Oxygen activities in transition-metal oxide based battery cathodes defines many critical performance parameters of batteries, e.g., safety, cyclability, stability, and energy density. While recent researches have been trying to breakthrough some of the conventional wisdom on the understanding and employment of oxygen activities in battery cathodes, debates on both the fundamental mechanism and practicability of oxygen being a redox center remain active with controversy results and claims.<br/>This presentation tries to revisit some of the representative systems of oxide-based cathodes, in particular, Li-rich systems with different transition metals, and conventional materials with stoichiometric Li contents. Through soft X-ray spectroscopy, we try to clarify the different types of oxygen oxidations involved in cathode charged to high voltages, which were often confused together, leading to the misconception of oxygen redox effects on performance. We then further dig into the comparative studies of the oxygen redox activities in various Li-rich and conventional compounds to conclude that oxygen oxidation behaviors are not bounded to any specific Li configurations, instead, it is a common phenomenon among all transition metal oxide cathodes cycled to high voltages.

Oxygen redox in Li-rich and conventional cathode materials: Myth and truth revealed by oxygen spectroscopy

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.