2020 Volume 56 Issue 5 Pages 214-222
The manufacture of materials using slurry-based processes, such as the electrodes of Li secondary batteries and fuel cells, can be made more productive by increasing the concentration of the slurry. Shear thickening, which is a particular issue for such highly concentrated slurries for the electrodes of Li secondary batteries, is derived from collisions between particles, it is important to control the size, size distribution, and concentration of the particles, as well as the solvent viscosity. Furthermore, the electrostatic interaction between the particles has a direct impact on shear thickening, and the concentration of salt in the slurry and the particle surface charge are also important characteristics. Since cracks in catalyst layers of a fuel cell affect performance and durability, it is important to obtain the factors that control crack formation. Crack behavior can be controlled by ionomer adsorption into the Pt/carbon in catalyst ink. A well-dispersed catalyst ink produces a homogeneous Pt/carbon and ionomer distribution in the catalyst layers with high fracture toughness, while catalyst inks with a network of agglomerates produce dense aggregates with small primary pores that generate high drying stress.
