Access Type

Open Access Thesis

Date of Award

January 2016

Degree Type


Degree Name



Mechanical Engineering

First Advisor

Chin-AN Tan


Lithium-ion battery is one the most popular types of batteries currently used in electric

vehicles. To meet the power requirement, hundreds of Lithium ion battery cells are connected together before being assembled into a battery pack. Ultrasonic welding is the most widely used joining technology to connect battery cells together. In an ultrasonic welding process, high frequency oscillation is used to generate small relative motions between sheet metals to be welded, and produce solid-state bonds between the sheet metals clamped under pressure. One of the major issues for battery pack ultrasonic welding is that sometimes the welding process damages the battery cell. It is hypothesized that, during the ultrasonic welding process, high frequency vibrations of battery tabs may transfer vibration energy into the battery cell, inducing high stresses and even causes damages at the interior joints of the battery cell. In this study, an analytical model to describe the vibration of battery tabs was developed. Experimental data shows good correlation to the analytical model in the stress value. For the experimental measurement, a signal conditioning and data acquisition system was developed which was shown to have good signal-noise ratios when compared to a commercially available

measurement system.