Characterization of interactions in battery slurry via MD simulation: Influence on miscibility, morphology, and dispersion with varying ACN content in HNBR

This paper investigates the phase behaviors, morphology changes, and degree of dispersion of a multi-component cathode battery slurry system. The slurry comprises polyvinylidene fluoride (PVDF) as the binder, hydrogenated nitrile butadiene rubber (HNBR) as the dispersant with varying acrylonitrile (ACN) content, N-methyl-2-pyrrolidone (NMP) as the solvent, and carbon nanotubes/graphene (CNTs/GRA) as the conductive agent. Several analytical methods, including visualized imaging, solubility parameters, radial distribution function (RDF) analysis, β phase PVDF analysis, near-atom analysis, and potential of mean force (PMF) analysis, were employed to compare the slurry's characteristics. The results indicate that an increase in ACN content in HNBR improves the miscibility between HNBR and PVDF, while HNBR with low ACN content results in a crystalline structure and phase separation of HNBR and PVDF. Conversely, increasing the ACN content in HNBR has a negative impact, making it a poorer dispersant itself. These findings provide essential insights into effectively regulating the phase behavior, miscibility, and dispersion ability of multi-component slurry systems, thereby enhancing the performance of lithium-ion batteries.