In this article, the development challenges of a fuel cell system are explained using the example of the BREEZE! fuel cell range extender (FC-REX) applied in an FEV Liiona. The FEV Liiona is a battery electric vehicle based on a Fiat 500 developed by FEV. The BREEZE! system is the first applied 30 kW low temperature polymer electrolyte membrane (LT PEM) fuel cell system in the subcompact vehicle class. Due to the highly integrated system approach and dry cathode operation, a compact design of the range extender module with a system power density of 0.45 kW/l can be achieved so that the vehicle interior including trunk remains completely usable.
System development for fuel cells significantly influences performance, efficiency, package, durability, and required maintenance effort of a fuel cell electric powertrain. In order to ensure safe and reliable operation, the fuel cell system has to be supplied with sufficient amounts of air, hydrogen, and coolant flows. At the same time, the requirements for the auxiliary components necessary for fluid supply differ considerably compared to combustion engines. With respect to the FC-REX application, the pros and cons of selected balance of plant components are explained and evaluated. The BREEZE! FC-REX achieves load-dependent system efficiencies between 40% and 50%. Without limiting the usability of the vehicle interior, an additional range of 140 km can be provided by the FC-REX.
