Nissan Motor Company Limited

Ryoichi Shimoi

Hayato Chikugo

Mitsunori Kumada

Takashi Fukuda

Kazuo Sato

Takashi Iimori

Takahiro Fujii

Kenichi Goto

Kazuo Saito

Hitoshi Igarashi

Takashi Aoyama

Susumu Maeshima

Tetsuya Kamihara

Kenji Yonekura

Akira Matsunaga

Shinichi Miyazaki

Masashi Sato

Keigo Ikezoe

Kazuhiro Kageyama

Yoshitaka Ono

Yasushi Ichikawa

Tetsuya Mashio

Keiji Ichihara

Hidetaka Nishimura

Hiroshi Iden

Daigo Iwasaki

Takehiko Okui

Satoshi Takaichi

Seiho Sugawara

Yohei Kaneko

Yoshiki Nagahara

Yusuke Ito

Nobuo Matsuba

Taiji Nishiyama

Takashi c/o Nissan Motor Co Ltd Intellectual Property Department Iimori

Susumu Maejima

Hikoshi Iden

A cathode electrode for a fuel cell, includes a conductive carrier having pores and a catalyst having a platinum alloy supported in the pores of the conductive carrier, wherein the catalyst has in a pore diameter range of 2 to 6 nm when diameters of the pores is plotted in relation with volumes of the pores a peak value of more than 1 cm/g and also a BET specific surface area of 1300 m/g.

Cathode electrode for fuel cell

A fuel cell stack obtained by stacking a plurality of fuel cells has an internal manifold that extends in a stacking direction of the fuel cells to externally discharge a gas used in the fuel cell, and an extension member that adjoins an inner wall surface of the internal manifold and extends in the stacking direction. The extension member is a bar-shaped member provided in an opposite side to a side where a gas from the fuel cells flows to the inside of the internal manifold and has a sloping surface making an acute angle with an inner-wall lower surface of the internal manifold.

Fuel cell stack and fuel cell system

A fuel cell system is basically provided with a fuel cell, a pressure adjusting valve, a purge valve and an anode pressure controller. The fuel cell includes an anode that receives an anode gas and a cathode that receives a cathode gas to generate electric power corresponding to a load. The pressure adjusting valve is disposed in a supply path to adjust anode gas pressure to the anode. The purge valve is disposed in a discharging flow path to discharge an anode-off gas containing impurities from the fuel cell. The anode pressure controller is configured to control the pressure adjusting valve to perform a pulsation operation that pulsates the anode gas pressure of the fuel cell. The anode pressure controller decreases a median pressure of the pulsation operation as a wetness level of an electrolyte membrane of the fuel cell stack is determined to become higher.

Fuel cell system comprising an anode pressure controller

A performance recovery operation for a fuel cell system effectively restores a fuel electrode such that, upon starting or stopping of operation of the fuel cell, both fuel and oxidizing electrodes are disposed in a hydrogen atmosphere and then the fuel electrode is maintained at a higher potential level than in a normal operation.

Fuel cell system with regeneration of electrode activity during start or stop

For implementing a stop control which extracts a current from a fuel cell and consumes a cathode side oxygen at a system stop, the current extraction from the fuel cell is ended in a state that a certain quantity of oxygen smaller than when the current extraction is started remains on a cathode side of the fuel cell. With this, the hydrogen movement to the cathode side after the system stop can be effectively suppressed and thereby a cathode internal hydrogen concentration at the system start can be kept low, thus making it possible to properly process the cathode side hydrogen at the system start.

Fuel cell system, and method of stopping fuel cell system

Deterioration at the start-up and deterioration during the leaving period are suppressed in a good balance. As a system shutdown process, a controller () causes consumption of the air (oxygen) present in an oxidant electrode of a fuel cell stack () (oxygen consumption control). Further, after the termination of the oxygen consumption control, the controller () performs control to set a medium pressure hydrogen valve () and a hydrogen pressure adjustment valve () in a closed state. The controller () thereby causes hydrogen to be held in a passage located between the medium pressure hydrogen valve () and the hydrogen pressure adjustment valve (). During a system shutdown period, a predetermined amount of hydrogen (medium pressure hydrogen) held in the hydrogen supply passage (L) at a position between the medium pressure hydrogen valve () and the hydrogen pressure adjustment valve () can be supplied to the fuel electrode of the fuel cell stack () through a bypass passage (L).

Fuel cell system and method of controlling fuel cell system

A fuel cell system includes a fuel cell having an anode, a cathode, and an electrolyte membrane disposed therebetween. An oxidant gas supplying device supplies oxidant gas to the cathode, an oxidant gas backpressure regulating device regulates the pressure of the oxidant gas at the cathode according to a valve opening, and a pressure detecting device detects the oxidant gas pressure at the cathode. During a start-up fuel gas disposal process, a controller controls the oxidant gas supplying device to supply the oxidant gas at a standard oxidant gas flow, controls the valve opening of the oxidant gas backpressure regulating device to a first valve opening, and controls the valve opening of the oxidant gas backpressure regulating device to a second valve opening which is greater than the first valve opening when the oxidant gas pressure detected by the pressure detecting device reaches an elevation target pressure.

Fuel cell system and method for controlling fuel cell system

A fuel cell system can be initiated in shorter time while minimizing the deterioration of a fuel cell. The fuel cell system includes a fuel cell stack having a fuel electrode, an oxidizer electrode and an electrolyte membrane disposed there between, the fuel cell producing electricity by an electrochemical reaction of a fuel gas and an oxidizer gas, which are supplied to the fuel electrode and the oxidizer electrode, respectively; a fuel gas supplying device for supplying the fuel gas to the fuel cell stack; an oxidizer gas supplying device for supplying the oxidizer gas to the fuel cell stack; a current controlling device for extracting a current from the fuel cell stack; and a voltage sensor disposed in at least two of the fuel cell stacks. A controller controls the current controlling device such that a minimum voltage, which is obtained from the voltage sensor after a fuel gas is supplied to the fuel electrode without supplying the oxidizer gas to the oxidizer electrode at the time of initiating, becomes zero volts or more. Then, the oxidizer gas is supplied to the oxidizer to start producing electricity.

Fuel cell system having decreased deterioration during initiation

A fuel cell system which prevents the deterioration of the fuel cell stack when feeding of the oxidant gas is paused under a load to perform a fuel conservation operation. Controller shuts down oxidant gas compressor and cooling water circulating pump to execute fuel conservation operation at a low fuel cell system load. The controller gives a current draw instruction to electric power controller. In the fuel conservation operation, electric power controller draws a current larger than zero from fuel cell stack, and keeps the total charge drawn per unit time constant or substantially constant.

Fuel cell system and method for operating the same

When stopping an operation of a fuel cell power plant, a controller () first stops fuel gas supply to an anode (), then supplies a dry oxidant gas to a cathode () such that the output voltage of the fuel cell stack () decreases. The controller () then connects a secondary battery () to the fuel cell stack () so as to consume an output power generated by a reaction of the residual fuel gas in the anode (). After this processing, the controller () replaces the residual fuel gas in the anode () with dry oxidant gas, then maintains the fuel cell stack () in a closed state, thereby preventing local cell formation in the anode due to mixing of the residual fuel gas with oxidant gas, and hence preventing corrosion of a catalyst layer of the cathode () due to local cell corrosion.

Fuel cell power plant and control method thereof

A fuel cell system has a plurality of fuel cells stacked in one or more groups of fuel cells. Each fuel cell includes a fuel electrode supplied with fuel gas at a fuel gas supply pressure, an oxidizing electrode supplied with oxidizing gas at an oxidizing gas supply pressure, and an electrolyte membrane disposed between the fuel electrode and the oxidizing electrode. A pressure-difference control unit generates a pressure difference across the membrane such that the fuel gas supply pressure is greater than the oxidizing gas supply pressure in each fuel cell, a cell-voltage measuring device measures a cell voltage for each fuel cell or each group of fuel cells in the fuel cell stack, and a leakage determination unit determines the presence or absence of a leaking cell based on the behavior of the cell voltage of each fuel cell while the pressure difference is increased with time.

Fuel cell system

A fuel cell system has a purge valve that adjusts the amount of nitrogen in a hydrogen circulation channel and a fuel electrode to be discharged through a discharge channel. A purge rate correcting unit variably sets a target control value of the nitrogen content in the hydrogen circulation channel and the fuel electrode by taking into account whether a driving mode is set in a normal power generation mode or an idle mode. An opening of the purge valve is controlled on the basis of the target control value.

A fuel cell system for removing sulfur compounds adsorbed on the surfaces of a catalyst. The fuel cell system includes a fuel cell in which a plurality of unit cells, each having an electrolyte membrane held between electrode catalyst layers, are stacked, and a control device for recovering catalytic activity of the electrode catalyst layers by increasing an amount of water discharged from the electrode catalyst layers to a predetermined amount or more.

At shutdown of a fuel cell system, a system-shutdown controller is configured to cause a current extraction device to extract current from a fuel cell in a state where a supply of a fuel gas through a fuel supply system is continued and a supply of an oxidant gas through an oxidant supply system is stopped, and the system-shutdown controller is configured to airtightly close fresh-air control valves after increasing pressure of the fuel gas in a fuel electrode to not less than atmospheric pressure and not less than pressure of the oxidant gas in an oxidant electrode.

Fuel cell system and shutdown method of the same

The disclosure describes fuel cell systems including a fuel cell stack that generates electricity, an exhaust valve that externally vents a fuel gas from a fuel chamber of the fuel cell stack, and a controller that computes an estimated time to replace an oxidant gas in at least the fuel chamber with a newly supplied fuel gas, wherein at a time of starting-up the fuel cell system the controller maintains the exhaust valve in an open position for the estimated time. In some embodiments, the controller computes the estimated time as a summation of a first time Tmeasured from the fuel cell start-up time to a time when contents of a supply conduit are replaced with fuel gas, a second time Tmeasured from the time when contents of a supply conduit are replaced with fuel gas to a time when contents of the fuel chamber are replaced with fuel gas, and a third time Tmeasured from the time when contents of the fuel chamber are replaced with fuel gas to a time when contents of the exhaust conduit are replaced with fuel gas. The disclosure further describes methods of operating a fuel cell system, particularly during fuel cell start-up.

Growing community of inventors

Yokohama, Japan

Ryoichi Shimoi