Interconnector-electrochemical reaction unit cell composite body, electrochemical reaction cell stack, and method of manufacturing interconnector-electrochemical reaction unit cell composite body

An interconnector-electrochemical reaction unit cell composite body comprising:

• an electrochemical reaction unit cell including an electrolyte layer, and a cathode and an anode which face each other in a first direction with the electrolyte layer intervening therebetween;
• and
• an interconnector which is disposed on one side of the electrochemical reaction unit cell in the first direction,
• the interconnector-electrochemical reaction unit cell composite body being characterized in that
• the interconnector has a plurality of combinations of protrusions protruding in the first direction and recesses provided on a side opposite the protrusions in the first direction and being concave toward the protrusions;
• and
• at least one of the plurality of combinations is configured such that,
• as viewed in the first direction, a bottom of the recess is located on a side toward an open end of the recess with respect to a proximal end of the protrusion, and
• in a section parallel to the first direction, the recess is located within a range of a width t2 of the protrusion in a second direction orthogonal to the first direction, and a width t1 of the recess in the second direction is smaller than the width t2 of the protrusion, a depth h of the recess in the first direction and a distance H in the first direction between the open end of the recess and the proximal end of the protrusion satisfy a relation of 0.563≤h/H≤0.750.