Abstract: In an electrochemical device of an embodiment, a cell stack has a spacer disposed to be arranged next to an insulating sealing member in a direction orthogonal to a stack direction. A plurality of the spacers are arranged in the stack direction between a pair of end plates, and the spacer is interposed between a pair of separators adjacently arranged in the stack direction. The spacer is formed of a material whose thickness reduction ratio when an operation of the electrochemical device is executed is smaller than that of the insulating sealing member. Before the execution of the operation of the electrochemical device, the thickness of the spacer is thinner than the thickness of the insulating sealing member. Further, the thickness of the spacer keeps a state of being equal to or less than the thickness of the insulating sealing member when the operation of the electrochemical device is executed.

Abstract: An interconnector for a solid oxide electrochemical cell stack of at least one embodiment includes a metal base that contains an iron-base alloy containing chromium, a protective film provided on a surface of the metal base, and an interlayer provided between the metal base and the protective film arranged to relieve stress.

Abstract: There is provided a metal member capable of effectively preventing a coating layer from peeling off from a base. The metal member in an embodiment is a metal member that is used in a solid-oxide type electrochemical stack, and includes: a base formed of ferritic stainless steel; and a metal film provided on the base, in which the metal film includes a first metal layer containing Co and a second metal layer made of Mn, and is a stack in which the first metal layer and the second metal layer are sequentially stacked from the side of the base.

Abstract: To provide an electrochemical device capable of sufficiently ensuring sealing performance, and the like. The electrochemical device of this embodiment has an electrochemical cell with an electrolyte membrane interposed between a hydrogen electrode and an oxygen electrode; a plurality of separators formed of a metal material; and gas-sealing materials that seal at least one of between the electrochemical cell and the separator and between the plurality of separators. In the electrochemical device, diffusion-preventing coatings, which prevent diffusion of metal elements in the metal material composing the separators, cover surfaces of the separators. The diffusion-preventing coating is formed of a material that reacts with a material composing the gas-sealing material. There are portions where the separators are in direct contact with the gas-sealing materials.

Abstract: A solid oxide electrochemical cell includes an oxygen electrode containing a strontium-containing perovskite-type composite oxide represented by Ln1-xSrxCo1-y-zFeyBzO3-? (Ln is a trivalent lanthanide element, B is a tetravalent element, 0<x<1, 0?y<1, 0<z<1, and 0<z+y<1, and ? is a value that is determined to satisfy charge neutrality conditions), a solid electrolyte containing zirconium oxide, a hydrogen electrode, and an interlayer containing a rare-earth-doped cerium oxide that is provided between the solid electrolyte and the oxygen electrode.

Abstract: An electrochemical cell according to an embodiment includes a hydrogen electrode, an electrolyte laminated on the hydrogen electrode, a barrier-layer laminated on the electrolyte, and an oxygen electrode laminated on the barrier-layer. The barrier-layer has a porous structure having a thickness of greater than 20 ?m and a porosity of greater than 10%.

Abstract: An interconnector for a solid-oxide electrochemical cell stack of the embodiment includes: a metal base containing an iron-based alloy containing chromium; and a protective film provided on a surface of the metal base. The protective film includes a protective film body containing at least one selected from a spinel oxide and a perovskite oxide, and dispersed phases scattered in the protective film body and containing an oxide of at least one element selected from the group consisting of rare earth elements and zirconium.

Abstract: [Problem] Provided are a protective-layer-coated-interconnector, a cell stack, and a hydrogen energy system. A component (particularly Cr) of the interconnector is prevented from diffusing even if the interconnector is exposed to high temperature for a long time. The interconnector has sufficient diffusion barrier performance and protective performance even with a protective layer thinner than conventionally, is inhibited from being degraded through use, and has excellent electrical conductivity. [Solution] A protective-layer-coated-interconnector including an interconnector material and a protective layer on the surface of the interconnector material, wherein the protective layer contains a metal layer constituted by a Group 11 element. A cell stack and a hydrogen energy system that each include this interconnector.

Abstract: A metal component for electrochemical stack in an embodiment includes: a metal base material having a first surface exposed to an atmosphere containing hydrogen and a second surface exposed to an atmosphere containing oxygen; and a hydrogen permeation inhibition and protection coating provided on the first surface of the metal base material. The metal component for electrochemical stack in the embodiment can suppress metallic corrosion also in the case where one side is in contact with air and the other side is in contact with an atmosphere containing hydrogen.

Abstract: There is provided a metal member capable of effectively preventing a coating layer from peeling off from a base. The metal member in an embodiment is a metal member that is used in a solid-oxide type electrochemical stack, and includes: a base formed of ferritic stainless steel; and a metal film provided on the base, in which the metal film includes a first metal layer containing Co and a second metal layer made of Mn, and is a stack in which the first metal layer and the second metal layer are sequentially stacked from the side of the base.

Abstract: A hydrogen electrode includes: a first layer; and a second layer located on the side of the electrolyte membrane relative to the first layer. The first layer is formed of a sintered body of a first metal and a first oxide. The second layer is formed of a sintered body of a second metal and a second oxide different from the first oxide. The first metal and the second metal each are a single metal of at least one element selected from the group consisting of Fe, Co, Ni, and Cu or an alloy of the element. The first oxide is zirconia stabilized with an oxide of at least one element selected from the group consisting of Y, Sc, Ca, and Mg. The second oxide is ceria doped with an oxide of at least one element selected from the group consisting of Sm, Gd, and Y.

Abstract: Provided is a protective-layer-coated-interconnector, a cell stack, and a fuel cell. A component (particularly Cr) of the interconnector is prevented from diffusing even if the interconnector is exposed to high temperature for a long time. The interconnector has sufficient diffusion barrier-performance and protective performance. [Solution] A protective-layer-coated-interconnector, a cell stack including the interconnector, and a fuel cell including the interconnector, wherein the interconnector includes an interconnector material and a protective layer on the surface of the interconnector material, wherein the interconnector material is composed of a Fe—Cr alloy containing a rare earth element or a Zr element in a total amount of 1.0 weight % or less, and wherein the protective layer is composed of a Co oxide or an oxide containing: at least one element selected from the group consisting of Al, Ti, Cr, Fe, Ni, Cu, and Zn; and a Co element.

Abstract: An electrochemical cell according to an embodiment includes a hydrogen electrode, an electrolyte laminated on the hydrogen electrode, a barrier-layer laminated on the electrolyte, and an oxygen electrode laminated on the barrier-layer. The barrier-layer has a porous structure having a thickness of greater than 20 ?m and a porosity of greater than 10%.

Abstract: There is provided a metal member capable of effectively preventing a coating layer from peeling off from a base. The metal member in an embodiment is a metal member that is used in a solid-oxide type electrochemical stack, and includes: a base formed of ferritic stainless steel; and a metal film provided on the base, in which the metal film includes a first metal layer containing Co and a second metal layer made of Mn, and is a stack in which the first metal layer and the second metal layer are sequentially stacked from the side of the base.

Abstract: An electrochemical cell includes an electrolyte arranged between a hydrogen electrode and an oxygen electrode. The electrolyte contains a ceria-based material having a fluorite crystal structure and a stabilized zirconia-based material. The electrolyte may include a first electrolyte located on a side close to the hydrogen electrode and containing the ceria-based material. The electrolyte may further include a second electrolyte located on a side close to the oxygen electrode and containing the ceria-based material. The electrolyte may further include a third electrolyte located between the first electrolyte and the second electrolyte and containing the stabilized zirconia-based material.

Abstract: A hydrogen production system that achieves a highly-efficient hydrogen production operation even when a time-varying electric power source is used is provided. A hydrogen production system includes a capacitor inputting electric power energy from a renewable power supply, and storing electric power, a pulse voltage generation unit generating a pulse voltage having a set amplitude and a set cyclic period by using the electric power stored in the capacitor, and an electrolytic cell applying the generated pulse voltage, and generating hydrogen by high temperature steam electrolysis by using steam supplied into the electrolytic cell.

Abstract: A hydrogen production system that achieves highly-efficient hydrogen production even when hydrogen is produced by using the plurality of cell stacks is provided. A hydrogen production system includes a plurality of cell stacks provided within a reaction containment, the cell stacks generating hydrogen by high temperature steam electrolysis by supplying steam to the plurality of cell stacks, a first flow path guiding the steam to each of the cell stacks, a second flow path causing a carrier gas containing air as a main component to flow into the reaction containment, and a flow regulation device provided at an inlet of the steam in each of the cell stacks, the flow regulation device regulating a flow rate of the steam caused to flow into each of the cell stacks to be uniform.

Abstract: In one embodiment, an electrical power storage system using hydrogen includes a power generation unit generating power using hydrogen and oxidant gas and an electrolysis unit electrolyzing steam. The electrical power storage system includes a hydrogen storage unit storing hydrogen generated by the electrolysis and supplying the hydrogen to the power generation unit during power generation, a high-temperature heat storage unit storing high temperature heat generated accompanying the power generation and supplying the heat to the electrolysis unit during the electrolysis, and a low-temperature heat storage unit storing low-temperature heat, which is exchanged in the high-temperature heat storage unit and generating with this heat the steam supplied to the electrolysis unit.

Abstract: A fuel electrode for a solid oxide electrochemical cell includes: an electrode layer constituted of a mixed phase including an oxide having mixed conductivity and another oxide selected from the group including an aluminum-based oxide and a magnesium-based composite oxide, said another oxide having, supported on a surface part thereof, particles of at least one member selected from nickel, cobalt, and nickel-cobalt alloys.

Abstract: A hydrogen production system that achieves highly-efficient hydrogen production even when hydrogen is produced by using the plurality of cell stacks is provided. A hydrogen production system includes a plurality of cell stacks provided within a reaction containment, the cell stacks generating hydrogen by high temperature steam electrolysis by supplying steam to the plurality of cell stacks, a first flow path guiding the steam to each of the cell stacks, a second flow path causing a carrier gas containing air as a main component to flow into the reaction containment, and a flow regulation device provided at an inlet of the steam in each of the cell stacks, the flow regulation device regulating a flow rate of the steam caused to flow into each of the cell stacks to be uniform.