Model-Based Design of an Electric Bus Lithium-Ion Battery Pack

Abstract This study details a framework for an iterative process which is utilized to optimize lithium-ion battery (LIB) pack design. This is accomplished through the homogenization of the lithium-ion cells and modules, the finite element simulation of these homogenized parts, and submodeling. This process enables the user to identify key structures and materials to be modified to optimize performance while keeping simulation time per iteration to a minimum. These iterations can be used to accurately estimate the force and strain values at various points including the lithium-ion cells and can be used to determine failure locations. The study demonstrates this through the examination of an electric bus lithium-ion battery pack as it is processed through the aforementioned steps and iterations to arrive at a conclusion that enabled the author to select appropriate fasteners and optimize for lithium-ion battery integrity in the event of a side impact with a pole on the bus chassis and battery assembly. The steps outlined in the study could be expanded to include an array of different loading scenarios and to include additional levels of homogenization/submodeling such as jellyroll components.