Recent Advances in X-ray Absorption Spectroscopy for Battery Applications

The optimization of batteries is a challenge for sustainable human development. Batteries have played a pivotal role in reducing greenhouse gas emissions across diverse sectors, including light and heavy transportation, power generation, stationary energy storage, and industrial processes, thereby mitigating environmental pollution. Despite these advancements, a comprehensive understanding of battery operational processes remains elusive. Critical aspects, such as reaction mechanisms, side reactions, ion transport, and the formation of solid electrolyte interphases (SEI) are still not fully elucidated. Recently, with the continuous improvement of synchrotron-related technology, the advantages of X-ray absorption spectroscopy (XAS) in the research of battery materials have become more and more prominent, providing an important skill for the research of battery materials. This review focuses on the application of XAS in the research of lithium-ion (Li-ion) batteries, all-solid-state batteries (ASSBs) and lithium–sulfur (Li–S) batteries and demonstrates the key role of XAS in analyzing the interface changes between electrode materials and electrolytes and optimizing battery performance. Moreover, XAS technology enables researchers to monitor the structural and chemical state changes of battery materials under real-world operating conditions in real time, providing a theoretical basis for the development of safer, environmentally friendly, and more cost-effective battery materials. Despite the significant progress made by XAS technology in the study of battery materials, challenges remain, such as the difficulty of capturing fast dynamic processes in real time. In the future, advances in XAS technology for batteries will need to be further developed in conjunction with other characterization methods to gain deeper insights.