INFLUENCE OF THE OPERATING-CONDITIONS AND OF THE AGING UPON THE ELECTROCHEMICAL PERFORMANCE OF A PHOSPHORIC-ACID FUEL-CELL

As a key step towards the development of a prototype of a 1 kW phospho ric acid fuel cell at the CNR-TAE Institute, the first made in Europe based on an 'in-house' know-how, tests in a subscale monocell station have been performed. The main objective of these studies was to establ ish the optimum operating conditions as well as to determine the effec ts of ageing on the cell performance. Prolonged tests totalling more t han 40 000 h operations in a monocell have provided useful information to select and scale up the range of optimal operating conditions for the 1-kW stack. This paper illustrates the main findings for phosphori c acid management, humidifier temperature of gases and cell working cu rrent density. The endurance tests indicated that the most predominant mechanism of decay is the PTFE-carbon electrostatic corrosion, its ex tent being strongly a function of cell potential. Performance losses d ue to platinum catalyst dissolution and/or sintering have been estimat ed to be in the order of 2mV/1000 h.