Mesoscale Understanding of Lithium Electrodeposition for Intercalation Electrodes

Stringent performance and operational requirements in electric vehicles can push lithium-ion batteries toward unsafe conditions. Electroplating and possible dendritic growth are a cause for safety concern as well as performance deterioration in such intercalation chemistry-based energy storage systems. There is a need for better understanding of the morphology evolution because of electrodeposition of lithium on the graphite anode surface and the interplay between material properties and operating conditions. In this work, a mesoscale analysis of the underlying multimodal interactions is presented to study the evolution of morphology due to lithium deposition on typical graphite electrode surfaces. It is found that electrodeposition is a complex interplay between the rate of reduction of Li ions and the intercalation of Li in the graphite anodes. The morphology of the electrodeposited film changes from dendritic to mossy structures because of the surface diffusion of lithium on the electrodeposited film.