This book begins with an overview of the manufacturing, particularly joining processes used predominately in lithium-ion battery and battery electric vehicles. The rest of the book then focuses on the theories, methods and recent advances in battery ultrasonic welding, the detailed conclusions of which are included in each chapter. Each chapter focuses on a specific topic related to the battery ultrasonic welding process or system using either a physics-based or data-driven approach. In summary,
Chapters 2 and 3 start with the definition of ultrasonic weld quality followed by a discussion of post-weld attributes and weld qualities. Two complementary quality metrics for an ultrasonic weld, i.e., interfacial bond quality and circumferential material fracture, are then discussed. The chapters represent a first-ever systematic attempt to quantitatively define ultrasonic weld quality through material characterization and lay a foundation for post-process quality evaluation.
Chapters 4 and 5 describe two methods for real-time, in-process welding attributes measurements, i.e., in situ welding temperature and workpiece vibration measurements. The measurements are critical to the understanding of the welding physics, as well as the in-process weld quality evaluation.
Chapters 6 and 7 present metallo-thermo-mechanical models of ultrasonic welding processes, in which the welding temperatures, deformations, stresses, and microstructures can be simulated, and the bonding quality and weld fracture can be deduced.
Chapters 8 and 9 are research endeavors to devise in-process monitoring system of the ultrasonic welding processes for both the welding quality and weld tool conditions.
Chapters 10 and 11 investigate the effects of ultrasonic welding dynamics on the system by employing analytical resonance response models. Though the methods are limited to specific modeling conditions, they represent the most quantitative analyses of the dynamics, stresses, and energy losses in battery ultrasonic welding and can be readily broadened to other ultrasonic welding conditions.
