Discrete element simulations of Li-ion battery electrodes using colloidal and granular dynamics

Electrochemical performance of Li-ion battery electrodes is crucially governed by the morphology of carbon-binder domain (CBD) \'97 composed of carbon black nanoparticles and polymeric binder \'97 in the local vicinity of electro-active particles. However, the effect of CBD properties, such as cohesive strength of CBD and adhesive strength of CBD and electro-active particles, on electrode microstructure is not well-established. The lack of such microstructural details results from experimental challenges in visualizing CBD within an electrode, and numerical challenges in accurately modeling CBD within the complex and tortuous electrode microstructure. This talk will present our large-scale high-fidelity discrete element simulations modeling the dynamics of large non-colloidal electro-active particles embedded in a dense cohesive gel composed of colloidal CBD particles.\'a0\'a0Various compositions of CBD, electroactive material, and electrode porosities are considered. The role of cohesive and adhesive strength of CBD on its local morphology around electroactive particles and on the porous microstructure will be discussed. Lastly, conformal decomposition finite element modeling of electronic and ionic conductivities of these simulated electrode microstructures will be presented, and correlations between CBD material properties and electrochemical transport will be discussed.