Developing a battery system with high energy-density, stability and safety standards is critical for today’s sustainable energy applications. However, the performance improvement of batteries has been slow and remains a formidable challenge. The pressing demand calls for novel approaches based on advanced characterization tools, such as synchrotron-based soft x-ray spectroscopy.

This presentation will start with a simple introduction of the link between electron states and battery performance. We then discuss several synchrotron-based spectroscopy results for understanding the mechanism, for optimizing the materials, and for delivering new design concepts of batteries. We show that critical electronic states, directly detected by soft x-ray experiments, could provide guidelines for developing commercially viable materials. Clarifying cycling mechanism of battery electrodes could lead to new hint on how to avoid the failing mode. Revealing the chemical and physical activities on surfaces/interfaces suggests novel concepts for developing new types of high-performance batteries.

In addition to the established role of soft x-ray spectroscopy in fundamental researches, this talk hopes to showcase that soft x-ray spectroscopy could also be employed as a powerful development tool to advance the battery technology.