Electrode material is usually applied as a thin paste to a copper or aluminum film. However, since it is repeatedly interrupted by sections of uncoated film in order to discharge the electrons, the coating process has to be restarted over and over, making it slow and costly.
A team led by PhD student Ralf Diehm at the Karlsruhe Institute of Technology (KIT) has now developed an innovative method that is not only much faster, but also improves the quality of the electrodes. The nozzle for the electrode material features a vibrating membrane that periodically stops and restarts the application of the coating paste. “Since this membrane is much lighter than mechanical valves, it enables very fast reaction times and thus high speeds,” explains Ralf Diehm. While electrode coating speed has been limited to about 30 to 40 meters per minute to date, the new technology boosts this figure to up to 150 meters, enabling a threefold increase in battery cell production. Product quality apparently also improves, and there are less rejects.
Ralf Diehm and his team aim to further develop the technology in a spin-off in order to apply it to industrial production. New production technology findings are also being channeled into the Post Lithium Storage (POLiS) excellence cluster, in which KIT and the University of Ulm are jointly developing the battery of the future.