Degradation Processes in (Post-)Lithium-Ion Batteries
Prof. Hubert A. Gasteiger, TU München
Increasing the cycle-life of lithium-oxygen and lithium-ion batteries (LiBs) requires a detailed understanding of the various materials degradation mechanisms which lead to capacity fading and a concomitant loss of energy storage capacity. This is caused by a loss of active lithium due to electrolyte reduction, largely prevented by the formation of a so-called solid electrolyte interphase (SEI) at the negative electrode, by the consumption of electrolyte by reduction/oxidation, and/or by an impedance build-up which is due to SEI growth or the formation of a passivating surface film at the positive electrode.
In this presentation, we will utilize electrochemical diagnostics, ex-situ XRD, operando spectroscopies (EPR, XAS), and on-line mass spectrometry (OEMS) to examine: i) the decomposition of electrolyte during the charging of lithium-oxygen batteries; ii) the decomposition of electrolyte as well as of electrolyte impurities, which leads to so-called “gassing” phenomena in LiBs; iii) the dissolution of transition metal ions from transition metal oxide based LiB cathodes; and, iv) the loss of active lithium.