The present invention provides a catalyst layer, a catalyst layer ink and a membrane-electrode assembly which enable provision of fuel cells with high power efficiency. The catalyst layer of the present invention comprises a carbon alloy catalyst and an ion exchange polymer which comprises at least one species of units having a cyclic ether structure selected from the group consisting of units represented by the formula (u11), units represented by the formula (u12), units represented by the formula (u21), units represented by the formula (u22) and units represented by the formula (u24).

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A metal-gas battery including: a battery core, gas container and a movable member. The battery core including a metal anode; a non-aqueous electrolyte; a porous cathode; and terminals for providing electrical power from the battery core. The gas container being configured to hold a pressurized gas. The movable member being configured to be movable from a non-activated position in which the pressurized gas in the container is sealed from entering the porous cathode and an activated position in which the pressurized gas flows into the porous cathode to activate the battery core.

Provided is a shortened fibrous carbon nanohorn aggregate (CNB) obtained by shortening a CNB having a length of 1 μm or more and a diameter in the short direction in the range of 30 to 100 nm, by oxidizing, stirring in an acid solution, subjecting to an ultrasonic treatment in a liquid, followed by cutting. The shortened CNB has an end surface on which no tip of the plurality of single-walled carbon nanohorns is disposed toward the longitudinal direction at least one end in the longitudinal direction, and has an excellent dispersibility by shortening the length to less than 1 μm.

Provided is a shortened fibrous carbon nanohorn aggregate (CNB) obtained by shortening a CNB having a length of 1 μm or more and a diameter in the short direction in the range of 30 to 100 nm, by oxidizing, stirring in an acid solution, subjecting to an ultrasonic treatment in a liquid, followed by cutting. The shortened CNB has an end surface on which no tip of the plurality of single-walled carbon nanohorns is disposed toward the longitudinal direction at least one end in the longitudinal direction, and has an excellent dispersibility by shortening the length to less than 1 μm.

A membrane electrode assembly for a fuel cell includes a catalyst layer having a first main surface and a second main surface, a gas diffusion layer disposed on a side of the first main surface, and an electrolyte membrane disposed on a side of the second main surface, wherein the gas diffusion layer includes a conductive material and a polymer resin, the conductive material comprises a fibrous carbon material, an average fiber diameter D of the fibrous carbon material is equal to or less than 25% of a thickness T of the catalyst layer, and in a cross section in a thickness direction of the catalyst layer, an arithmetic mean roughness Ra1 of the first main surface and an arithmetic mean roughness Ra2 of the second main surface satisfies the relation, Ra1>Ra2.

A membrane electrode assembly for a fuel cell includes a catalyst layer having a first main surface and a second main surface, a gas diffusion layer disposed on a side of the first main surface, and an electrolyte membrane disposed on a side of the second main surface, wherein the gas diffusion layer includes a conductive material and a polymer resin, the conductive material comprises a fibrous carbon material, an average fiber diameter D of the fibrous carbon material is equal to or less than 25% of a thickness T of the catalyst layer, and in a cross section in a thickness direction of the catalyst layer, an arithmetic mean roughness Ra1 of the first main surface and an arithmetic mean roughness Ra2 of the second main surface satisfies the relation, Ra1>Ra2.

The electrode structure for electronic devices according to the present invention comprises a powdered electrode material, and carbon nanotubes having a volume resistivity of not more than 2×10.sup.−2 Ω.Math.cm.

The electrode structure for electronic devices according to the present invention comprises a powdered electrode material, and carbon nanotubes having a volume resistivity of not more than 2×10.sup.−2 Ω.Math.cm.

In accordance with the principles of the present invention, a system and method for the management of the power applied to electrolytic cell is provided. The power management consists a constant current regulation, H-bridge control by pulse width modulation (PWM), and dimming control of the applied current to the electrolytic cell. The constant current regulation is an analog control that maintains the applied current at a user-defined current setpoint. The time scale of constant current regulation ranges from tenth of microseconds to milliseconds. The PWM control of the H-bridge allows for the instant adjustment of the electrolytic production output by turning the cell on and off; the time scale of the PWM control ranges from tenths of milliseconds to seconds. The dimming control allows the change of the applied constant current; the time scale of the dimming control ranges from milliseconds to hours and longer.

In accordance with the principles of the present invention, a system and method for the management of the power applied to electrolytic cell is provided. The power management consists a constant current regulation, H-bridge control by pulse width modulation (PWM), and dimming control of the applied current to the electrolytic cell. The constant current regulation is an analog control that maintains the applied current at a user-defined current setpoint. The time scale of constant current regulation ranges from tenth of microseconds to milliseconds. The PWM control of the H-bridge allows for the instant adjustment of the electrolytic production output by turning the cell on and off; the time scale of the PWM control ranges from tenths of milliseconds to seconds. The dimming control allows the change of the applied constant current; the time scale of the dimming control ranges from milliseconds to hours and longer.