Solid polymer fuel cell
It is an object of the present invention to provide a means for integrating an MEA and a pair of separators and regulate their positions without using parts that are specifically dedicated for position regulation use. More specifically, the present invention provides a polymer electrolyte fuel cell including a frame-integrated MEA, a separator having a channel for supplying and releasing a fuel gas, and a separator having a channel for supplying and releasing an oxidizer gas, and, in this fuel cell, the frame body of the frame-integrated MEA has a plurality of projections having a hook-shaped tip on both planes of the frame body and each separators has a plurality of stepped parts, and the projections on the frame body and the stepped parts on the pair of separators are integrated by fitting together with each other.
1. A polymer electrolyte fuel cell comprising:
a frame-integrated membrane electrode assembly including a frame body in which a gas channel opening is formed, a polymer electrolyte membrane provided inside the frame body, a pair of electrodes sandwiching the polymer electrolyte membrane, and a sealant enclosing the gas channel opening and the electrodes;
a separator having a channel for supplying and releasing a fuel gas to and from one of the pair of electrodes; and
a separator having a channel for supplying and releasing an oxidizer gas to and from the other one of the pair of electrodes, wherein:
the frame body has a plurality of projections having a hook-shaped tip on both planes of the frame body and each separator has a plurality of stepped parts; and
the projections of the frame body and the stepped parts of the pair of separators are integrated by fitting together with each other.
2. The fuel cell according to claim 1 , wherein the projections are located in the vicinity of the gas channel opening.
3. The fuel cell according to claim 1 , wherein the hook-shaped part at the tip of the projection is oriented inward of the frame body.
4. The fuel cell according to claim 1 , wherein:
a pressure of the fuel gas and a pressure of the oxidizer gas flowing through the channel of each of the separators are different; and
the plurality of projections having a hook-shaped tip formed on a plane of the frame body facing the separator where a gas of a higher pressure flows, are placed further inside the frame than the plurality of projections having a hook-shaped tip formed on a plane of the frame body facing the separator where a gas of a lower pressure flows.
5. A polymer electrolyte fuel cell stack including two or more stacked fuel cells, in which each fuel cell comprising:
a frame-integrated membrane electrode assembly including a frame body in which a gas channel opening is formed, a polymer electrolyte membrane provided inside the frame body, a pair of electrodes sandwiching the polymer electrolyte membrane, and a sealant enclosing the gas channel opening and the electrodes;
a separator having a channel for supplying and releasing a fuel gas to and from one of the pair of electrodes; and
a separator having a channel for supplying and releasing an oxidizer gas to and from the other one of the pair of electrodes, wherein:
the frame body has a plurality of projections having a hook-shaped tip on both planes of the frame body and each separator has a plurality of stepped parts; and
the projections of the frame body and the stepped parts of the pair of separators are integrated by fitting together with each other.
6. The fuel cell stack according to claim 5 , wherein:
the fuel cell stack includes a fuel cell A and a fuel cell B stacked neighboring each other;
each of the frame bodies of the fuel cell A and the fuel cell B has a plurality of second projections having a hook-shaped tip and separators of the fuel cell B has a plurality of second stepped parts; and
the second projections on the frame body of the fuel cell A and the second stepped parts of the fuel cell B are integrated by fitting together with each other.
7. The fuel cell stack according to claim 5 , wherein:
the fuel cell stack includes a fuel cell A and a fuel cell B stacked neighboring each other;
each of the frame bodies of the fuel cell A and fuel cell B has a plurality of second projections and a plurality of notches, said projections and notches being arranged alternately; and
the second projections and notches of fuel cell A fit together with the second projections and notches of fuel cell B.