Visualization and characterization of ionic distribution in solid state battery materials using atomic force microscopy

Abstract

An ever-growing demand for portable electronic devices has driven technological advances in allsolid-state batteries. Although mixing the electrodes and solid electrolytes are widely used for processing composite electrodes to improve the sluggish ionic channel, it remains insufficiently characterized how the ionic channel is distributed and changed during the charging at the microscale. Here, we probed the spatial variation of diffusivity in the cross-sectional graphite composite electrodes depending on the state-of-charge using electrochemical strain microscopy, one of the various modes in AFM. we figured out the correlation between ESM amplitude and capacity. Also, we analyzed the distribution of lithium along depth. Finally, we visualized the diffusivity in the cross-section area depending on state-of-charge. This study will provide insights for understanding the local charging mechanism of the composite electrode in all-solid-state Li-ion batteries.