Development and characterization of a new welding process for Al and Cu layers for Lithium ion battery manufacturing

The goal of this thesis project is to characterize and develop a new welding process for two Al and two Cu layers applicated to lithium ion battery manufacturing. To reach this scope two different technology have been tested: a punch system (which has been included in an automated trimmer machine) and a burin system (whose tip has been inserted in a milling machine). Different material thicknesses have been used; for Al: 17 µm, 23 µm, 106 µm and 154 µm and for Cu: 11 µm. Two types of tensile tests, pull-off and peel-off, have been used to evaluate the goodness of the weldings, since there is no evidence in literature. Cu weldings did not give a positive response while Al weldings give really interesting results. Burin system compared to punch system (only for Al 17 µm) has resulted the best one cold welding technology, so that it has been patented. Lastly, a comparison among this technique, Ultrasonic Metal Welding and Laser Beam Welding has been effectuated.