Solid oxide fuel cell including electrode containing dense bonding portions and porous non-bonding portions

A solid oxide fuel cell comprising:

• a fuel electrode that is in contact with a fuel gas to react the fuel gas;
• a solid electrolyte film bonded to the fuel electrode;
• an air electrode that reacts a gas containing oxygen, and that is bonded to the solid electrolyte film in order that the solid electrolyte film is sandwiched between the fuel electrode and the air electrode;
• and
• a conductive current-collecting member that is bonded to one of the air electrode and the fuel electrode so as to be electrically connected thereto, wherein
• a surface of the one electrode excluding a bonding surface with the solid electrolyte film includes one or plural bonding portions bonded to the current-collecting member, and one or plural non-bonding portions not bonded to the current-collecting member, and
• the one electrode includes a first portion that includes the one or plural bonding portions, and that extends continuously from the one or plural bonding portions, and a second portion that is a remaining portion other than the first portion and includes the one or plural non-bonding portions, wherein
• a porosity of the first portion is smaller than a porosity of the second portion, and the one electrode is a sintered body of a ceramic, and
• wherein the one electrode has a plate-like shape;
• the solid electrolyte film is bonded to a first major surface of the one electrode, the first major surface being the bonding surface with the solid electrolyte film;
• the one or plural bonding portions and the one or plural non-bonding portions are present on a second major surface, that is opposite to the first major surface, of the one electrode, the second major surface being the surface of the one electrode excluding the bonding surface with the solid electrolyte film;
• the first portion extends from the one or plural bonding portions to a position in the middle of the thickness of the one electrode;
• and
• the first major surface is composed of only the second portion, while the second major surface is composed of the first portion and the second portion.