Design and Optimization of An Electric Vehicle with Two Battery Cell Chemistries

This paper describes the design and optimization of an electric vehicle (EV) prototype which will be built as part of a large collaborative project between researchers and industry. The goal is to develop a long-range EV that can travel 600km on a single charge. To keep the battery mass reasonable, the proposed design combines lithium-ion (Li-ion) cells with lithium-silicon (Li-Si) cells, an emerging battery chemistry which provides a 16% mass reduction compared to lithium-ion cells. In this study, two powertrain topologies are investigated using the dual-battery hybrid energy storage system (HESS). The vehicles are modeled in MATLAB/Simulink and a combined plant-controller optimization study is conducted. The results quantify the energy use benefit from selecting certain sizes of Li-Si packs, and find the Pareto front which characterizes the trade-off between energy use and cost of the emerging battery cell technology.