New findings on the lithium-oxygen battery: Overpotential and its causes

The research results can help accelerate the development of more effective and efficient lithium-oxygen batteries and other rechargeable batteries. This is because the factors that are causally involved in overpotential can now be clearly distinguished from one another. In particular, these include the long-term kinetics of lithium peroxide (Li₂O₂) oxidation and surface passivation by lithium carbonate (Li₂CO₃). Electrochemical impedance spectroscopy (EIS) is able to monitor these processes separately during battery charging.

"In our study, we integrated electrochemical impedance spectroscopy, using the distribution of capacitive times and the distribution of relaxation times, alongside in situ differential electrochemical mass spectrometry. This enabled a temporally resolved examination of the charging mechanism within an established model catalyst deployed as a representative LiO₂ battery electrode," says Prof. Dr. Francesco Ciucci, who holds a professorship in electrode design for electrochemical energy storage at the University of Bayreuth. He is a member of the Bavarian Center for Battery Technology (BayBatt). The research work published in "Chem" demonstrates the efficiency of this research approach. At the same time, however, the authors emphasize that further experimental studies are needed to further establish the mechanism.

Publication:
Juan Chen, Emanuele Quattrocchi, Francesco Ciucci, Yuhui Chen: Charging processes in lithium-oxygen batteries unraveled through the lens of the distribution of relaxation times. Chem (2023). DOI: https://doi.org/10.1016/j.chempr.2023.04.022