Cell Assembly

Cell Assembly

Cell assembly is divided into various sub-processes, which, in turn, can be differentiated according to the type of cell. In contrast to the round or prismatic cell, the pouch cell has a flexible housing, which is why pouch cells go through additional manufacturing steps. 

In pouch cell production, the individual electrode sheets are stacked. Vacuum grippers are used for precise and efficient positioning. For such classic Pick&Place applications, rough vacuum is required. For the energy-efficient supply of coarse cake for these applications, our efficient SOGEVAC, CLAWVAC or VACUBE are used. 

During the subsequent packaging of the pouch cell, the pouch foil is first deep drawn in order to insert the electrodes in the next step. The deep drawing of the foil can be done with the help of a vacuum seal formed at a pressure of approximately 50 mbar. Our oil-sealed SOGEVAC or dry-running CLAWVAC pumps are suitable for this application due to their energy efficiency and high reliability.

Both cell types (flexible and rigid housing) are filled with electrolytes during the cell assembly process. To ensure a homogeneous distribution of the electrolytes in the cell and to exclude impurities or gas inclusions, the filling is performed using a vacuum seal. An inhomogeneous distribution of the electrolytes in the Li-ion cell (as well as gas inclusions) significantly impair the quality of the cell and its service life. In addition, the electrolytes, which react quickly with humidity in the air, require a clean and dry filling environment. This places special demands on the vacuum installation. Since all process gases can also enter the vacuum installation, also some electrolyte vapors or droplets might enter the vacuum pump. If this effect is limited, oil-sealed rotary-vane type pumps offer a reliable and cost-efficient vacuum solution. As most robust pump solution for electrolyte filling, dry-running screw pumps are recommended. These can tolerate potential electrolyte contamination, offer longest service life and lowest maintenance costs for this process, since, for example, no frequent oil changes are required.