초록 |
Polymer electrolyte membrane fuel cells(PEMFCs) is generally used below 80℃. And Nafion membrane is frequently used as the membrane material for the PEMFCs, due to its superior physical and chemical properties. Below 80 ℃, proton conductivity of the Nafion membrane shows high proton conductivity under fully hydrated state. However, the conductivity is easily affected by both temperature and humidity, and it drastically decreases at high temperature(>80℃) and/or under low humidity condition. In this study, the changes of proton conductivity, ion exchange capacity (IEC), water uptake, and thermal stability of Nafion membrane under aging test at fixed conditions with different temperature and humidity, have been investigated, and their relationship with chemical changes at the membrane surface was studied. Detailed results will be presented. |