Fuel cell structure

Abstract

A fuel cell including a unit cell and a separator panel alternatingly stacked on one another. The unit cell includes an electrolyte membrane sandwiched between a fuel electrode and an oxidant electrode. The separator panel includes parallel fuel flow paths extending from a fluid supply port to a fluid discharge port for supplying fluid fuel to the fuel electrode and parallel oxidant flow paths extending from a fluid supply port to a fluid discharge port for supplying oxidant fluid to the oxidant electrode. At least the oxidant flow paths include groups of parallel flow paths, which extend back and forth within divided regions of the main surface of the separator panel. The oxidant flow paths may include groups of parallel flow paths, positions along the groups of the parallel flow paths at equal distance from the respective fluid supply port being distributed substantially evenly over the main surface of the separator panel. Also, groups of parallel flow paths extend back and forth within a region defined by a projection of the divided regions through which the oxidant flow paths extend. The ridge width of ridges defined between grooves within the parallel flow path group is smaller than the ridge width of the ridges defined between the grooves of the parallel flow path group adjacent to each other.