Laser welding of aluminum battery tab to variable Al/Cu busbars in Li-ion battery joint

The trend is shifting from internal combustion engines (ICEs) to battery electric vehicles (BEVs). One of the important battery joints is battery tabs to the busbar connection. Aluminum (Al) and copper (Cu) are among the common materials for busbar and battery tab manufacturing. A wide range of research shows that the laser welding of busbar to battery tabs is a very promising technique. It can enhance the battery module's safety and reliability owing to its unique properties. The desired strength, ductility, fatigue life as well as electrical resistivity are crucial to attain in laser welding of dissimilar materials aluminum and copper in busbar to battery tab in BEVs. Therefore, an adequate understating of the principal factors influencing the Al-Cu busbar to battery tabs joint properties are of prime importance. The current review paper provides information on laser welding and laser brazing of dissimilar Al-Cu with thin thicknesses. Also, the common defects, the effect of materials properties on laser joining, and laser-materials interaction during the laser welding process are discussed. Laser process parameters adjustment (e.g., laser power or speed), laser operational mode, and proper choice of materials (e.g., base metals, alloying elements, filler metals, etc.) may enhance the joint properties in terms of mechanical and electrical properties.