An Overview of Supercapacitors as New Power Sources in Hybrid Energy Storage Systems for Electric Vehicles

Supercapacitors are widely used nowadays. They are known as ultracapacitors or electrochemical double layer capacitors (EDLC), which are energy storage devices providing high energy and efficiency. Their good characteristics make them suitable for usage in energy storage systems and the possibility to be charged/discharged rapidly without loss of efficiency for a lot of cycles. The supercapacitor pack can be successfully used in HESS (battery-supercapacitor system) combining different energy storage technologies with special control strategy using all the advantages of each energy source for improving and reaching overall performance. This paper summarizes the performance of supercapacitors in terms of energy density, equivalent series resistance and their optimal usage in the automotive sector. The paper also presents a brief review of benefits, features, advantages and disadvantages of hybrid energy systems based on batteries and supercapacitors.