Powder Compaction Characteristics and Modeling of Calendering Process for Powder-Based Solvent-Free Manufacturing of Electrodes for Lithium-Ion Batteries

Abstract

Powder-based solvent-free manufacturing of electrodes for Li-ion batteries represents an emerging and promising technology in electrode fabrication. This method involves a two-roll powder calendering process, where electrode powder materials are compressed onto a current collector to form electrodes with desired properties. The calendering or compaction of dry powders onto a current collector is a crucial step in solvent-free electrode manufacturing, significantly impacting the microstructures, mechanical properties, and electrochemical performance of the produced electrodes. In this article, we investigate the compaction characteristics of electrode powders to gain insights into their behavior. A powder-on-current collector calendering model is developed based on Johanson's rolling theory of granular solids. This model enables us to infer the underlying calendering parameters essential for the solvent-free manufacturing of Li-ion batteries. To validate the model, we compare it with experimental calendering results, utilizing measured powder properties and roll design parameters as inputs. This approach offers a comprehensive understanding of the effects of roll geometries, particularly roll diameter, and various equipment design parameters on final electrode properties. Such insights have not been thoroughly explored in the emerging field of solvent-free battery electrode manufacturing, thereby contributing to advancements in this area.