Advanced multilayer model electrode for binder distribution within composite electrodes of lithium batteries

Abstract

The loading levels of composite electrodes are increasing continuously to satisfy the energy density requirements of lithium-ion batteries (LIBs) in electric vehicles (EVs). Furthermore, a faster coating and drying process in the mass-production line yields a nonuniform binder distribution. Thus, it is necessary to understand its distribution within the composite electrode and control it for a better and more reliable electrochemical performance. Therefore, we propose the utilization of an advanced multilayer electrode model consisting of several electrode layers with different binder contents. Using these controlled electrode models, the adhesive strength within each layer was examined using a surface and interfacial cutting analysis system (SAICAS). This was followed by a composition analysis using EDX on each surface. Subsequently, the electronic conductivities of the model electrodes were measured using an electrode resistance meter to determine the bulk and interfacial electrode resistances. Furthermore, the electrochemical properties of each model electrode were evaluated to correlate their relationships and design the optimum binder distribution. Thus, this multilayer model provides a highly effective platform for determining the optimum binder distribution in highly loaded composite electrodes for high-energy–density and long-lasting LIBs.