Current-Based Heating for Drying Lithium-Ion-Battery Electrodes: Assessment of Feasibility and Effects on Electrode Properties

Abstract

Although convective drying represents the current state of the art in electrode production, its limitations in production speed and economic drawbacks related to overall energy consumption necessitate the exploration of alternative drying technologies. This study thoroughly investigates the applicability of a new drying method based on electrical conduction. Through an experimental approach, conductive drying experiments are performed on aqueous-processed graphite anodes at various drying intensities. A combination of thermographic and gravimetric measurements is utilized to comprehensively analyze the ensuing drying process and assess the achievable drying rates. Results indicate that electrodes can be effectively dried, achieving drying rates of up to 1.45 g m⁻² s⁻¹, which approaches industrial relevance. Additionally, edge heating is observed at the coating interface regions, facilitating an accelerated drying process with up to 23% higher drying rates in the affected areas. Although this effect results in a measurable discrepancy in mechanical strength across the electrode area, conductively dried electrodes still exhibit improved mechanical properties as well as both electrical and electrochemical properties comparable to those of convectively dried electrodes. Based on these findings, the potential of the conductive drying method as a viable alternative for electrode production is successfully demonstrated.