Study on particle dispersion changes over time in aqueous Al2O3 slurries containing ammonium polyacrylate

Adsorption and Dispersion Effect of Sodium Lignosulfonate on Fine SiC Particles in Aqueous Media

This study presented a novel modification method for fine SiC powder by using sodium lignosulfonate as a dispersant. The adsorption behavior of sodium lignosulfonate on the SiC/water interface and its effect on the performance of a fine SiC slurry were systematically investigated. The adsorption results showed that sodium lignosulfonate formed monolayer adsorption on the surface of fine SiC and that the saturated adsorption capacity was 1.3263 mg/g. The adsorption reached equilibrium within 3 h and was mainly controlled by active sites on the SiC surface. The dispersion, stability, and zeta potential of modified SiC powder were improved after sodium lignosulfonate adsorption. The zeta potential of modified SiC reached a minimum value of -44.8 mV at pH 12. Modified SiC suspensions had great stability in a wider pH range of 6-12. Modified SiC slurry with 54 vol % solid loading had a low viscosity of 173 mPa·s at pH 10. Subsequently, coarse SiC powder was added for slip casting. A mixed slurry with high solid loading (69 vol %) and low viscosity (583 mPa·s) was prepared using modified SiC and coarse SiC powders at a mass ratio of 2:3. Finally, recrystallized SiC green body with high density (2.6492 g/cm3) was obtained.

Effects of the mixing sequence on the graphite dispersion and resistance of lithium-ion battery anodes

The performance of lithium-ion battery electrodes is influenced by particle dispersion in the slurry used for their production. In this study, we elucidate the effects and mechanism of the binder mixing sequence on the characteristics of the slurry used in the production of negative electrodes. Therefore, we optimize the preparation of the negative electrode slurry by evaluating the electrode characteristics resulting from changing the binder mixing sequence. During the preparation of the electrode slurry, the state of the adsorption of the binder to the particle changes when the sequence of binder addition is changed. The change in the adsorption state of the binder influences the particle dispersion in the slurry, rheological properties of the slurry, and packing characteristics of the particles. Under the influence of the aforementioned changes, electrodes possessing identical compositions exhibited different performances. The slurry in which the particles were dispersed produced an electrode possessing a low volume-resistivity, whereas the slurry in which the particles were agglomerated produced an electrode with a high volume-resistivity. Evidently, controlling the adsorption state of the binder by altering the binder mixing sequence is essential for fabricating electrodes possessing a low volume-resistivity.