Experimental behaviour of Li-ion and supercapacitors cells for HEVs under standardized and tailored-life cycle testing

A large European Project, named HCV (Hybrid Commercial Vehicles) started in January 2010 with the participation of 18 European organizations (vehicle manufacturers, components integrators and suppliers, and research organizations) and with the scope to develop and demonstrate the next generation of hybrid heavy duty (HD) commercial vehicles by using various types of storage systems. In this project, seven research (AIT, ENEA, University of Pisa) and industrial organizations (IVECO, Volvo, Magna, DimacRed) from various European countries have been working together to experimentally analyse, with electrical and safety tests, the behaviour of Li-ion and supercapacitor cells and modules to support the design and the optimization of the final storage systems to be installed on different HEV (Hybrid Electric Vehicles): urban buses and commercial vans.
This paper summarizes the experimental work carried out at ENEA and is focussed on electrical and safety tests, which fully characterized the selected storage samples according to conventional and testing procedures, tailored on the technical specifications of the HEV under development. Initially, basic characterization testing, together with safety tests, confirmed the technical performances of the two storage technologies, and, subsequently, project-specific testing, including cycle life and accelerating procedures, verified the behaviour in operating conditions, adapted to the selected HEV. The final results substantiated the suitability of the storage systems in powering the commercial hybrid vehicles under development in HCV project, and gave innovative inputs to the definition and validation of mathematical models and control algorithms, not analysed in this paper, to be used in the BMS (battery management systems) for both storage technologies, suitable for thermal management and overall storage control.