Measuring Li-ion battery film thickness after coating and calendering

An essential step in the manufacturing process of lithium-ion batteries is applying electrode coatings on copper (anode) or aluminum (cathode) films. The film is continuously or intermittently coated with the isolation substance using an application tool, such as a slot die, a doctor blade or an anilox roller. After coating, the wet foil is transferred to the dryer stages.

Hammer-IMS offers quality control systems that gauge wet coated films to identify sections where the coating layer is too thin or missing. Such deficiencies potentially lead to degraded battery performance and short circuits. The thickness measurement system with one or multiple sensors scans the entire width of the wet coated films. Dynamic graphic displays with underlying reporting data allow operators and production supervisors to monitor wet coated film thickness. Optionally, it is possible to use the reporting data to automatically control the electrode coating step in closed loop.

The Hammer-IMS systems are equally suitable to measure the thickness of the coated film after the upstream calendering stage. The coated film is then compressed by a rotating pair of rollers. This step is essential in obtaining the required line pressure, to ensure the subsequent wetting properties of the electrodes and the energy density of the cells. Accurate thickness measurement of the coated film after calendering is an important quality indication in battery production lines.