Development of PEFC stack working at low pressure

Fuel cell technology development is one of the main activities at the CNR-TAE Institute. The matured experience on polymer electrolyte fuel cells (PEFC), especially on electrodes evolution, optimisation and characterisation of membrane-electrodes assemblies (MEAs) and new membrane research, has provided the opportunity to start with a project addressed to the realization of a small size PEFC stack. The first goal of this work was the development of a 100 W stack prototype based on low Pt loading electrodes evolved at CNR-ITAE and working at low pressure. This work reports our experience on stack evolution and performance obtained using H2/air as fuel and oxidant, respectively. The stack with 50 cm2 cells size was designed to produce a rated power of 100 W and a potential of 6 V. MEAs with a total Pt loading of 0.5 mg/cm2 and Nafion® 115 membranes were used. Humidifying conditions for fuel and oxidant based on water amount were studied at a working temperature of 80°C. The experimental activity was finalized to study the optimal operative conditions as a function of gases flux and water amount at 1.5 abs bar for both fuel and oxidant. A monitoring system of several parameters for each cell was a valid help to associate the stack failure with reagent management problems.