Abstract: Realized is an element having an electrolyte layer that is dense and has high gas barrier characteristics. A metal-supported electrochemical element includes at least a metal substrate as a support, an electrode layer formed on/over the metal substrate, a buffer layer formed on the electrode layer, and an electrolyte layer formed on the buffer layer. The electrode layer is porous and the electrolyte layer is dense. The buffer layer has density higher than density of the electrode layer and lower than density of the electrolyte layer.

Abstract: Realized is an element having an electrolyte layer that is dense and has high gas barrier characteristics. A metal-supported electrochemical element includes at least a metal substrate as a support, an electrode layer formed on/over the metal substrate, a buffer layer formed on the electrode layer, and an electrolyte layer formed on the buffer layer. The electrode layer is porous and the electrolyte layer is dense. The buffer layer has density higher than density of the electrode layer and lower than density of the electrolyte layer.

Abstract: An electrochemical element (Q) has a metal substrate (1) and multiple electrochemical reaction portions. The metal substrate (1) has gas flow allowing regions that allow the flowing of a gas between the upper side (4) and the lower side (5) of the metal substrate (1). The electrochemical reaction portions each have at least an electrode layer (A), an electrolyte layer (B), and a counter electrode layer (C), and are arranged on the upper side (4) of the metal substrate (1). The electrolyte layer (B) is arranged between the electrode layer (A) and the counter electrode layer (C), and the gas flowing through the gas flow allowing regions is supplied to the electrode layer (A).

Abstract: A gas alarm device is provided, where a heating control section extends a heating period of time of a heater section if a first determination section determines that electrical characteristics of a sensing section of a gas sensor satisfy a first condition, and continues extension of the heating period of time of the heater section according to a determination result, by a second determination section, of whether or not the electrical characteristics upon lapse of extension of the heating period of time satisfy a second condition, and a gas detection section determines, according to the electrical characteristics upon lapse of extension time, that detection target gas is detected.

Abstract: Provided is a low-cost electrochemical element that has excellent reliability and durability. A substrate with an electrode layer for a metal-supported electrochemical element includes a metal support and an electrode layer formed on/over the metal support, and the electrode layer has a region with a surface roughness of 1.0 ?m or less.

Abstract: A metal plate configured such that sufficient strength and performance are ensured and the workability and cost of mass production are improved, and a metal-supported electrochemical element and the like including the metal plate. Also, a method for manufacturing a metal plate including a rolling step for rolling a metal material provided with a penetration space passing through the metal material in a thickness direction to reduce the thickness of the metal material and reduce the area of a surface opening formed in the surface of the metal material by the penetration space, thereby producing a plate-like metal plate.

Abstract: Provided are a low-cost electrochemical device and the like that have both durability and high performance as well as excellent reliability. The electrochemical device includes at least one metal material, and the metal material is made of a Fe—Cr alloy that contains Ti in an amount of more than 0.10 mass % and 1.0 mass % or less.

Abstract: A metal support for an electrochemical element has a plate shape as a whole, and is provided with a plurality of penetration spaces that pass through the metal support from a front face to a back face. The front face is a face to be provided with an electrode layer. Each of front-side openings that are openings of the penetration spaces formed in the front face has an area of 3.0×10?4 mm2 or more and 3.0×10?3 mm2 or less.

Abstract: A metal plate is formed by stacking a plurality of thin metal plates. The thin metal plates are respectively provided with a plurality of through holes passing therethrough in the thickness direction. The metal plate is provided with penetration spaces 1c formed by the through holes of the plurality of thin metal plates that are in communication with each other in a state in which thin metal plates are stacked. A metal plate aspect ratio that is a value obtained by dividing the thickness of each of the thin metal plates by the inner diameter of the through holes is 2 or less. A metal support aspect ratio that is a value obtained by dividing the overall thickness of the metal plate by the minimum inner diameter of the penetration spaces is 3 or more.

Abstract: A metal support for an electrochemical element has a plate shape as a whole, and is provided with a plurality of penetration spaces 1c that pass through the metal support from a front face 1a to a back face. The front face 1a is a face to be provided with an electrode layer. A region of the front face 1a provided with the penetration spaces is a hole region, and openings of the penetration spaces formed in the front face are front-side openings. An aperture ratio that is a ratio of the front-side openings to the hole region is 0.1% or more and 7.0% or less.

Abstract: An electrochemical element including a conductive plate-like support provided with an internal passage therein. The plate-like support includes, in at least a portion of a metal support included in the plate-like support: a gas-permeable portion through which gas is permeable between the internal passage, which is located inside the plate-like support, and the outside; and an electrochemical reaction portion that entirely or partially covers the gas-permeable portion and includes at least a film-like electrode layer, a film-like electrolyte layer, and a film-like counter electrode layer in the stated order. The plate-like support is provided with a plurality of passages in the internal passage.

Abstract: An electrochemical element stack that includes a plurality of stacked electrochemical elements, each of the electrochemical elements including a plate-like support provided with an internal passage. The plate-like support includes: a gas-permeable portion through which gas passes between the internal passage located inside the plate-like support and the outside; an electrochemical reaction portion covering the gas-permeable portion; and a first penetrated portion forming a supply passage through which fuel gas flows from the outside of the plate-like support to the internal passage.

Abstract: Provided is a low-cost electrochemical element that includes a high-performance electrode layer. The electrochemical element includes an electrode layer, and the electrode layer contains small particles and large particles. The small particles have a particle diameter of 200 nm or less in the electrode layer, and the large particles have a particle diameter of 500 nm or more in the electrode layer.

Abstract: Realized is an element having an electrolyte layer that is dense and has high gas barrier characteristics. A metal-supported electrochemical element includes at least a metal substrate as a support, an electrode layer formed on/over the metal substrate, a buffer layer formed on the electrode layer, and an electrolyte layer formed on the buffer layer. The electrode layer is porous and the electrolyte layer is dense. The buffer layer has density higher than density of the electrode layer and lower than density of the electrolyte layer.

Abstract: A gas alarm for detecting a target gas based on a resistance value of a sensor element comprises a measuring unit to measure a characteristic value of the sensor element, a heating control unit to control a heater to perform a heating process to heat the sensor element, a determining unit to determine, based on the characteristic value, whether the sensor element is in a blunt state in which sensitivity of the sensor element is decreased, and an aborting control unit to abort the heating process to determine whether the sensor element is in the blunt state when a characteristic value of the sensor element measured by the measuring unit after beginning of the heating process by the heating control unit meets a predetermined condition.

Abstract: Realized is an element having an electrolyte layer that is dense and has high gas barrier characteristics. A metal-supported electrochemical element includes at least a metal substrate as a support, an electrode layer formed on/over the metal substrate, a buffer layer formed on the electrode layer, and an electrolyte layer formed on the buffer layer. The electrode layer is porous and the electrolyte layer is dense. The buffer layer has density higher than density of the electrode layer and lower than density of the electrolyte layer.

Abstract: Realized is an element having an electrolyte layer that is dense and has high gas barrier characteristics. A metal-supported electrochemical element includes at least a metal substrate as a support, an electrode layer formed on/over the metal substrate, a buffer layer formed on the electrode layer, and an electrolyte layer formed on the buffer layer. The electrode layer is porous and the electrolyte layer is dense. The buffer layer has density higher than density of the electrode layer and lower than density of the electrolyte layer.

Abstract: Provided is an alloy material including a metal oxide thin layer that can be formed using a simple method at low cost and can further suppress volatilization of Cr, which causes deterioration of a fuel cell, compared with a case where conventional expensive materials are used. Disclosed is a manufacturing method for an alloy material including a coating treatment step for coating a substrate made of a Fe—Cr based alloy with Co, and an oxidation treatment step for performing oxidation treatment on the substrate in a moisture-containing atmosphere after the coating treatment step.

Abstract: Provided are an electrochemical element and the like that have both durability and high performance as well as excellent reliability. The electrochemical element includes a metal support, and an electrode layer formed on/over the metal support. The metal support is made of any one of a Fe—Cr based alloy that contains Ti in an amount of 0.15 mass % or more and 1.0 mass % or less, a Fe—Cr based alloy that contains Zr in an amount of 0.15 mass % or more and 1.0 mass % or less, and a Fe—Cr based alloy that contains Ti and Zr, a total content of Ti and Zr being 0.15 mass % or more and 1.0 mass % or less.

Abstract: Provided is a low-cost electrochemical element that has excellent performance, reliability, and durability. Also, provided is a manufacturing method for an electrochemical element including a metal substrate (metal support) and an electrode layer formed on/over the metal substrate. The method includes an electrode layer forming step of forming an electrode layer having a region with a surface roughness of 1.0 ?m or less on/over the metal substrate, and an electrolyte layer forming step of forming an electrolyte layer by spraying aerosolized metal oxide powder onto the electrode layer.