Tab Design and Failures in Cylindrical Li-ion Batteries

Lithium-ion (Li-ion) batteries play a vital role in today's portable and rechargeable products, and the cylindrical format is used in applications ranging from e-cigarettes to electric vehicles due to their high density and power. The tabs that connect the electrodes (current collectors) to the external circuits are one aspect of the cylindrical battery design that plays a role in reliability and safety. This paper overviews various tab materials, structures, and welding methods and then discusses failures in commercial 18650-type Li-ion batteries due to the tab defects. The recommendations for tab design and manufacturing are given.