Utilising a novel multi-electrode approach for improving micro-resistance spot welding productivity for electric-mobility battery interconnects

The micro-resistance spot welding is widely used for low-to-medium-volume applications due to its low cost, especially for cylindrical Lithium-ion cell-based modules. Using typical micro-resistance spot welding electrodes in a series configuration, two nuggets/welds are created in a single welding operation. As it is a contact joining process, productivity is limited. This paper developed a novel approach to enhance the productivity of micro-resistance spot welding, where four nuggets were produced instead of two nuggets in a single operation. The critical-to-quality criteria, including joint strength, microstructure, electrical resistance and temperature rise at joints, were demonstrated by comparing the existing and proposed approaches. A reduction in cycle time by up to 57% can be achieved by adopting the proposed approach while maintaining the weld quality.