Understanding the influence of local structure distortions on Na-ion migration in perovskite solid electrolytes

• Published in: Journal of power sources 2024-10, Vol.617, p.235154, Article 235154
• Main Authors: Marlton, Frederick P., Yang, Frederick Z.T., Everett, S. Michelle, Neuefeind, Joerg, Schmid, Siegbert
• Format: Article
• Language: English
• ISSN: 0378-7753
• DOI: 10.1016/j.jpowsour.2024.235154

The perovskite structured oxides of composition ABO3 are considered strong candidates for solid-state electrolytes in all-solid-state batteries due to their chemical and structural flexibility. However, further improvements must be made before they become commercially viable, and this requires a clear understanding of the structure-property relationships. In this study, the local structure of the perovskite sodium-ion solid electrolyte series Na1/2−xLa1/2−xSr2xZrO3 (NLSZ, x = 14, 16, 18, 116) was investigated via neutron total scattering. Small-box modelling against the neutron pair distribution function with the orthorhombic Pbnm structure showed local-scale features that deviate from the average structure. Big-box modelling revealed significant differences between the bonding configurations of the different A-site cations, which impacts the ionic conductivity of the material. This study demonstrates how understanding local-scale disorder is important for tuning the structure-property relationships of inorganic solid-state electrolyte materials in sustainable battery technologies. [Display omitted] •Local structure of Na1/2−xLa1/2−xSr2xZrO3 investigated via neutron total scattering.•Small-box modelling shows local-scale features deviate from the average structure.•Big-box modelling shows differences for bonding configurations of the A-site cations.