Katerina Aifantis

Abstract:

Si and Sn are the most promising anodes for Li-ion and Na-ion batteries, respectively. Despite their high capacity upon the formation of Li and Na rich alloys, the main drawback in commercializing these promising electrodes lies in the severe volume expansion and subsequent fracture they experience upon electrochemical cycling. The present talk, hence, focuses on capturing and modeling this severe fracture, by electrochemically cycling Si and Sn films with respect to Li and Na. Scanning electron microscopy can illustrate the extent of fracture and reveal that additional plasticity mechanisms occur in the case of Na-Sn. The experimental data are complemented by a phase field model, which can accurately predict the fracture in patterned Si anodes during lithiation. This is the first rigorous correlation between experiments and modelling in fracture of anodes and paves the way for developing design criteria that predict the onset of fracture initiation based on the anode material and geometric properties.