High Temperature Operation of a Solid Polymer Electrolyte Fuel Cell Stack Based on a New Ionomer Membrane

Polymer electrolyte fuel cell stacks assembled with Johnson Matthey Fuel Cells and SolviCore MEAs based on the Aquivion (TM) E79-03S short-side chain (SSC), chemically stabilised perfluorosulphonic acid membrane developed by Solvay Solexis were investigated at CNR-ITAE in the EU Sixth Framework 'Autobrane' project. Electrochemical experiments in fuel cell short stacks were performed under practical automotive operating conditions at pressures of 1-1.5 bar abs. over a wide temperature range, up to 130 degrees C, with varying levels of humidity (down to 18% R. H.). The stacks using large area (360 cm(2)) MEAs showed elevated performance in the temperature range from ambient to 100 degrees C (cell power density in the range of 600-700 mWcm(-2)) with a moderate decrease above 100 degrees C. The performances and electrical efficiencies achieved at 110 degrees C (cell power density of about 400 mWcm(-2) at an average cell voltage of about 0.5-0.6 V) are promising for automotive applications. Duty-cycle and steady-state galvanostatic experiments showed excellent stack stability for operation at high temperature. A performance comparison of Aquivion (TM) and Nafion (TM)-based MEAs under practical operating conditions showed a significantly better capability for the Solvay Solexis membrane to sustain high temperature operation.