 2023 Elsevier B.V. All rights reserved.

Automated summary

The ERD technique was used to measure the depth distributions of Li and hydrogen isotopes near the surface of LATP solid electrolytes soaked in water. The results showed H and D absorption on the surface, Li segregation to the top surface, and the formation of black substances and Li dissolution in water. It is suggested that Li migration from the bulk to the surface occurs through reactions with Ge and traps H and D at substitutional sites.