Abstract: A fuel cell assembly includes first and second compression members. Two or more membrane electrode assembly (MEA) stacks are disposed between the compression members, each MEA stack having a positive and negative end. A first current collector is electrically coupled to a positive end of a first stack of the MEA stacks. A second current collector is electrically coupled to a negative end of a second stack of the MEA stacks. A current shunt is disposed between the compression members and electrically couples the MEA stacks.

Abstract: A fuel cell assembly includes a membrane electrode assembly (MEA) stack has a plurality of stacked planar membranes. The MEA stack further includes gas passageways arranged so that anode and cathode gases flow perpendicular to the planar membranes between a first side and a second side of the fuel cell assembly. Anode gas inlet and outlet ports and cathode gas inlet and outlet ports are disposed on the first side of the fuel cell assembly and coupled to the gas passageways of the MEA stack.

Abstract: A cooling apparatus for a fuel cell assembly includes a heat transfer fluid and at least one fluid flow field plate configured to facilitate essentially passive, two-phase cooling for an membrane electrode assembly (MEA) as the MEA is subject to changes in heat flux to the heat transfer fluid from about 0 W/cm2 to about 1.5 W/cm2. The flow field plate includes fluid flow channels that have a channel depth, a channel spacing, a channel length, and a channel width, which are dimensioned to promote nucleated boiling of the heat transfer fluid below a critical heat flux and to prevent dryout as the heat transfer fluid passes along the length of the channels. The channels may include coatings and/or features, such as microporous or nanostructured coatings, that extend the critical heat flux and preclude dryout at the distal sections of the fluid flow channels.

Abstract: A fuel cell cathode catalyst is provided which comprises nanostructured elements comprising microstructured support whiskers bearing nanoscopic catalyst particles. The nanoscopic catalyst particles are made by the alternating application of first and second layers, the first layer comprising platinum and the second layer being an alloy or intimate mixture of iron and a second metal selected from the group consisting of Group VIb metals, Group VIIb metals and Group VIIIb metals other than platinum and iron, where the atomic ratio of iron to the second metal in the second layer is between 0 and 10, where the planar equivalent thickness ratio of the first layer to the second layer is between 0.3 and 5, and wherein the average bilayer planar equivalent thickness of the first and second layers is less than 100 ?.

Abstract: Disclosed are sulfonated aromatic perfluorocyclobutane polymers meeting a condition selected from: a) the equivalent weight of the polymer is 5000 or less, and b) the proton conductivity of the polymer at 25° C. is 0.

Abstract: A flow field for an electrochemical cell such as a fuel cell is provided, having micro-flow channels having a width or depth of less than 800 &mgr;m, a pitch of less than 800 &mgr;m, or a proportion of inter-channel land area of less than 25%. The channels may further comprise micro-features within the channels. A flow field plate comprising the subject flow field is provided.

Abstract: The present invention provides fuel cell electrode catalysts comprising alternating platinum-containing layers and layers containing suboxides of a second metal, where the catalyst demonstrates an early onset of CO oxidation. Preferred second metals are selected from the group consisting of Group IIIb metals, Group IVb metals, Group Vb metals, Group VIb metals and Group VIIb metals, most preferably Ti, Ta, W and Mo. The present invention additionally provides methods of making such catalysts, preferably by alternate deposition of platinum and second metals in the presence of substoichiometric amounts of gaseous oxygen.

Abstract: The present invention provides fuel cell electrode catalysts comprising alternating platinum-containing layers and layers containing suboxides of a second metal, where the catalyst demonstrates an early onset of CO oxidation. Preferred second metals are selected from the group consisting of Group IIIb metals, Group IVb metals, Group Vb metals, Group VIb metals and Group VIIb metals, most preferably Ti, Ta, W and Mo. The present invention additionally provides methods of making such catalysts, preferably by alternate deposition of platinum and second metals in the presence of substoichiometric amounts of gaseous oxygen.

Abstract: Hybrid membrane electrode assemblies (MEAs) are presented, having an anode comprising a dense distribution of catalyst that may be borne on small, high-aspect ratio supports, such as nanostructured elements, and a cathode comprising a less dense distribution of catalyst that may be borne on lower-aspect ratio supports, such as carbon particle supported catalyst.

Abstract: A fuel cell including an electrode assembly, a cell assembly mounted to the electrode assembly forming an anode and at least one cathode channel, and a flow facilitator located within each cathode channel. The flow facilitator functions as a wick during the operation of the fuel cell to drain fluid from the cathode channels. It also provides resistance to water vapor flow within the cathode channels, thereby increasing humidification of the fuel cell. Moreover, the flow facilitator increases residence time of oxidant within the cathode channels. The flow facilitator is preferably a thread made of any one or any combination of cotton, silk, fiberglass, nylon or polyester, and may be coated with polytetraflouroethylene. The flow facilitator may be a single element that is weaved in specific patterns through the cathode channels or it can include a plurality of elements, one element for each of the cathode channels.