Devices and methods for preparing a slurry and coating a substrate with a slurry

A method comprising the steps of:

• providing a slurry in a closed volume with at least one passage, the closed volume including two cylinders connected by the at least one passage, each of the two cylinders including a piston, the slurry including a solvent, a powder, a binder, and a dispersion agent selected for forming a battery cell electrode once applied to a substrate;
• forcing the slurry repeatedly under high pressure to flow through the at least one passage in a first flow direction and then back through the at least one passage in a second flow direction, opposite the first flow direction, based on a reciprocal actuation of the two pistons of the two cylinders to homogenously disperse the powder and the binder within the solvent;
• coating opposite sides of the substrate facing away from each other simultaneously with the slurry extruded from the closed volume after the forcing;
• freezing at least the solvent and the dispersion agent coated on the substrate;
• sublimating at least the solvent and the dispersion agent frozen on the substrate;
• after the sublimating, heating the substrate under vacuum to above the standard freezing points of the at least one solvent and the dispersion agent;
• calendering the substrate after the heating;
• and
• forming the battery cell electrode with the substrate after the calendering,
• wherein a ratio of the binder to the powder is about 0.02:1 to about 0.1:1 by weight,
• wherein the powder is a carbon black powder, and a ratio of the solvent to the carbon black powder is about 4.5:1 to about 8:1 by weight,
• wherein the slurry is about 0.01-2 wt % of the dispersion agent, and
• wherein about 10 to 15 kWh of energy per kilogram of solid powder is required to form the dispersion of the powder and the binder in the slurry.