Synchrotron Based Operando Methods for Characterization of Non-Aqueous Rechargeable Battery Electrode Materials

Abstract

Lithium-ion batteries (LIBs) are the power source of choice for portable devices and electric vehicles. The technology is increasingly used for large-scale stationary energy storage to balance supply and demand of intermittent renewable energy. Lithium and sodium have similar chemistries and sodium-ion batteries (SIBs) may provide cost advantages over LIBs. Huge research efforts are currently underway to develop suitable SIB materials. Understanding working and degradation mechanisms of electrode materials at the atomic scale is fundamental to optimize battery materials. For this purpose a set-up that enables combined quasi-simultaneous operando X-ray diffraction and X-ray absorption spectroscopy coupled with electrochemical characterization was developed. A range of LIB and SIB electrode materials were studied with the emphasis on sodium negative electrode materials. Various material-related properties such as vacancy and water content, transition metal ordering, degree of amorphization, crystallite size and nanostructuring were found to affect the structural chemistry during cycling, which was put into context with the electrochemical properties of the battery system.