Li-induced Stress Distributions in Si Thin Films with Chevron-like Nanostructures

Silicon is one of the most promising anode materials in solid-state batteries due to its very high specific capacity. Current results are however still in an infant state in terms of electrochemical performance, analytical characterization and mechanistic understanding. During lithiation/delithation, Si undergoes a substantial ∼300 % volume change, can lead to structural damage. The underlying electro-chemo-mechanical behavior of Si anodes remains so far inadequately understood and validating theoretical models has proven to be a challenging task. The objective is to precisely quantify the evolution of cross-sectional stress distributions in thin Si films with varying grain boundary morphology during lithiation and delithiation processes. To achieve this, we will employ cross-sectional X-ray nanodiffraction to characterize Si and LixSi phases. The experiment will reveal, how the chevron-like nanostructure of the films correlate with the observed electro-chemo-mechanical behavior.