Drying and calendering of Lithium Ion battery electrodes: A combined simulation approach

Abstract

In drying of battery electrodes, high drying speeds are desirable but lead to binder segregation resulting in lower adhesion strength and poorer electrochemical performance. During calendering, the elastic recovery of the electrode makes it difficult to estimate the line load required to achieve the desired porosity. The approach we present incorporates various drying and binder migration models and combines them with a calendering model as Sangros used it. The drying models taken from literature put a special focus on drying kinetics, binder segregation and particle dynamics. This information is passed to a solid-state bridge-based Discrete Element Method, which is additionally extended to include the interactions between the coating and the current collector. Through the interaction of these models, the mechanical behavior by means of stress and elastic recovery of model cathodes can be predicted for different degrees of compaction as well as areal loadings.