Multi-scale quantification and modeling of aged nanostructured silicon-based composite anodes

• DOI: 10.1038/s42004-020-00386-x
• Publication Date: 2020-10-16T10:02:55Z
• Authors: Thomas Vorauer; Praveen Kumar; Christopher L. Be...; Fereshteh F. Cham...; Pierre-Henri Jouneau; David Aradilla; Samuel Tardif; Stephanie Pouget; Bernd Fuchsbichler; Lukas Helfen; Selcuk Atalay; Widanalage D. Wid...; Stefan Koller; Sandrine Lyonnard; Roland Brunner
• Keywords: Technology; ddc:600; PHASE CONTRAST MICROTOMOGRAPHY; MATERIALS RESEARCH; Li-ion batteries; 600; advanced characterization; tomography; simulation; [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation; 01 natural sciences; 7. Clean energy; Article; 620; 0104 chemical sciences; BATTERY MATERIALS; BATTERY ELECTRODE; [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci]; info:eu-repo/classification/ddc/600; SAXS-WAXS; LI IONIC CONDUCTORS

AbstractAdvanced anode material designs utilizing dual phase alloy systems like Si/FeSi2 nano-composites show great potential to decrease the capacity degrading and improve the cycling capability for Lithium (Li)-ion batteries. Here, we present a multi-scale characterization approach to understand the (de-)lithiation and irreversible volumetric changes of the amorphous silicon (a-Si)/crystalline iron-silicide (c-FeSi2) nanoscale phase and its evolution due to cycling, as well as their impact on the proximate pore network. Scattering and 2D/3D imaging techniques are applied to probe the anode structural ageing from nm to μm length scales, after up to 300 charge-discharge cycles, and combined with modeling using the collected image data as an input. We obtain a quantified insight into the inhomogeneous lithiation of the active material induced by the morphology changes due to cycling. The electrochemical performance of Li-ion batteries does not only depend on the active material used, but also on the architecture of its proximity.