In situ X-ray based analysis of anode materials for lithium-ion batteries: Current status and future implications

The past several decades witnessed a significant advance in the X-ray based analytical devices, which were employed in various applications ranging from airport security to material analysis. Particularly, since the early 1990s, much work has been devoted to employ various kinds of real time (in situ ) X-ray based analytical tools such as in situ X-ray diffractometers (XRD), in situ X-ray absorption spectroscopy, and in situ X-ray tomography to understand the redox reactions within the lithium-ion batteries. Amongst components in the lithium-ion batteries, anode materials play an important role in that they are responsible for Li + storage during the charging process. Reaction mechanisms of graphite, Si, and many other prospective anode materials have been elucidated by various in situ X-ray analytical tools but none of the comprehensive summary and evaluation on the current status of the research and future directions on employing in situ X-ray based analysis for further investigating these anode materials are presented up to this point. In this review, we have examined and highlighted our focus on X-ray based analysis that was used to probe the reaction pathway of various anode materials used for lithium-ion batteries, which provides a milestone and comprehensive understanding for reaction mechanism of anode materials in lithium-ion batteries using in situ X-ray methods.