CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2019-045550 filed on Mar. 13, 2019, the contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a method of, and an apparatus for producing a dummy cell provided at least at one end of a power generation cell stack body formed by stacking a plurality of power generation cells together in a stacking direction.

Description of the Related Art

In general, a solid polymer electrolyte fuel cell employs a solid polymer electrolyte membrane (hereinafter, also simply referred to as the electrolyte membrane). The solid polymer electrolyte membrane is a polymer ion exchange membrane. The fuel cell includes a membrane electrode assembly (MEA) including an anode provided on one surface of the electrolyte membrane, and a cathode provided on the other surface of the electrolyte membrane.

The membrane electrode assembly is sandwiched between separators to form a power generation cell, and a plurality of the power generation cells are stacked together to form a stack body. At both ends of the stack body in the stacking direction, components such as power collection terminal plates for collecting electric current generated in power generation by each of the power generation cells, and end plates for holding the power generation cells in the stacked state are provided to form a fuel cell stack.

In this regard, at ends of the stack body in the stacking direction (hereinafter also simply referred to as the ends), for example, heat dissipation is facilitated through the terminal plates, etc. Therefore, the ends of the stack body in the stacking direction tend to have low temperature in comparison with the central side of the stack body in the stacking direction. When the temperature at the ends of the stack body becomes low due to the influence of the outside temperature, etc., there is a concern that diffusion performance of the fuel gas and the oxygen-containing gas (reactant gases) becomes low, and the power generation stability of the fuel cell stack is degraded.

Under the circumstances, for example, in the fuel cell stack disclosed in Japanese Patent No. 4727972, so called a dummy cell is provided at least at one end of the stack body in the stacking direction. The dummy cell employs a metal plate instead of the electrolyte membrane. Therefore, no power generation is performed in the dummy cell, and thus, no water is produced in the dummy cell. Therefore, the dummy cell itself functions as a heat insulating layer between the terminal plate and the stack body. Thus, by providing the dummy cell as described above, it is possible to suppress decrease in the temperature at the ends of the stack body. That is, it is possible to suppress the influence of the outside temperature on the fuel cell stack, and improve the power generation stability.

SUMMARY OF THE INVENTION

The present invention has been made in relation to the technique of this type, and an object of the present invention is to provide a method of, and an apparatus for producing a dummy cell in which, at the time of joining a dummy resin frame member and a dummy structural body together, it is possible to effectively suppress deformation of the dummy resin frame member.

According to an aspect of the present invention, a method of producing a dummy cell provided at least at one end of a power generation cell stack body of a fuel cell stack in a stacking direction is provided. The fuel cell stack includes the power generation cell stack body including a plurality of power generation cells stacked in the stacking direction, the power generation cells each including a membrane electrode assembly including an electrolyte membrane and electrodes provided on both sides of the electrolyte membrane, the electrodes each having a gas diffusion layer of electrically conductive porous body, and a resin frame member provided around an outer periphery of the membrane electrode assembly, the method including the steps of a dummy structural body forming step of obtaining a dummy structural body corresponding to the membrane electrode assembly by stacking a plurality of electrically conductive porous bodies together, and a joining step of joining components of a dummy stack body together into a single piece of the dummy stack body, the dummy stack body being formed by stacking the dummy structural body and a dummy resin frame member provided around an outer periphery of the dummy structural body together in a state where an adhesive is interposed between the dummy structural body and the dummy resin frame member, the joining step being performed by applying heat and pressure to a portion of the dummy stack body where at least the adhesive is present, to harden the adhesive, wherein, in the joining step, in a state where a limitation projection is brought into contact with an outer peripheral end surface of the dummy resin frame member to limit outward deformation of the dummy resin frame member, heat and pressure are applied to the dummy stack body.

According to another aspect of the present invention, an apparatus for producing a dummy cell provided at least at one end of a power generation cell stack body of a fuel cell stack in a stacking direction is provided. The fuel cell stack includes the power generation cell stack body including a plurality of power generation cells stacked in the stacking direction, the power generation cells each including a membrane electrode assembly including an electrolyte membrane and electrodes provided on both sides of the electrolyte membrane, the electrodes each having a gas diffusion layer of electrically conductive porous body, and a resin frame member provided around an outer periphery of the membrane electrode assembly, the apparatus including a lower plate where a dummy stack body is placed, the dummy stack body including the dummy structural body and a dummy resin frame member stacked around an outer periphery of the dummy structural body in a state where an adhesive is interposed between the dummy structural body and the dummy resin frame member, the dummy structural body including a plurality of stacked electrically conductive bodies, a frame shaped upper plate, an outer peripheral portion of the dummy resin frame member being held between the lower plate and the upper plate, and a limitation projection configured to contact an outer peripheral end surface of the dummy resin frame member held between the lower plate and the upper plate to limit outward deformation of the dummy resin frame member, at time of applying heat and pressure to a portion of the dummy stack body where at least the adhesive is present by a heating and pressing mechanism, to harden the adhesive.

In the present invention, in the state where the limitation projection is brought into contact with the outer peripheral end surface of the dummy resin frame member to limit outward deformation of the dummy resin frame member, heat and pressure are applied to the dummy stack body. By joining the dummy resin frame member and the dummy structural body together in this manner, it is possible to obtain the dummy cell in which deformation of the dummy resin frame member is suppressed effectively.

The above and other objects features and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings in which a preferred embodiment of the present invention is shown by way of illustrative example.

