Abstract: A unitized electrode assembly (10; 110; 210; 310; 410) for a fuel cell includes, in addition to an anode catalyst layer (54; 254) and a cathode catalyst layer (56; 256), a polymer electrolyte membrane (52) having an acid functional group normally including H+ ions and an edge seal (66; 166; 266, 366, 466) containing alkali metal ions in a form, concentration, and/or location for delivery and dispersion into the membrane. The edge seal of the unitized electrode assembly is proximate, and typically contacts, the peripheral edge region (68) of the membrane in ion-transfer relation therewith, and alkali metal ions leach into the membrane during fuel cell operation to provide a desired ion exchange in the membrane.

Abstract: An example of a stable electrode structure is to use a gradient electrode that employs large platinum particle catalyst in the close proximity to the membrane supported on conventional carbon and small platinum particles in the section of the electrode closer to a GDL supported on a stabilized carbon. Some electrode parameters that contribute to electrode performance stability and reduced change in ECA are platinum-to-carbon ratio, size of platinum particles in various parts of the electrode, use of other stable catalysts instead of large particle size platinum (alloy, etc), depth of each gradient sublayer. Another example of a stable electrode structure is to use a mixture of platinum particle sizes on a carbon support, such as using platinum particles that may be 6 nanometers and 3 nanometers. A conductive support is typically one or more of the carbon blacks.

Abstract: According to an embodiment, a method of preparing a catalyst for a fuel cell component includes soaking catalyst particles in citric acid. The catalyst particles are then rinsed after having been soaked in the citric acid. Catalyst particles are dried after they have been rinsed. When desired, the pre-treated catalyst particles may be incorporated into a catalyst ink used for making a fuel cell component.

Abstract: A unitized electrode assembly (10; 110; 210; 310; 410) for a fuel cell includes, in addition to an anode catalyst layer (54; 254) and a cathode catalyst layer (56; 256), a polymer electrolyte membrane (52) having an acid functional group normally including H+ions and an edge seal (66; 166; 266, 366, 466) containing alkali metal ions in a form, concentration, and/or location for delivery and dispersion into the membrane. The edge seal of the unitized electrode assembly is proximate, and typically contacts, the peripheral edge region (68) of the membrane in ion-transfer relation therewith, and alkali metal ions leach into the membrane during fuel cell operation to provide a desired ion exchange in the membrane.

Abstract: A unitized electrode assembly (10; 110; 210; 310; 410) for a fuel cell includes, in addition to an anode catalyst layer (54; 254) and a cathode catalyst layer (56; 256), a polymer electrolyte membrane (52) having an acid functional group normally including H+ ions and an edge seal (66; 166; 266, 366, 466) containing alkali metal ions in a form, concentration, and/or location for delivery and dispersion into the membrane. The edge seal of the unitized electrode assembly is proximate, and typically contacts, the peripheral edge region (68) of the membrane in ion-transfer relation therewith, and alkali metal ions leach into the membrane during fuel cell operation to provide a desired ion exchange in the membrane.

Abstract: According to an embodiment, a method of preparing a catalyst for a fuel cell component includes soaking catalyst particles in citric acid. The catalyst particles are then rinsed after having been soaked in the citric acid. Catalyst particles are dried after they have been rinsed. When desired, the pre-treated catalyst particles may be incorporated into a catalyst ink used for making a fuel cell component.

Abstract: An exemplary method of processing a catalyst ink includes ultrasonicating the catalyst ink. The exemplary method includes high shear mixing the catalyst ink.

Abstract: An example of a stable electrode structure is to use a gradient electrode that employs large platinum particle catalyst in the close proximity to the membrane supported on conventional carbon and small platinum particles in the section of the electrode closer to a GDL supported on a stabilized carbon. Some electrode parameters that contribute to electrode performance stability and reduced change in ECA are platinum-to-carbon ratio, size of platinum particles in various parts of the electrode, use of other stable catalysts instead of large particle size platinum (alloy, etc), depth of each gradient sublayer. Another example of a stable electrode structure is to use a mixture of platinum particle sizes on a carbon support, such as using platinum particles that may be 6 nanometers and 3 nanometers. A conductive support is typically one or more of the carbon blacks.

Abstract: A unitized electrode assembly (10; 110; 210; 310; 410) for a fuel cell includes, in addition to an anode catalyst layer (54; 254) and a cathode catalyst layer (56; 256), a polymer electrolyte membrane (52) having an acid functional group normally including H+ ions and an edge seal (66; 166; 266, 366, 466) containing alkali metal ions in a form, concentration, and/or location for delivery and dispersion into the membrane. The edge seal of the unitized electrode assembly is proximate, and typically contacts, the peripheral edge region (68) of the membrane in ion-transfer relation therewith, and alkali metal ions leach into the membrane during fuel cell operation to provide a desired ion exchange in the membrane.

Abstract: A fuel cell proton exchange membrane electrolyte is formed of a first layer (6) having its stronger tensile strength oriented in one direction, laminated to a second layer (7) having its stronger tensile strength oriented perpendicular to the stronger direction of the first layer.

Abstract: A fuel cell stack (31) includes a plurality of fuel cells (9) each having an electrolyte such as a PEM (10), anode and cathode catalyst layers (13, 14), anode and cathode gas diffusion layers (16, 17), and water transport plates (21, 28) adjacent the gas diffusion layers. The cathode diffusion layer of cells near the cathode end (36) of the stack have a high water permeability, such as greater than 3×10?4 g/(Pa s m) at about 80° C. and about 1 atmosphere, whereas the cathode gas diffusion layer in cells near the anode end (35) have water vapor permeance greater than 3×10?4 g/(Pa s m) at about 80° C. and about 1 atmosphere. In one embodiment, the anode gas diffusion layer of cells near the anode end (35) of the stack have a higher liquid water permeability than the anode gas diffusion layer in cells near the cathode end; a second embodiment reverses that relationship.

Abstract: A freeze tolerant fuel cell power plant (10) includes at least one fuel cell (12), a coolant loop (18) including a freeze tolerant accumulator (22) for storing and separating a water immiscible fluid and water coolant, a direct contact heat exchanger (56) for mixing the water immiscible fluid and the water coolant within a mixing region (72) of the heat exchanger (56), a coolant pump (21) for circulating the coolant through the coolant loop (18), a radiator loop (84) for circulating the water immiscible fluid through the heat exchanger (56), and a radiator (86) for removing heat from the coolant. The plant (10) utilizes the water immiscible fluid during steady-state operation to cool the fuel cell and during shut down of the plant to displace water from the fuel cell (12) to the freeze tolerant accumulator (22).

Abstract: A performance enhancing break-in method for a proton exchange membrane (“PEM”) fuel cell (12) includes cycling potentials of an anode electrode (14) and a cathode electrode (16) from a first potential to a second potential and back to the first potential, and repeating the cycling for each electrode (14, 16) for at least two electrode cycles. The potential cycling may be achieved in a first embodiment by applying a direct current from a programmable direct current power source (80) to the electrodes. Alternatively the potential cycling may be achieved by varying reactants to which the anode and cathode electrodes (14, 16) are exposed.