Mitigation of Binder Migration Behavior during the Drying Process by Applying an Electric Field for Fast-Charging in Lithium-Ion Batteries

Abstract

The binder migration due to the capillary force-driven solvent evaporation during the drying process in the electrode manufacturing process induces inhomogeneous binder distribution in the electrode, which deteriorates Li-ion kinetics and corresponding poor fast-charging properties in lithium-ion batteries (LIBs). Here, we report an effective strategy to mitigate the binder migration behavior by applying an electric field during the drying process. As the employed carboxymethyl cellulose (CMC) and styrene-butadiene rubber (SBR) binders have a negative charge in an aqueous anode slurry system (pH 7), the binder migration behavior could be mitigated by generating an electrical attraction force into the bottom direction by positive electrification of the current collector. The anode prepared with electric field exhibits homogeneous binder distribution in the longitudinal direction, which enhances Li-ion kinetics, corresponding constant current charging capacity, and cycling stability compared to those of the anode prepared without electric field.