Abstract: An electrochemical-cell stack assembly is provided. The assembly has an electrochemical-cell stack and a compression system that holds the electrochemical-cell stack in a state of compression. The compression system has a first endplate and a second endplate positioned at opposite ends of the electrochemical-cell stack. The compression system has a set of tension members coupled to the first endplate and the second endplate that maintain a fixed distance between the first endplate and the second endplate. The compression system has a compression plate disposed between the second endplate and the electrochemical-cell stack. The compression system has a compression member in contact with the compression plate, wherein the compression member is configured to transfer a force to the compression plate. The compression system has a locking nut fastened to the second plate. The locking nut secures the position of the compression member and compression plate relative to the second endplate.

Abstract: An electrochemical-cell stack assembly is provided. The assembly has an electrochemical-cell stack and a compression system that holds the electrochemical-cell stack in a state of compression. The compression system has a first endplate and a second endplate positioned at opposite ends of the electrochemical-cell stack. The compression system has a set of tension members coupled to the first endplate and the second endplate that maintain a fixed distance between the first endplate and the second endplate. The compression system has a compression plate disposed between the second endplate and the electrochemical-cell stack. The compression system has a compression member in contact with the compression plate, wherein the compression member is configured to transfer a force to the compression plate. The compression system has a locking nut fastened to the second plate. The locking nut secures the position of the compression member and compression plate relative to the second endplate.

Abstract: An electrochemical cell includes a pair of bipolar plates and a membrane electrode assembly between the bipolar plates. The membrane electrode assembly comprises an anode compartment, a cathode compartment, and a proton exchange membrane disposed therebetween. The cell further includes a sealing surface formed in one of the pair of bipolar plates and a gasket located between the sealing surface and the proton exchange membrane. The gasket is configured to plastically deform to create a seal about one of the cathode compartment or the anode compartment. The sealing surface can include one or more protrusions.

Abstract: One aspect of the present disclosure is directed to a fuel cell power system. The system may include one or more fuel cells configured to generate electric power and a compressor configured to supply compressed air to the one or more fuel cells. The system may further include one or more sensors. The sensors may be configured to generate a signal indicative of at least one measured parameter of air flow across the one or more fuel cells. The system may also include a controller in communication with the one or more fuel cells, the compressor, and the sensors. The controller may be configured to determine a desired pressure drop based on at least one calculated parameter, determine a control command for the compressor based on the desired pressure drop, and adjust the control command based on a feedback gain parameter and a feed forward gain parameter.

Abstract: A modular fuel cell includes a membrane electrode assembly interposed between a pair of bipolar plates, and the membrane electrode assembly has a total active area measured in an x-y plane that is generally perpendicular to the z-axis. Each bipolar plate includes a plurality of common passages extending generally parallel to the z-axis. The total active area of the membrane electrode assembly includes a plurality of base active areas arranged co-planar in the x-y plane along an x-axis.

Abstract: The present disclosure is directed towards the design of electrochemical cells for use in high pressure or high differential pressure operations. The electrochemical cells of the present disclosure have non-circular external pressure boundaries, i.e., the cells have non-circular profiles. In such cells, the internal fluid pressure during operation is balanced by the axial tensile forces developed in the bipolar plates, which prevent the external pressure boundaries of the cells from flexing or deforming. That is, the bipolar plates are configured to function as tension members during operation of the cells. To function as an effective tension member, the thickness of a particular bipolar plate is determined based on the yield strength of the material selected for fabricating the bipolar plate, the internal fluid pressure in the flow structure adjacent to the bipolar plate, and the thickness of the adjacent flow structure.

Abstract: An electrochemical cell stack having a plurality of electrochemical cells stacked along a longitudinal axis. The electrochemical cells include a membrane electrode assembly comprising a cathode catalyst layer, an anode catalyst layer, and a polymer membrane interposed between the cathode catalyst layer and the anode catalyst layer. The electrochemical cells also include an anode plate and a cathode plate with the membrane electrode assembly interposed therebetween, and the anode plate defines a plurality of channels that form an anode flow field facing the anode catalyst layer. The electrochemical cells further include a cathode flow field positioned between the cathode plate and the cathode catalyst layer, wherein the cathode flow field comprises a porous structure.

Abstract: Check valves include a valve seat and a movable valve member, or piston. Movement of the piston is what allows fluid to either flow or be prevented from flowing. A magnetic check valve is provided that contains an annular piston, which is configured such that the fluid flows through a central aperture in the piston. Fuel cell systems include a cathode loop which is in contact with the proton exchange membrane (PEM). The PEM is sensitive to fowling by contaminants that may be present in the ambient air. The magnetic check valve apparatus disclosed herein prevents backflow of air through the exhaust side of the cathode loop. The valve is used on the inlet side of the cathode as well.

Abstract: An electrochemical cell stack is provided. The electrochemical cell stack has a plurality of electrochemical cells. Each electrochemical cell has a membrane electrode assembly which includes a cathode catalyst layer, an anode catalyst layer, and a polymer membrane interposed between the catalyst layer and the anode layer. Each electrochemical cell also has an anode plate and a cathode plate with the membrane electrode assembly interposed therebetween, and a cathode flow field positioned between the cathode plate and the cathode catalyst layer. The cathode flow field includes a porous structure having a plurality of pores having an average pore size. The plurality of electrochemical cells has a first electrochemical cell positioned at a first end of the electrochemical cell stack. The porous structure of the first electrochemical cell has an average pore size greater than the average pore size of the porous structures of the plurality of electrochemical cells.

Abstract: An electrochemical cell stack having a plurality of electrochemical cells stacked along a longitudinal axis. The electrochemical cells include a membrane electrode assembly having an anode plate and a cathode plate with the membrane electrode assembly interposed therebetween. The electrochemical cells also include an anode plate and a cathode plate with the membrane electrode assembly interposed therebetween, and the anode plate defines a plurality of channels that form an anode flow field facing the anode catalyst layer. The electrochemical cells further include a cathode flow field positioned between the cathode plate and the cathode catalyst layer, wherein the cathode flow field comprises a porous structure.

Abstract: An electrochemical cell stack having a plurality of electrochemical cells stacked along a longitudinal axis. The electrochemical cells include a membrane electrode assembly comprising a cathode catalyst layer, an anode catalyst layer, and a polymer membrane interposed between the cathode catalyst layer and the anode catalyst layer. The electrochemical cells also include an anode plate and a cathode plate with the membrane electrode assembly interposed therebetween, and the anode plate defines a plurality of channels that form an anode flow field facing the anode catalyst layer. The electrochemical cells further include a cathode flow field positioned between the cathode plate and the cathode catalyst layer, wherein the cathode flow field comprises a porous structure.

Abstract: The present disclosure is directed to a fuel cell module. The fuel cell module may include a fuel cell having an anode, a cathode, and an electrolyte positioned between the anode and the cathode. The fuel cell module may also include an enclosure housing the fuel cell therein. The enclosure may include an air inlet and an air outlet. The fuel cell module may further include an air pressurizing mechanism fluidly connected to the enclosure. The air pressurizing mechanism may be configured to draw air through the air inlet into the enclosure and from the enclosure to the air pressurizing mechanism through the air outlet. The air pressurizing mechanism may be configured to pressurize the air to form a pressurized air stream that is directed to the cathode.

Abstract: This disclosure related to polymer electrolyte member fuel cells and components thereof, including fuel cell endplates.

Abstract: The design and method of fabrication of a three-dimensional, porous flow structure for use in a high differential pressure electrochemical cell is described. The flow structure is formed by compacting a highly porous metallic substrate and laminating at least one micro-porous material layer onto the compacted substrate. The flow structure provides void volume greater than about 55% and yield strength greater than about 12,000 psi. In one embodiment, the flow structure comprises a porosity gradient towards the electrolyte membrane, which helps in redistributing mechanical load from the electrolyte membrane throughout the structural elements of the open, porous flow structure, while simultaneously maintaining sufficient fluid permeability and electrical conductivity through the flow structure.

Abstract: A system and method of controlling water imbalance in an electrochemical cell is provided. The method includes determining a present water imbalance in the electrochemical cell by summing a waterin and a watercreated less a waterout. Waterin represents an amount of water introduced into the electrochemical cell by an oxidant feed gas; watercreated represents an amount of water created by the electrochemical cell from the electrochemical reaction; and waterout represents an amount of water discharged from the electrochemical cell by an oxidant exhaust gas. The method includes tracking a cumulative water imbalance during operation of the electrochemical cell by repeatedly determining the present water imbalance and continuing to sum the results during operation. And, the method also includes adjusting a flow rate of the oxidant feed gas entering the electrochemical cell based on the cumulative water imbalance.

Abstract: The electrochemical cell stack assembly has electrochemical cell sub-stacks. A first and second electrochemical cell sub-stack are connected electrically in series and fluidly in parallel. The first and second electrochemical cell sub-stacks have electrochemical cells. The electrochemical cells have a membrane electrode assembly with an cathode catalyst layer, an anode catalyst layer, and a polymer membrane therebetween. The electrochemical cells have an anode plate and a cathode plate with the membrane electrode assembly interposed therebetween, a cathode flow field, and the anode plate.

Abstract: A fuel cell system has a gas delivery-means that circulates the anode exhaust gas back to the anode compartment of the fuel cell for further reaction.

Abstract: A modular fuel cell includes a membrane electrode assembly interposed between a pair of bipolar plates, and the membrane electrode assembly has a total active area measured in an x-y plane that is generally perpendicular to the z-axis. Each bipolar plate includes a plurality of common passages extending generally parallel to the z-axis. The total active area of the membrane electrode assembly includes a plurality of base active areas arranged co-planar in the x-y plane along an x-axis.

Abstract: The present disclosure is directed to a method for tuning the performance of at least one electrochemical cell of an electrochemical cell stack. The method includes supplying power to an electrochemical cell stack. The electrochemical cell stack includes a plurality of electrochemical cells. The method further includes monitoring a parameter of at least one electrochemical cell and determining if an electrochemical cell becomes impaired. The method also includes diverting a fraction of the current flow from the impaired electrochemical cell during operation of the electrochemical cell stack.

Abstract: A method of fabricating a catalytic reactor assembly having an outer tube and an inner tube is provided. The method may include inserting a catalyst into the outer tube and inserting the inner tube through the catalyst. The method may further include radially expanding the inner tube against the catalyst.