Patent ID: 8012646
Filing Date: 2011-09-06
Classification: H01M,Y02E,Y02P

Abstract:
1. A polymer electrolyte fuel cell comprising a cell stack having a plurality of unit cells tightened in a stacking direction of the stack, each unit cell comprising: an electrolyte membrane-electrode assembly comprising a hydrogen ion conductive polymer electrolyte membrane and first and second electrodes respectively placed on opposite major surfaces of the electrolyte membrane, each of the electrodes comprising a gas diffusion layer and a catalyst layer; the gas diffusion layer comprising a non-woven fabric, a first electrically conductive separator plate contacting the first electrode and having a first gas flow channel for supplying and exhausting a fuel gas to and from the first electrode; and a second electrically conductive separator plate contacting the second electrode and having a second gas flow channel for supplying and exhausting an oxidant gas to and from the second electrode, at least two laterally spaced-apart sealing members, each sealing member encircling a periphery of one of at least two laterally spaced-apart manifold holes in at least one of the separator plates, and end plates and tightening members being disposed so as to sandwich the cell stack for applying a tightening pressure to each of the first and second electrodes, wherein each of the sealing members is configured to be placed in contact with a surface of each first electrically conductive separator plate and each second electrically conductive separator plate, wherein the electrolyte membrane-electrode assembly has a short-circuit conductivity of not greater than 1.5 mS/cm wherein a tightening pressure applied to each of the first and second electrodes is about 4.0 to 8.0 kgf/cm wherein at least one of the first gas flow channel and the second gas flow channel has a form of a groove having lateral groove walls, and wherein a groove wall of at least one of the first gas flow channel and the second gas flow channel is tapered so that a top of the groove is wider than a bottom of the groove.