Applying the Lessons Learned from PAFC to PEM Fuel Cells

Abstract

As PEM fuel cells advance it is useful to compare and contrast the experiences from phosphoric acid fuel cells. Early in the development of PEM Fuel cells, the poor membrane durability seen in the GEMINI program prevented PEM technology from being selected for follow-on space programs. However, the subsequent development of Nafion® greatly improved membrane durability, and the focus moved from durability to improving power density and cost. It is only recently that attention has returned to durability. Here we will discuss the major degradation challenges of PEM fuel cells, and more specifically compare the experiences of PAFC with that of PEM fuel cells. Phosphoric acid fuel cells have been available commercially for over a decade with about 250 units accumulating more than 7 million hours of operation in the field. How relevant is the field data to PEM fuel cells and what can we learn from this experience?