Sustainable Transportation Energy Pathways (STEPS), Plug-In Hybrid & Electric Vehicle Research Center
Burke, Andrew and Hengbing Zhao (2015) Applications of Supercapacitors in Electric and Hybrid Vehicles. Institute of Transportation Studies, University of California, Davis, Research Report UCD-ITS-RR-15-09
This paper is concerned with supercapacitors (electrochemical capacitors) and their applications in electric drive vehicles in place of or in combination with batteries. The electric drive vehicles considered are hybrid vehicles (HEVs and PHEVs) and fuel cell vehicles. The first section of the paper deal with the performance of advanced devices based on recent test data for commercial and proto-type devices taken at the University of California-Davis. Various vehicle applications of supercapacitors are reviewed in detail. Simulation results are presented for light duty vehicles and transit buses using supercapacitors in place of lithium batteries in hybrid vehicles and in combination with advanced batteries in plug-in electric vehicles. It was found in all cases that the vehicles using the supercapacitors had the same as or better performance than those using batteries and in general were more efficient. The cost of supercapacitors compared to lithium batteries was discussed briefly. It was shown that when one recognizes that the energy stored in the capacitors is less than 1/10 that in the batteries for hybrid applications, the price of supercapacitors needs to decrease to about .5- 1 cent Farad for capacitors to be cost competitive with high power batteries at $500-700/kWh. In addition, there is a good possibility that the life of the capacitors would be equal to that of the hybrid vehicles.