Abstract
Visualization and quantification of the morphological changes of Si-based electrodes occurring upon cycling are essential for better understanding their degradation mechanism and for optimizing their formulation. In this context, in-situ and ex-situ X-ray computed tomography (XRCT) analyses are here performed on Si-based electrodes for different cycling steps and at different scales ( i.e. from the composite electrode level down to the Si particle one). Three different cell configurations and four different X-ray sources (one laboratory and three synchrotrons) have been used and their impact on the image resolution/quality and the segmentation of the different solid, electrolyte and gas phases of the composite electrodes is highlighted. From these complementary XRCT analyses with a voxel size ranging from 0.8 to 0.05 μm, key morphological features have been studied such as (i) the volume expansion/contraction of the electrode, (ii) the dynamics of the electrode macrocracking, (iii) the initial solid electrolyte interphase (SEI) layer growth and related formation of gas and consumption of electrolyte, which strongly depend on the presence of fluoroethylene carbonate in the electrolyte, (iv) the evolution of the electrode porosity and macrocrack volume fraction/connectivity/width after prolonged cycling. • Morphological changes of Si-based electrodes are studied by in- and ex-situ XRCT. • XRCT analyses are performed at different scales and spatial resolutions. • The impact of the cell configuration and X-ray source is highlighted. • The electrode volume change, macrocracking and SEI formation are characterized.
Submitted Version (
Free)
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call