Presenter:  Claire Villevieille
Title: Operando synchrotron and neutron based techniques to probe battery materials
Affiliation: Université Grenoble-Alpes, Grenoble INP, LEPMI laboratory, France

Abstract

The Li-ion chemistry is thus far the most advanced chemistry employed in battery technology. To date, Li-ion batteries dominate the market of the electronics and portables devices. However, in the field of electric and hybrid vehicles further improvements are required in terms of performance, safety, and cost. The same set of criteria concerns other systems based on alternative chemistries such as Na-ion and solid-state batteries. Advanced Li-ion batteries and the pre-cited novel systems utilize less understood electroactive materials and thus show new reaction mechanisms during electrochemical cycling, the understanding of which requires new characterization tools and techniques.

Unfortunately, in most cases the electrochemical cells used for operando measurement are not ideal and suffer from low internal pressure (i.e. poor contact between the electrodes). It shorts the lifespan of the cell and as a consequence most of the studies presented in the literature focus on the first/second cycle. Herein we present different cell designs developed in our laboratory and used for operando/in situ studies. Having overcome earlier mentioned obstacle our operando/in situ cells are able to sustain more than 100 cycles and simultaneously to perform structural studies such as X-ray and neutron diffraction. For the latter one, we also developed a new set-up called stroboscopic mode. It allows operando study of the batteries that are cycling at very high rates (e.g. 10C) with a neutron patterns collected each 1 s along 200 cycles and more.

Additionally, we will use bulk, surface and imaging techniques to better understand the limitation of all solid state batteries. As an example, Operando neutron imaging has been employed to understand the Li diffusion within the electrode and inside an all-solid state batteries employing Li3PS4 as solid electrolyte whereas operando X-ray microscopic tomography was employed to follow the possible electro-mechanical fracture occurring during cycling and the possible impact on the electrochemical performance.

Other examples based on different operando/in situ techniques such as X-ray diffraction, neutron diffraction, neutron imaging, and X-ray tomography microscopic used to characterize batteries will be presented during the talk.