Slurry composition
Lithium-ion power battery slurry is basically composed of active materials, conductive agents, binders, and solvents, and its general composition is shown in the figure below.
Slurry characteristics
As the incoming material for the coating process, the properties of the slurry directly affect the coating quality. Based on its composition, the slurry is a solid-liquid two-phase fluid. In production, the main quality control points for the slurry include viscosity, solid content, density, fineness, and pH value. The uniformity of the slurry is crucial for the coating process, and this uniformity can be verified by testing quality control points in different areas of the slurry.
Since the viscosity of slurry is affected by temperature, stirring speed, and settling time, we classify slurry as a non-Newtonian fluid based on the definitions of Newtonian and non-Newtonian fluids. After relatively homogenization, the viscosity of the slurry gradually decreases with increasing stirring time, eventually reaching a stable value. According to relevant literature, lithium-ion battery slurries, under homogenized and proportioned conditions, exhibit a decrease in viscosity with increasing shear rate, i.e., shear dilution. In summary, we classify lithium-ion battery slurries as non-Newtonian fluids exhibiting shear dilution. Because the fluid properties of slurry vary under different conditions depending on the materials, proportions, and homogenization status, this paper only introduces the fluid properties of slurry under general and relatively homogenized conditions.
Density ρ: The density of lithium battery slurry is generally between 1400 and 2000 kg/m³.
Viscosity μ: The viscosity of lithium battery slurry is generally controlled between 1 and 10 Pa·s depending on different process conditions.
