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: Provided is a polymer electrolyte membrane fuel cell stack, comprising a first bipolar plate, a second bipolar plate, an electrochemical package comprising a cathode, an anode, and a polymer membrane interposed between the cathode and the anode, an anode compartment disposed between the first bipolar plate and the anode, the anode compartment comprising at least one inlet and at least one outlet, a cathode compartment disposed between the second bipolar plate and the cathode, the cathode compartment comprising at least one inlet and at least one outlet, and wherein the geometric area of the anode compartment is larger than the geometric area of the anode.

Abstract: The present disclosure is directed to a fuel cell system for generating oxygen depleted air. The fuel cell system may include a fuel cell having an anode, a cathode, and an electrolyte positioned between the anode and the cathode. The cathode may be configured to receive an air flow and discharge an oxygen depleted air flow. The fuel cell system may further include a sensor configured to generate a first signal indicative of a presence of hydrogen in the oxygen depleted air flow and a controller in communication with the sensor and the fuel cell. The controller may be configured to detect the presence of hydrogen in the oxygen depleted air flow based on the first signal, and in response to detecting the presence of hydrogen in the oxygen depleted air flow, selectively cause a current density of the fuel cell to decrease and/or increase a flow rate of the air flow to the cathode.

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.

Abstract: A cooling system is provided for use with a fuel cell. The cooling system comprises a first heat exchanger fluidly connected to an outlet passage of the fuel cell. The first heat exchanger can be configured to condense at least a portion of a fluid passing through the outlet passage of the fuel cell into liquid water. The cooling system can also comprise a second heat exchanger fluidly connected to an outlet passage of the first heat exchanger and an inlet passage of the fuel cell. The second heat exchanger can be configured to cool a fluid passing into the inlet passage of the fuel cell. In addition, the outlet passage of the fuel cell and the inlet passage of the fuel cell can be fluidly connected to a cathode of the fuel cell, and the inlet passage of the fuel cell can be configured to supply water to the cathode.

Abstract: The present disclosure is directed to a bipolar plate of an electrochemical cell. The bipolar plate may have a frame and a base. The bipolar plate may also have a polymeric coating applied to at least one of the frame and the base. The present disclosure is also directed to a method of assembling a bipolar plate for an electrochemical cell. The method may include compressing a frame and a base of the bipolar plate, at least one of the frame and the base has a polymeric coating. The polymeric coating may be an electrical insulator for the electrochemical cell, a seal for sealing one or more zones of the electrochemical cell, and a corrosion protection later of the electrochemical cell.

Abstract: The present disclosure is directed towards the design of bipolar plates for use in conduction-cooled electrochemical cells. Heat generated during the operation of the cell is removed from the active area of the cell to the periphery of the cell via the one or more bipolar plates in the cell. The one or more bipolar plates are configured to function as heat sinks to collect heat from the active area of the cell and to conduct the heat to the periphery of the plate where the heat is removed by traditional heat transfer means. The boundary of the one or more bipolar plates can be provided with heat dissipation structures to facilitate removal of heat from the plates. To function as effective heat sinks, the thickness of the one or more bipolar plates can be determined based on the rate of heat generation in the cell during operation, the thermal conductivity (“k”) of the material selected to form the plate, and the desired temperature gradient in a direction orthogonal to the plate (“?T”).

Abstract: The present disclosure is direct to a bipolar plate of an electrochemical cell. The bipolar plate may have a frame and a base. The bipolar plate may also have a polymeric coating applied to at least one of the frame and the base. The present disclosure is also directed to a method of assembling a bipolar plate for an electrochemical cell. The method may include compressing a frame and a base of the bipolar plate, at least one of the frame and the base has a polymeric coating. The polymeric coating may be an electrical insulator for the electrochemical cell, a seal for sealing one or more zones of the electrochemical cell, and a corrosion protection later of the electrochemical cell.

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: 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: 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 electrochemical cell stack has electrochemical cells stacked along a longitudinal axis. The electrochemical cells have a membrane electrode assembly (MEA) with a 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 MEA interposed therebetween, and a cathode flow field between the cathode plate and catalyst layer. The anode plate or the cathode plates are formed of uncoated 316 stainless steel. Portions of the cathode or anode plate have an arithmetic average roughness from about 5 ?in to about 35 ?in. The cathode flow field is a porous structure. Surface regions on a side of the porous structure facing the MEA are smooth and align with a subgasket of the MEA.

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 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: An electrochemical cell is disclosed comprising, a first flow structure, a second flow structure, and a membrane electrode assembly disposed between the first and second flow structures. The electrochemical cell further comprises a pair of bipolar plates, wherein the first flow structure, the second flow structure, and the membrane electrode assembly are positioned between the pair of bipolar plates. The electrochemical cell also includes a spring mechanism, wherein the spring mechanism is disposed between the first flow structure and the bipolar plate adjacent to the first flow structure, and applies a pressure on the first flow structure in a direction substantially toward the membrane electrode assembly.

Abstract: The present disclosure is directed to a compressed fuel dispensing station having a compressor configured to compress a fuel source, a plurality of fuel dispensing units, at least one low pressure compressed fuel reservoir fluidly connected to the fuel compressor and the plurality of fuel dispensing units, and a plurality of high pressure compressed fuel reservoirs, wherein each high pressure compressed fuel reservoir is fluidly connected to the fuel compressor and at least one fuel dispensing unit.

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: 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: A method of sealing a multi-component bipolar plate is disclosed. The method may include inserting a first seal between a first component and a second component, wherein the first seal is aligned with a first plurality of protrusions formed on a surface of at least one of the first component and the second component. The method may also include compressing the first component and the second component to cause the penetration of the first plurality of protrusions into the first seal. The method may further include plastically deforming the first seal in order to create a first sealing surface between the first component and the second component.