Abstract: Embodiments relate to a fuel cell system. In an embodiment, the fuel cell system includes advanced leak test capabilities. In another embodiment, the fuel cell system includes a system to bypass one or more separation units while permitting the fuel cell system to continue to produce electricity. In another embodiment, the fuel cell system includes an alignment system that permits ease of alignment when a fuel cell module is installed proximate a fuel processing module. In another embodiment, the fuel cell system includes a system of supplying auxiliary fuel from a mobile auxiliary fuel supply. In an embodiment, one or more or all of these embodiments may be practiced together in combination.

Abstract: An oxygen-containing gas flow field for supplying an oxygen-containing gas from an oxygen-containing gas supply passage to an oxygen-containing gas discharge passage is formed on a first metal plate. The oxygen-containing gas flow field includes oxygen-containing gas flow grooves as serpentine flow grooves having two turn regions T1, T2. The oxygen-containing gas flow grooves have substantially the same length. The oxygen-containing gas flow grooves are connected to an inlet buffer and an outlet buffer at opposite ends. The inlet buffer and the outlet buffer have a substantially triangular shape, and are substantially symmetrical with each other.

Abstract: Corrosion of a metal portion such as a pipe connected to a fuel cell stack is suppressed. The fuel cell stack has a plurality of single cells which generate electrical power using an aqueous methanol solution and air and are stacked in a vertical direction. An inlet of a fuel supply manifold for distributing the aqueous methanol solution to each cell and an outlet of a fuel discharge manifold for collecting the fuel discharged from the single cells are provided in a common conductive end plate. Hence, when the discharge fuel discharged from the fuel cell stack is circulated and resupplied to the stack, the potential of the discharged fuel becomes equal to that of the liquid fuel to be supplied to the stack, whereby the corrosion of the metal portion such as a pipe, a tank, a pump, or a heat exchanger is suppressed.

Abstract: Disclosed is a sealing assembly for metal components, wherein the sealing assembly has an electrical insulating effect, and wherein the sealing assembly comprises a ceramic layer and a base brazing material disposed thereon, to which germanium is added. The addition of germanium advantageously ranges from 0.1 to 5.0 mol %, and preferably between 0.5 and 2.5 mol %. A particular embodiment provides for the use of a brazing material which additionally comprises silicon in the range of>0 to 2.5 mol %, and preferably between 0.1 and 0.9 mol %. Furthermore, a brazing material having a further addition of 10 to 40% by volume of Al2TiO5, and preferably between 20 and 30% by volume of Al2TiO5, has proven to be particularly suited for the sealing assembly.

Abstract: Disclosed is a fuel cell including a fuel cell stack; a stack case which contains the fuel cell stack; and a blocking device including connecting portions which electrically connect, to output terminal portions of the fuel cell stack, output cables to transmit the output of the fuel cell stack to a device provided outside the stack case, the blocking device being capable of blocking the mutual connection performed by the mechanical operation of the connecting portions from the outside of the stack case. Moreover, at least a portion of the blocking device in which the output cables are electrically connected to the connecting portions is arranged outside the stack case.

Abstract: A fuel cell power system comprises an internal or self-regulating control of a system or device requiring a parasitic load. The internal or self-regulating control utilizes certain components and an interconnection scheme to produce a desirable, variable voltage potential (i.e., power) to a system or device requiring parasitic load in response to varying operating conditions or requirements of an external load that is connected to a primary fuel cell stack of the system. Other embodiments comprise a method of designing such a self-regulated control scheme and a method of operating such a fuel cell power system.

Abstract: The invention, in various embodiments, provides planar fuel cell stack of a plurality of fuel cells, comprising an anode layer including a first anode and a second anode, an electrolyte layer, a cathode layer including a first cathode and a second cathode, and at least one interconnect at least partially disposed within the electrolyte layer, and electrically and mechanically coupling the first anode and the second cathode. In various embodiments, structural supports are provided, the fuel cells are sized to be portable, and are manufactured to produce desired power densities and/or voltages.

Abstract: A clamping structure for a planar solid oxide fuel cell stack comprising a flexible sheet and a rigid, thermally insulating end block, the flexible sheet being capable of bending into a primarily convex shape, the rigid, thermally insulating end block shaped as a rectangular base with a planar surface and an opposing surface that is primarily convex in shape, the flexible sheet being placed adjacent to the opposing surface of the rigid, thermally insulating end block, the flexible sheet thereby bending to obtain a shape that is primarily convex. The invention also relates to a solid oxide fuel cell stack and a process for the compression of the stack.

Abstract: There are provided a membrane electrode assembly in which favorable water circulation is brought about within a cell and which is superior in self-humidification performance, and a fuel cell stack comprising fuel cells comprising such a membrane electrode assembly. A membrane electrode assembly 4 comprises: an electrolyte membrane 1; and an anode-side catalyst layer 3 and a cathode-side catalyst layer 2, which are respectively disposed on both sides of the electrolyte membrane 1 and which comprise a catalyst support, in which a catalyst is supported on a conductive support, and a polymer electrolyte. With respect to this anode-side catalyst layer 3, I/C (i.e., the ratio of the mass of the polymer ionomer (I) to the mass of the conductive support (C)) is within the range of 1.0 to 2.0, EW (sulfonic acid equivalent weight) is within the range of 750 to 1,100, and polymer electrolyte thickness is within the range of 10 nm to 24 nm.

Abstract: The object of the present invention is to provide a fuel cell stack with improved corrosion resistance of metal separators and reduced cost. To attain this object, the fuel cell stack according to the present invention has a cell stack constituted by stacking a prescribed number of unit cells obtained by sandwiching both surfaces of an electrolyte membrane between an anode and a cathode and sandwiching the outer sides thereof with a pair of metal separators, wherein the metal separator positioned on the plus side of the cell stack is subjected to surface treatment providing for relatively higher corrosion resistance than the metal separator positioned on the minus side of the cell stack. Cost reduction can be realized, while maintaining corrosion resistance comparable with that obtained in the case when all the separators are subjected to the anticorrosive surface treatment to the same degree.

Abstract: A fuel cell stack includes a plurality of solid oxide fuel cell tubes and a heat recuperator. The heat recuperator is formed from sheet metal. The plurality of walls define an exhaust gas channel having an exhaust gas flowing therethrough and an oxidant channel having an oxidant flowing therethrough. The exhaust gas channel is in thermal communication with the oxidant channel such that heat is transferred between the exhaust gas and the oxidant.

Abstract: Provided is a fuel cell or a fuel cell stack, wherein a means for reducing the concentration of unreacted alcohol is disposed on the cathode exhaust gas side. This means comprises in particular an additional electrochemical cell, to which a voltage is applied and which at least partially converts the unreacted alcohol into CO2 and hydrogen or water by way of an electrochemical reduction reaction. Since the concentration of unreacted alcohol is generally low, the loss of power required for the additional reduction reaction does not result in any notable impairment of the efficiency of the fuel cell stack. The invention is thus not limited to direct-methanol fuel cells, but may also be similarly applied to high-temperature fuel cells, and particularly to high-temperature PEM fuel cells, in which the additional electrochemical cell disposed on the cathode exhaust gas side is advantageously able to convert the residual CO.

Abstract: A fuel cell system module (10) for use in an aircraft (32) comprises at least one fuel cell system component (12, 22, 24). The fuel cell system module (10) is connectable modularly to a fuselage section (30) of the aircraft (32). A housing element (16, 26) of the fuel cell system module (10) is designed to form a section of an outer skin (34) of the aircraft (32) when the fuel cell system module (10) is in the state connected to the fuselage section (30) of the aircraft (32).

Abstract: The invention provides an MEA-gasket assembly (1) comprising: an MEA (5) having a polymer electrolyte membrane (5A), catalyst layers and gas diffusing layers (5C); a plate-like frame (6) which is joined to a portion of the polymer electrolyte membrane (5A) so as to enclose the MEA (5), the portion being located in a peripheral region of the MEA (5) and which has a plurality of fluid manifold holes (12, 13, 14); and an annular gasket (7) formed on both faces of the frame (6), wherein an annular gap formed between the inner peripheral edge of the annular gasket (7) and the outer peripheral edges of the gas diffusing layers (5C) is at least partially closed.

Abstract: A fuel cell system is provided including a fuel cell stack having a plurality of fuel cells disposed between a first end unit and a second end unit. The fuel cell system includes a compression retention system comprising a first sheet coupled to the first end unit and a second sheet coupled to the second end unit. A plurality of springs is disposed between the first sheet and the second sheet and is adapted to apply a compressive force to the fuel cell stack. The claimed invention includes methods for assembling the fuel cell system.

Abstract: In order to easily transport a fuel cell stack, without increasing costs, the fuel cell stack according to the present invention includes a stack body 5 in which end plates 8, 8 are arranged at both ends in a cell lamination direction, and suspension hangers 10 provided on the end plates 8, 8. The suspension hangers 10 project outward from a case 6 in which the stack body 5 is stored. With this arrangement, the fuel cell stack can be suspended from outside the case 6, and transported. Also using the suspension hangers 10, this fuel cell stack can be secured in a predetermined installation location.

Abstract: Systems and methods for protecting fuel cell systems from frost by introduction of a freezing point depressant into the fuel cell system and/or flushing the fuel cell system with an insert gas are provided.

Abstract: A method of forming a fuel cell pile including a porous anode and a porous cathode separated by a dense electrolyte is disclosed. A solid oxide fuel cell incorporating the fuel cell pile is formed on a substrate by a series of lithography, etch and deposition steps that create a solid oxide fuel cell. Individual cells may be interconnected by micro-channels and metal interconnects to form fuel cell stacks. The structure of the cell and a method of manufacturing are disclosed.

Abstract: A fuel cell system that employs a technique for safely removing hydrogen gas that accumulates within a cooling fluid reservoir. The fuel cell system includes a fuel cell stack and a compressor for providing airflow to the cathode side of the fuel cell stack. The system also includes an air filter box having an air filter that is in fluid communication with an air pocket in the reservoir. The air intake to the compressor flows through the air filter box, and sucks the gas from the reservoir, which is then sent to the cathode side of the fuel cell stack to be converted to water by the electro-chemical reaction therein.

Abstract: A fuel cell stack includes unit cells. At one side of the unit cells, an oxygen-containing gas supply passage and a fuel gas discharge passage having different opening areas are provided. At the one side of the unit cells, a recess is provided near the fuel gas discharge passage having a relatively small opening area. A cell voltage terminal is provided in the recess such that the cell voltage terminal does not protrude outwardly from the side of the unit cells.

Abstract: A bipolar plate for electro-chemical applications is proposed, comprising a first cover layer of a metallic material, a second cover layer of a metallic material, and a supporting layer of a metallic material which is arranged between the first cover layer and the second cover layer and is connected to the first cover layer and the second cover layer, wherein the supporting layer comprises at least one row of contact areas for the first cover layer and/or the second cover layer and free spaces are formed between neighboring contact areas, wherein at least one passage opening is provided for conveying fuel and/or oxidizer, and wherein an insert element by means of which point forces are introducible over an area is arranged between the first cover layer and the second cover layer in the region of the at least one passage opening.

Abstract: There are provided a pump of a noise suppression and vibration proof structure and a fuel cell system using the same. The fuel cell system includes at least one electricity generator including an electrolyte membrane and an anode and a cathode attached to the both surfaces of the electrolyte membrane to generate electricity energy by the electrochemical reaction between fuel containing hydrogen and oxidant supplied to the anode and the cathode, a fuel supplying unit including a pump for supplying the oxidant to the electricity generator, and a fixed frame that is provided on a lower frame and to which the pump is fixed. The pump is separated from the lower frame and is fixed to and combined with the fixed frame by the belt-shaped fixing member on the side surface of the fixing frame with a buffering member interposed. Therefore, it is possible to reduce the noise and vibration of the pump.

Abstract: A fuel cell stack is provided with a plurality of stacked separators. This fuel cell stack includes: terminals that extend from the separators; packing in which are formed a plurality of through holes through which the terminals are inserted; a packing casing that has a packing housing concave portion that envelops side surfaces of the packing and supports a bottom surface of the packing, and has through holes through which the terminals are inserted; and a connector housing that has a pressing surface that presses a top surface of the packing. Mountain-shaped protruding portions whose apex portions are formed by circumferential edges of apertures of the respective through holes are provided on the top surface of the packing, and the pressing surfaces of the connector housing are formed in a configuration that conforms to the side surfaces of the protruding portions. Internal surfaces of the through holes in the packing are in contact without a gap in between with external surfaces of the terminals.

Abstract: Method and apparatus for cooling a fuel cell stack. The cooling system uses vaporization cooling of the fuel stack and supersonic vapor compression of the vaporized coolant to significantly increase the temperature and pressure of the liquid coolant flowing through a heat exchanger. By increasing the heat rejection temperature of the coolant delivered to the heat exchanger, the heat transfer area of the heat exchanger can be reduced and the mass flow rate of coolant can also be reduced. The increased fluid pressure is used to circulate the coolant through the cooling system, thereby eliminating the circulation pump associated with conventional systems.

Abstract: A cathode for a fuel cell includes a gas diffusion layer contacting with a separator having a channel and a catalyst layer interposed between the gas diffusion layer and an electrolyte membrane. The catalyst layer of the cathode has two portions with different water-repelling properties, and a portion of the catalyst layer that does not face a channel has a higher water-repelling property than a portion that faces a channel. This cathode controls water-repelling property of the catalyst layer differently according to locations, so it is possible to keep an amount of moisture in an electrode in a suitable way and to restrain generation of flooding, thereby improving the performance of the cell.

Abstract: In an electrochemical energy conversion system with at least one electrically conducting component with at least two cells connected in series, at least one of the electrically conducting components is divided into at least two segments which are electrically insulated from one another, and a transfer plate, consisting of electrically non-conducting material with at least two conducting sections and/or areas is provided to conduct currents from at least one segment to at least one other segment. A transfer plate for such an electrochemical energy conversion system consists of electrically non conducting material and exhibits at least two electrically conducting sections and/or areas.

Abstract: A proton exchange membrane fuel cell has a unit cell assembly including an anode side and a cathode side. The anode side has a cooling base plate, a conductor assembly, a hydrogen flow field, a water absorbing element, and a hydrogen duct assembly. The cathode side has an air flow field, a conductor assembly, an air flow distributor, and an insulating compression plate with wing extensions. A membrane electrode assembly is disposed between the anode side and the cathode side physically connecting the flow fields on both the anode and cathode sides. A sealed anode assembly creates a sealed hydrogen volume and includes the anode conductor assembly, the hydrogen duct assembly, and the membrane electrode assembly all disposed between the insulating compression plate and the cooling base plate. The fuel cell may comprise multiple unit cell assemblies arranged in planar, folded, stacked, or pancake configurations.

Abstract: A modular direct methanol fuel cell system includes a housing having a pump for supplying fuel from a fuel tank to a fuel cell stack and a system controller for electronically controlling the modular direct methanol fuel cell system. An integrated processor is contained in the housing, the integrated processor integrating a water condenser and a gas/liquid stream separator. A first fluid connection unit is between the fuel cell stack and the integrated processor for feeding air and fuel exiting from the fuel cell stack to the integrated processor. A second fluid connection unit is between the fuel cell stack and the integrated processor for feeding a fuel mixture from the integrated processor to the fuel cell stack. The direct methanol fuel cell system also includes a third fluid connection unit for feeding pure fuel from the fuel tank to the integrated processor.

Abstract: A fuel cell bipolar plate assembly is disclosed which includes a reinforcement positioned between the anode and cathode plates to strengthen the assembly.

Abstract: The single fuel cell of the present invention includes an MEA (membrane electrode assembly), GDLs (gas diffusion layers) and separators, a pair of catalyst layers being provided on both surfaces of a polymer electrolyte membrane in the MEA, a pair of the GDLs being disposed opposite the pair of catalyst layers of the MEA, the separators including gas flow channels of an air electrode and a fuel electrode, the MEA and the pair of the GDLs being interposed between the separators, and at least one of an area of the GDL of the air electrode and an area of the GDL of the fuel electrode being smaller than an effective area of the gas flow channel of the separator, which is an inner area specified by tracing and connecting outermost edge parts of a groove of the gas flow channel of the separator.

Abstract: A front terminal plate (31) that is joined to a fuel cell unit (40) at the front end of a fuel cell stack has a metal-plating layer (31b) formed on the side to be joined to the fuel cell unit (40). The metal-plating layer (31b) is formed so as to cover the surface of a plate (31a), and the surface of the metal-plating layer (31b) is flat. The thickness of the metal-plating layer (31b) in an electrode-facing region (31c) that faces an electrode region of the fuel cell unit (40) is different from the thickness of the metal-plating layer (31b) in a peripheral region (31d) that surrounds the electrode-facing region (31c), and the thickness of the metal-plating layer (31b) in the peripheral region (31d) is larger than the thickness of the metal-plating layer (31b) in the electrode-facing region (31c).

Abstract: There is disclosed a fuel cell in which an insulating material is disposed, whereby the thermal diffusion of the inside and outside of a fuel cell can be suppressed to suppress the deterioration of the performance of the fuel cell due to a temperature drop. Moreover, the physical properties of the insulating material are specified, whereby appropriate insulating properties required in the fuel cell can be obtained, and startup properties are improved. A fuel cell has a cell stack in which a plurality of unit cells are stacked, and terminal plates disposed on both sides of the cell stack in a cell stack direction thereof. The fuel cell comprises an insulating portion having an insulating material and holding plates which hold the insulating material from both the sides of the insulating material in the cell stack direction, the insulating material is held between the holding plates, and the insulating material has a thermal conductivity of 0.1 W/mK or less and a porosity of 70% or more.

Abstract: A fuel cell bipolar plate has a front surface and a rear surface opposite to each other, and flash and a receding portion. The flash is provided on the front surface at an outer peripheral portion of the bipolar plate and projects in a direction crossing the front surface. The receding portion is provided on the rear surface at an outer peripheral portion of the bipolar plate in a geometry capable of accommodating flash.

Abstract: A fuel cell module (1) with a fuel cell (2), a residual gas burner (4) and a heat exchanger (6). The service life of the module (1) can be improved by at least one compensator (27) for establishing a flow-carrying connection between the residual gas burner (4) and the heat exchanger (6).

Abstract: The present invention provides a fuel sensor-less control method for supplying fuel to a fuel cell, in which a fixed control amount is determined for controlling the fuel supply of fuel cell, and then a feeding timing of the fixed fuel quantity is determined by integrating characteristic values generated from the fuel cell within the limit of fixed control amount. In another embodiment, it is further comprising a step of determining the variation profile associated with the characteristic values during the period so as to judge whether it is necessary to feed the fuel into the fuel cell or not. By means of the present invention, the supplying of fuel to the fuel cell under dynamic loadings can be effectively controlled for optimizing the performance of the fuel cell as well as reducing the cost without installing any fuel concentration sensor.

Abstract: An electrically conductive porous body for a fuel cell has a porous metal body and an electrically conductive layer that is disposed on one surface side of the porous metal body and that has gas permeability, wherein at least a part of the one surface side of the porous metal body is buried into one surface side of the electrically conductive layer, and wherein the flatness of the other surface side of the electrically conductive layer, into which the porous metal body is not buried, is higher than the flatness of the one surface side of the porous metal body. Sufficient contact surface area is obtained between the porous metal body and the membrane electrode assembly, without applying pressure to the porous metal body. It is therefore possible to achieve a low contact resistance with the membrane electrode assembly, without causing a change in the internal condition of the porous metal body.

Abstract: A direct methanol fuel cell is described. The DMFC uses a solid electrolyte that prevents methanol crossover. Optional chemical barriers may be employed to prevent CO2 contamination of the electrolyte.

Abstract: There is provided a fuel cell in which produced water can be efficiently conveyed to an upstream region of hydrogen gas flow, thereby quickly increasing the power generation performance of an electrolyte membrane after activation in a short period of time and giving a stable output for a long period of time and in which the directions of hydrogen gas flows in a first and a second fuel supply layers that share one oxygen supply layer are set to be opposite to each other.

Abstract: The present invention provides a cathode and a fuel cell, which are built to prevent escape of liquids, e.g. water and fuel solution, from the cell. Thus, according to a first aspect thereof, the present invention provides a cathode suitable for use in a fuel cell having a proton conducting membrane, the cathode comprising a plurality of layers including a catalyst layer and a hydrophobic porous support layer, wherein at least one of said plurality of layers is a liquid water leak-proof layer, which allows gas to pass through it and prevents passage of liquid water and/or aqueous fuel solution.

Abstract: Multiple stacks of tubular electrochemical cells having a dense electrolyte disposed between an anode and a cathode preferably deposited as thin films arranged in parallel on stamped conductive interconnect sheets or ferrules. The stack allows one or more electrochemical cell to malfunction without disabling the entire stack. Stack efficiency is enhanced through simplified gas manifolding, gas recycling, reduced operating temperature and improved heat distribution.

Abstract: An end plate of an air breathing fuel cell stack and an air breathing fuel cell stack including the same. The air breathing fuel cell stack includes a membrane electrode assembly, including an anode electrode, a cathode electrode, and an electrolyte positioned between the anode electrode and the cathode electrode; and an end plate contacting the membrane electrode assembly. The end plate includes a first surface contacting the membrane electrode assembly, an opposing second surface; and a collector positioned at the first surface and contacting the cathode electrode.

Abstract: A fuel cell system is provided including a fuel cell stack having a first end and second end; an upper end unit adjacent the first end of the fuel cell stack; a lower end unit adjacent the second end of the fuel cell stack; and a compression retention system disposed external to the fuel cell stack. The compression retention system includes at least one restraining member extending from the upper end unit to the lower end unit, fastening means disposed at opposite ends of the at least one restraining member, and compressive means interposed between at least one of the fastening means and the end units; wherein the fastening means and the compressive means urge the upper end unit toward the lower end unit, thereby applying compressive force to the fuel cell stack. Also provided is a method for assembling the fuel cell system.

Abstract: A fuel cell stack configuration and method of removing gas from the coolant flow path within a fuel cell stack is provided. The fuel cell stack has an internal vent passageway that communicates with the coolant supply header to enable gas entrapped therein to be vented from the fuel cell stack. The vent passageway can be formed by a plurality of apertures in the components that comprise the fuel cell stack and run parallel and adjacent to the coolant supply header. Alternatively, a vent line can be connected to the coolant supply header with a valve therein to selectively vent gas from the coolant supply header.

Abstract: The present invention relates to single chamber fuel cells and systems and methods associated with the same. Architectures and materials that allow for high performance, enhanced fuel utilization, mechanical robustness, and mechanical flexibility are described. In some embodiments, multiple fuel cell units are arranged in a single chamber and may be, in some cases, connected to each other (e.g., connected in series, connected in parallel, etc.). Each fuel cell unit can be defined as one or more anode(s), one or more cathode(s), and an electrolyte able to maintain electrical separation between the anode(s) and cathode(s). The multiple fuel cell units are arranged in stacks in some cases. In one set of embodiments, the stacks of fuel cell units can be shaped and/or arranged to enhance the mixing of fuel and oxidant, thus improving distribution of reactants in the reaction zone. For example, the stacks of fuel cells may be arranged as fins within the fuel cell chamber.

Abstract: A solid electrolyte fuel cell configuration provided with a single sheet shaped solid electrolyte substrate formed with a plurality of fuel cells and thereby not having a sealed structure, achieving a reduction of the size and a reduction of the cost, and able to improve the durability and improve the power generation efficiency, a single sheet shaped solid electrolyte substrate, in particular a solid electrolyte fuel cell configuration provided with a single sheet shaped solid electrolyte substrate, a plurality of anode layers formed on one side of the solid electrolyte substrate, and a plurality of cathode layers formed on the side opposite to the one side of the solid electrolyte substrate at positions facing the anode layers, the anode layers and cathode layers facing each other across the solid electrolyte substrate forming a plurality of fuel cells, the anode layers and cathode layers being connected in series.

Abstract: A fuel cell stack has fuel cell units. Each of the fuel cell units includes first and second membrane electrode assemblies and first to third separators sandwiching the first and second membrane electrode assemblies. A positioning mechanism is used for positioning the first to third separators in alignment with each other. The positioning mechanism includes a first protruded portion and a second protruded portion. The first protruded portion protrudes from one surface of the second separator for positioning the first separator. The second protruded portion protrudes from the other surface of the second separator for positioning the third separator.

Abstract: A method of operating a fuel cell system includes providing a fuel inlet stream into a fuel cell stack, operating the fuel cell stack to generate electricity and a hydrogen containing fuel exhaust stream having a temperature above 200 C, lowering a temperature of the fuel exhaust stream to 200 C or less, separating the fuel exhaust stream into a first separated fuel exhaust stream and a second separated fuel exhaust stream, and recycling the first separated fuel exhaust stream into the fuel inlet stream.

Abstract: In a cell stack of fuel cells according to the present invention, an output power density is measured at each of an upstream-side electricity generating section, which is located at an upstream-side of flow of fuel, and a downstream-side electricity generating section located at a downstream-side thereof. If the voltage at the upstream-side is higher than that at the downstream-side, a control operation to increase the concentration of fuel is performed. Conversely, if the voltage at the upstream-side is lower, a control operation to decrease the concentration of fuel is performed. Control directed to fuel concentration maximizing electricity generating efficiency may be implemented by repeatedly performing such control operations. There is no necessity for providing a concentration sensor in each of the generating sections. Consequently, simplification of configuration of and reduction in the size of the fuel cell may be achieved.

Abstract: A fuel cell stack includes a first fuel cell assembly and a last fuel cell assembly. The first fuel cell assembly includes a first end plate assembly, which has a first end plate cooling channel adapted to receive a coolant. The last fuel cell assembly includes a last end plate assembly that has a last end plate cooling channel. A first electrical potential exists between the first end plate and the last end plate. The fuel cell stack also includes a connecting cooling channel is in fluid communication with the first end plate cooling channel and the last end plate cooling channel. A coolant is contained within the connecting coolant channel, the first end plate cooling channel, and a last end plate cooling channel. The fuel cell stack further includes a coolant electrode positioned in the coolant channel, which contacts the coolant.

Abstract: An alignment system and method for assembling a fuel cell stack. Components of the fuel cell stack have internal alignment features and are aligned to a predetermined orientation during assembly. The system and method allow fuel cell stacks to be assembled within high tolerance levels while improving access to each component during assembly. Additionally, the system and method can provide additional rigidity to a fuel cell stack.