Joining Lithium-Ion Battery Tabs Using Solder-Reinforced Adhesive

Reliable and robust tab joints in pouch cells are key to the functional reliability and durability of lithium-ion batteries. In this study, a novel solder-reinforced adhesive (SRA) bonding technology is applied to lithium-ion battery tab joining, and its feasibility is explored by the application of simplified specimens. The three main components involved in the implementation of the SRA process are the substrate, solder ball, and adhesive system. The application of flux to the solder balls and the size of the adhesive application area are the two main process variables. Results showed that both the flux and adhesive area have positive correlation with the mechanical performance due to the formation of a robust connection of the solder and the substrate. In addition, the SRA joints have a relatively lower resistivity than joints fabricated by conventional ultrasonic welding (USW) technology. Thus, there is significant potential for this process to be applied for joining of battery tabs.