Electrode Mesoscale as a Collection of Particles: Coupled Electrochemical and Mechanical Analysis of NMC [post]

Mark E. Ferraro, Bradley L. Trembacki, Victor E. Brunini, David R. Noble, Scott Alan Roberts
2019 unpublished
Battery electrodes are composed of polydisperse particles and a porous, conductive binder phase whose complex arrangement into a mesostructure whose morphology impacts both electrochemical and mechanical performance. We present image-based, particle-resolved, mesoscale finite element model simulations of coupled electrochemical-mechanical performance on a representative NMC electrode domain. Beyond predicting macroscale quantities such as half-cell voltage and evolving electrical conductivity,
more » ... tudying behaviors on a per-particle and per-surface basis enables performance and material design insights previously unachievable. Voltage losses are primarily attributable to a complex interplay between interfacial charge transfer kinetics, lithium diffusion, and, locally, electrical conductivity. Mesoscale heterogeneities arise from particle polydispersity and lead to material underutilization at high current densities. Particle-particle contacts, however, reduce heterogeneities by enabling lithium diffusion between connected particle groups. While the porous conductive binder phase may have slower ionic transport and less available area for electrochemical reactions, its high electrical conductivity makes it the preferred reaction site late in electrode discharge. This work enables improvements in materials design by providing a tool for optimization of particle sizes, CBD morphology, and manufacturing conditions.
doi:10.1149/osf.io/v7cwp fatcat:3le3oriiv5cg5lmjvqudzcf4fi