Sealing design for stamped plate fuel cells

A fuel cell stack of at least two fuel cells, each fuel cell each fuel cell comprising a unitized electrode assembly (UEA) of 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 the sub-gasket, the framed MEA being disposed between a pair of gas diffusion media (DM), each UEA being disposed between a pair of stamped flow-field plates, each flow-field plate configured with reactant channel and land features such that alignment of flow-field plates of adjacent fuel cells forms a bipolar plate comprising coolant passages, wherein the plates comprise 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 defined as co-extensive in area with the overlap area between the MEA and the sub-gasket, wherein the overlap region comprises a modified configuration of channel and land features, “modified” being with respect to a configuration of channel and land features in the active region, the modified configuration comprising a pattern of channel and land features, coolant blocking channel features, and reactant blocking land features designed to substantially avoid channel-over-channel and land-over-land alignment between adjacent plates, and further designed to form substantially isolated coolant passages upon alignment of adjacent plates, each isolated coolant passage being in fluid communication with active area coolant passage by only a single interconnection positioned to permit venting of coolant passages necessary to effectuate coolant fill, wherein the channel and land features of the overlap region have substantially the same pitch and height as the channel and land features of the active region and the channel features of the overlap region are configured to have an angle similar to or orthogonal to an angle of the channel features of the active region.

A stamped flow-field plate for a fuel cell comprising an active region, an overlap region and a seal region, the overlap region abutting an outer perimeter of the active region and extending to an inner perimeter of the seal region, the active region being configured with channel and land features such that alignment between adjacent flow-field plates forms a bipolar plate comprising a configuration of reactant channel and coolant passages in the active region and a modified configuration of features in the overlap region, “modified” being with respect to the configuration of channel and land features in the active region, the modified configuration comprising one or more of:

• coolant blocking channel features;
• reactant blocking land features;
• substantially isolated coolant passages, each isolated coolant passage in fluid communication with active region coolant flow by only a single interconnection positioned to permit venting of coolant passages necessary to effectuate coolant fill;
• wherein all features are designed to substantially avoid channel-over-channel and land-over-land alignment between adjacent plates and further wherein the channel and land features of the overlap region have substantially the same pitch and height as the channel and land features of the active region.