Morphology Matters: Surface Properties Inform ALD Deposition and Subsequent Electrochemical Performance in Graphite Substrates

Abstract

The physical properties of graphite, such as pore volume, shape, and crystallinity; are critical factors in determining the performance of a li-ion cell. These properties are determined by the graphite manufacturing process, which often terminates with a surface treatment process to optimize the morphology. Currently most surface treatments are done using a carbon pitch coating, which involves a high temperature, multi-step process. Coatings using atomic layer deposition (ALD) are, by comparison, less energy intensive and a more customizable approach to target specific physical properties leading to increased cycle life, higher coulombic efficiency, and better rate performance. In this work we will show how ALD coatings are optimized based on the graphite production process and resulting particle morphology. We will demonstrate that these optimized coatings will serve to reduce surface area, prevent graphite exfoliation, and improve li-ion diffusion pathways.