This thesis studied various metal combinations, including Cu-Al, Ni-plated Cu-Al, Al-Al, Sn-plated Cu-Sn-plated Cu, Cu-Cu, and Cu foil-Cu foil, utilizing the ultrasonic metal welding (USMW) technique. The primary objective was to identify the necessary process parameters for successful welds and to understand the bonding mechanisms. The study becomes even more significant in the context of pouch cells used in electric vehicles, as USMW which consumes relatively less energy offers, a sustainable approach to joining metals, in line with environmental responsibility. Through extensive experimentation and analysis, the study was able to determine the fundamental bonding mechanism and establish the critical process parameters for each metal combination. This knowledge develops USMW technology and its implementation in various industries. In conclusion, this thesis investigated the bonding characteristics of various metal combinations using USMW, with a particular emphasis on their applicability to pouch cells in electric vehicles.