In terms of ensuring safety and reliability, as the "lifeline" of new energy vehicles, batteries have extremely high reliability and conductivity requirements for their internal connection links, such as welding of the internal terminals of the battery cells, series and parallel connections between battery cells, and welding of busbars. Any minor virtual soldering, over soldering, or material damage can lead to serious safety accidents such as thermal runaway. Ultrasonic welding, as a solid-state welding technology (without melting), has a very small heat affected zone, avoiding splashing, porosity, and the formation of brittle compounds between metals. It can achieve low resistance, high-strength metallurgical bonding, significantly enhancing the safety and long-term stability of the connection.

In the battery manufacturing process, heat sensitive thin sheet materials such as copper foil and aluminum foil are widely used, as well as connection operations between different metals, such as copper aluminum connections. Ultrasonic welding technology is particularly suitable for welding highly conductive soft metals such as copper, aluminum, and nickel, and has become one of the effective methods for connecting dissimilar metals, especially copper and aluminum. This technology effectively avoids the brittle phases that may occur in traditional fusion welding.

Multi layer thin film welding technology: Battery lugs are usually made by stacking multiple layers of extremely thin metal foils, sometimes even up to tens of layers. Ultrasonic welding technology has demonstrated outstanding performance in this field, capable of accurately welding multiple layers of thin films in one go, ensuring that each layer can effectively conduct electricity. This advantage is difficult to achieve with other welding methods.