JPS61190862A - Whole carbon component for fuel cell and its manufacture - Google Patents

Abstract

PURPOSE:To decrease contact resistance and improve sealing ability by forming an electrode for fuel cell by bonding together a porous electrode comprising carbon porous body and a separator comprising impermeable carbon with carbon adhesive. CONSTITUTION:Organic polymer is carbonized and formed in powder. The powder is sintered to form a carbon porous body. A porous electrode 1 is formed by installing ribs on both sides of the carbon porous body. Separators 2 each of which consists of impermeable carbon are bonded to the both sides of the porous electrode 1 with an organic adhesive 5 having large carbon yield after carbonization and low baking shrinkage. The organic adhesive 2 is carbonized in an inactive atmosphere to make a carbon adhesive 7, and the porous electrode 1 and the separators 2 are bonded together to form an electrode for phosphoric acid fuel cell. Thereby, contact resistance of the electrode is decreased and sealing ability is increased, and workability and power generating efficiency are improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a monolithic all-carbon fuel cell member and a method for manufacturing the same. Specifically, the present invention provides a method in which side plates made of impermeable carbon are provided on one or both sides of a separator made of impermeable carbon of a phosphoric acid electrolyte fuel cell, as required, or not provided on both end faces of the set. , a porous electrode made of a carbon porous body sintered in the form of granules and/or a porous electrode made of a porous carbon body sintered in the form of fibers is provided, and each material, that is, a separator porous electrode, is used as necessary. The present invention relates to an all-carbon fuel cell member having an integral structure in which side plates are firmly bonded via a carbon adhesive layer.

(Prior Art) Carbon products exhibit properties such as excellent corrosion resistance, heat resistance, and excellent electron conductivity at low cost. Therefore, it has been used as an electrode and separator for phosphoric acid electrolyte fuel cells. For example, for porous carbon electrodes for fuel cells, short carbon fibers are made into prepreg using a binder such as furan resin or thermosetting resin such as phenol resin.

However, it is known that it can be obtained by subjecting it to a back-element treatment after shaping, and then cutting if necessary. On the other hand, the carbon separator is a flat plate of carbon type impermeable to the electrolyte, fuel gas, and air, or a plate with ribs on one or both sides. To assemble these electrodes and separators into a battery, a catalyst such as platinum is supported on one side of the electrode, and the separator, fuel electrode, electrolyte, oxygen electrode, and separator are assembled into one
A method is used in which tens to hundreds of units are connected in series. At this time, in order to reduce the contact resistance of the electrode and separator as much as possible and reduce the loss due to contact resistance at the contact part, it is necessary to make the surfaces of both the electrode and separator as smooth as possible. In order to reduce the contact resistance between the separator and the separator, the entire unit must be mechanically clamped.

Therefore, the smoothness of the contact portion between the electrode and the separator is required to be extremely precise. However, carbon is a brittle material that lacks flexibility, so if there are slight irregularities on the contact surface between the electrode and separator or the pressing force is not applied uniformly, the electrode or separator may may be damaged. In order to reduce the battery's internal resistance and produce greater output, the electrodes and separators must be evenly pressed into tight contact, which is extremely technically difficult. In addition, the porous electrode made from the short fibers of carbon fiber is made into a bleep rig using a resin binder, and in the process of carbonization treatment, the carbon fiber has a smooth surface with low surface energy. This is caused by insufficient adhesion of the resin binder, concentration of internal stress due to volumetric shrinkage during carbonization of the resin binder, difference in thermal expansion coefficient during the temperature rising or cooling process during carbonization between the carbon fiber and the resin binder, etc. It has the disadvantage of low structural strength due to microcracks.

Therefore, it is well known that there are problems such as part of the carbon fibers coming apart during cutting after firing, battery assembly work, or pressing, and electrodes being easily damaged. Another disadvantage is that the electrode itself is expensive because the carbon fiber itself is expensive.

In order to overcome the above-mentioned drawbacks, the inventors of the present application have prepared an electrode molded body made of a coarse-structured carbon body and a separator molded body made of a dense-structured carbon body in a green state or a carbon precursor state, after carbonization. We have proposed a method for manufacturing fuel cell members consisting of a carbonaceous monolithic structure, which consists of bonding using an organic liquid composition with a high carbon residue yield and then performing an adhesive treatment (Japanese Patent Application No. 126-189-1989). . According to additional tests conducted by the inventors of the present invention, it was possible to integrate the separator and the electrode using this method, but the separator, which is a dense structure, and the electrode part, which is a coarse structure, were left in a green state or a carbon precursor was used. Since the bonding process is performed in the oxidized state, internal stress concentration occurs during the subsequent firing process due to differences in firing shrinkage rates and thermal expansion coefficients, which has the disadvantage of easily causing cranks and warping. , each side is 200III11
In the case of components used in small batteries of the following size, the disadvantages should be covered by selecting suitable raw materials for separators and electrodes, adjusting the degree of carbon precursor treatment, and considering the material of adhesive raw materials. It is possible, but
Large batteries, particularly members larger than 600 mm, have a problem in that it is difficult to finish them with desirable dimensional accuracy.

On the other hand, fuel cells, especially phosphoric acid electrolyte fuel cells, use pure hydrogen or hydrogen gas obtained by reforming LNG as fuel, and use oxygen in the air as an oxidizing agent. It is necessary to prevent the two from mixing outside the reaction area. Therefore, it is necessary to completely seal the end face of the electrode in the direction perpendicular to the gas passage, and there is a need for a sealing material that is excellent in phosphoric acid corrosion resistance under high temperatures, but a satisfactory sealing material has not yet been obtained. Another sealing method is to impregnate both ends of the electrode perpendicular to the gas passage with phosphoric acid and use a phosphoric acid liquid seal. In order to achieve this, it is necessary to design the electrode so that its pore distribution differs between the central part where the electrode reaction occurs and the end part, which has the disadvantage of increasing the cost of the electrode itself. The scattering of phosphoric acid due to battery operation also remains an unavoidable problem, and there is also the drawback that liquid sealing properties tend to deteriorate over time due to long-term operation.

(Problems to be Solved by the Invention) An object of the present invention is to provide electrodes and separators for fuel cells, particularly phosphoric acid electrolyte fuel cells, by connecting electrodes made of a carbon porous material with high structural strength to separators via a carbon adhesive layer. By firmly adhering a part of the separator and molding it into an integral part, there is no need for a pressing process to reduce contact resistance when assembling the battery.Furthermore, carbon adhesion of the electrode part and part of the separator completely eliminates contact resistance. In addition to dramatically improving electronic conductivity and greatly increasing the power generation efficiency of fuel cells, the seals on the electrodes were also made complete by carbon bonding using the same method, greatly contributing to the stable power generation of fuel cells. By providing a component for an all-carbon fuel cell with an integrated structure that contributes greatly to the service life of a battery system, and a method for manufacturing the component accurately, easily, and at low cost. be.

(Means for Solving the Problems) In order to achieve the above object, the inventors of the present application have conducted further intensive research and found that the surface layer of organic polymer particles is dissolved to cause spot adhesion between the particles. By forming a porous body and then carbonizing it, a porous electrode consisting essentially of a granularly sintered carbon porous body is obtained, or an organic polymer fiber having the property of solid phase carbonization, or after an insoluble and infusible treatment. Paper, cloth, or felt obtained by processing one or more types of organic fibers that have the property of carbonizing while maintaining the fiber shape into paper, woven fabric, or felt can be used as is, origami, glued, or pressed. Alternatively, a porous electrode made of a carbon porous body sintered into a fiber shape is obtained by shaping it by sewing and carbonizing the obtained shaped body, and one or two of these porous electrodes are Example of sealing a porous electrode made of permeable carbon. An organic adhesive with a high yield of carbon residue after carbonization and low shrinkage upon firing is applied to one or both sides of a separator made of impermeable carbon, with or without the addition of a plate. It was discovered that an all-carbonaceous fuel cell member having an integral structure can be obtained by adhering the organic adhesive using an organic adhesive and then carbonizing the organic adhesive in an inert atmosphere, and the present invention was achieved based on this discovery.

A method for producing an integral molded product of a carbon electrode for a fuel cell and a carbon separator and an integral molded product including a seal portion according to the present invention will be specifically described.

First, a porous electrode made of a porous carbon material is formed.

First, the surface layer of organic polymer particles is melted to create point adhesion between the particles to form an organic polymer porous body, which is then carbonized and basically consists of a carbon porous body sintered into granules. A method for forming a porous electrode will be explained.

In order to obtain the granularly sintered carbon porous material used as the porous electrode in the present invention, first, organic polymer particles are scattered on a flat plate or in a mold, and then melted by heating, dissolving with a solvent, or both. is used to soften the particles, causing point adhesion between the particle surfaces and forming a porous organic polymer. Next, if necessary, the organic polymer porous body is subjected to a carbon precursor treatment and carbonized by gradually raising the temperature in an inert atmosphere, thereby obtaining a carbon porous body. The carbon porous material obtained in this way is sintered into granules with the skeleton of the organic polymer porous material maintaining its shape, so it has excellent dimensional accuracy, high mechanical strength, and the structure of the raw resin particles. By adjusting the particle size, a product with a pre-designed pore size and porosity can be obtained.

The organic polymer particles used in the present invention must first be softened to form point adhesion between the particle surfaces and form an organic polymer porous body, and secondly required to be effectively carbonized by firing. It is a condition. Such organic polymer particles include particles of thermoplastic resins such as vinyl chloride resin, chlorinated vinyl chloride resin, polyacrylonitrile resin, polyvinyl alcohol, polyphenylene ether, polyamideimide, and polydivinylbenzene, furan resin, and phenol resin. , thermosetting resin monomers such as bismaleimide triazine resins, or initial condensates are cured to the extent that they can be thermally deformed before being completely three-dimensionally crosslinked, using a crusher, ball mill, etc. crushed particles,
Natural polymer particles having a condensed polycyclic aromatic group in the basic molecular structure such as gum tragacanth, gum arabic, and saccharides, as well as formalin condensates of naphthalene sulfonic acid, indanthrene dyes, and their intermediates, which are not included in the above. Synthetic polymer particles that have condensed polycyclic aromatics in the basic structure of the molecule, stone asphalt, coal tar pitch, and carbonized pitch of synthetic resin sugar are treated at 300 to 500°C, and low-molecular compounds are removed using a solvent. One or more types are selected as appropriate from among the particles obtained by pulverizing the particles.

Preferably, vinyl chloride resin, chlorinated vinyl chloride resin,
By selecting one or more particles of chlorine-containing vinyl resin such as vinylidene chloride resin, it is possible to easily mold the organic polymer porous body, simplify the carbon precursor treatment, and improve the carbon porous body obtained after carbonization. Good results can be obtained in terms of mechanical strength and superior quality as a plant foam material. More preferably, among the chlorine-containing vinyl resins, the degree of polymerization is 50.
By selecting one or more particles of chlorinated vinyl chloride resin with a degree of chlorination of 60 to 71% by weight, which is obtained by post-chlorinating a vinyl chloride resin of 0 to 2000,
Better results are obtained.

The organic polymer particles referred to in the present invention do not include particles that are insoluble and infusible and do not weld to each other, such as particles obtained by pulverizing completely cured thermosetting resins such as furan resins and phenol resins. do not have. In addition, for materials such as polyethylene, acrylic resin, polyoxymethylene, etc., for which carbon precursor treatment cannot be effectively performed and the carbon yield after carbonization is less than 5%, carbon porous materials that can be used after carbonization are used. Since carbon is not obtained or leaves no carbon at all, it is not included in the polymer particles referred to in the present invention.

In order to increase the pore size and porosity of the carbon porous material, it is preferable to use raw material particles with a large particle size, and conversely, to decrease the pore size and porosity, it is preferable to use particles with a small particle size. In addition, making the pore size uniform can be achieved by classifying the organic polymer particles in advance using a vibrating sieve, blower, etc. to make the particle size uniform; conversely, making the pore size non-uniform It is better to use particles with a large particle size distribution.

Next, in the present invention, a process for manufacturing a granular sintered carbon porous body used as a porous electrode will be specifically explained.

First, organic polymer particles are scattered on a flat plate or inside a mold,
A porous organic polymer is obtained by melting the surface layer of the particles and causing point adhesion between the particles. In order to scatter organic polymer particles on a flat plate or in a mold, in addition to depositing them by gravity or building a particle layer by powder coating, it is also possible to increase the mechanical strength of the carbon porous material or reduce the porosity. If necessary, vibration or pressure may be applied, or both may be applied for the purpose of

Next, while being spread on a flat plate or in a mold, it is heated using a heating opener or the like to form a continuous porous organic polymer. The heating temperature is at least higher than the softening point and lower than the melting point of the organic polymer particles used, and is adjusted so that the organic polymer particles soften and point adhesion occurs between their surface layers. If the temperature is too low, the fluidity due to softening will be too small and point adhesion will not occur, and if the temperature is too high, the fluidity due to softening will be too large and the pores of the generated organic polymer porous material may be closed. Furthermore, a drawback arises in that the pores themselves disappear. In order to make an organic polymer porous body from organic polymer particles using a solvent, first, a solvent that is soluble in the organic polymer particles is applied to the organic polymer particles, but the amount is preferably 10% or less, although it depends on the degree of solubility. is added in an amount of 5% by weight or less, and the particle surfaces are uniformly wetted using a high-speed mixer such as a Henschel mixer. A mixture is then spread onto a flat plate or into a mold using the same method. It is sufficient to add only the amount of solvent necessary to dissolve only the surface layer of the organic polymer particles and form a continuous porous organic polymer. This is not preferable because the degree of softening of the molecular particles becomes too large, which causes the pores of the organic polymer porous material to close or even disappear. Thereafter, after leaving it as it is, or performing heating and/or pressurizing operations as necessary to form a continuous porosity solvent-containing organic polymer porous body, drying it by vacuum drying, heating drying, or leaving it naturally. The organic polymer porous material is obtained by volatilizing the solvent from the porous material.

Next, if necessary, the organic polymer porous material obtained by any of the above methods is subjected to a carbon precursor treatment. There are methods such as heating to ℃, immersing in strong acid such as concentrated sulfuric acid, and irradiating with radiation. In the present invention, the organic polymer porous material prepared by the above method was used in such a way that the carbon porous material as designed in advance could be obtained by the carbonization treatment in the next step while maintaining the pore state as it was. A carbon precursor treatment method should be selected that is appropriate to the properties of the organic polymer particles. The method of carbon precursor treatment is not particularly limited, and the carbon precursor treatment may be omitted. Next, the organic polymer porous material subjected to carbon precursor treatment or not subjected to carbon precursor treatment is gradually heated from room temperature in an inert atmosphere such as nitrogen or argon to 700°C or higher, preferably 1000°C. Carbonize by heating above ℃. There is no upper limit to the firing temperature, and for the purpose of improving thermal shock resistance or achieving high purity, it may be heated to 2000° C. or higher, and up to 3000° C. if necessary. The obtained porous carbon material is cooled and taken out.

Second, one or more types of organic polymer fibers that have the property of solid phase carbonization, or organic fibers that have the property of carbonizing while maintaining the fiber shape after insoluble and infusible treatment, are used to make paper, woven fabric, or felt. A porous carbon material obtained by sintering paper, cloth, or felt into a fiber shape, which is obtained by shaping the paper, cloth, or felt as it is or by origami, glue layering, pressing, sewing, etc., and carbonizing the obtained shape. A method for forming a porous electrode obtained from the following will be explained.

In the present invention, in order to obtain a sintered carbon porous body used as a porous electrode, basically fibers of organic substances that follow solid phase carbonization or crosslinking by air oxidation, or acid treatment with concentrated sulfuric acid etc. Fibers that undergo a dehydrogenation reaction and the subsequent carbonization path follows solid-phase carbonization are used as raw materials and are directly shaped into designed complex irregular shapes, or are processed into papermaking, woven fabrics, and felt. First, paper, cloth, and felt are obtained through processing, and then this is processed into origami.
A primary molded body of a desired product is obtained by shaping it into a pre-designed shape by means such as glue layer processing, press processing, sewing processing, etc.

Next, if the organic polymer fiber aggregate used in this primary compact basically undergoes solid phase carbonization, it may be transferred to the next step as it is, but during carbonization. If insoluble and infusible treatment is required, after sufficiently carrying out the crosslinking reaction by air oxidation or the dehydrogenation reaction by acid treatment (referred to as carbon precursor treatment) required at this stage,
Use as a primary molded body.

Basically, organic polymer fibers that undergo solid phase carbonization are selected from pulp, cellulose derivatives, cotton, novoloid (phenolic) fibers, aramid (aromatic polyamide) fibers, polyamide-imide fibers, etc., and are made insoluble and infusible. The organic fibers that require treatment are selected from polyacrylonitrile, polyvinyl chloride, chlorinated vinyl chloride, polyvinyl alcohol, and the like.

In the present invention, a fibrous sintered carbon porous electrode that exhibits sufficient mechanical strength can be obtained even if the primary molded body is fired as is. For the purpose of adjusting the pore size, if necessary, immersion treatment is performed in a liquid organic material that leaves a relatively high carbon residue after firing.
It is preferable to perform a coating treatment or an impregnation treatment by vacuum or pressure using an autoclave or the like.

Organic materials for impregnation include thermosetting resins such as phenol resins, furan resins, polyimide resins, polyamideimide resins, and aromatic polyamide resins, or their initial condensates;
Or polyvinyl chloride, chlorinated vinyl chloride, chlorinated rubber,
It is best to select from thermoplastic resins such as vinylidene chloride, pitch, tar, and lignin. The viscosity of the organic material is preferably 50 to 5000 cps, and in the case of a thermosetting resin, a curing agent may be added during the impregnation treatment, or the organic material may be dissolved in a solvent. In this case, after the impregnation treatment, a step of drying to an absolutely dry state is added.

The primary molded body, or the secondary molded body that has been subjected to impregnation treatment as necessary, is then gradually heated from room temperature to 700°C or higher in an inert atmosphere such as nitrogen or argon. Preferably, carbonization is performed by heating to 1000° C. or higher. There is no upper limit to the firing temperature, and for the purpose of improving thermal shock resistance or achieving high purity, it may be heated to 2000° C. or higher, and up to about 3000° C. if necessary. The obtained porous carbon material is cooled and taken out.

Porous electrodes used in fuel cells usually take the form of a flat electrode shown at 2 in FIG. 1 or a ribbed electrode shown at 4 in FIG. 2. In the case of flat electrodes, both the granular sintered carbon porous material and the fibrous sintered porous carbon material are obtained by molding using a flat mold, but in the case of ribbed electrodes, the ribbed porous material is molded during molding. Either using a mold or molding into a flat plate, the green state after molding,
Although ribs may be formed by cutting after the carbon precursor treatment or after firing, the means for forming the ribs is not particularly limited in the present invention.

Next, a separator made of impermeable carbon and a side plate to be used as necessary are formed.The gas permeability of impermeable carbon is 10-' x 10-'c+s''/5e
c (Ile, ΔP = 1 atm) The following values are required, but in order to manufacture the separator and side plates, coke powder is molded under high pressure using a binder such as pitch using a rubber press method, and then fired. 1 in Figure 1. The ribbed separator shown in Figure 2, the flat plate separator shown in Figure 2, 3, or the side plate shape shown in Figure 3, 6, can be obtained by processing, but it is impermeable, mechanically strong, and economical. Preferably, a thermosetting resin monomer, one or more initial condensates, and one or more chlorine-containing vinyl resins are used as a binder.
Further, mechanical energy is applied to the blended composition containing the carbon fine powder, and the kneaded product is mixed using a casting method, injection method, injection molding method, or roll molding method to form the above-mentioned ribbed separator, flat plate separator, etc. It is formed into a side plate shape, subjected to carbon precursor treatment if necessary, and gradually heated from room temperature to 700°C in an inert atmosphere such as nitrogen or argon.
As mentioned above, it is preferable to use a material that has been carbonized by heating to 1000° C. or higher. More preferably, the thermosetting resin is a furan resin or a phenolic resin,
More preferable results can be obtained by using scaly graphite with a particle size of 20 μm or less as the fine carbon powder, or by using a chlorinated vinyl chloride resin as the chlorinated vinyl resin added as needed.

Next, the porous electrode, the impermeable separator, and the impermeable side plate obtained by the above operation are removed as shown in FIGS. The bonding operation is performed using an organic adhesive that has a high shrinkage rate and a low firing shrinkage rate. In the next step, the carbonization step of the organic adhesive, the electrodes, separators and side plates are
In order for the carbonized carbon adhesive layer of the organic adhesive to firmly adhere to each other and form an integral structure, the carbon residue yield of the organic adhesive should be 30% by weight or more, preferably 50% by weight.
or more, and the firing shrinkage rate is 30% or less, preferably 1
5% or less is good.

Adhesives having such properties include natural resins such as gum arabic, gum tragacanth, glue, vinyl chloride resin, chlorinated vinyl chloride resin, chlorinated rubber, polyacrylonitrile,
Synthetic resins such as polyvinyl alcohol, bismaleimide/triazine resin, polyimide resin, epoxy resin, furan resin, phenol resin, coal tar pitch, petroleum-
Pitch such as border, carbonized pinch, soluble sugars such as glucose, sucrose, lactose, etc., using one or more selected from these, and if these do not exhibit a liquid state at room temperature, they may be in a heatable molten state, It is preferable to use it in a solution state using a solvent, or as a monomer or an initial condensate in the case of a thermosetting resin. Preferably, increasing carbon residue yield;
For the purpose of reducing the firing shrinkage rate, fine-grained carbon powder with an average particle size of 100 μm or less, preferably 20 μm or less, is used.
It is good to use a mixture of 15 to 80% by weight, preferably 15 to 80% by weight, but more preferably, after adding and mixing fine grain carbon powder, uniformly disperse it with a mixer etc., and then mix it with two rolls, Three rolls, ball mill, pressure kneader
Using a Banbury mixer or the like, mechanical energy such as shearing force is applied to induce a mechanochemical phenomenon, and a composition in which an organic substance is physicochemically bonded to the surface of the primary particles of fine carbon powder is bonded. Good to use as a medicine.

More preferably, as the organic substance to be physicochemically bonded to the surface of the primary particles of the fine carbon powder, monomers of thermosetting resins such as furan resin, phenol resin, bismaleimide/triazine resin, polyimide resin, and epoxy resin,
Alternatively, by selecting one or more types of initial condensates, a carbon adhesive layer with stronger adhesive strength can be obtained after carbonization, resulting in strong adhesion between the porous electrode, the separator, and the side plate provided as necessary. It is possible to ensure sex.

The adhesive is applied by brushing, spraying, or by once forming the adhesive into a film, placing it between the adherends, and melting it by heating (hot melt method). After the adherends are pasted together, the adhesive is dried, three-dimensionally crosslinked, or cooled to solidify and complete the adhesion to form an integral molded object.

This is then combined with air oxidation, ozone oxidation,
Carbon precursor treatment such as strong acid treatment is performed, and the temperature is raised from room temperature to 700°C in an inert atmosphere such as nitrogen or argon gas.
As described above, the adhesive is preferably heated to a temperature of 1000° C. or higher to carbonize the adhesive, and after cooling, the adhesive is taken out and used as a product.

There is no upper limit to the firing temperature, and the thinner the coating thickness of the organic adhesive layer, the higher the firing temperature can be.
The temperature may be raised from room temperature to about 100'O<0>C in hours. The upper limit temperature for firing is also 3000°C, if necessary.
The temperature may be raised to a certain degree.

(Example) Next, the present invention will be explained in more detail with reference to Examples.

Note that the present invention is not limited to these embodiments, and can be freely modified within the scope of the technical idea of the present invention.

Forging team - The first molded product, which is a flat cardboard with a thickness of 1.5 mm, was made from polyimide resin using a conventional method! tJ11?
15 of f combination (Kelimide 1050 manufactured by Mitsui Petrochemicals)
%N-methyl and lolidone solution, and after thorough impregnation, remove excess impregnating liquid, dry to volatilize the solvent, and further heat-treat for 60 minutes in an air path at 120°C for impregnation. The resulting kelimide was cured to form a secondary molded body. Next, this was heated for 50 minutes in a nitrogen gas atmosphere.
20℃/hour up to 0℃, 50℃ from 500 to 1000℃
/ hour to carbonize it, and after cooling, take it out to form a flat plate, which is an aggregate of fibrous carbon reinforced by a carbon binder made of carbonized polyimide resin, as shown in 2 in Figure 1. A shaped carbon porous electrode was obtained. The obtained electrode had a thickness of 1.2 mm, a bulk specific gravity of 0.85, and high mechanical strength of 40 MPa in bending strength and 150 MPa in compressive strength.

Next, 60% by weight of a modified phenolic resin initial condensate (FR-16475 manufactured by Sumitomo Bakelite ■) and natural scaly graphite (
Nippon Graphite Industries ■ part average particle size 7μ-CSP) 20% by weight,
After uniformly mixing 15% by weight of pitch (MS manufactured by Kureha Chemical Industry Co., Ltd.) and furfuryl alcohol 5 resin with a Henschel mixer and kneading with a rotating ball mill, kneaded product 1 was obtained.
00 parts by weight of hardening agent (HP-44 manufactured by Sumitomo Bakelite)
)097 parts by weight were added, stirred and defoamed, and then a shaped body with ribs on both sides was obtained by a solid casting method.

Next, the obtained excipient was subjected to carbon precursor treatment in an air path at 120°C for 4 hours, and then heated at 25°C/hour from room temperature to 600°C, and from 600 to 1000°C in a nitrogen gas atmosphere.
was carbonized by raising the temperature at 50° C./hour, and after cooling, it was taken out to obtain a double-sided ribbed separator as shown in 1 in FIG. The obtained separator has a gas permeability of 1.9
It exhibited a high impermeability of 10-cm 7 seconds and a high bending strength of 180 MPa.

Next, 65% by weight of furan resin initial condensate (Promine-1-Q100I manufactured by Narita Pharmaceutical Co., Ltd.) and 35% by weight of natural scaly graphite (Nippon Graphite Co., Ltd. part average particle diameter 5 μm C3P-E)
After stirring and mixing, the furan resin initial clamping material was kneaded using a heated three-roll roll until the furan resin initial clamp was physicochemically bonded to the graphite surface by a mechanochemical phenomenon. ■Made by Prominate Q2001
) was added to obtain a paste-like adhesive.

This adhesive was applied to the convex parts on both sides of the double-sided ribbed separator prepared earlier to a thickness of 0.2 mm using a roller, and the flat carbon porous electrodes prepared earlier were attached to both sides of the separator. Ta. Then, 1
After holding for 0 hours to solidify the adhesive, the temperature was raised from room temperature to 1000°C in 5 hours in a nitrogen gas atmosphere, and after cooling, the integrally structured fuel cell member product shown in Figure 4 was taken out. . The electrical resistance of the obtained product was found to be 40% lower than that of a unit in which the electrode and separator were compressed into the same shape as shown in FIG. 4 under a pressure of 10 MPa using the conventional method. In addition, in the adhesive failure test, all the failure points were in the porous electrode, and no interfacial failure phenomenon was observed. In addition, a 0.2 mm thick film of the adhesive used was formed,
When cured and fired separately under the same conditions, the residual aroma of the coal was 7.
5% by weight, and the firing shrinkage rate was 8%, whereas the same formulation that omitted the kneading with three heated rolls had a small coal residue of 65% and a high firing shrinkage rate of 11%.
In an adhesive failure test under the same conditions after bonding and carbonizing the electrode and the separator, 90% of the cases were interfacial failures and 10% of the cases were failures in the porous electrode portion.

Great Arashi History - 1 Particles of chlorinated vinyl chloride resin powder (Nikatenbu T-742 manufactured by Nippon Carbide) with a degree of chlorination of 65% by weight, which is obtained by post-chlorination of vinyl chloride resin with a degree of polymerization of 700, are ground in a ball mill for 24 hours. Pour into the attached mold and heat to 220℃ for 15 minutes.
The mixture was heated for a minute to obtain a ribbed organic polymer porous body. This is heated in a nitrogen gas atmosphere at 10°C/hour from room temperature to 300°C, 30°C/hour from 300 to 500°C, and 500 to 10
The temperature was raised to 00° C. at a rate of 50° C./hour to carbonize, and after cooling, the electrode was taken out to obtain a granular sintered ribbed carbon porous electrode shown in 4 in FIG. The total thickness of the obtained electrode is 20+u
+, rib height is 1.5 ++u++, bulk specific gravity is 0.
90, bending strength 35MPa, compressive strength 170MPa
It had a high mechanical strength of a.

Next, 50% by weight of furan resin initial fasteners (Prominate Q2001, manufactured by Takeda Pharmaceutical Co., Ltd.), 30% by weight of chlorinated vinyl chloride resin powder (Nikatemp T-742, manufactured by Nippon Carbide), and natural scaly graphite (Nippon Graphite Co., Ltd. Average particle size 7μr
a A mixture of 20% by weight of C3P) was kneaded with a mixing roll and formed into a sheet using a calendar roll.
After heating at 180°C in an air path for 24 hours and performing carbon precursor treatment, the temperature can be raised at a rate of 10°C/hour from room temperature to 500°C and at a rate of 50°C/hour from 500 to 1000°C. Carbonize it, take it out after cooling, and proceed to step 3 in Figure 2.
A flat plate separator having a thickness of 0.5 mm as shown in FIG. The gas permeability of the obtained separator was 8.5
It exhibited a high impermeability of xlO-"c+*" of 7 seconds, and a high bending strength of 220 MPa.

Next, the same adhesive as in Example 1 was applied to both sides of the flat plate separator prepared earlier to a thickness of 0.2 m using a roller, and the ribbed surface of the ribbed carbon porous electrode was applied to both sides of the flat separator prepared earlier. was attached to both sides of the separator.

Thereafter, the adhesive was solidified and carbonized under the same conditions as in Example 1 to obtain an integrally structured fuel cell member product as shown in FIG. The electrical resistance value of the obtained product was found to be 40% lower than that of a unit in which the electrode and separator were pressed into the same shape as shown in FIG. 5 at a pressure of 10 MPa using the conventional method. In addition, in the adhesive failure test, all the failure points were in the porous electrode, and no interfacial failure phenomenon was observed.

Large Breath ■-1 Both sides parallel to the ribs of the ribbed carbon porous electrode of Example 2 were cut as shown in 4 in FIG.

Next, using the compound for solid cast molding used in Example 1, it was molded into a rectangular parallelepiped shape by the same solid cast molding method, and subjected to carbon precursor treatment and carbonization treatment under the same conditions as Example 1. to a thickness of 2.0 ms as shown in 6 in Figure 3.
+ impermeable side panels were obtained. Next, as shown in FIG. 3, the adhesive of Example 1 was applied with a roller to a thickness of 0.2 cm on one side of the flat separator of Example 2 and the surfaces of the two side plates that would contact the electrodes. Coat the electrode, side plate,
Separators were bonded to each other. Thereafter, the adhesive was solidified and carbonized under the same conditions as in Example 1 to obtain a fuel cell member having an integral structure as shown in FIG. 6. One of the end faces perpendicular to the ribs of the product was sealed with a sealing material, and air was blown from the opposite direction. top surface)
There was no leakage from the side plate or the adhesive surface between the side plate and the separator, and the seal on the side plate was perfect.

(Effects of the Invention) As shown in the examples, the integrally structured fuel cell member produced by the method of the present invention uses a carbon porous body with high structural strength as a porous electrode, and also uses carbon as a separator. Because it is firmly bonded via an adhesive layer,
This eliminates the need for a clamping process to reduce contact resistance when assembling into a battery, dramatically increasing the power generation efficiency of fuel cells. In addition, the electrode parts are completely sealed by carbon bonding using the same method, greatly contributing to the stability and safety of power generation and greatly increasing the service life of the battery system. These useful quality improvements can be achieved with good precision.
It can be said that the present invention is extremely useful and beneficial as a simple and inexpensive manufacturing method.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing how single cells of a ribbed separator type fuel cell are bonded together using an organic adhesive. FIG. 2 is a schematic diagram when a single cell of a ribbed electrode type fuel cell is bonded using an organic adhesive. FIG. 3 is a schematic diagram when one electrode with side plate ribs is bonded to a separator using an organic adhesive. FIG. 4, FIG. 5, and FIG. 6 are schematic diagrams of the monolithic molded product after the carbonization treatment shown in FIGS. 1, 2, and 3, respectively. In the figure, 1 is a ribbed separator, 2 is a flat plate electrode, 3 is a flat plate separator, 4 is a ribbed electrode, 5 is an organic adhesive, 6 is a side plate, and 7 is an adhesive carbon.

Claims (1)

[Claims] 1. An all-carbon material characterized in that a porous electrode made of a porous carbon material and a separator made of impermeable carbon are integrally bonded via a carbonaceous adhesive. Fuel cell parts. 2. The all-carbon fuel cell member according to item 1, in which a side plate made of impermeable carbon is integrally bonded for sealing the porous electrode. 3. A porous electrode consisting of a carbon porous body basically sintered into granules by melting the surface layer of organic polymer particles to create point adhesion between the particles to form a porous organic polymer and then carbonizing it. paper, woven fabric or felt using one or more types of organic polymer fibers that have the property of obtaining carbon or solid phase carbonization, or organic fibers that have the property of carbonizing while maintaining the fiber shape after insoluble and infusible treatment. Paper, cloth or felt obtained by processing can be used as is or origami,
A porous electrode made of a carbon porous body sintered into a fiber shape is obtained by shaping the shaped body by gluing, pressing or sewing, and carbonizing the obtained shaped body, and then forming one or two of these porous electrodes. The sheet is applied to one or both sides of a separator made of impermeable carbon with or without adding a side plate for sealing the porous electrode made of impermeable carbon. 1. A method for producing all-carbon fuel cell components, which comprises bonding using a small organic adhesive and then carbonizing the organic adhesive in an inert atmosphere. 4. The method for producing an all-carbon fuel cell member according to item 2, wherein the organic adhesive is one or more selected from natural or synthetic resins, pitches, and soluble sugars. 5. The organic adhesive is made by blending fine carbon powder with one or more selected from natural or synthetic resins, pitches, and soluble sugars, uniformly dispersing the mixture, and applying mechanical energy to induce a mechanochemical phenomenon. 2. The method for producing an all-carbon fuel cell member according to item 2, characterized in that the composition is a composition in which an organic substance is physicochemically bonded to the surface of the primary particles of fine carbon powder by inducing the organic substance.