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Laser Welding of Batteries

The increased application for lithium batteries in electric cars and many electronic devices now utilize fiber laser welding in the product design. Components carrying electric current produced from copper or aluminum alloys join terminals using fiber laser welding to connect a series of cells in the battery.

Today’s electric vehicle batteries are designed for a life exceeding 10 years. To ensure reliable operation over this lifespan, individual components and cells within the battery are connected with numerous welds. 

Aluminum alloys, typically 3000 series, and pure copper are laser welded to create electrical contact to positive and negative battery terminals. The full range of materials and material combinations used in batteries which are candidates for the new fiber laser welding processes include those shown below.

Overlap, butt and fillet-welded joints make the various connections within the battery. Welding of tab material to negative and positive terminals creates the pack’s electrical contact. The final cell assembly welding step, seam sealing of the aluminum cans, creates a barrier for the internal electrolyte.

Since the battery is expected to operate reliably for 10 or more years, these laser welds are consistently high quality. The bottom line: with the correct fiber laser welding equipment and process, laser welding is proven to consistently produce high quality welds in 3000 series aluminum alloys that have connections within dissimilar metal joints.