Nanoscale characterization of solid electrolyte by Scanning Probe Microscopy techniques

Abstract All-solid-state battery is potentially for the next generation lithium ion battery. In all-solid-state battery, the solid electrolyte plays the most important role. However, the nanoscale electrochemical properties of the solid electrolyte are not well understood yet. In this study, by using Scanning Probe Microscopy (SPM) based techniques, including Atomic Force Microscopy (AFM) and Electrochemical Strain Microscopy (ESM), the electrochemical deformation within grains and grain boundaries in the NASICON-structured (sodium (Na) Super Ionic CONductor) Li1.5Al0.5Ge1.5(PO4)3 (LAGP) solid electrolyte is studied at the nanoscale first time. The different electrochemical responses at grains and grain boundaries of the LAGP solid electrolyte are observed clearly due to different lithium ion conductivities insides the grains and along the grain boundaries. These results provide the new insights on the nanoscale electrochemical mechanisms and development of the solid electrolyte materials.