Correlating Nanoscale Structures with Electrochemical Properties of Solid Electrolyte Interphases in Solid-State Battery Electrodes

Abstract

Here, we investigate the nonlinear relationship betweenthe contentof solid electrolytes in composite electrodes and the irreversiblecapacity via the degree of nanoscale uniformity of the surface morphologyand chemical composition of the solid electrolyte interphase (SEI)layer. Using electrochemical strain microscopy (ESM) and X-ray photoelectronspectroscopy (XPS), changes of the chemical composition and morphology(Li and F distribution) in SEI layers on the electrodes as a functionof solid electrolyte contents are analyzed. As a result, we find thatthe solid electrolyte content affects the variation of the SEI layerthickness and chemical distributions of Li and F ions in the SEI layer,which, in turn, influence the Coulombic efficiency. This correlationdetermines the composition of the composite electrode surface thatcan maximize the physical and chemical uniformity of the solid electrolyteon the electrode, which is a key parameter to increase electrochemicalperformance in solid-state batteries.