(V) Performance And Safety Implications Of Ultrasonic Spot Welding For Lithium-Ion Batteries: Best Practices And Case Study

Tuesday, September 14, 2021: 10:20 AM
241 (America's Center)
Dr. Vir Nirankari , Exponent, Inc., Natick, MA
Dr. John McGann , Exponent, Inc., Natick, MA
Dr. Kevin White , Exponent, Inc., Natick, MA
Manufacturing of Li-ion batteries requires a significant amount of joining (i.e., welding) to fulfill the desired power characteristics. Ultrasonic spot welding (USSW) is one technology used to join battery tabs to cell current collectors. In late 2016, the Samsung Note 7 experienced large numbers of failures, manifesting as a devastating failure mode known as thermal runaway. For one manufacturer, the ultrasonic spot welded tabs and areas around them were found responsible. In this talk, both the non-destructive tools used to investigate these ultrasonic welds and how these findings helped to narrow down the root cause of the failures will be discussed.