Fuel battery

Abstract

To provide a fuel battery capable of suppressing inhibition of gas supply to a power generation part.SOLUTION: In a fuel battery, the fuel battery may include at least: a pair of separators; and a resin frame, the pair of separators may include at least one manifold, the pair of separators may be adhered via the resin frame, the resin frame may include adhesive layers on both sides, and the resin frame may include: a manifold opening part corresponding to the manifold; and a power generation opening part corresponding to the power generation part. An inner diameter of the manifold opening part is smaller than an inner diameter of the manifold, and the resin frame has at least one ventilation part between the manifold opening part and the power generation opening part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to fuel cells. [Background technology]

[0002] Various technologies have been proposed regarding fuel cells such as those disclosed in Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2016-018703 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 discloses a fuel cell in which a pair of separators are fixed with an adhesive. To prevent short circuits, the manifold portion of the pair of separators is typically molded so that a resin frame, which serves as a sealing member within the cell, protrudes beyond the edges of the separators. However, because gas flows forcefully through the manifold, using an adhesive sealing member can cause the sealing member to bend, blocking the gas flow path from the manifold to the power generation section and potentially impeding the supply of gas to the power generation section.

[0005] The present disclosure has been made in consideration of the above-described circumstances, and has as its main object to provide a fuel cell that can suppress interruptions in the supply of gas to a power generation section. [Means for solving the problem]

[0006] That is, the present disclosure includes the following aspects. <1> A fuel cell, The fuel cell includes at least a pair of separators and a resin frame, The pair of separators has at least one manifold, the pair of separators are adhered via the resin frame, the resin frame has adhesive layers on both sides, the resin frame has a manifold opening corresponding to the manifold and a power generation opening corresponding to the power generation unit, an inner diameter of the manifold opening that is smaller than an inner diameter of the manifold; The resin frame has at least one ventilation portion between the manifold opening and the power generation opening.

[0007] <2> the ventilation portion is capable of ventilating gas regardless of whether the resin frame is deformed or not. <1> The fuel cell according to claim 1.

[0008] <3> the ventilation section is not able to pass gas when the resin frame is not deformed, but is able to pass gas when the resin frame is deformed. <1> The fuel cell according to claim 1.

[0009] <4> The shape of the ventilation part is at least one shape selected from the group consisting of a circular shape, a horizontally elongated shape, a diagonal shape, a vertically elongated shape, and a polygonal shape. <1> or <2> The fuel cell according to claim 1. [Effects of the Invention]

[0010] The fuel cell of the present disclosure can suppress interruptions in the supply of gas to the power generation section. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional schematic diagram showing an example of a gas inlet manifold and its periphery in a fuel cell according to the present disclosure. [Figure 2] FIG. 2 is a plan view schematically illustrating an example of a resin frame in a gas inlet section of a fuel cell according to the present disclosure. [Figure 3] FIG. 3 is a plan view schematically illustrating another example of a resin frame in a gas inlet portion of a fuel cell according to the present disclosure. [Figure 4] FIG. 4 is a plan view schematically illustrating another example of a resin frame in a gas inlet portion of a fuel cell according to the present disclosure. [Figure 5] FIG. 5 is a plan view schematically illustrating another example of a resin frame in a gas inlet portion of a fuel cell according to the present disclosure. [Figure 6] FIG. 6 is a plan view schematically illustrating another example of a resin frame in a gas inlet portion of a fuel cell according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present disclosure will be described. It should be noted that matters other than those specifically mentioned in this specification that are necessary for implementing the present disclosure (for example, the general configuration and manufacturing process of a fuel cell that do not characterize the present disclosure) can be understood as design matters for those skilled in the art based on prior art in the relevant field. The present disclosure can be implemented based on the contents disclosed in this specification and common general technical knowledge in the relevant field. Furthermore, the dimensional relationships (length, width, thickness, etc.) in the drawings do not reflect the actual dimensional relationships. In this disclosure, the gas supplied to the anode of a fuel cell is a fuel gas (anode gas), and the gas supplied to the cathode of a fuel cell is an oxidant gas (cathode gas). The fuel gas is a gas that contains mainly hydrogen and may be hydrogen. The oxidant gas is a gas that contains oxygen and may be oxygen, air, etc. In this disclosure, the fuel gas and the oxidant gas are collectively referred to as reactant gases or gases.

[0013] The present disclosure provides a fuel cell, comprising: The fuel cell includes at least a pair of separators and a resin frame, The pair of separators has at least one manifold, the pair of separators are adhered via the resin frame, the resin frame has adhesive layers on both sides, the resin frame has a manifold opening corresponding to the manifold and a power generation opening corresponding to the power generation unit, an inner diameter of the manifold opening that is smaller than an inner diameter of the manifold; The resin frame provides a fuel cell having at least one ventilation portion between the manifold opening and the power generation opening.

[0014] To ensure an adequate supply of gas to each cell, a large amount of gas flows forcefully through the manifold, which generates a force that pushes down on the resin frame. In conventional resin frames with thermoplastic heat-sealed layers on both sides, the heat-sealed layers soften when melted at high temperatures (e.g., 160°C or higher) during cell formation, but the heat-sealed layers remain hard within the operating temperature range of a fuel cell, preventing the resin frame from bending due to the force of the gas and blocking the gas flow path between the resin frame and the separator. However, in a resin frame having adhesive layers on both sides, the adhesive layers are soft in the operating temperature range of the fuel cell, so the resin frame may bend due to the flow of gas, and the gas flow path between the resin frame and the separator may be blocked.

[0015] In the present disclosure, by providing a ventilation section in part of the resin frame to prevent blockage at the gas inlet section from the manifold of the resin frame, even if the resin frame bends or bends, the ventilation section makes it possible to supply gas from the manifold to the power generation section, thereby reducing the decrease in the amount of gas supplied to the power generation section.

[0016] 1 is a cross-sectional view showing an example of a gas inlet manifold and its periphery in a fuel cell according to the present disclosure, in which F indicates the flow of gas. The fuel cell of the present disclosure includes a pair of separators 10 and a resin frame 20 having adhesive layers on both sides. A pair of separators 10 has at least one manifold 60. The manifold 60 in Fig. 1 is a gas inlet manifold. Although Fig. 1 shows an example of a gas inlet manifold, the manifold 60 of the present disclosure is not limited to a gas inlet manifold and may be a gas outlet manifold. The pair of separators 10 are adhered to each other at their sealing surfaces 40 via the resin frame 20 . The resin frame 20 has a manifold opening 21 corresponding to the manifold 60 . The resin frame 20 has a power generation opening portion (not shown) on the power generation section side 50 that corresponds to the power generation section. The inner diameter D 1 of the manifold opening 21 is smaller than the inner diameter D 2 of the manifold 60 . The resin frame 20 has at least one ventilation section 30 between the manifold opening 21 and the power generation opening on the power generation section side 50.

[0017] FIG. 2 is a plan view schematically illustrating an example of a resin frame in a gas inlet section of a fuel cell according to the present disclosure. At the gas inlet portion from the manifold 60 of the resin frame 20, a circular vent hole 31 as shown in Fig. 2 is provided in the resin frame 20. As a result, even if the resin frame 20 is pushed down in the direction of gas flow F shown in Fig. 1, the vent hole 31 ensures a gas flow path, allowing gas to be supplied from the manifold 60 to the power generation section, and reducing a decrease in the amount of gas supplied to the power generation section. The circular vent hole 31 is easy to process, can ensure a sufficient gas flow rate, is highly reliable in terms of ensuring the gas flow rate, and is highly safe in terms of preventing short circuits.

[0018] FIG. 3 is a plan view schematically illustrating another example of a resin frame in a gas inlet portion of a fuel cell according to the present disclosure. 3, the resin frame 20 may be provided with a horizontally elongated ventilation hole 31. The horizontally elongated ventilation hole 31 can ensure a sufficient gas flow rate and is highly reliable in terms of ensuring the gas flow rate.

[0019] FIG. 4 is a plan view schematically illustrating another example of a resin frame in a gas inlet portion of a fuel cell according to the present disclosure. As shown in FIG. 4, the resin frame 20 may be provided with an oblique ventilation hole 31. The oblique vent hole 31 can ensure a sufficient gas flow rate, and is highly reliable in terms of ensuring the gas flow rate. Although not shown, the resin frame 20 may be provided with a vertically elongated ventilation hole 31 .

[0020] FIG. 5 is a plan view schematically illustrating another example of a resin frame in a gas inlet portion of a fuel cell according to the present disclosure. As shown in FIG. 5, the resin frame 20 may be provided with a polygonal ventilation hole 31. The polygonal vent hole 31 can ensure a sufficient gas flow rate, is highly reliable in terms of ensuring the gas flow rate, and is highly safe in terms of preventing short circuits.

[0021] FIG. 6 is a plan view schematically illustrating another example of a resin frame in a gas inlet portion of a fuel cell according to the present disclosure. As shown in FIG. 6, the resin frame 20 may be provided with vertical slits 32. The vertical linear cuts 32 are easy to process. Although not shown, horizontal linear cuts 32 may be provided in the resin frame 20. The horizontal linear cuts 32 are easy to process and can ensure a sufficient gas flow rate. 1, the force of the resin frame 20 causing it to fall causes the slits 32 to tear, thereby ensuring a gas flow path.

[0022] The fuel cell of the present disclosure may have only one unit cell (cell) of the fuel cell, or may be a fuel cell stack, which is a cell laminate in which a plurality of cells are stacked. In this disclosure, both cells and fuel cell stacks may be referred to as fuel cells. The number of cells stacked in the fuel cell stack is not particularly limited, and may be, for example, from 2 to several hundred.

[0023] A cell of the fuel cell includes at least a pair of separators and a resin frame, and may have a power generation section.

[0024] The cell has a pair of separators. The pair of separators has at least one manifold. The manifold may be a gas inlet manifold or a gas outlet manifold. The fuel cell of the present disclosure may include a gas inlet manifold and a gas outlet manifold. The manifold may be a fuel gas manifold or an oxidant gas manifold. The fuel cell of the present disclosure may include a fuel gas manifold and an oxidant gas manifold. The fuel cell of the present disclosure may include a fuel gas inlet manifold, a fuel gas outlet manifold, an oxidant gas inlet manifold, and an oxidant gas outlet manifold. The pair of separators are adhered to each other via a resin frame. The separators collect the current generated by power generation and function as partition walls. In a fuel cell, the separators are usually arranged on both sides of the power generation section in the stacking direction so that the power generation section is sandwiched between a pair of separators. One of the pair of separators is an anode separator, and the other is a cathode separator. The anode separator may have grooves that serve as fuel gas flow paths on the surface facing the power generation section. The cathode separator may have grooves that serve as oxidant gas flow paths on the surface facing the power generation section. The separator may be made of, for example, dense carbon made by compressing carbon to make it gas impermeable, or a press-molded metal (for example, iron, aluminum, stainless steel, etc.). The separator may have holes that constitute manifolds such as supply holes and discharge holes for passing fluids such as reaction gases and coolants in the stacking direction of the cells. The refrigerant may be water, a mixed solvent of water and ethylene glycol, or the like.

[0025] The resin frame is a three-layer sheet with adhesive layers on both sides. The resin frame has a manifold opening corresponding to at least one manifold, and a power generation opening corresponding to the power generation section. The inner diameter of the manifold opening is smaller than the inner diameter of the manifold. The resin frame is an insulating resin frame that is placed on the outer periphery (periphery) of the membrane electrode assembly in the planar direction between the anode separator and the cathode separator. The resin frame is molded into a plate-like frame shape, and seals the gap between the anode separator and the cathode separator while holding the membrane electrode assembly in the power generation opening in its central region. The resin frame may be made of resin such as PE, PP, PET, or PEN. The adhesive layer may be made of, for example, a thermoplastic resin such as a polyester resin or a modified olefin resin, or a thermosetting resin such as a modified epoxy resin.

[0026] The resin frame has at least one ventilation section between the manifold opening and the power generation opening. The number of ventilation sections is not particularly limited. The area between the manifold opening and the power generation opening may be a gas inlet section or a gas outlet section. The gas inlet section is an area on the gas inlet side that supplies gas from the gas inlet manifold to the power generation section. The gas outlet section is an area on the gas outlet side that discharges gas from the power generation section to the gas outlet manifold. The ventilation portion may be capable of passing gas regardless of whether the resin frame is deformed. The ventilation portion may be a ventilation hole. The shape of the ventilation hole, which is the ventilation portion, may be at least one shape selected from the group consisting of a circular shape, a horizontally elongated shape, a diagonal shape, a vertically elongated shape, and a polygonal shape. The ventilation portion may be such that it does not allow gas to pass through when the resin frame is not deformed, but allows gas to pass through when the resin frame is deformed. The ventilation portion may be a linear slit. The linear slit may be a diagonal slit, a vertical slit, or a horizontal slit.

[0027] The power generating section may have a rectangular shape in a plan view. The power generation section may be a membrane electrode assembly (MEA) including an electrolyte membrane and two electrodes that sandwich the electrolyte membrane. The electrolyte membrane may be a solid polymer electrolyte membrane. Examples of the solid polymer electrolyte membrane include a fluorine-based electrolyte membrane such as a thin film of perfluorosulfonic acid containing water, and a hydrocarbon-based electrolyte membrane. The electrolyte membrane may be, for example, a Nafion membrane (manufactured by DuPont). The two electrodes are an anode (fuel electrode) and a cathode (oxidant electrode). The electrodes include catalyst layers and may include gas diffusion layers as needed, and the power generation section may be a membrane electrode gas diffusion layer assembly (MEGA). In this case, the cell may include a cathode separator, an anode separator, and a membrane electrode gas diffusion layer assembly disposed between the cathode separator and the anode separator. The membrane electrode gas diffusion layer assembly has, in this order, an anode gas diffusion layer, an anode catalyst layer, an electrolyte membrane, a cathode catalyst layer, and a cathode gas diffusion layer. The anode catalyst layer and the cathode catalyst layer are collectively referred to as catalyst layers. The anode side gas diffusion layer and the cathode side gas diffusion layer are collectively referred to as gas diffusion layers. The catalyst layer includes a catalyst, and the catalyst may include a catalytic metal that promotes an electrochemical reaction, an electrolyte having proton conductivity, and a carrier having electron conductivity. Examples of catalyst metals that can be used include platinum (Pt) and alloys of Pt with other metals (e.g., Pt alloys mixed with cobalt and nickel, etc.) The catalyst metal used as the cathode catalyst and the catalyst metal used as the anode catalyst may be the same or different. The electrolyte may be a fluorine-based resin, etc. As the fluorine-based resin, for example, a Nafion solution may be used. The catalytic metal is supported on a carrier, and in each catalyst layer, the carrier supporting the catalytic metal (catalyst-supported carrier) and the electrolyte may be mixed together. Examples of the carrier for supporting the catalytic metal include carbon materials such as carbon, which are generally available commercially. The gas diffusion layer (GDL) may be composed of a substrate and a mesoporous layer (MPL). The GDL may have a substrate on the side that contacts the separator and an MPL on the side that contacts the catalyst layer. The substrate may be a gas-permeable conductive member or the like. Examples of the substrate include porous carbon materials such as carbon cloth and carbon paper, and porous metal materials such as metal mesh and foam metal. The MPL may comprise a mixture of a water-repellent resin, such as PTFE, and a conductive material, such as carbon black. MPL may contain an antioxidant such as Ce, which can prevent the generation of radicals.

[0028] The fuel cell stack may have gaskets, resin sheets, etc. between the cells and between the cell stack and the end plates to seal the gases. The resin sheets may be the resin frames described above.

[0029] The fuel cell stack may include end plates disposed at the ends of the cell stack. The end plates may be disposed at one end of the cell stack in the stacking direction of the cells, or at both ends. The cell stack may be sandwiched between two end plates. The manifold may provide communication between the cell stack and the end plate. [Explanation of symbols]

[0030] 10 Separator 20 Resin frame 21 Manifold opening 30 Ventilation section 31 Ventilation hole 32 Break 40 sealing surface 50 Power generation side 60 Manifold F Gas flow D1 Inner diameter of manifold opening D2 Manifold inner diameter

Claims

1. A fuel cell, The fuel cell includes at least a pair of separators and a resin frame, The pair of separators has at least one manifold, the pair of separators are adhered via the resin frame, the resin frame has adhesive layers on both sides, the resin frame has a manifold opening corresponding to the manifold and a power generation opening corresponding to the power generation unit, an inner diameter of the manifold opening that is smaller than an inner diameter of the manifold; The resin frame has at least one ventilation portion between the manifold opening and the power generation opening.

2. 2. The fuel cell according to claim 1, wherein the ventilation portion is capable of allowing gas to pass therethrough regardless of whether the resin frame is deformed or not.

3. 2. The fuel cell according to claim 1, wherein the ventilation portion does not allow gas to pass through when the resin frame is not deformed, but allows gas to pass through when the resin frame is deformed.

4. 2. The fuel cell according to claim 1, wherein the shape of the ventilation portion is at least one shape selected from the group consisting of a circular shape, a horizontally elongated shape, a diagonal shape, a vertically elongated shape, and a polygonal shape.

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