Gaining More Insights from Synchrotron-Based X-ray Spectroscopy for Alkali Ion Rechargeable Batteries

Abstract

Alkali ion rechargeable batteries play a significant part in portable electronic devices and electronic vehicles. The rapid development of renewable energy technology nowadays demands batteries with even higher energy density for grid storage. To fulfill such demand, extensive research efforts have been devoted to optimizing electrochemical properties as well as developing novel energy storage schemes and designing new systems. In the investigation process, synchrotron-based X-ray spectroscopy plays a vital role in investigating the detailed degradation mechanism and developing novel energy storage schemes. Herein, we critically review the applications of synchrotron-based X-ray spectroscopy in battery research in recent years. This review begins with a discussion of the different scientific issues in alkali ion rechargeable batteries within various time and space scales. Subsequently, the principle of synchrotron-based X-ray spectroscopy is introduced, and the characteristics of various characterization techniques are summarized and compared. Typical application cases of synchrotron-based X-ray spectroscopy are then introduced into battery investigations. The final part presents perspectives in the development direction of both alkali ion rechargeable battery systems and synchrotronbased X-ray spectroscopy in the future.

Structural regulation-induced Li-electron disentanglement for stabilized oxygen redox of Li-excess disordered rock-salt cathode materials

“…Technically, spectroscopic techniques including X-ray photoemission spectroscopy (XPS), X-ray absorption spectroscopy (XAS), and resonant inelastic X-ray scattering (RIXS) have been extensively employed to discern the capacity contribution from oxygen oxidation in cathode materials. 19 The relatively uniform oxygen environment in conventional oxide cathodes facilitates the establishment of the correlation between the measured average oxygen redox contribution and bulk structure evolution. However, the diverse local structural features in the DRX material obstruct discerning the site-specific redox behaviour, as shown by bulk-averaged spectroscopic results.…”