PREPARATION AND EVALUATION OF ELECTRODES FOR SOLID POLYMER FUEL-CELLS

Thin film electrodes for solid polymer fuel cells (0.06-0.1 mg Pt/cm(2 )) were prepared by spraying electrode material directly onto the Nafi on 117 membrane. Variations in cell potential obtained by changing the electrode composition and preparation conditions were investigated. T he results showed that both increased polymer content and higher Pt-lo ading had positive effect on cell performance, whereas increased dryin g temperature caused a decline in cell performance. Commercial electro des were modified by vacuum-deposition of a thin layer of Pt/Rh alloy on top of the electrode followed by Nafion impregnation. This treatmen t also gave improved cell performance. Comparison showed that Pt-utili zation was better for the thin film electrodes than for the modified c ommercial electrodes, due to a more optimal composition of the electro active layer. A test station for studying single cell performance was described. The test station provided cell tests over a wide range of o perating conditions. Cell performance was tested automatically through computer control.