Assembly of battery packs and solar cell arrays requires joining multiple thin metal layers in a single step. In some cases, different metals must be joined to make a good electrical connection. This connection must also be mechanically robust to provide acceptable long-term performance.
There are four joining processes that have been used for this application: ultrasonic metal welding, laser welding, resistance welding and soldering. Resistance welding and soldering are traditional processes that have been used to make electrical connections for many years. For battery and solar applications, however, the electrical current required for resistance welding and the heat required for soldering may damage battery or solar cells. Ultrasonic metal welding and laser welding avoid introducing potentially damaging energy into the system. Because these techniques are new, some manufacturers are reluctant to use them for cell and pack manufacturing.
EWI is beginning a comparative study of these joining processes as applied to the assembly of battery cells and packs. This study will generate the data necessary for manufacturers to make good choices about their product assembly processes. Contact me at 614.688.5162 or firstname.lastname@example.org if you have suggestions for substrate combinations that should be included in the study.