Multi-scale quantification and modeling of aged nanostructured silicon-based composite anodes
Thomas Vorauer, Praveen Kumar, Christopher L. Berhaut, Fereshteh Falah Chamasemani, Pierre‐Henri Jouneau, David Aradilla, Samuel Tardif, Stéphanie Pouget, Bernd Fuchsbichler, Lukas Helfen, Selçuk Atalay, Widanalage Dhammika Widanage, Stefan Koller, Sandrine Lyonnard, Roland Brunner
Abstract
Abstract Advanced anode material designs utilizing dual phase alloy systems like Si/FeSi 2 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-FeSi 2 ) 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.