Model fluid for coating flows of Li-ion battery anode slurry

Slot coating is commonly used in lithium-ion battery electrode manufacturing. As the coating flow stability is sensitive to the processing conditions and physical properties of the coating solution, various studies have been conducted to obtain stable coating conditions with a battery slurry. However, there are some limitations to using the slurry in coating experiments. For instance, the opacity of the slurry poses a challenge to the visualization of the slurry coating. Herein, we propose a carboxymethyl cellulose (CMC) solution as a candidate for battery anode slurry for coating flows. Because a model fluid may not cover all rheological properties of the anode slurry, we focused on the high-shear viscosity with respect to the characteristics of the coating flows. The rheological properties of the slurry and model fluid were measured. To compare the coating flow at high-shear conditions, a computational analysis of the coating flow was conducted. Although the flow curves of the slurry and model fluid show slight deviations, the computed velocity profile of the model fluid is similar to that of the slurry. Furthermore, blade coating with the slurry and model fluid at a shear rate of 5000 s−1, produced a comparable coating thickness. Consequently, the CMC solution has proven to be a valuable candidate for experimental research on the coating flow of battery anode slurries.