Abstract
Electrochemical capacitors (SC) are receiving increasing attention as possible enabling technologies in applications where high power is required for short times, such as in hybrid vehicles (HEV) and uninterruptible power systems (UPS). Moreover, there are some applications using fuel cells (FC) as power generators, whose energy efficiency is greatly reduced whenever FC power variations are significant. In 2005 the European Commission (EC) funded the ILHYPOS project, mainly aimed at the research and development of innovative SCs with highly improved specific performances (specific energy and power), and based on environmentally acceptable materials, such as ionic liquids, a novel electrolyte class of materials, with a working voltage in excess of 5 V. The improvements of SC performances were pursued also studying new electrode materials and/or cell designs: specific energy in excess of 40 Wh/kg, based only on active material weights have been estimated, in configurations with electronic conducting polymers or activated carbons in asymmetric configurations. As part of the Project ILHYPOS, the possible impact of the studied SCs has been evaluated by means of simulations in defined applications, such as those in fuel cell vehicles (FCV) and UPS, powered by fuel cells. The simulations for vehicle applications have been performed by using conventional standardized and real duty cycles. The sizing of the ILHYPOS SCs has been carried out with developed mathematical models and applied to a FC hybrid electric van, a test prototype developed by an Italian small enterprise. This paper first highlights the most recent achievements of the ILHYPOS Project and, then, presents the impacts of the developed SCs with respect to commercial SCs and a drivetrain with and without SCs.