Modeling of Hierarchical Granular Packing Effects on Lithium‐Ion Cathode Performance

Microstructure engineering of lithium‐ion battery (LIB) electrodes is an important approach for optimizing the design and thereby enhancing the batteries’ performance especially at high rate. There are diversified approaches going into the engineering of LIB electrode microstructures by creating less tortuous diffusion pathways. In this study, we employ a microstructure‐controlled electrode with a designed porosity gradient. By maintaining constant active material (AM) loading, constant overall porosity, and constant surface area, we systematically evaluate the influence of having a porosity gradient has on electrochemical performance. With this modeling, we have determined the effect of the porosity gradient on the battery discharge performance for NMC111 electrodes. It was observed that having a gradient in porosity with higher porosity nearer to the separator benefits the fuller utilization of the electrode AM, which enables a more uniform high‐rate discharge process for deep cycling. The reverse gradient (RG) packing arrangement on the other hand provides advantages for short pulse operation since more cathode mass is closer to the separator for faster lithium uptake.