In Situ Synchrotron X-Ray Absorption Spectroscopy Studies of Anode Materials for Rechargeable Batteries

Taking advantage of a high-flux light source, synchrotron X-ray absorption spectroscopy (XAS) beamline is able to perform in situ/ex situ, element-selective, and qualitative/quantitative experiments to elucidate electrochemical reaction mechanisms of batteries accurately and efficiently. In situ synchrotron XAS probes dynamic electronic and local atomic structure information, including valence state, charge transfer, local geometry and symmetry, bond number/length/type and disorder degree, of target elements of significance during battery operation, which facilitates to promote the development of rechargeable batteries by building accurate structure-performance relationships fundamentally. In this review, the basic principles for XAS are briefly introduced, design strategies for in situ XAS experiments are proposed, salient in situ XAS studies of battery anodes are summarized, and current challenges and future opportunities based on XAS measurements are also outlined.