The impact of lithiated active binder on Li-ion battery charge–discharge and rate capability, Part II: Mesoscale modeling of LCO based Half-cell

Even though thick electrodes are essential to increasing the energy density of LIBs, high current rates cause them to lose power density due to high polarization and ion depletion in the pore spaces. Mixed active binders with lithiated bound charges can improve the battery capacity and voltage at high C-rates, even compared to similar high concentrated electrolyte. The lithiated binders also provide a more uniform spatial distribution of intercalation reaction current, electric potential, and open circuit potential. The LIB half cell is modeled at mesoscale by taking into account the diffusion-reaction physics of the bound charge mixed electrolyte in active carbon-binder-domain (CBD), that accounts the dissociation of anionic ligands. Electrolyte in separator and active CBD are coupled by Donnan theory at the interface, and the reaction interfaces are modeled by the standard Butler-Volmer equation. By means of a thermodynamically consistent model and its implementation in a FEM code, we investigate the impact of particle distribution, electrode thickness, and separator thickness for both standard binder and active binder mixed cathodes in terms of ion depletion, current density, and electric potential. This mathematical model can also be extended to the modeling of ion conducting polymer electrolytes, gel polymers, and other conductive materials for battery applications.