Mathematical Modeling of Energy-dense NMC Electrodes: Part II. Data Analysis with Newman Model and with an Extended Model Accounting for Particle Agglomeration

Abstract : In this second part of this series of papers, the use of two physics-based models to analyze the discharge performance of a set of high-energy-density electrodes is discussed. The measured set of parameters from the first part is implemented into these models. First, the regular Newman pseudo-2D model shows a large discrepancy against the experimental values. Then, an extension of the Newman model considering the particle agglomeration due to the calendering effects is presented, allowing for the validation of discharge rate capabilities of all studied industry-grade electrodes with different electrolytes. At the agglomerate scale, the model accounts for both the ionic transport in sub-pores and the inter-particle solid diffusion. The simulation results from this work demonstrate that increasing the electrode loading and/or density leads to either a higher fraction of sub-pores (at the expense of that of macropores) or larger porous agglomerate size, resulting in a poor rate performance. The model analysis suggests that a substantial gain in performance at high C-rates is expected if agglomeration effects are mitigated in these high-energy electrodes.