Abstract: A fuel cell system comprising a fuel cell having plural membrane-electrode assemblies and plates, fuel and oxidant humidifiers and heater exchanger. Heat exchange between a supply inlet and discharge outlet is carried out between first and second heat exchange mediums. Fuel gas and oxidant gas are directed to flow parallel to each other in the fuel cell. A circulation path is established through the fuel and oxidant humidifiers and the heat exchanger by interconnection among discharge outlet, heat exchanger, fuel and oxidant humidifiers, and inlet.

Abstract: A method of shutting down operation of a fuel cell system comprising a fuel cell stack, the method comprising the sequential steps of: i) ceasing a supply of fuel to the fuel cell stack; ii) closing a shut-off valve on an exhaust line in fluid communication with a cathode system of the fuel cell system, the cathode system comprising a cathode fluid flow path passing through the fuel cell stack; iii) pressurising the cathode system with an air compressor in fluid communication with a cathode air inlet port in the fuel cell stack; and iv) ejecting water from the cathode flow path.

Abstract: A fuel cell having a capability of making uniform a water distribution in an in-plane direction of a polymer electrolyte membrane and supplying a reactive gas to an air electrode catalyst layer efficiently is provided. The fuel cell of the present invention has a polymer electrolyte membrane, a pair of catalyst electrodes, and a pair of metal separators. An air electrode separator has an oxidizing gas flow channel used to supply an oxidizing gas to the catalyst electrodes. The oxidizing gas flow channel is formed in such a manner that a flow channel near an oxidizing gas supply manifold and a flow channel near an oxidizing gas exhaust manifold are adjacent to each other in the same plane, and is formed in an S-shaped or spiral pattern.

Abstract: A fuel cell system includes a fuel cell stack, an oxygen-containing gas supply apparatus, a fuel gas supply apparatus, a pressure reduction apparatus, and a dilution apparatus. The oxygen-containing gas supply apparatus supplies an oxygen-containing gas to the fuel cell stack. The oxygen-containing gas supply apparatus is capable of supplying the air to the fuel gas flow field at the time of stopping operation of the fuel cell system. The fuel gas supply apparatus supplies a fuel gas to the fuel cell stack. The pressure reduction apparatus suctions gases in the oxygen-containing gas flow field and the fuel gas flow field. The dilution apparatus dilutes the fuel gas suctioned by the pressure reduction apparatus using the air.

Abstract: In a fuel cell stack, fuel, such as often hydrogen, electrochemically reacts with an oxidant, such as ambient air, and electric energy is generated from chemical energy. During the reaction, a proton exchange membrane (PEM) separates the fuel from the oxidant during the electrochemical process. A supply system for the fuel cell stack comprises an adjustable humidifying device for humidifying a supply gas which is supplied to the fuel cell stack, as a function of a control signal; and a dehumidifying device, which is configured to dehumidify an exhaust gas that is formed from the supply gas conducted through the fuel cell stack, and to discharge the same as a dehumidified exhaust gas. A controller, which generates the control signal, is configured from a programming and/or switching point of view to generate the control signal based on the gas temperature of the dehumidified exhaust gas.

Abstract: A fuel cell system is disclosed that employs a humidifier and an oxygen sensor for measuring the oxygen concentration in the cathode exhaust gas from the fuel cell stack to determine a system diagnostic, such as a fluid leak from or across the humidifier.

Abstract: To provide a solid oxide fuel cell in which the reformer is compact but is capable of supplying an appropriate quantity of fuel. The present invention is a solid oxide fuel cell (1) for generating electricity using fuel reformed by a reformer (20) and air, including a fuel supply means (38), a reformed air supply means (44), a water supply means (28) for supplying water to the reformer, a fuel supply quantity detection sensor (132) for detecting the quantity of fuel actually supplied, a fuel cell module (2), and a control means (110) for controlling each supply means so that the target quantities of fuel, reforming air, and water are fed into the reformer; the control means controls the fuel supply means to match the target fuel supply quantity, and controls the fuel supply means so that tracking performance of fuel supply quantity relative to target fuel supply quantity is higher when reforming air is being supplied to the reformer than when it is not being supplied.

Abstract: An apparatus for providing a humidified cathode fluid stream to a fuel cell stack is disclosed. The apparatus comprising a first humidifier including membranes and a compressor. The first humidifier is configured to receive a cathode fluid stream and to humidify the cathode fluid stream with water from a recirculated fluid stream to provide a first humidified cathode stream. The compressor is configured to receive the first humidified cathode stream and to provide a first pressurized humidified cathode stream. The compressor is further configured to generate a pressure differential across the first humidifier such that the membranes are humidified with the water.

Abstract: A method of estimating water vapor transfer unit degradation without having to remove the unit from a fuel cell system to which it cooperates, and a device performing the same. The method includes using a combination of a backward-looking model and a forward-looking model. The first of these models is used to evaluate changes in water vapor transfer effectiveness in the unit, while the second is for determining the water transfer rate of the unit. Together, the models provide a more accurate way to estimate and control relative humidity for both stack inlet and outlet flowpaths, as well as provide an indication of when service or replacement of the water vapor transfer unit may be warranted.

Abstract: A humidifier includes an inlet assembly provided in an air exhaust pipe, through which water-supersaturated exhaust gas is discharged from a fuel cell stack, to supply water condensed from the exhaust gas to the fuel cell stack and an outlet assembly provided in an air supply pipe, through which a reactant gas to be humidified and supplied to the fuel cell stack passes, to supply the water transferred through a pumping pipe to the air supply pipe such that the reactant gas is humidified. A pumping pipe including a porous material disposed therein along with electrodes are disposed between the inlet assembly and the outlet assembly so that the water is transferred through a capillary path in the porous material via a pumping force by electroosmosis when the electrodes apply a voltage.

Abstract: The water content estimation apparatus for a fuel cell includes an estimating unit for estimating a residual water content distribution in a reactant gas flow channel and a moisture content distribution in an electrolyte membrane in a cell plane of a single cell while taking into consideration water transfer that occurs between an anode electrode and a cathode electrode via the electrolyte membrane between the anode electrode and the cathode electrode. The fuel cell system performs control based on an estimation result by the estimating unit so that the fuel cell assumes a predetermined water condition.

Abstract: The present invention provides a method for controlling the operation of a fuel cell system at low temperature that can suitably prevent flooding in a cathode of a fuel cell stack during low-temperature operation, thus improving the operation stability and durability of the fuel cell stack.

Abstract: The present invention discloses a hydrogen-recyclable fuel cell comprising anode set, cathode set, catalytic layer, proton exchange membrane, hydrogen delivering device, hydrogen-storage complex metal layer and hydrogen drawing device. The hydrogen delivering device delivers hydrogen to the catalytic layer which ionizes hydrogen into electrons and hydrogen ions. After the hydrogen ions pass through the proton exchange membrane, they react with the hydrogen-storage complex metal layer and the electrons to produce complex metal hydrides. The hydrogen drawing device draws hydrogen from the complex metal hydrides into the storage tank for further reuse.

Abstract: A fuel cell includes a membrane electrode assembly comprised of a membrane sandwiched between anode and cathode catalyst structures. An anode separator plate and a cathode separator plate are arranged adjacent to the membrane electrode assembly opposite from one another. The anode and cathode separator plates include opposing sides in which one of the opposing sides of the anode and cathode respectively have fuel and oxidant flow fields in communication with the membrane. The anode separator plate is a structure having a first water permeability and is configured to permit passage of water between its opposing sides and with its flow field, and the cathode separator plate comprises a structure having a second water permeability less than the first water permeability of the anode separator plate. In one example, the anode is provided by a porous separator plate, and the cathode is provided by a non-porous, or solid, plate.

Abstract: A fuel cell system mounted in a vehicle includes a fuel cell stack, a coolant supply mechanism, and a fuel gas supply mechanism. The coolant supply mechanism includes a coolant supply pipe and a coolant discharge pipe, provided on a front side in a traveling direction of the vehicle, relative to the fuel cell stack. The fuel gas supply mechanism includes a fuel gas supply pipe, provided on a rear side in the traveling direction, relative to the fuel cell stack.

Abstract: Disclosed is a fuel cell system comprising a reformer and a fuel cell body to which a fuel gas reformed through the reformer and air are supplied and in which the supplied fuel gas and air are separated from each other and caused to flow and contact on respective electrodes to perform electric power generation. A moisture quantity adjustment device is configured to adjustably separate a portion of moisture included in the fuel gas supplied from the reformer in order for the moisture included in the fuel gas to be supplied to the fuel cell body in an appropriate quantity.

Abstract: A fuel cell system includes a fuel cell; a voltage measuring portion that measures a voltage of the fuel cell; an electric current adjusting portion that adjusts an electric current flowing in the fuel cell; an electric current-voltage characteristic information obtaining portion that controls the electric current adjusting portion to change the electric current, and obtains electric current-voltage characteristic information that is information indicating a correspondence relation between an electric current value and a voltage value measured by the voltage measuring portion; and a negative voltage cause determining portion that determines, if the voltage of the fuel cell is a negative voltage, a cause of the negative voltage of the fuel cell, based on the obtained electric current-voltage characteristic information.

Abstract: A fuel cell system includes: a fuel cell having laminated cells; a measuring unit that measures an impedance of the cell and a purging unit that performs purging to discharge residual water from a gas passage. The cell includes a wet region and a dry region which are set depending on a distribution of water in the cell when the purging is executed so as to set a total amount of water in the fuel cell to be a necessary amount of water to start up the fuel cell; the measuring unit measures the impedance at a local portion located at a boundary portion between the wet region and the dry region in the cell; and the purging unit terminates the purging when the impedance measured by the measuring means is larger than a predetermined reference threshold value.

Abstract: The present invention provides a hydrogen exhaust system for a fuel cell vehicle, which is configured to actively control an exhaust path of hydrogen discharged from an anode of a fuel cell stack to maximize the safety of the vehicle by minimizing the possibility of explosion due to hydrogen exhaust and ensure the silence of the vehicle by minimizing noise generated during hydrogen exhaust. Moreover, the present invention provides a hydrogen exhaust system for a fuel cell vehicle, which can improve the performance and power of the fuel cell stack by supplying water discharged from the fuel cell stack to an air supply line of the fuel cell stack together with purge hydrogen discharged to a hydrogen exhaust line to increase the humidification performance of the fuel cell stack.

Abstract: A membrane electrode assembly includes solid polymer electrolyte membrane, an anode, and cathode. The cathode has a stacked body formed of a catalyst layer and a gas diffusion layer. The catalyst layer, which contains catalyst metal-supporting carbon particles and an ion conductor, further contains a mesoporous humidity control agent whose amount of water adsorption rises steeply as a relative humidity increases in a specific relative humidity region.

Abstract: An operation method of a polymer electrolyte fuel cell system including an anode (3) supplied with a fuel gas containing hydrogen, a cathode (4) supplied with an oxidizing gas containing oxygen, and a polymer electrolyte membrane (5) sandwiched between the anode (3) and the cathode (4), comprises supplying to the anode (3) the fuel gas humidified with a higher level than the oxidizing gas to cause the anode (3) to have a humidified state with a higher level than the cathode (4), in start-up of the polymer electrolyte fuel cell system.

Abstract: A technique for determining the relative humidity of the cathode input airflow to a fuel cell stack that eliminates the need for a dew-point sensor. The cathode input airflow is humidified by a water vapor transfer unit that uses water in the cathode exhaust gas. The technique employs an algorithm that determines the flow of water into the cathode inlet of the stack. In one embodiment, the algorithm determines the volume flow of water through the water vapor transfer unit using the Arrhenius equation, and then converts the water volume flow to a water mole flow. The algorithm then uses the water mole flow through the water vapor transfer unit and the water mole flow of ambient air to determine the water mole flow into the cathode inlet. The algorithm then uses the water mole flow into the cathode inlet to determine the relative humidity of the cathode airflow.

Abstract: Disclosed herein are catalyst degradation detection assemblies and methods of catalyst degradation detection that can be performed in-situ. One embodiment of an in-situ fuel cell catalyst degradation detection assembly comprises a humidified hydrogen supply configured to supply humidified hydrogen to an anode of a fuel cell, a humidified nitrogen supply configured to supply humidified nitrogen to a cathode of the fuel cell, a collection cell containing a liquid, the collection cell configured to receive either cathode exhaust from the fuel cell through a cathode exhaust line or anode exhaust from the fuel cell through an anode exhaust line and means for detecting a gas.

Abstract: An open type fuel cell system is provided. The fuel cell system can have an unreacted material removing function, including a main fuel cell reacting an oxidant and a reductant to generate electricity, a supply means supplying material containing an oxidant and a reductant for the main fuel cell, a recirculating means recirculating unreacted material, a detector detecting voltages, a regenerating means, a humidification means, an exhausting means, and a controller controlling actions of the supply means, the recirculating means, the detector, the regenerating means, the humidification means, and the exhausting means.

Abstract: A fuel cell system is provided with a fuel cell, a gas supply passage which supplies a reaction gas to the fuel cell, a humidifier which humidifies the reaction gas, a first gas discharge passage which leads from a first gas discharge outlet of the fuel cell through the humidifier to the outside, and a second gas discharge flow passage which leads from a second gas discharge outlet of the fuel cell to the outside. A flow rate control mechanism which controls the flow rate of discharge gas is provided in at least one of the first gas discharge passage and the second gas discharge passage. The configuration reduces the distance between the fuel cell and the humidifier to obtain a compact system structure.

Abstract: A system and method for determining when to trigger reconditioning of a fuel cell stack and when to disable the reconditioning of the fuel cell stack. In one embodiment, the stack reconditioning is triggered when a maximum stack power estimation falls below a first predetermined power threshold. The reconditioning of the stack can be disabled so it is not performed when the trigger occurs if the reconditioning process does not raise the maximum power estimation above a second predetermined power threshold or the time from one reconditioning trigger to a next reconditioning trigger is less than a predetermined time threshold, or both.

Abstract: A humidifier assembly for humidifying fuel for use in a fuel cell system, comprising a water heater adapted to receive recycled water and to generate heated water using cathode exhaust, and a fuel saturator adapted to receive deaerated cleansed water, at least a portion of the deaerated cleansed water comprising the heated water, and fuel and to humidify the fuel with a first portion of the deaerated cleansed water, the fuel saturator tower outputting humidified fuel for use in the fuel cell system and a second portion of the deaerated cleansed water for use as recycled water in the water heater.

Abstract: A fuel cell system includes a fuel cell stack and a heat exchanger. The heat exchanger vaporizes water which is provided to the fuel cell stack during start-up of the fuel cell system and heats a heat transfer medium which is provided to a facility associated with the fuel cell system during steady-state operation of the fuel cell system.

Abstract: A fuel cell system that employs a surface active agent that reduces the surface tension of the water in the flow field channels. The fuel cell system includes humidifiers that humidify the cathode inlet airflow and the hydrogen anode gas. The surface active agent is mixed with the humidifying water in the humidifiers so that the surface active agent enters the flow field channels to reduce the surface tension of the water therein, thus allowing the water to wick the channels. In one non-limiting embodiment, the surface active agent is ethanol. Ruthenium can be added to the platinum in the catalyst layers of the fuel cells to mitigate the poisoning of platinum by carbon monoxide, which is one of the oxidation products of ethanol on the cathode side of the fuel cell.

Abstract: A fuel cell system capable of accurately and precisely determining the wet condition inside a fuel cell. The fuel cell system includes a solid polymer electrolyte type fuel cell having a stack structure. The fuel cell is connected to an air supply system, a hydrogen gas supply system, an output system, and a control unit. The control unit receives flow rates of air and hydrogen gas which flow into the fuel cell, their pressures when exhausted, and a generated current measurement signal. The control unit calculates the amounts of water exhausted from the fuel cell as a gas component and as a liquid component and determines the water balance in the fuel cell.

Abstract: A method for determining the water transfer in a water vapor transfer unit of a fuel cell system that employs a model based approach. The method includes determining a capacity ratio of wet streams and dry streams flowing through the water vapor transfer unit, determining the number of mass transfer units of the water vapor transfer unit, estimating a mass transfer effectiveness value given the capacity ratio and the number of mass transfer units for the water vapor transfer unit, and determining the amount of water transferred in the water vapor transfer unit using the mass transfer effectiveness value, the mass flow rates on a dry basis of the dry stream and the wet stream, and the mass flow rates of water of the dry inlet stream and the wet inlet stream.

Abstract: A humidifier for a fuel cell has a stacked unit of several water-permeable membranes which are parallel to each other and are arranged spaced apart form each other. On the edges of the membranes, a sealant is applied which closes a flow space between neighboring membranes fluid-tightly and serves as a spacer.

Abstract: A fuel cell system capable of restraining temperature change in a fuel cell caused by a refrigerant. The fuel cell system has a refrigerant circulating system for circulating the refrigerant. The refrigerant circulating system has flow control means for restraining the inflow of the refrigerant, which has a predetermined difference in temperature from that of the fuel cell, into the fuel cell.

Abstract: A fuel cell system mounted in a vehicle includes a fuel cell stack, a coolant supply mechanism, and a fuel gas supply mechanism. The coolant supply mechanism includes a coolant supply pipe and a coolant discharge pipe, provided on a front side in a traveling direction of the vehicle, relative to the fuel cell stack. The fuel gas supply mechanism includes a fuel gas supply pipe, provided on a rear side in the traveling direction, relative to the fuel cell stack.

Abstract: An electrochemical power system is provided that generates an electromotive force (EMF) from the catalytic reaction of hydrogen to lower energy (hydrino) states providing direct conversion of the energy released from the hydrino reaction into electricity, the system comprising at least two components chosen from: a catalyst or a source of catalyst; atomic hydrogen or a source of atomic hydrogen; reactants to form the catalyst or source of catalyst and atomic hydrogen or source of atomic hydrogen, and one or more reactants to initiate the catalysis of atomic hydrogen. The electrochemical power system for forming hydrinos and electricity can farther comprise a cathode compartment comprising a cathode, an anode compartment comprising an anode, optionally a salt bridge, reactants that constitute hydrino reactants during cell operation with separate electron flow and ion mass transport, and a source of hydrogen.

Abstract: In a device for humidifying a gas flow, an atomized liquid is combined with a gas flow in a spray chamber, and passed through a generally U-shaped gas flow passage having a first generally vertical part 3 through which the atomized liquid and gas passes to a lower part 4. From there, the gas passes generally vertically upwardly to an outlet 9. The lower part of the passage incorporates an opening 6 to a water separator 7. The opening 6 is closable by a float device 10, or includes a flow restricting control valve 13.

Abstract: A control device of a fuel cell system sets a required output of a fuel cell stack that is required according to a present power demand and predicts the required output and the current according to the temperature of the fuel cell stack from a predetermined output state map that is preset. The control device sets an operation state quantity according to the predicted current and the temperature of the fuel cell stack from a predetermined operation state quantity map that is preset. The control device includes at least one of a pressure at an air supply port of air that is supplied to the cathode electrode of the fuel cell stack, a utilization rate of the air at the cathode electrode, a flow rate of a cooling medium that cools the fuel cell stack, and humidity of the air at the air supply port as the operation state quantity.

Abstract: A polymer electrolyte fuel cell includes a cathode, an anode, and an electrolyte membrane sandwiched between the cathode and the anode. A plurality of projections each having a height of 5 to 15 ?m or a plurality of depressions each having a depth of 5 to 15 ?m are formed on a surface of the electrolyte membrane, the surface being opposed to the cathode. The cathode is constituted by a catalyst layer formed to tightly contact the surface of the electrolyte membrane and having a maximum thickness that is one to three times the height of the projection or the depth of the depression. An oxygen-containing gas having a relative humidity of 10% or less is supplied to the cathode, and electric power is generated by using the polymer electrolyte fuel cell.

Abstract: A fuel cell system is disclosed having at least a first section that operates in a hydrogen filtration mode to filter an incoming hydrogen-rich fuel, specifically a reformate, and at least a second section that operates in a power generation mode. The second section may receive filtered hydrogen fuel from the first section. Also, to rejuvenate the first section after anode poisoning, the first section may switch modes to operate in the power generation mode.

Abstract: A control strategy results in a relative humidity profile that is substantially the same or constant regardless of the operational power level of the fuel cell stack. The strategy maintains the relative humidity profile within a range that enables high current density operation of the fuel cell stack. The profile is achieved by adjusting a coolant flow rate through the fuel cell stack to maintain a temperature change across the coolant flow path from inlet to outlet substantially constant regardless of the operational power level of the fuel cell stack.

Abstract: Disclosed is a membrane humidifier for a fuel cell, which uniformly humidifies entire hollow fiber membranes from an outer side to a central portion of an interior of the membrane humidifier to improve the distribution of wet air and dry air, thereby improving a humidification performance. The membrane humidifier for the fuel cell includes a hollow upper case including first wet air inlet apertures and first wet air outlet apertures and a membrane module assembly including a plurality of unit membrane modules received lengthwise within the upper case along the flow direction of dry air.

Abstract: A fuel cell system and a control method therefor are provided. The fuel cell system includes: a fuel cell formed of a plurality of stacked power generating elements; a cell voltage measuring unit detecting negative voltage in any one of the power generating elements; a control unit controlling electric power output from the fuel cell; and an accumulated current value measuring unit measuring an accumulated current value obtained by time integration of current output from the fuel cell. The control unit prestores a correlation between accumulated current values and current densities that are allowable for the fuel cell in a period during which negative voltage is generated. When negative voltage has been detected, the control unit executes output restricting process of restricting electric power output from the fuel cell so as to fall within an operation allowable range defined by the accumulated current values and current densities of the correlation.

Abstract: Process for operating a high temperature fuel cell stack, the process comprising the following steps: b) connecting the fuel cell stack in parallel to a power supply unit at a predefined temperature and/or voltage of the fuel cell stack, h) applying a voltage from the power supply unit of between 700 to 1500 mV per fuel cell across the fuel cell stack irrespective of the electro-motive force of the fuel cell stack, i) heating up the fuel cell stack from the predefined temperature to operation temperature while maintaining the voltage per fuel cell the power supply unit, j) maintaining the fuel cell stack at or above a predetermined operation temperature and/or above a predetermined voltage until the fuel cell stack is to be put into operation, k) supplying fuel to the fuel cell stack, l) disconnecting the power supply unit followed by m) connecting a power-requiring load to the fuel cell stack.

Abstract: The present invention provides a fuel cell system including a fuel cell configured to cause reactant gas to be electrochemically reacted to generate electrical power when the reactant gas is supplied to the fuel cell, power consuming equipment such as a reactant gas supply apparatus and a heating device operable to consume electrical power generated by the fuel cell, and a controller for controlling operation of the fuel cell system. During a warm-up operation, the controller causes the reactant gas supply apparatus to start a flow of the reactant gas and to increase the flow of the reactant gas over time, such that the reactant gas supply device starts to consume power and consumes increased power over time. After starting the flow of the reactant gas, the controller causes the heating device to start heating the coolant such that the heating device consumes power.

Abstract: A method of operating a fuel cell system includes the steps of temporarily supplying a raw fuel to an electrode surface of an anode at the time of starting operation of the fuel cell system, supplying water vapor to the electrode surface of the anode at least based on any of the temperature of a fuel cell stack and the temperature of an evaporator after stopping the supply of the raw fuel, and supplying a fuel gas to the electrode surface of the anode by supplying the raw fuel and the water to the evaporator at least based on any of detection results of the pressure of the water supplied to the evaporator, the flow rate of the water supplied to the evaporator), the pressure of the water vapor discharged from the evaporator, and the flow rate of the water vapor discharged from the evaporator.

Abstract: A water recovery assembly for use in a fuel cell system having an anode and a cathode, the anode being adapted to receive fuel and output anode exhaust, the water recovery assembly comprising a first cooling assembly adapted to receive and quench cool the anode exhaust and to recover a first portion of water including electrolyte from the anode exhaust, and to output quenched anode exhaust and the first portion of water, and a second cooling assembly adapted to receive the quenched anode exhaust and to recover a second portion of water from the quenched anode exhaust, the second portion of water being suitable for humidifying the fuel supplied to the anode.

Abstract: A three-way diverter assembly with a movable member is provided. The three-way diverter assembly includes a housing having a first inlet, a second inlet, a first outlet, and a second outlet. The first inlet and the second inlet are adapted to receive a fluid. The movable member, disposed in the housing adjacent the first inlet, is rotatable about an axis from a first positional limit to a second positional limit, and selectively positional therebetween. Fuel cell systems having the three-way diverter assembly for regulating temperature and humidity of a fuel cell stack are also provided.

Abstract: A device and a method for controlling the air humidity in a fuel cell detect a step response in the output voltage of a fuel cell when the supply to electrical loads is interrupted, and determine parameters of the dynamic time characteristic from the detected step response, and thus calculate a capacitance of the fuel cell. As a function of any deviation from a predetermined capacitance, a humidity control unit is caused to increase or decrease the humidity. This makes in situ detection of the humidity balance of a fuel cell possible, and this can keep the electrical power thereof constant for a relatively long period, and this can increase the intervals between maintenance.

Abstract: A fuel cell includes an electrolyte membrane, an anode which is disposed on one surface of the electrolyte membrane and includes an anode catalyst layer, a cathode which is disposed on the other surface of the electrolyte membrane and includes a cathode catalyst layer, and an adjustment unit which allows at least one of a relative humidity of a gas which is in contact with the anode catalyst layer and a relative humidity of a gas which is in contact with the cathode catalyst layer to be decreased down to less than 100% before a fuel is supplied at the time of starting.

Abstract: Disclosed is an apparatus and method for activating a fuel cell stack, which significantly reduces the time required for activation and the amount of hydrogen used for the activation by employing a vacuum wetting process in a shutdown operation. In particular, a high humidity open circuit voltage operation humidifies the fuel cell stack and operates the fuel cell stack at an open circuit voltage, and a vacuum wetting operation wets the surface of a polymer electrolyte membrane by creating a vacuum atmosphere in the fuel cell stack. The high humidity open circuit voltage operation and the vacuum wetting operation are performed alternately and repeatedly.