JP2001236982A - End plate for fuel cell and fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light and well-productive end plate and a light fuel cell using the same. SOLUTION: The end plate for the fuel cell is formed of a resin material having a compression strength of 100 MPa or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin end plate for pressing and fixing a cell stack when assembling a fuel cell, and a fuel cell using the same.

[0002]

2. Description of the Related Art A fuel cell using hydrogen gas and oxygen gas or air as a reaction gas is a stack of a plurality of unit cells each composed of a solid electrolyte membrane and a separator, and these cell stacks are pressurized and fixed from both sides. End plates are used for this.

Since the reaction gas flows through the cell stack to form a pressurized system, it is necessary to firmly fix the end plate with bolts or the like. For this reason, high strength is required for the end plate, and usually a metal is used.

[0004]

However, the metal end plate is heavy. For this reason, a fuel cell manufactured using a metal end plate is heavy, and hinders transportation and installation. Further, in the case of metal, there is a problem that cutting is required, and productivity is low.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art, that is, to provide a fuel cell end plate having high productivity because it can be reduced in weight and easily formed. And a fuel cell using the end plate.

[0006]

The end plate for a fuel cell according to the present invention mainly has the following construction. That is, the fuel cell end plate is made of a resin material having a compressive strength of 100 MPa or more.

[0007] The fuel cell of the present invention mainly has the following configuration. That is, a fuel cell using the fuel cell end plate.

[0008]

DETAILED DESCRIPTION OF THE INVENTION The resin used for the fuel cell end plate of the present invention has a compressive strength of 100 MPa.
Or more, preferably 200 MPa or more, more preferably 3 MPa or more.
It is 00 MPa or more. If the compressive strength is less than 100 MPa, the unit cells in the cell stack are sufficiently adhered to each other so that internal contact electric resistance is sufficiently reduced. . Alternatively, even if the internal contact electric resistance is small at the beginning of tightening, if left as it is, the tightening is loosened and the internal contact resistance increases. In the present invention, the compressive strength refers to a compressive strength measured according to ASTM D695.

The resin materials usable in the present invention include epoxy resins, unsaturated polyester resins, phenol resins,
Thermosetting resins such as urea resin, melamine resin, thermosetting polyurethane resin, thermosetting silicone resin, thermosetting polyimide resin, polyethylene, polypropylene,
Ethylene / α-olefin copolymer, poly (4-methyl-1-pentene), polyvinyl chloride, polyvinylidene chloride, ABS (acrylonitrile-butadiene-styrene), AS (acrylonitrile-styrene), aliphatic polyketone, polystyrene, Polymethyl methacrylate,
Polyvinyl alcohol, polyvinyl acetate, nylon 6,
Nylon 66, Nylon 12, Nylon 11, other nylon resin, PBT, PET, other polyester resin, modified polyphenylene ether, polycarbonate, polyacetal, PPS, polyarylene sulfide, liquid crystal polyester, polysulfone, polyether sulfone, polyetherimide, Although thermoplastic resins such as polyether ketone and polyether ether ketone can be used, thermoplastic resins are preferred from the viewpoint of moldability and productivity, and particularly nylon 6, nylon 66, PBT, PET, modified polyphenylene ether, polycarbonate, Polyacetal, PPS, polyarylene sulfide, liquid crystal polyester, polysulfone, polyethersulfone, polyetherimide, polyetherketone, and polyetheretherketone are preferred.

It is preferable that these resin materials contain a reinforcing filler from the viewpoint of improving strength. As the reinforcing filler, glass fiber, carbon fiber, potassium whisker, zinc oxide whisker, aluminum borate whisker, aramid fiber, alumina fiber, silicon carbide fiber, ceramic fiber,
Fibrous filler such as asbestos fiber, masonry fiber, metal fiber, silicate, alumina, oxidized silicate such as walasteinite, zeolite, sericite, kaolin, mica, clay, pyrophyllite, bentonite, asbestos, talc, alumina silicate Metal compounds such as silicon, magnesium oxide, zirconium oxide, titanium oxide and iron oxide; carbonates such as calcium carbonate, magnesium carbonate and dolomite; sulfates such as calcium sulfate and barium sulfate; magnesium hydroxide; calcium hydroxide; Hydroxides such as aluminum, glass beads, glass flakes,
Non-fibrous fillers such as ceramic beads, boron nitride, silicon carbide and silica. These reinforcing fillers may be solid or hollow, and two or more of these reinforcing fillers may be used in combination. The form of the reinforcing filler may be a cloth, a nonwoven fabric, a roving cloth, or the like. Among these reinforcing fillers, glass fibers are particularly preferred.

It is not possible to use these fibrous / non-fibrous reinforcing fillers after pretreatment with a coupling agent such as an isocyanate compound, an organic silane compound, an organic titanate compound, an organic borane compound, or an epoxy compound. ,
It is preferable from the viewpoint of obtaining more excellent mechanical strength.

Further, the resin used for the end plate of the present invention includes a nucleating agent such as talc, kaolin, an organic phosphorus compound, polyetheretherketone, a coloring inhibitor such as hypophosphite, a hindered phenol, Antioxidants such as hindered amines, heat stabilizers, lubricants, UV inhibitors, coloring agents such as dyes and pigments, and additives such as antistatic agents can be added as necessary within a range not to impair the purpose of the present invention. it can.

The method for producing the end plate of the present invention is not particularly limited, such as injection molding, injection compression molding, extrusion molding, and cutting of an extruded square plate. In addition, injection molding or injection compression molding may be performed by cutting.

Although the shape of the end plate of the present invention is usually a square plate shape as shown in FIG. 1A, as long as it functions, a disk, a cross shape as shown in FIG. It can be a type. From the viewpoint of making the tightening force uniform, it is preferable that the square plate has a shape in which four corners are cut.

Since the fuel cell of the present invention uses the above-described end plate for a fuel cell, the fuel cell can be reduced in weight and can be easily molded, so that the productivity is high. FIG. 1 shows an example of the fuel cell of the present invention. Where A
Is a rectangular plate-shaped resin end plate, B is a fastening bolt, and C is a cell stack. FIG. 2 shows another example of the fuel cell of the present invention. Here, A indicates a cross-shaped resin end plate, B indicates a fastening bolt, and C indicates a cell stack.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on embodiments. Reference Example 1 A fuel cell having the shape shown in FIG. 1 was produced using an end plate made of duralumin (specific gravity 2.70). When the internal contact electric resistance was measured, it was 0.55 mΩ. Also, there was no change in the internal electric resistance value even when left for half a day. Example 1 A fuel cell having the shape shown in FIG. 1 was manufactured using an end plate manufactured using an epoxy resin (specific gravity: 1.85, compressive strength: 385 MPa) reinforced with glass cloth. Even if the bolt was tightened until the internal contact electric resistance showed 0.55 mΩ, no cracking, bending or bending occurred. Also, there was no change in the internal electric resistance value even when left for half a day. Example 2 A fuel cell having a shape as shown in FIG. 1 was produced using an end plate produced using a phenol resin (specific gravity: 1.87, compressive strength: 345 MPa) reinforced with glass cloth. 0.55m internal contact electric resistance
Even if the bolt was tightened to Ω, no cracking, breakage, or bending occurred. Also, there was no change in the internal electric resistance value even when left for half a day. Example 3 A fuel cell having a shape as shown in FIG. 1 was manufactured using an end plate manufactured using nylon 66 resin (specific gravity: 1.37, compressive strength: 210 MPa) containing 30% by weight of glass fiber. . Even if the bolt was tightened until the internal contact electric resistance showed 0.55 mΩ, no cracking, bending or bending occurred. Also, there was no change in the internal electric resistance value even when left for half a day. Example 4 A fuel cell having the shape shown in FIG. 1 was produced using an end plate produced using a PBT resin containing 30% by weight of glass fiber (specific gravity: 1.52, compressive strength: 118 MPa). 0.55 internal contact electrical resistance
Even if the bolt was tightened to a value of mΩ, no cracking, breakage, or bending occurred. Also, there was no change in the internal electric resistance value even when left for half a day. Example 5 A fuel cell having a shape as shown in FIG. 1 was manufactured using an end plate manufactured using a PPS resin (specific gravity: 1.67, compressive strength: 182 MPa) containing 40% by weight of glass fibers. 0.55 internal contact electrical resistance
Even if the bolt was tightened to a value of mΩ, no cracking, breakage, or bending occurred. Also, there was no change in the internal electric resistance value even when left for half a day. Example 6 Using an end plate manufactured using a PPS resin (specific gravity: 1.96, compressive strength: 191 MPa) containing 45% by weight of glass fiber and 20% by weight of calcium carbonate, a shape as shown in FIG. 1 was used. A fuel cell was manufactured. Even if the bolt was tightened until the internal contact electric resistance showed 0.55 mΩ, no cracking, bending or bending occurred. Also, there was no change in the internal electric resistance value even when left for half a day. Example 7 Using an end plate made of a PPS resin (specific gravity 1.56, compressive strength 177 MPa) containing 40% by weight of glass fiber and 9% by weight of a polyolefin elastomer, a shape as shown in FIG. Was manufactured. Even if the bolt was tightened until the internal contact electric resistance showed 0.55 mΩ, no cracking, bending or bending occurred. Also, there was no change in the internal electric resistance value even when left for half a day. Example 8 Using an end plate made of a PPS resin (specific gravity: 1.96, compressive strength: 191 MPa) containing 45% by weight of glass fiber and 20% by weight of calcium carbonate, a shape as shown in FIG. 2 was used. A fuel cell was manufactured. Even if the bolt was tightened until the internal contact electric resistance showed 0.55 mΩ, no cracking, bending or bending occurred. Also, there was no change in the internal electric resistance value even when left for half a day. Comparative Example 1 A fuel cell having the shape shown in FIG. 1 was manufactured using an end plate manufactured using nylon 66 resin (specific gravity: 1.13, compressive strength: 82 MPa). Even if the bolts were tightened until the internal contact electric resistance showed 0.55 mΩ, the electric resistance exceeded 0.55 mΩ when left for half a day. Comparative Example 2 A fuel cell having the shape shown in FIG. 1 was manufactured using an end plate manufactured using polypropylene (specific gravity: 1.23, compressive strength: 65 MPa) containing 40% by weight of glass fibers. Internal contact electric resistance is 0.5
Even if the bolt was tightened to 5 mΩ, the electric resistance exceeded 0.55 mΩ when left for half a day.

[0017]

By using the end plate of the present invention, a fuel cell which is lighter in weight than a conventional fuel cell using a metal end plate can be manufactured. Also,
Since the resin end plate is easily formed, the productivity has been improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a fuel cell using a resin end plate of the present invention.

FIG. 2 is a perspective view showing another example of a fuel cell using the resin end plate of the present invention.

[Explanation of symbols]

 A: Resin end plate B: Tightening bolt C: Cell stack

Claims (5)

[Claims] 1. An end plate for a fuel cell comprising a resin material having a compressive strength of 100 MPa or more. 2. The method according to claim 1, wherein the resin material is a thermoplastic resin.
The end plate for a fuel cell according to the above. 3. The fuel cell end plate according to claim 1, wherein the resin material is a thermoplastic resin containing a reinforcing filler. 4. The method according to claim 3, wherein the reinforcing filler is glass fiber.
The end plate for a fuel cell according to the above. 5. A fuel cell using the fuel cell end plate according to claim 1.