In the first step, the active material (usually lithium metal oxides) is mixed with solvents and binders to form a so-called "slurry". To achieve the highest possible homogeneity, purity and viscosity of the slurry, the mixing process takes place in a vacuum. The vacuum atmosphere prevents air inclusions and contamination of the slurry. This plays an important role in the quality of the final product. Reliable pumping systems are important here in order to achieve a high level of process reliability. Depending on the solvent, ATEX pumps may be necessary. The size of the slurry mixer determines the pump size. Leybold offers a wide range of both dry and oil-sealed pumps for this step in the process. 

In further steps the electrodes are rolled to coils and then dried. The drying is done with heat in a vacuum atmosphere to remove any solvent and water residues. The electrodes must be absolutely dry in order to obtain a high-quality product. This is only possible in a vacuum atmosphere, as the solvent residues and water molecules inside the coils diffuse only under vacuum. A stable and controllable vacuum atmosphere is essential for a high process quality. Vacuum drying takes place in a mostly customer specific process with specific temperature-pressure curves, usually between 0.1 - 30 mbar and 100° - 150°C. Depending on the size of the battery production, either batch ovens or in-line ovens are used. This process determines the pump selection, and Leybold offers the perfect pump configuration for a wide variety of processes. Depending on the requirements, various oil-sealed or dry pumps can be used to achieve the highest possible level of process purity and minimized investment and operation costs.