Abstract: A fuel cell interconnect includes a first side containing a first plurality of channels and a second side containing a second plurality of channels. The first and second sides are disposed on opposite sides of the interconnect. The first plurality of channels are configured to provide a serpentine fuel flow field while the second plurality of channels are configured to provide an approximately straight air flow field.

Abstract: A method of controlling a fuel cell system includes applying alternating current (AC) signals to an individual fuel cell. The AC signals have a plurality of different frequencies. A voltage across the individual fuel cell is determined at each of the plurality of different frequencies. An impedance characteristic of the individual fuel cell is determined based at least in part on the voltage across the individual fuel cell at each of the plurality of different frequencies. The individual fuel cell is controlled based at least in part on the impedance characteristic.

Abstract: A fuel cell system includes a plurality of fuel cell stacks, and one or more devices which in operation of the system provide an azimuthal direction to one or more anode or cathode feed or exhaust fluid flows in the system.

Abstract: Various embodiments include a fuel cell stack seal application method including the step of applying a seal paste to a fuel cell, placing the fuel cell in a fuel cell stack, and thermally treating the fuel cell stack to set the seal paste into a seal. Further embodiments include applying the seal paste to an interconnect using stencil printing.

Abstract: Systems and methods are provided in which ammonia is used as a fuel source for solid oxide fuel cell systems. In the various aspects a high temperature fuel cell stack exhaust stream is recycled through one or more separation or conversion devices to create a purified recycled fuel exhaust stream that is recycled back into the fuel inlet stream of the high temperature fuel cell stack. In various aspects a nitrogen separator may remove nitrogen from the recycled fuel cell stack exhaust stream, a water separator may remove water from the recycled fuel cell stack exhaust stream, and/or an ammonia reactor and hydrogen separator may be used to condition the fuel inlet stream of the high temperature fuel cell stack. In a further aspect a molten carbonate fuel cell and/or Sabatier reactor may be used to condition the fuel inlet stream of the high temperature fuel cell stack.

Abstract: Various embodiments include a fuel cell stack seal application method including the step of applying a seal paste to a fuel cell, placing the fuel cell in a fuel cell stack, and thermally treating the fuel cell stack to set the seal paste into a seal. Further embodiments include applying the seal paste to an interconnect using stencil printing.

Abstract: A spring compression assembly is configured to apply a load to a stack of electrochemical cells. The assembly includes a ceramic leaf spring, a tensioner configured to apply pressure to a first side of the spring and a bottom plate located on a second side of the spring opposite the first side of the spring. The bottom plate is configured to transfer a load from the spring to the stack of electrochemical cells.

Abstract: A fuel cell system includes a fuel cell stack which includes a plurality of fuel cells contacted in series by a plurality of interconnects. The various embodiments provide systems and methods for coupling a fuel cell stack with an electric bypass module within a hot zone. The bypass module may include elements for conducting a current between interconnects in a fuel cell stack and thereby bypass a failed fuel cell that has become a resistive parasitic load.

Abstract: A method for operating a fuel cell system during an interruption includes identifying a load interruption in which an external load is partially or fully unable to draw electrical power from the fuel cell system. At least a first fuel cell column of the fuel cell system is operated in an electrolysis mode such that the first fuel cell column generates fuel during the load interruption. Power is provided to the first fuel cell column in the electrolysis mode from at least a second fuel cell column of the fuel cell system. The second fuel cell column is operating in a normal power generation operating mode.

Abstract: A ceramic baffle is configured to place a load on a stack of electrochemical cells and direct a reactant feed flow stream to the stack.

Abstract: A fuel cell system includes a fuel cell stack which includes a plurality of fuel cells contacted in series by a plurality of interconnects. The various embodiments provide systems and methods for coupling a fuel cell stack with an electric bypass module within a hot zone. The bypass module may include elements for conducting a current between interconnects in a fuel cell stack and thereby bypass a failed fuel cell that has become a resistive parasitic load.

Abstract: Systems and methods for fuel cell stack part serialization and tracking. In an embodiment, a barcode may be applied to a fuel cell stack part which may identify the fuel cell stack part. In an embodiment, the barcode may be applied as ink on a green fuel cell stack part prior to sintering. In an embodiment, a portion of a fuel cell stack part may be imaged and pattern recognition techniques may be utilized to identify the fuel cell stack part based on the unique features of fuel cell stack part. In an embodiment, portion of a fuel cell stack part may be measured to generate one or more series of unique volume/area values and one or more series of unique volume/area values may be utilized to identify the fuel cell stack part.

Abstract: Various hot box fuel cell system components are provided, such as heat exchangers, steam generator and other components.

Abstract: A method of operating a high temperature fuel cell system containing a plurality of fuel cell stacks includes operating one or more of the plurality of fuel cell stacks at a first output power while operating another one or more of the plurality of the fuel cell stacks at a second output power different from the first output power.

Abstract: A fuel cell system includes a fuel cell stack which includes a plurality of fuel cells contacted in series by a plurality of interconnects. The various embodiments provide systems and methods for coupling a fuel cell stack with an electric bypass module within a hot zone. The bypass module may include elements for conducting a current between interconnects in a fuel cell stack and thereby bypass a failed fuel cell that has become a resistive parasitic load.

Abstract: Various embodiments include interconnects and/or end plates having features for reducing stress in a fuel cell stack. In embodiments, an interconnect/end plate may have a window seal area that is recessed relative to the flow field to indirectly reduce stress induced by an interface seal. Other features may include a thicker protective coating and/or larger uncoated area of an end plate, providing a recessed portion on an end plate for an interface seal, and/or recessing the fuel hole region of an interconnect relative to the flow field to reduce stress on the fuel cell. Further embodiments include providing intermittent seal support to minimize asymmetric seal loading and/or a non-circular seal configuration to reduce stress around the fuel hole of a fuel cell.

Abstract: Various embodiments include interconnects and/or end plates having features for reducing stress in a fuel cell stack. In embodiments, an interconnect/end plate may have a window seal area that is recessed relative to the flow field to indirectly reduce stress induced by an interface seal. Other features may include a thicker protective coating and/or larger uncoated area of an end plate, providing a recessed portion on an end plate for an interface seal, and/or recessing the fuel hole region of an interconnect relative to the flow field to reduce stress on the fuel cell. Further embodiments include providing intermittent seal support to minimize asymmetric seal loading and/or a non-circular seal configuration to reduce stress around the fuel hole of a fuel cell.

Abstract: Various embodiments include a fuel cell stack including a plurality of fuel cells including a cell anode electrode, a cell electrolyte, and a cell cathode electrode and separated by a plurality of conductive interconnects and at least one material located in a cell anode electrode of the plurality of fuel cells which provides a conductive path between adjacent interconnects when the cell anode electrode between the adjacent interconnects fails.

Abstract: A method of controlling a fuel cell system includes applying alternating current (AC) signals to an individual fuel cell. The AC signals have a plurality of different frequencies. A voltage across the individual fuel cell is determined at each of the plurality of different frequencies. An impedance characteristic of the individual fuel cell is determined based at least in part on the voltage across the individual fuel cell at each of the plurality of different frequencies. The individual fuel cell is controlled based at least in part on the impedance characteristic.

Abstract: A method of operating a high temperature fuel cell system containing a plurality of fuel cell stacks includes operating one or more of the plurality of fuel cell stacks at a first output power while operating another one or more of the plurality of the fuel cell stacks at a second output power different from the first output power.