Investigating Large Deformation and Amorphous Intermediates in Sb Electrodes

The key objective is to provide insight into how amorphous intermediates that form in high-capacity anodes during electrochemical cycling accommodate large volume changes and prevent microcracking in Antimony (Sb) electrodes. The electrochemical cycling of alloy anodes introduces an abrupt crystalline to amorphous structural transformation (in Na-based electrodes). This transformation, in turn, is accompanied by anisotropic volume expansion (>100%), abrupt changes to elastic stiffness, and an alteration to the Na-diffusion kinetics and alloying-reaction pathways. We hypothesize that these sudden changes to intrinsic material properties alter local stress distributions and phase transformation pathways in high-capacity anodes, which contributes to their characteristic mechanical response. We are developing a theoretical framework to understand the energy dissipation and deformation mechanism in large-volume change electrodes and to use these mechanistic insights to guide materials design.