Modeling and analysis of solvent removal during Li-ion battery electrode drying

Abstract

In this work, we study the design aspects and process dynamics of solvent removal from Lithium-ion battery electrode coatings. For this, we use a continuum level mathematical model to describe the physical phenomenon of cathode drying involving coupled simultaneous heat and mass transfer with phase change. Our results indicate that around 90% of solvent is removed in less than half of the overall drying time. We study the effect of varying temperature and air velocity on the drying process. We show that the overall drying energy can be reduced by at least 50% by using a multi-zone drying process. Also, the peak solvent flux can be reduced by at least 40%. We further present the effect of using an aqueous solvent instead of N-Methyl-2-pyrrolidone (NMP) in electrode drying. Our results indicate that Water dries nearly 4.5 times faster as compared to NMP and requires nearly 10 times less overall drying energy per kg of solvent.