Patent ID: 7014940

Claim:
A polymer electrolyte fuel cell comprising a cell stack including plural electrically conductive separator plates and electrolyte membrane-electrode assemblies inserted among said electrically conductive separator plates, wherein each of said electrolyte membrane-electrode assemblies comprises a hydrogen ion conductive polymer electrolyte membrane together with an anode and a cathode to sandwich said hydrogen ion conductive polymer electrolyte membrane, wherein each of said electrically conductive separator plates comprises plural striated gas communication grooves on one main surface thereof for supplying and exhausting a fuel gas to and from said anode, and plural striated gas communication grooves on the other main surface thereof for supplying and exhausting an oxidant gas to and from said cathode, wherein said gas communication grooves on one of said main surfaces out of both of said gas communication grooves of said each of said electrically conductive separator plates are arranged to correspond to ribs among said gas communication grooves on the other of said main surfaces, and wherein said gas communication grooves for supplying and exhausting said fuel gas to and from said anode of said each of said electrolyte membrane-electrode assemblies are positioned to correspond to ribs among said gas communication grooves for supplying and exhausting said oxidant gas to and from said cathode of said each of said electrolyte membrane-electrode assemblies; and wherein with respect to said each of said electrically conductive separator plates, a width of each of said ribs Wr and a width of each of said gas communication grooves Wg on said one main surface, and a width of each of said ribs Wr′ and a width of each of said gas communication grooves Wg′ on said other main surface respectively satisfies the equations: 1< Wr/Wg< 1.4, and 1< Wr′/Wg′< 1.4.