Designing highly packed silicon anode slurries for high capacity and prolonged lifespan of lithium-ion batteries

Despite its high theoretical specific capacity, silicon (Si) poses certain challenges including large volume expansion and thick SEI layer formation during the charge/discharge process. This study investigates the crucial role of interparticle interactions and particle packing densities, uncovering their significance in enhancing the coating abilities of Si anode slurries and improving the energy capacity and cycle life of lithium-ion batteries (LIBs). A microrheological model is employed to predict the rheological properties of Si anode slurries based on their packing densities. We find that a combination of Si nanoparticles (SiNPs) of varying sizes not only augments the specific capacity and mitigate volume expansion, but also promotes a uniform slurry coating on the electrode. We quantify the coating characteristics of Si anode slurries using dimensionless structural and deformation parameters, thus providing a robust foundation for future advancements in the preparation of LIB slurries. [Display omitted] •Highly packed silicon anode slurries enhance the capacity and lifespan of LIBs.•A microrheological model was used to analyze the rheological properties of slurries.•Uniform dispersion of particles provides superior slurry-electrode adhesion strength.•Optimal particle ratios achieve desirable electrochemical performance outcomes.