Interconnector for solid-oxide electrochemical cell stack and solid-oxide electrochemical cell stack

A solid-oxide electrochemical cell stack, comprising:

• a first electrochemical cell including a first electrode in contact with an atmosphere containing a substance having hydrogen atoms, a second electrode in contact with an atmosphere containing oxygen, and a solid-oxide electrolyte layer interposed between the first electrode and the second electrode;
• a second electrochemical cell including a first electrode in contact with an atmosphere containing a substance having hydrogen atoms, a second electrode in contact with an atmosphere containing oxygen, and a solid-oxide electrolyte layer interposed between the first electrode and the second electrode;
• and
• an interconnector disposed between the first electrode of the first electrochemical cell and the second electrode of the second electrochemical cell to be electrically connected with the first electrode and the second electrode, wherein
• the interconnector comprises a metal base containing an iron-based alloy containing chromium and a protective film provided on a surface of the metal base, and
• the protective film includes a protective film body containing at least one selected from the group consisting of a spinel oxide and a perovskite oxide, and dispersed phases scattered in the protective film body and containing yttrium oxide, wherein
• the protective film body contains at least one metallic element selected from the group consisting of Co, Ni, Mn, Cu, Fe, Cr, Zn, Al, Ti, La, and Sr, and
• the protective film contains 8 mass % or more and 16 mass % or less of the yttrium oxide in terms of yttrium.