Polimeric electrolyte membrane fuel cells: Characterization test under variable temperature and relative humidity conditions

The aim of this work is the performance study of a PEM stack. Extreme conditions of temperature and relative humidity, like those which may be found in practical situations (i.e. automotive), have been considered. The research has been developed by Department of Energetics of Politecnico di Milano in collaboration with Nuvera Fuel Cells Europe, under confidential agreement. In order to select the proper electrolyte that can be used to build a stack suitable for automotive applications, three different types of material have been tested in single fuel cells, under different conditions of temperature and relative humidity by mean of a climatic chamber. Both traditional (Nafion) and new materials have been tested in single cells of 16 cm2 of active area. The three electrolyte materials have been tested also by measuring the protonic conductance, in different conditions of relative humidity. After these tests, it has been choosen an electrolyte made with a a Coated Catalyst Membrane (CCM) having a thickness of 35 m, which has been used to build a 6 cells stack with an active area of 500 cm2. The performances of the stack have been evaluated, in continuous operation, with air temperatures ranging from 50 °C to – 40 °C. A series of start-up tests has been carried out with an air temperature ranging between 0 °C and –25 °C.