Batteries and battery packs have become an integral part of everyday life, in response to the growing demand for portable electronic devices, cordless power tools, energy storage, and hybrid and EV cars. In turn, this drives the need to manufacture batteries and battery packs that meet the quality and production requirements for such products. 

There are a number of materials joining requirements for battery manufacturing, depending on the specific type, size and capacity of the battery. Internal terminal connections, battery can and fill plug sealing, tab to terminal connections, and external electrical connections are a few key examples.

Several joining options can be considered for each of these requirements, including resistance, ultrasonic, micro-TIG and laser welding, including the newest fiber laser options. The decision to use one or the other is generally dictated by the specific type of weld required and production requirements.

Ultrasonic welding is commonly used for joining the internal electrode battery materials, which are usually constructed of thin foils of aluminum and copper. The remaining joining requirements – including the connections inside the can, and external terminal tab connections – are well suited to resistance, microTIG, and laser welding. For can and plug applications (seam sealing), laser welding is the joining technology of choice.

Following here is an overview of resistance, microTIG and laser welding technologies, along with examples of battery joining applications, detailing when and where to use each technology.