Executive Summary : | Electric vehicles (EVs), hybrid or plug-in hybrid, e-scooters, e-rickshaws, and e-bikes are increasingly being used to reduce greenhouse gas emissions and protect the environment. The Indian EV market is expected to grow by 90% from 2021 to 2030, reaching $150 billion. Battery packs used in EVs consist of several modules with a few to hundreds of individual cells, which need to be connected using efficient joining methods. Manufacturing these cells in India is a trend, and extensive research is needed to make them versatile and easy to implement. A large number of joints need to be produced at different hierarchical levels, such as cell-level, module-level, or pack-level, which demands good joining methods that can accommodate dissimilar material joining, highly conductive and reflective materials, multi-layered joining stack-up, and varying thickness of the materials. Ultrasonic metal welding (USMW) is one such joining process that can address these challenges. However, additional critical-to-quality criteria are needed, such as electrical resistance and temperature rise during charge-discharge current. Currently, main characterisation/optimisation works focus on mechanical and metallurgical characterisation of joints, lacking extensive electrical and thermal characterisation. The effect of joint location and number of joints on electrical resistance and temperature rise is not addressed in the literature. This project aims to develop an efficient and multipurpose ultrasonic metal welding process for multi-layered dissimilar materials joining through experimentation and prediction of electro-thermal behaviours using multi-physics simulation. |