Fuel cell separator member and fuel cell stack

A fuel cell stack comprising a stacked body that comprises a plurality of stack units stacked on each other, the stack units each including a membrane electrode assembly member and a separator member, wherein

• the separator member is a fuel cell separator member including a joint separator that comprises a pair of metal separators joined together, the joint separator including an outer peripheral portion provided with a positioning portion configured to position the stack units in a direction orthogonal to a separator thickness direction when the stack units are stacked on each other,
• the positioning portion is formed with a positioning hole formed by cutting out the outer peripheral portion of the joint separator so as to open toward an outside of the joint separator, and
• the positioning portion includes:
• a reinforcing rib extending linearly outside the positioning hole and protruding in the separator thickness direction from at least one of the pair of metal separators;
• and
• a joint portion located between the reinforcing rib and the positioning hole and configured to join together the pair of metal separators.

A fuel cell stack comprising a stacked body that comprises a first membrane electrode assembly member, a first separator member, a second membrane electrode assembly member, and a second separator member that are stacked in this order, wherein

• each of the first separator member and the second separator member is a fuel cell separator member including a joint separator that comprises a pair of metal separators joined together, the joint separator including an outer peripheral portion provided with a positioning portion configured to position a plurality of stack units in a direction orthogonal to a separator thickness direction when the stack units are stacked on each other, the stack units each including the joint separator and the first membrane electrode assembly member or the second membrane electrode assembly member,
• the positioning portion is formed with a positioning hole formed by cutting out the outer peripheral portion of the joint separator so as to open toward an outside of the joint separator,
• the positioning portion includes:
• a reinforcing rib extending linearly outside the positioning hole and protruding in the separator thickness direction from at least one of the pair of metal separators;
• and
• a joint portion located between the reinforcing rib and the positioning hole and configured to join together the pair of metal separators, and wherein
• a cutout portion is formed in the outer peripheral portion of the joint separator, at a position adjacent to the positioning portion so as to open toward the outside of the joint separator,
• the cutout portion is larger than the positioning hole, and
• when viewed in a stacking direction of the first membrane electrode assembly member, the first separator member, the second membrane electrode assembly member, and the second separator member, an outline of the positioning hole of the first separator member is located inside an outline of the cutout portion of the second separator member, and an outline of the positioning hole of the second separator member is located inside an outline of the cutout portion of the first separator member.