A chemo-mechanical phase-field framework for dynamic fracture with viscoplastic flow for large-deformed electrode in lithium-ion batteries

Fracture of the high-capacity electrode materials during electrochemical cycling is still an overwhelming limitation restricting the further development of lithium-ion batteries. Here, we investigate the chemo-mechanical dynamic fracture phenomenon in the large-deformed ductile electrode materials by using the thermodynamically consistent phase-field method and provide a fundamental insight for the complicated chemo-mechanical coupling process with considering the competition mechanisms of several governing factors. In the present work, we are able to evaluate the inertia driven intricate dynamic fracture phenomena such as crack branching and complete breakage with a series of governing mechanisms including different electrode size, applied current density and yield stress for viscoplastic flow. The results have shown that the crack propagation velocity controlled by multiple factors above will finally determine whether the phenomenon of crack propagation or branching occurs at the rapid crack propagation stage. Furthermore, a safety limit for fracture and the specific failure modes have also been demarcated under certain circumstances, which provide a further understanding for the underlying electrochemical performance and mechanical stability of the high-capacity ductile electrodes, and may be instructive for the next-generation design and evaluation of lithium-ion batteries.