- Continuum Model
- Interface / Phase Separation / Particle Dispersion
- Material Science
[Analysis Example] Simulation of evaporation of liquid film
Filler density distribution analysis during evaporation drying by particle method
Objectives and Methods
Electrode slurries for lithium-ion batteries and coated products include a process for evaporating and drying the liquid film produced in the previous process. In the evaporation-drying process of these liquid films, the phenomenon of small particles agglomerating near the surface (particle segregation) due to the size difference of the particles contained in the liquid film may become a problem. It’s reported that polymer latex particles (small particles) in the coating film segregate on the film surface after evaporation drying, resulting in reduced adhesion strength between the coating film and the metal substrate, peeling, and other defects [1].
We performed evaporation drying calculations for a liquid film containing two types of fillers, large and small, and analyzed particle segregation by calculating the density of the large and small fillers in the direction of the liquid film thickness.
Fig. 1: calculation model
Result
An animation of the evaporation-drying process is shown in Movie 1. It was confirmed that the filler agglomerates near the surface as the solvent evaporates. To quantify the particle segregation, the distribution of filler density along the film thickness at the end of calculation is shown in Figure 2. Compared to large fillers, the density of small fillers is higher near the surface than large fillers, reproducing the segregation tendency of small fillers.
The VSOP-PS evaporation drying calculation makes it possible to analyze the particle structure of liquid films containing fillers of different shapes after evaporation drying.
Fig. 2: Filler density distribution as a function of film thickness direction (Distance 15=thickness 1.5um)
- References
- 1. https://www.jstage.jst.go.jp/article/nig/56/2/56_85/_pdf
