Design of an energy storage system with blended of Li-ion batteries for pure electric vehicle of high performance

The state of art in Li-ion cells has one technologic gap to find in the same cell all requirements of performance to a vehicle that need high impulse and high autonomy combined. Certain Li-ion cells have characteristics of high energy density that exhibit high voltage and high rate capability, but have poor cycling and low power capacity. Alternately, other types of cells have high power density exhibit good thermal stability, good cycling, and high rate regime operation characteristics but have low rate capability and low voltage. Blending different cathode Li-ion cells in the same Energy Storage System is a new approach to design the better batteries for Pure Electric Vehicle of High Performance. This paper is intended to develop an Energy Storage System that take the advantage of the unique properties of each electric type of Li-ion cell and optimize its performance with respect to the automotive operating requirements. Therefore is presented the constrain requirements for selection of the batteries, the performance results, the thermal design considerations, the differences of strategies of state estimators and balancing of charge, the differences in hardware of battery management system as well as are discussed the energy balance during determined drive cycle operation. Several simulations based in model based design was performed considering the differences in the parameterization of each type Li-ion cells as well several laboratory tests have realized for validation of the design.