A buffer layer between an interconnect and an electrolyte of a solid oxide fuel cell, the buffer layer having a gradient in coefficient of thermal expansion (CTE), wherein the buffer layer minimizes electrolyte damage due to a difference in CTE between the interconnect and electrolyte.

A buffer layer between an interconnect and an electrolyte of a solid oxide fuel cell, the buffer layer having a gradient in coefficient of thermal expansion (CTE), wherein the buffer layer minimizes electrolyte damage due to a difference in CTE between the interconnect and electrolyte.

Improved contact between interconnect and oxygen electrode material in solid oxide cell (SOC) stacks is achieved through a contact point between the oxygen electrode or an oxygen-side contact layer of the SOC and a coated ferritic stainless steel interconnect in the SOC stack, where the coating on the metallic interconnect comprises Cu.

Improved contact between interconnect and oxygen electrode material in solid oxide cell (SOC) stacks is achieved through a contact point between the oxygen electrode or an oxygen-side contact layer of the SOC and a coated ferritic stainless steel interconnect in the SOC stack, where the coating on the metallic interconnect comprises Cu.

An alloy member includes a base member constituted by an alloy material containing chromium, a chromium oxide layer for covering at least a portion of a surface of the base member, a pore that is formed in an interface region of the base member that is located 30 μm or less from an interface between the chromium oxide layer and the base member, and an extending portion extending from the pore into the base member. The pore is configured to inhibit the separation of the chromium oxide layer from the base member The extending portion contains an oxide of an element whose equilibrium oxygen pressure is lower than that of a major element of the base member.

A bipolar plate includes a substrate and a coating film that is formed at least on a part of a surface of the substrate. The coating film includes a phosphide having a composition represented by M.sub.2−xTi.sub.xP, where M is any one or more elements selected from the group consisting of Ni, Co, Fe, Mn and Cr, and 0.1≤x≤1.9. The coating film preferably includes two kinds or more of the metal elements M, and preferably has a thickness ranging from 0.05 μm or greater to 100 μm or less.

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.

Layers for a bipolar plates are disclosed, as well as bipolar plates including the layers and fuel cells and/or electrolyzers including the bipolar plates. The layer may include a homogeneous or heterogeneous solid metallic solution or compound which either contains a first chemical element from the group of the noble metals in the form of iridium; or contains a first chemical element from the group of the noble metals in the form of iridium and a second chemical element from the group of the noble metals in the form of ruthenium. The layer may also include at least one further nonmetallic chemical element from the group consisting of nitrogen, carbon, boron, fluorine, and hydrogen.

Layers for a bipolar plates are disclosed, as well as bipolar plates including the layers and fuel cells and/or electrolyzers including the bipolar plates. The layer may include a homogeneous or heterogeneous solid metallic solution or compound which either contains a first chemical element from the group of the noble metals in the form of iridium; or contains a first chemical element from the group of the noble metals in the form of iridium and a second chemical element from the group of the noble metals in the form of ruthenium. The layer may also include at least one further nonmetallic chemical element from the group consisting of nitrogen, carbon, boron, fluorine, and hydrogen.

An electrochemical device includes an electrolyte membrane, an anode disposed on a first main surface of the electrolyte membrane, a cathode disposed on a second main surface of the electrolyte membrane, an anode separator disposed on the anode, and a cathode separator disposed on the cathode. At least one of the anode separator or the cathode separator includes a metal substrate sheet and a conductive layer disposed on the metal substrate sheet and containing a metal oxide and a metal hydroxide.