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The viscosity and microstructure of Li-ion battery slurries and the performance of the resulting electrodes have been shown to depend on the mixing protocol. This work applies rheology to understand the impact of shear during mixing and polymer molecular weight on slurry microstructure and electrode performance. Mixing protocols of different shear intensity are applied to slurries of LiNi0.33Mn0.33Co0.33O2 (NMC), carbon black (CB), and polyvinyldiene difluoride (PVDF) in N-methyl-2-pyrrolidinone (NMP), using both high-molecular-weight (HMW) and low-molecular-weight (LMW) PVDF. Slurries of both polymers are observed to form colloidal gels under high-shear mixing, even though unfavorable interactions between high molecular weight PVDF and CB should prevent this microstructure from forming. Theoretical analysis and experimental results show that increasing shear rate during the polymer and particle mixing steps causes polymer scission to decrease the polymer molecular weight and allow colloidal gelation. In general, electrodes made from high molecular weight PVDF generally show increased rate capability. However, high shear rates lead to increased cell variability, possibly due to the heterogeneities introduced by polymer scission. 

The microstructure of solid coatings produced by solution processing is highly dependent on the coupling between growth, solute diffusion, and solvent evaporation. Here, a quasi-2D numerical model coupling drying and solidification is used to predict the transient lateral growth of two adjacent nuclei growing toward each other. Lateral gradients of the solute and solvent influence the evolution of film thickness and solid growth rate. The important process parameters and solvent properties are captured by the dimensionless Peclet number (Pe) and the Biot number (Bi), modified by an aspect ratio defined by the film thickness and distance between nuclei. By variation of Pe and Bi, the evaporation dynamics and aspect ratio are shown to largely determine the coating quality. These findings are applied to drying thin films of crystallizing halide perovskites, demonstrating a convenient process map for capturing the relationship between the modified Bi and well defined coating regimes, which may be generalized for any solution processed thin film coating systems. 

Abstract Laser zone‐drawing is shown to significantly enhance control over nanofiber properties. This study investigates the dynamics of nanofiber laser zone‐drawing. It is hypothesized that the equilibrium between heating and cooling guides fiber temperature. The high heating rate of laser irradiation and the high convective cooling rate of nanofibers facilitate fast heating and cooling kinetics. Results showed fiber thinning in the presence of laser irradiation until reaching a steady‐state diameter. Final fiber diameter is correlated to laser power independent of initial fiber diameter. The relationship between final fiber diameter and laser power is used to estimate the heat transfer coefficient, which is used to create a computational model of the thermodynamic system. These simulations predict rapid heating and cooling up to 36 000 K min⁻¹for the lowest fiber diameters tested experimentally. While laser‐induced softening of polymer nanofibers is described in detail, the forces driving fiber drawing, particularly under different thermal kinetics, remain unexplored. This research showcases the capabilities of laser zone‐drawing in nanofiber manufacturing and facilitates future investigations aimed at enhancing fiber processing by producing highly aligned molecular structures via rapid cooling. This work signifies a pivotal methodological leap, promising transformative nanofiber materials useful across multiple industries including aerospace, electronics, and biomedicine.