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: An exemplary method includes of operating a fuel cell at a first power output level that includes a plurality of operation parameters. Each operation parameter has a value to satisfy a first power demand. A change between the first power demand and a second power demand is determined. At least a first one of the operation parameters is maintained at a value corresponding to the first power output level or at an intermediate value while at least a second one of the operation parameters is changed to a value corresponding to a second power output level to satisfy the second power demand. The first operation parameter is delayed from changing to a value corresponding to the second power output level until a predetermined criterion is met.

Abstract: A method of heat treating a substrate for a fuel cell includes stacking substrates to form a group. A dimension is determined for a plate corresponding to a resulting mass that is less than a predetermined mass. The plate is arranged above the group to apply a weight of the plate to the group. The resulting masses for spacer plates and intermediate lifting plates, for example, are minimized to reduce the pressure differential between the bottom and top substrates in the heat treat assembly. In another disclosed method, a dimension for a plate, such as a top plate, is determined that corresponds to a resulting mass that is greater than a predetermined mass. The plate is arranged above the group to apply a weight of the plate to the group. The top plate resulting mass is selected to minimize a variation in the average pressure of the substrates throughout the heat treat assembly.

Abstract: A method of manufacturing a flow field plate includes mixing graphite and resin materials to provide a mixture. The mixture is formed into a continuous flow field plate, for example, by ram extrusion or one or more press belts. The continuous flow field plate is separated into discrete flow field plates. Flow field channels are provided in one of the continuous flow field plate and the discrete flow field plates.

Abstract: A fuel cell includes a separator sheet and a perforated support sheet connected to the separator sheet. The perforated support sheet and separator sheet are comprised of a nickel-based alloy. A porous layer is located between the separator sheet and the support sheet and provides an electrical connection between the separator sheet and the support sheet.

Abstract: An exemplary fuel cell system includes a cell stack assembly having a plurality of cathode components and a plurality of anode components. A first reactant blower has an outlet situated to provide a first reactant to the cathode components. A second reactant blower has an outlet situated to provide a second reactant to the anode components. The second reactant blower includes a fan portion that moves the second reactant through the outlet. The second reactant blower also includes a motor portion that drives the fan portion and a bearing portion associated with the fan portion and the motor portion. The motor portion has a motor coolant inlet coupled with the outlet of the first reactant blower to receive some of the first reactant for cooling the motor portion.

Abstract: A fuel cell includes a cell having a solid oxide electrolyte between electrodes. The cell has a first coefficient of thermal expansion. A metallic support is in electrical connection with one of the electrodes. The metallic support includes a metal substrate and a compliant porous nickel layer that is bonded to the metal substrate between the cell and the metal substrate. The metal substrate has a second coefficient of thermal expansion that nominally matches the first coefficient of thermal expansion of the cell. The metal substrate has a first stiffness and the compliant porous nickel layer has a second stiffness that is less than the first stiffness such that the compliant porous nickel layer can thermally expand and contract with the metal substrate.

Abstract: A fuel cell power plant includes a cell stack assembly having an anode and a cathode. A component is arranged in fluid connection with at least one of the anode and cathode. The component has a first shut-down cooling rate. A heat exchanger is arranged in fluid communication with and between the component and one of the anode and cathode. The heat exchanger has a second shut-down cooling rate greater than the first shut-down cooling rate. Water vapor within the fuel cell power plant outside of the cell stack assembly will condense and freeze in the heat exchanger rather than the component, avoiding malfunction of the component upon start-up in below freezing environments.

Abstract: A fuel cell installation includes a support structure and a cell stack assembly that is removably insertable into the support structure from an uninstalled position to an installed position during an installation procedure. The cell stack assembly includes a fitting. An interfacing structure is mounted on one of the support structure in the cell stack assembly. The interfacing structure carries a connector that is configured to receive the fitting in interconnected relationship. At least one of the fitting and the connector floats in a plane relative to the support structure during the installation procedure. In operation, the fitting engages the connector when the cell stack assembly is inserted into the support structure. The fitting is repositioned relative to the connector to ensure that the fitting and connector are aligned with one another and connected upon installation.

Abstract: In solid polymer fuel cells employing framed membrane electrode assemblies, a conventional anode compliant seal is employed in combination with a cathode non-compliant seal to provide for a thinner fuel cell design, particularly in the context of a fuel cell stack. This approach is particularly suitable for fuel cells operating at low pressure.

Abstract: A fuel cell power plant (5) includes a stack (6) of fuel cells, each of which have an anode (9), a cathode (10), and a PEM (11) disposed between the anode and the cathode. A controller (17) recognizes an indication (67) of no load demand (68) by a load (59), to operate (45) an air recycle loop (44-46) utilizing the process air blower (35) and transfer the power output (57) of the stack from the load (59) to an auxiliary load (60), comprising a resistance which will consume a predetermined small amount of power in response to the current applied thereto, when the stack operates at a critical voltage above which fuel cell corrosion is unacceptable. Fuel and air will also be reduced (16, 40). The controller may cause increased cathode recycle when the critical voltage is reached and increased air when the voltage is a fraction of a volt below the critical voltage.

Abstract: A flow field plate for use in a fuel cell includes a porous, wettable plate body including a first reactant gas channel having an inlet portion, a second reactant gas channel having an outlet portion that is adjacent the inlet portion of the first reactant gas channel, and at least one moisture reservoir fluidly connected with pores of the porous, wettable plate body. The at least one moisture reservoir can selectively collect and release moisture received from a reactant gas in the outlet portion to thereby selectively move the moisture from the outlet portion toward the adjacent inlet portion.

Abstract: A fuel cell includes an inlet manifold that communicates with an inlet pipe. The inlet pipe enters the inlet manifold at a port. A baffle is positioned about the port. The baffle captures and directs fuel away from a side of the inlet manifold that will face a cell stack. A fuel cell incorporating such an inlet manifold is also claimed.

Abstract: Coolant velocity greater than zero everywhere within the coolant channels (78, 85) of fuel cells (38) in a fuel cell stack (37) is assured by providing a flow of biphase fluid in the coolant channels, the flow being created by the outflow of a condenser (59). Positive pressure is applied to the coolant inlet (66) of the coolant channels. Biphase flow from an oxidant exhaust condenser, which may be a vehicle radiator (120), renders the coolant return flow more freeze tolerant. Using biphase flow within the coolant channels eliminates the need for a bubble-clearing liquid pump and reduces liquid inventory and other plumbing; this makes the fuel cell power plant more freeze tolerant.

Abstract: A fuel cell assembly (110, 210) has a plurality of fuel cell component elements (112) extending between a pair of end plates (114, 115) to form a stack (116), and plural reactant gas manifolds (120, 220; 122, 222; 124, 224; 126, 226) mounted externally of and surrounding the stack, in mutual, close sealing relationship to prevent leakage of reactant gas in the manifolds to the environment external to the manifolds. The reactant gas manifolds are configured and positioned to maximize sealing contact with smooth surfaces of the stack and the manifolds. One embodiment is configured for an oxidant reactant manifold (120, 124) to overlie the region where the fuel reactant manifold (122, 126) engages the stack. Another embodiment further subdivides an oxidant reactant manifold to include a liquid flow channel (270, 274), which liquid flow channel overlies the region where the fuel reactant manifold (122, 126) engages the stack.

Abstract: A fuel cell installation includes a support structure and a cell stack assembly that is removably insertable into the support structure from an uninstalled position to an installed position during an installation procedure. The cell stack assembly includes a fitting. An interfacing structure is mounted on one of the support structure in the cell stack assembly. The interfacing structure carries a connector that is configured to receive the fitting in interconnected relationship. At least one of the fitting and the connector floats in a plane relative to the support structure during the installation procedure. In operation, the fitting engages the connector when the cell stack assembly is inserted into the support structure. The fitting is repositioned relative to the connector to ensure that the fitting and connector are aligned with one another and connected upon installation.

Abstract: A flow field plate comprises a first flow field; an opposing second flow field; and at least one flow channel formed in the first flow field, the at least one flow channel comprising: a first side and an opposing second side separated by an open-faced top and a bottom; and a first side channel formed in a portion of the open-faced top and in a portion of the first side along a continuous length of the at least one flow channel, the first side channel comprising a first side wall and a first bottom wall; wherein the first side wall of the first side channel and the first bottom wall of the first side channel form an obtuse angle in cross-section; and a depth of the bottom of the at least one flow channel is greater than a depth of the bottom wall of the first side channel.

Abstract: In solid polymer fuel cells employing framed membrane electrode assemblies, a conventional anode compliant seal is employed in combination with a cathode non-compliant seal to provide for a thinner fuel cell design, particularly in the context of a fuel cell stack. This approach is particularly suitable for fuel cells operating at low pressure.

Abstract: Current pulsing improves the performance of fuel cells in a fuel cell stack based power system. Voltage clamping limits the voltage peaks that occur after a current pulse. In a hybrid power system, an electric storage device supplies the loads during current pulsing. The electric storage device may sink current to achieve the voltage clamping, and/or power system may employ other the voltage clamping circuits.

Abstract: A hybrid power module suitable for use in an array of hybrid power modules comprises a fuel cell stack, an energy storage device, charger circuit operable to charge the energy storage device from the fuel cell stack and/or an external power source at approximately a defined voltage; a stack disconnect switch operable to provide and remove an electrical path between the fuel cell stack and a terminal of the power module, and a unidirectional current flow device electrically coupled to provide a unidirectional current path from the charger circuit to the terminal of the power module when forward biased.