THERMOELECTRIC-POWER RELEVANT FOR THE SOLID-POLYMER-ELECTROLYTE FUEL-CELL

The Nafion(R) 117 membrane was investigated by measuring the emf as a function of the temperature difference between the electrodes in the f ollowing cell: )\Nafion(R)117\HCl(aq,c,T-2)\AgCl(s,T-2)\Ag(s,T-2) The reversible entropy transferred due to the membrane, was S(HM)-t(w)S(w ) = 13.4 +/- 0.2 J K-1 mol(-1) at 25.0 degrees C, where S(HM) is the transported entropy of protons in the membrane and S-w is the partial molar entropy of water in the bulk solution. The membrane transference coefficient of water, measured by the streaming potential technique, was t(w) = 2.6 +/- 0.2. The results were used to calculate the reversi ble heat effects at the electrodes in the solid-polymer-electrolyte fu el cell (SPEFC). We concluded that water management in the fuel cell h ad a strong impact on the heat effects. The total operation of the SPE FC was discussed in view of the new results. The stack method presente d here, is simple and accurate for finding the Seebeck coefficient in electrochemical cells with ion-exchange membranes.