Variable area fuel cell process channels

An improved fuel cell arrangement having a non-uniform distribution of fuel and oxidant flow paths (26,28), on opposite sides of an electrolyte matrix sized and positioned to provide approximately uniform fuel and oxidant utilization rates across the entire cell. In conventional cross-flow type fuel cells, the entry corner exposed to both fresh fuel and fresh oxidant tends to develop a higher EMF than the exit corner exposed to both depleted fuel and depleted oxidant. The resulting uneven reaction distribution is undesirable. This invention improves the current, density and temperature distributions by providing the largest fuel channel (26 min ) nearest the oxidant inlet and decreasing the fuel channels as the oxidant outlet is approached, while providing the largest oxidant channel (28 min ) nearest the fuel inlet and decreasing the oxidant channels as the fuel outlet is approached.