Potential Cost Savings of Combining Power and Energy Batteries in a BEV 300 2016-01-1213

Present-day battery technologies support a battery electric vehicle with a 300mile range (BEV 300), but the cost of such a vehicle hinders its large-scale adoption by consumers. The U.S. Department of Energy (DOE) has set aggressive cost targets for battery technologies. At present, no single technology meets the cost, energy, and power requirements of a BEV 300, but a combination of multiple batteries with different capabilities might be able to lower the overall cost closer to the DOE target. This study looks at how such a combination can be implemented in vehicle simulation models and compares the vehicle manufacturing and operating costs to a baseline BEV 300. Preliminary analysis shows an opportunity to modestly reduce BEV 300 energy storage system cost by about 8% using a battery pack that combines an energy and power battery. The baseline vehicle considered in the study uses a single battery sized to meet both the power and energy requirements of a BEV 300. The alternate option considered is a combination of two battery packs controlled by a power conditioner. The energy battery has lithium sulphur (Li-S) cells, and the power battery has lithium manganese oxide (LMOG) cells. The Li-S and LMOG cells have different cost characteristics. While it is relatively cheap to increase the capacity of an energy battery, adding more power to an energy battery is expensive. Similarly, more discharge power capability can be inexpensively added to the power battery, but storing more energy in that battery is expensive. However, it should be noted that this approach is not compatible with a high-rate, fast-charging requirement. This study looks at the levelized cost of driving (LCOD) for BEV 300s when different battery types and combinations are used.