SEALING DESIGN FOR STAMPED PLATE FUEL CELLS

摘要

A fuel cell stack of at least two fuel cells, each fuel cell having a unitized electrode assembly (UEA) including a membrane electrode assembly (MEA), a sub-gasket and gas diffusion media (DM), and positioned between modified stamped field-flow plates. The sub-gasket frames the MEA resulting in an overlap area between the MEA and the inner perimeter of the sub-gasket. The UEA is disposed between a pair of stamped flow-field plates which align in adjacent fuel cells to form a bipolar plate. The bipolar plate has an active region, an overlap region and a seal region. The active region is configured with channel and land features which provide reactant flow channels and coolant passages for the fuel cell. The configuration of features in the overlap region, however, is modified from the configuration in the active region so that the overlap region may sustain sufficient mechanical sealing pressure, and to prevent coolant and reactant bypass without impeding coolant and reactant flow in the active area. Modified channel and land feature configurations for the overlap region are exemplified.

主权项

1. A fuel cell stack of at least two fuel cells, each fuel cell comprising a unitized electrode assembly (UEA) comprising a thrifted electrolyte membrane disposed between a pair of electrodes forming a membrane electrode assembly (MEA), the MEA being framed on a sub-gasket such than an overlap exists between an outer perimeter of the MEA and an inner perimeter of the sub-gasket defining an overlap area, the framed MEA being disposed between a pair of gas diffusion media (DM), a pair of stamped flow-field plates, one on each side of a UEA such that flow-field plates of adjacent fuel cells align to form a bipolar plate comprising an active region, a seal region, and an overlap region, said overlap region disposed between an outer perimeter of the active region and an inner perimeter of the seal region and substantially corresponding in area to the overlap area, wherein the active region comprises a configuration of channel and land features and the overlap region comprises a modified configuration of channel and land features which permit a level of mechanical pressure sufficient to seal the overlap region and to substantially prevent coolant and reactant bypass without impeding coolant and reactant flow in the active area.