Spatially resolved lithium‐ion battery simulations of the influence of lithium‐nickel‐manganese‐cobalt‐oxide particle roughness on the electrochemical performance

This publication deals with the influence of the roughnesses of single lithium‐nickel‐manganese‐cobalt‐oxide‐based active material particles on the electrochemical behaviour. A roughness model is used to create particles with a defined roughness depth. Subsequently, comparative calculations are performed using a 3D spatially resolved electrochemical model under different operating conditions. The results show that for small C‐rates below 1C, the usage of the widespread assumption of smooth and spherical active material particles in models is justified. For higher C‐rates, the particle's shape and roughness are not negligible. Small, rough particles show the best performance characteristics for high rate applications. For operation in the diffusion‐limited state (low diffusion coefficient and high C‐rate), the smallest absolute diffusion length represents a better correlation in terms of utilizable capacity compared to the volume‐specific active surface area.