Abstract: A membrane-electrode assembly for a direct oxidation fuel cell includes an electrolyte membrane, and an anode and a cathode sandwiching said electrolyte membrane. The cathode includes a catalyst layer in contact with the electrolyte membrane and a diffusion layer formed on the catalyst layer, and the catalyst layer contains 2 to 20% by volume of pores. A direct oxidation fuel cell including this membrane-electrode assembly has excellent power generating performance and durability.

Abstract: A direct oxidation fuel cell of the invention includes at least one unit cell, the unit cell including a membrane-electrode assembly including an electrolyte membrane and an anode and a cathode sandwiching the electrolyte membrane, an anode-side separator being in contact with the anode, and a cathode-side separator being in contact with the cathode. The anode includes an anode catalyst layer and an anode diffusion layer, the anode catalyst layer containing an anode catalyst. The cathode includes a cathode catalyst layer and a cathode diffusion layer, the cathode catalyst layer containing a cathode catalyst. The anode-side separator has a fuel flow channel for supplying fuel to the anode. A portion of the cathode catalyst layer facing the upstream of the fuel flow channel has an effective reaction area per unit area larger than that of a portion of the cathode catalyst layer facing the downstream of the fuel flow channel.

Abstract: An external additive including titanium dioxide having a water-soluble component of at least 0.2% by weight and a fluorosilane compound, wherein the titanium dioxide is surface-reformed by the fluorosilane compound.

Abstract: In order to prevent the crossover of an organic fuel such as methanol in a fuel cell and to exhibit excellent electricity generation characteristics without impairing the utilization efficiency of the fuel, at least either of (1) a discontinuous catalyst layer being formed on a surface of an anode catalyst layer and having a higher density (existence probability) of platinum type catalyst than the anode catalyst layer and (2) an electrolyte polymer layer is formed at the interface between the anode catalyst layer and a polymer electrolyte membrane.

Abstract: For give a direct methanol fuel cell which secures the fuel supply to the catalyst layer, reliably discharge generated carbon dioxide gas, and has excellent electricity generation ability, at least a portion of the anode side flow path is divided by a film having water-repellency and gas permeability to a first flow path portion positioned at the membrane electrode assembly side and a second flow path portion positioned at the bottom side of the anode side flow path where a fuel mainly flows in the first flow path portion and carbon dioxide mainly flows in the second flow path portion.

Abstract: A direct oxidation fuel cell of this invention has at least one unit cell including: a membrane-electrode assembly comprising an electrolyte membrane sandwiched between an anode and a cathode, each of the anode and the cathode including a catalyst layer and a diffusion layer; an anode-side separator with a fuel flow channel for supplying a fuel to the anode; and a cathode-side separator with an oxidant flow channel for supplying an oxidant containing oxygen gas to the cathode. The fuel flow channel and the oxidant flow channel are so structured that the concentration of the oxygen gas in the oxidant flow channel is higher at a part opposing an upstream part of the fuel flow channel than at a part opposing a downstream part of the fuel flow channel.

Abstract: An anode electrode for use in a fuel cell comprises a stacked structure including, in sequence: a catalyst layer, a hydrophobic, microporous layer (“MPL”), a porous gas diffusion layer (“GDL”), and an anode plate with at least one recessed fuel supply-fuel/gas exhaust channel formed in a surface thereof facing the GDL, wherein the stacked structure further comprises at least one hydrophobic region aligned with the at least one recessed channel. The electrode is useful in direct oxidation fuel cells and systems, such as direct methanol fuel cells operating with highly concentrated liquid fuel.

Abstract: A direct oxidation fuel cell of this invention has at least one unit cell including: a membrane-electrode assembly including an electrolyte membrane sandwiched between an anode and a cathode, each of the anode and the cathode including a catalyst layer and a diffusion layer; an anode-side separator with a fuel flow channel for supplying a fuel to the anode; and a cathode-side separator with an oxidant flow channel for supplying an oxidant to the cathode. The catalyst layer of at least one of the anode and the cathode includes high-porosity regions and low-porosity regions, and the high-porosity regions and the low-porosity regions are arranged in a mixed configuration.

Abstract: Disclosed is a milling and classifying apparatus, adapted to produce toner fine particles, comprising a collision mill, and an air classifier, wherein the collision mill comprises a jet nozzle room, a path, a collision plate, and a collision member mounted to a support of the collision plate at downstream of the collision plate, the air classifier comprises a dispersion room and a classification room, the classification room is disposed below the dispersion room, and a flow stabilizer is arranged at a central suction of the separator core to control swirl stream generated within the classification room so as to centrifuge the powder into coarse particles and fine particles by action of the swirl stream.

Abstract: A fuel cell system, comprising a fuel cell having an anode, a cathode, and an electrolyte interposed therebetween and a purification device having a catalyst layer purifying substances discharged from the anode. The fuel cell system is characterized in that the purification device comprises a porous sheet having a catalyst layer and two flow passages disposed on both sides of the porous sheet, an inlet to which the substances discharged from the anode is led is formed in one flow passage, an inlet to which air is led and an outlet are formed in the other flow passage, and the substances discharged from the anode are discharged from the outlet after being purified through the porous sheet.

Abstract: An anode electrode for use in a fuel cell comprises a stacked structure including, in sequence: a catalyst layer, a hydrophobic, microporous layer (“MPL”), a porous gas diffusion layer (“GDL”), and an anode plate with at least one recessed fuel supply-fuel/gas exhaust channel formed in a surface thereof facing the GDL, wherein the stacked structure further comprises at least one hydrophobic region aligned with the at least one recessed channel. The electrode is useful in direct oxidation fuel cells and systems, such as direct methanol fuel cells operating with highly concentrated liquid fuel.

Abstract: The fuel cell of this invention includes at least one unit cell that includes: a membrane-electrode assembly including an electrolyte membrane sandwiched between an anode and a cathode; an anode-side separator in contact with the anode and having a fuel flow path for supplying a fuel to the anode; and a cathode-side separator in contact with the cathode and having an oxidant flow path for supplying an oxidant to the cathode. The fuel flow path has a first flow channel and a second flow channel, and each of the first flow channel and the second flow channel has a fuel inlet and a fuel outlet. The first flow channel and the second flow channel are adjacent to each other, and the direction of the flow of fuel through the first flow channel is opposite to the direction of the flow of fuel through the second flow channel.

Abstract: A fuel cell system includes a fuel cell including at least one unit cell having an anode, an anode-side flow channel for supplying a fuel to the anode, a cathode, and a cathode-side flow channel for supplying an oxidant to the cathode. The fuel cell system further includes a gas-liquid separator for catalytically purifying the effluent from the anode and the effluent from the cathode to collect liquid. The gas-liquid separator is connected to an anode-side discharge path for the effluent and a cathode-side discharge path for the effluent, which are in fluid communication with a fuel outlet of the anode-side flow channel and an oxidant outlet of the cathode-side flow channel, respectively.

Abstract: A fuel cell system includes a fuel cell stack which is composed of an assembly of fuel cells, each of which is provided with an anode that is supplied with fuel and a cathode that is supplied with oxygen. The fuel cell system further includes an air duct for supplying oxygen, which is disposed along the fuel cell stack, and at least a fuel tank and a recovery tank unit of a gas-liquid separator, namely, a tank for supplying water to be mixed with fuel, which both are disposed on a side opposite to the fuel cell stack with the air duct interposed therebetween. Accordingly, vaporization of fuel due to heat generated in the fuel cell stack which is the power generating section is suppressed, and a deterioration of generating characteristics attributable to insufficient fuel supply is prevented.

Abstract: A method for operating a fuel cell system including a fuel cell stack composed of a plurality of cells connected in series. The method includes the steps of: (a) supplying a fuel and an oxidant to anodes and cathodes of the cells, respectively, depending on a load to generate power at a constant voltage under constant voltage control; (b) temporarily suspending the supply of the oxidant with the fuel being supplied; and (c) lowering the constant voltage to a predetermined voltage simultaneously with or immediately before the suspension of the supply of the oxidant. According to this operation method, when the supply of the oxidant is suspended, a platinum catalyst in the cathodes can be reduced and reactivated in all the cells.

Abstract: A direct oxidation fuel cell includes at least one unit cell. The at least one unit cell includes: an anode; a cathode; a hydrogen-ion conductive polymer electrolyte membrane interposed between the anode and the cathode; an anode-side separator having a flow channel for supplying and discharging a fuel to and from the anode; and a cathode-side separator having a gas flow channel for supplying and discharging an oxidant gas to and from the cathode. A water-repellent layer is formed on each side of the electrolyte membrane so as to surround the anode or the cathode. When the MEA is hydrated or when a liquid fuel is supplied to the cell for power generation, the part of the electrolyte membrane surrounding the electrodes is prevented from becoming swollen or deformed rapidly. It is therefore possible to ensure adhesion of the electrodes to the electrolyte membrane.

Abstract: An anode electrode for use in a fuel cell comprises a stacked structure including, in sequence: a catalyst layer, a hydrophobic, microporous layer (“MPL”), a porous gas diffusion layer (“GDL”), and an anode plate with at least one recessed fuel supply-fuel/gas exhaust channel formed in a surface thereof facing the GDL, wherein the stacked structure further comprises at least one hydrophobic region aligned with the at least one recessed channel. The electrode is useful in direct oxidation fuel cells and systems, such as direct methanol fuel cells operating with highly concentrated liquid fuel.

Abstract: A direct oxidation fuel cell includes at least one unit cell. The at least one unit cell includes an anode, a cathode, and a hydrogen-ion conductive polymer electrolyte membrane interposed between the anode and the cathode. The anode includes: a catalyst layer in contact with the polymer electrolyte membrane; and a diffusion layer. The diffusion layer includes: a porous composite layer containing a water-repellent binding material and an electron-conductive material; a first conductive porous substrate provided on the anode-side separator side of the porous composite layer; and a second conductive porous substrate provided on the catalyst layer side of the porous composite layer.

Abstract: A direct-type fuel cell having excellent power generating characteristics even under operating conditions utilizing a high concentration fuel at low air flow rates. The anode includes an anode-side diffusion layer that faces the fuel flow channel and an anode-side catalyst layer in contact with the electrolyte membrane. The cathode includes a cathode-side diffusion layer that faces the air flow channel and a cathode-side catalyst layer in contact with the electrolyte membrane. A surface area of the anode-side diffusion layer facing the fuel flow channel or both a surface area of the anode-side diffusion layer facing the fuel flow channel and a surface area of the cathode-side diffusion layer facing the air flow channel have a critical surface tension of penetrating wettability of 22 to 40 mN/m.

Abstract: A fuel container for storing a fuel liquid for a fuel cell has a double wall structure including an inner container for storing a fuel liquid and an outer container for housing the inner container, and a material capable of retaining the fuel between the inner container and the outer container. A fuel cell pack includes a fuel cell and a fuel container for storing a fuel liquid for the fuel cell. The fuel cell pack includes a double wall exterior casing having an inner casing for housing the fuel cell and the fuel container and an outer casing for housing the inner casing, and a material capable of retaining the fuel between the inner casing and the outer casing.