JP4773737B2 - Polar liquid supplier for fuel cell, method for producing the same, and fuel cell - Google Patents

Description

  The present invention relates to a polar liquid supply body for a fuel cell comprising an open cell body having an affinity surface for a polar liquid, particularly methanol or an aqueous methanol solution, and a method for producing the same. More specifically, the present invention relates to a polar liquid supplier for a fuel cell comprising an open-cell body in which a compound imparting a hydrophilic group is grafted to at least a part of the pore surface of the open-cell body comprising a hydrophobic polymer, And a manufacturing method thereof. The present invention also relates to a fuel cell using the polar liquid supplier.

  Mobile devices such as notebook PCs, electronic notebooks, and cellular phones require increasingly high-performance batteries due to the adoption of high-performance processors and increased functions such as video processing. For this reason, ordinary secondary batteries such as lithium-ion batteries do not satisfy the characteristics for enabling enhancement of functions and long-time driving of mobile devices.

  On the other hand, the fuel cell has a weight energy density (electric capacity per unit weight) that is about 10 times larger than that of a lithium ion battery. Coupled with being a clean energy source, the use of fuel cells in such devices has become a challenge.

  A fuel cell supplies fuel to the negative electrode and supplies a substance that oxidizes the fuel to the positive electrode, and converts the free energy of the chemical reaction into electric energy. A hydrogen-oxygen fuel cell, a hydrocarbon fuel cell, a hydrazine fuel cell Various fuel cells have been put to practical use or are approaching practical use. However, since explosive substances such as hydrogen and hydrazine are used, and especially hydrogen requires a high-pressure vessel, technical considerations for ensuring safety are necessary to disseminate it for general consumer use. is there. For example, instead of storing hydrogen supplied to the negative electrode as fuel, natural gas, propane, naphtha, methanol, or the like is stored and converted into hydrogen by a reformer and used (Non-Patent Document 1). 158-164).

  Since the fuel cell using methanol uses a relatively safe methanol or an aqueous solution thereof as a hydrogen source, there is no need for a high-pressure vessel, which is advantageous in terms of safety. Development of a direct methanol fuel cell that uses methanol as a direct fuel without converting it to hydrogen is also underway, and since a reformer is not used, it is more advantageous in terms of miniaturization, weight reduction, and safety ( Non-Patent Documents 1, pages 210 to 217; Non-Patent Document 2, pages 129 to 131).

  When a pump is used to supply methanol or an aqueous solution thereof from a methanol container to a reformer or a cell, it becomes a heavy burden for a device that needs to be reduced in size and weight, such as a mobile device.

  In order to supply methanol or an aqueous solution thereof, it is conceivable to use the capillary action of an open-cell shaped body. However, polyurethane foam has polar groups such as urethane bonds, and due to its affinity with polar liquids such as methanol or its aqueous solution, the foam swells and the dimensional stability such as pore diameter is poor, It cannot be put to practical use. On the other hand, an open-cell body made of a hydrophobic polymer such as polyolefin or polydiolefin has a hydrophobic pore surface and therefore has a poor affinity with a polar liquid, so that a sufficient sucking and supplying speed cannot be obtained. Further, when the surface of the pores is treated with a surfactant, the supply rate of a polar liquid such as methanol or an aqueous solution thereof increases, but the polar liquid passing therethrough is contaminated with the surfactant, and the carried surfactant is used as an electrode. When it reaches, the electric conduction is disturbed.

  Therefore, it is required to obtain a polar liquid supply body that can pass a polar liquid through pores without causing a dimensional change due to swelling, using an open cell body made of the above hydrophobic polymer.

Modification by grafting vinyl compounds or allyl compounds, especially hydrophilic compounds mentioned above, to nonpolar polymers such as polyolefins, or fibers such as woven or non-woven fabrics by irradiating them with an electron beam. Are known (Patent Documents 1 and 2). Further, it has been disclosed that acrylic acid is graft-polymerized to a crosslinked polyolefin open-cell body to make it hydrophilic and blended with soil to improve its water retention (Patent Document 3). However, it is not known that such a grafting reaction is applied to a fine open-cell body and does not swell and is used as a polar liquid supplier for a fuel cell.
Japanese Patent Application Laid-Open No. 07-279052 JP 2002-371471 A Japanese Patent Laid-Open No. 06-030656 Published by Hironosuke Ikeda, "All about fuel cells", published by Nihon Jitsugyo Publishing Co., Ltd., 2001 The Institute of Electrical Engineers, Fuel Cell Drivability Research Committee, “Fuel Cell Power Generation” Corona, 1994

  Therefore, an object of the present invention is to provide a polar liquid such as methanol or an aqueous solution thereof, instead of using a pump, in which there is no contamination of the supplied polar liquid, and it is an advantageous method for reducing the size and weight of the device. It is to provide a polar liquid supply body for a fuel cell that supplies a polar liquid. Moreover, another subject of this invention is providing the manufacturing method of the polar liquid supply body for fuel cells. Another object of the present invention is to provide a fuel cell that uses such a polar liquid supplier and is reduced in size and weight.

  As a result of repeated studies to achieve the above-mentioned problems, the present inventors have advantageously used the capillary action of the pores of the open cell body, and the pore surface of the open cell body of the hydrophobic polymer is advantageous. The inventors have found that the above problems can be achieved by grafting to give a hydrophilic surface and using this as a polar liquid supplier for a fuel cell, thereby completing the present invention.

  That is, the present invention provides a grafted continuous surface having a polar liquid-affinity pore surface in which a compound that gives a hydrophilic group to the pore surface is grafted to at least a part of the pore surface of an open-celled body made of a hydrophobic polymer. The present invention relates to a polar liquid supply body for a fuel cell comprising a bubble body. The present invention also includes a step of irradiating an open cell body of a hydrophobic polymer with an electron beam, and a compound that imparts a hydrophilic group to the pore surface or a solution thereof is present in the pores during or after the step. The present invention relates to a method for producing the open cell body for a fuel cell. Furthermore, the present invention provides a fuel cell using a polar liquid such as methanol or an aqueous solution thereof as a hydrogen source or fuel, wherein the polar liquid is supplied to the reformer or the fuel electrode via the polar liquid supply body. To a fuel cell.

  The open cell body used as the polar liquid supply body of the present invention may be any open cell body such as soft, semi-rigid, and hard, and is appropriately selected according to the purpose, for example, the type and shape of the fuel cell.

  The base polymer constituting the open cell body is a hydrophobic polymer that does not swell due to the polar liquid. Examples of the hydrophobic polymer include polyolefin resins such as polyethylene, polypropylene, ethylene-α-butene copolymer, and ethylene-higher alkylene copolymer obtained by various polymerization methods; polydiolefin resins such as polybutadiene resin. Copolymer and polymer blends; hydrocarbon rubbers such as EPR, EPDM, polybutadiene rubber, SBR, polyisoprene rubber, IIR; styrene-butadiene-styrene block copolymer, styrene-ethylene butene-styrene Hydrocarbons such as block copolymers, styrene-isoprene-styrene block copolymers, styrene-ethylene / propylene-styrene block copolymers, 1,2-polybutadiene, polypropylene-EPDM blends, and partially crosslinked products thereof Hydrocarbon polymer, such as thermoplastic elastomers. Furthermore, polyesters such as PET and PBT can also be mentioned as hydrophobic polymers. Of these, polyolefin is preferred because it is flexible, has no additive that decomposes upon irradiation, and is easy to recycle, and a polar liquid supplier having excellent polar liquid absorbability and dimensional stability can be easily obtained. Therefore, high-density polyethylene is particularly preferable.

  As a compound that imparts a hydrophilic group to the pore surface used as a grafting agent, a vinyl compound and an allyl compound each having a hydrophilic group, and a grafting reaction followed by a reaction such as a hydrolysis reaction. Mention may be made of vinyl compounds and allyl compounds which can be produced. Acrylic compounds such as acrylic acid, hydroxyethyl acrylate, hydroxypropyl acrylate, acrylamide, N- (hydroxymethyl) acrylamide, sodium acrylate, potassium acrylate as vinyl compounds and allyl compounds having hydrophilic groups themselves Corresponding methacrylic compounds; and other hydrophilic vinyl compounds such as ethylene glycol monovinyl ether, diethylene glycol monovinyl ether, N-methyl-N-vinylformamide, N-methyl-N-vinylacetamide, N-vinylpyrrolidone And the hydrophilic allyl compounds corresponding to these; Examples of the vinyl compound and allyl compound capable of generating a hydrophilic group include glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, and vinyl acetate. Of these compounds giving a hydrophilic group, acrylic acid, acrylamide, glycidyl methacrylate and the like are preferable because they are easy to handle, and can be selected from the target water absorption rate and other properties.

  Since the grafting is performed for the purpose of giving a hydrophilic group to the pore surface, the side chain generated by the grafting reaction (graft chain) does not necessarily need to be a polymer chain obtained by addition polymerization of the monomer. Can be selected in accordance with the properties of the intended polar liquid supplier, from those produced by reacting with the base polymer to polymer chains. In the present invention, a graft polymer and a grafted open cell are defined as a polymer having such a graft chain and an open cell. Further, a graft chain may be formed using a grafting agent having a hydrophilic polymer chain such as polyethylene glycol monovinyl ether.

The degree of grafting of the graft polymer is indicated by the graft ratio according to the following definition from the weight increase due to the grafting reaction.
G (% by weight) = [(w−w ₀ ) / w ₀ ] × 100
(In the formula, G represents the graft ratio, w ₀ represents the weight before the grafting reaction, and w represents the weight after the grafting reaction.)

  In the present invention, the graft ratio of the grafted open cell used as the polar liquid supply body depends on the type of hydrophobic polymer, the type of grafting agent, the type of polar liquid to be supplied, and the properties of the target polar liquid supply body. It is selected together. Since the foam is not swollen by the polar liquid and a sufficient supply rate can be obtained, the graft ratio is preferably in the range of 5 to 100% by weight, more preferably 20 to 90% by weight, and more preferably 50 to 80% by weight. Particularly preferred.

  The average pore diameter of the polar liquid supply body based on the hydrophobic polymer is preferably in the range of 1 to 200 μm from the supply speed of the polar liquid. The smaller the average pore diameter, the higher the supply speed. 10 to 120 μm is more preferable because it has a sufficient polar liquid supply rate and is easy to produce. However, when it is necessary to discharge the carbon dioxide gas generated from the fuel electrode or reformer through the polar liquid supply body on the structure of the fuel cell, the supply speed of the polar liquid may be reduced. The average pore diameter of the polar liquid supplier is more preferably in the range of 100 to 200 μm, particularly preferably more than 120 μm and 180 μm or less.

  The porosity of the polar liquid supply body is preferably 70 to 90%, more preferably 80 to 90%, since it exhibits an excellent polar liquid supply speed while having sufficient mechanical strength.

  As long as the polar liquid supply body of the present invention does not cause adverse effects such as blocking the transmission of electron beams or decomposing by electron beams, the filler, coloring material, plasticizer, softening material, lubricant, charging An inhibitor, an antioxidant, a flame retardant, an ultraviolet absorber, an antibacterial agent, and / or an antifungal agent can be blended. These can be introduced into the system by a method such as kneading into a hydrophobic polymer before forming an open cell body.

  The open cell body used in the polar liquid supply body of the present invention is an extraction in which, for example, a nucleating agent is dispersed or dissolved in a hydrophobic polymer or a system containing the same, and then the nucleating agent is extracted using water or a suitable solvent. Or a mechanical floss method in which an inert gas is mechanically mixed into a hydrophobic polymer or a system containing the same. The extraction method is preferable because an open-cell body having a more uniform pore diameter can be obtained. Nucleating agents used in the extraction method include sodium chloride, potassium chloride, calcium chloride, ammonium chloride, sodium nitrate, sodium nitrite, sodium sulfate anhydride, sodium carbonate anhydride, sodium metasilicate anhydride and sodium tetraborate anhydride. Inorganic compounds such as: trimethylolethane, trimethylolpropane, trimethylolbutane, sorbitol, sucrose, solubilized starch, glycine and various organic acid salts (for example, sodium salts such as malic acid, citric acid, succinic acid, glutamic acid) Organic compounds such as these are exemplified, and sodium chloride is preferred because it does not affect the environment. Nitrogen etc. are illustrated as an inert gas mixed by the mechanical froth method. In a system that involves vulcanization (crosslinking) in the formation of open-cell bodies such as hydrocarbon rubber, a polymer compound is mixed with a vulcanizing agent (crosslinking agent) and a vulcanization accelerator as necessary, Vulcanization is performed under appropriate conditions selected by the system.

  The grafted open cell of the present invention is one in which hydrophilic groups are formed in the pores of the open cell obtained as described above by grafting reaction or subsequent reaction.

  Among hydrophobic polymers, those having a functional group on the pore surface can form a graft chain by reacting a monomer or macromer to be grafted with the functional group. However, in the case of a polyolefin resin such as polyethylene, since such a functional group does not exist, a radical is generated by heating in the presence of an organic peroxide or electron beam irradiation, and the graft chain is formed by using it as a grafting site. Let it form. The present inventor has found that grafting can be performed by generating radicals with good control without causing deterioration of the polymer or structural change of the open cell body by electron beam irradiation.

  Electron beam irradiation can be performed at room temperature in air or in an inert gas atmosphere such as nitrogen or argon using an electron accelerator as a radiation source. The acceleration voltage varies depending on the actual thickness of the irradiation target, but is usually 150 to 1,500 kV. In order to prevent the open-cell body of the hydrophobic polymer from being melted by electron beam irradiation, irradiation is performed while the open-cell body is cooled, or irradiation is performed at a low level or intermittently. The absorbed dose of the electron beam is usually 10 to 300 kGy, preferably 50 to 200 kGy per unit volume.

  The grafting reaction can be carried out by allowing a compound that gives a hydrophilic group to the pore surface to be present in the pores of the open-cell body simultaneously with or after the electron beam irradiation. That is, the open-cell body of the hydrophobic polymer is immersed in a compound that gives a hydrophilic group or a solution in which the compound is dissolved and in a solvent that does not affect the open-cell body, or the above compound or its solution is made hydrophobic. Through the pores of the open cell of the conductive polymer. However, when the compound is a solid, it must be used as a solution. Examples of the solvent used include water, methanol, ethanol, isopropyl alcohol, diethyl ether, acetone, benzene, toluene, and a mixed solvent thereof. Many compounds that give hydrophilic groups are soluble in water or polar solvents. Therefore, as the solvent, water that dissolves these compounds; lower alcohols such as methanol, ethanol, and isopropanol; and mixed solvents thereof are preferable, because they do not swell the open cell body during the grafting reaction. More preferably, water is used. The presence of the organic solvent tends to increase the swelling rate. Most preferably, the grafting reaction is carried out without solvent. Further, if necessary, it is possible to take means such as sending the grafting agent under pressure or reduced pressure.

  The reaction temperature may be room temperature or high enough that the structure of the open cell body is not impaired. When grafting is performed after electron beam irradiation, the radicals generated by electron beam irradiation can be stabilized by cooling and storing, for example, dry ice-diethyl ether or liquid nitrogen. Can be saved.

  For example, when a (poly) acrylic acid graft chain is formed on the pore surface of a polyolefin open cell such as high-density polyethylene, the continuous cell is irradiated with an electron beam and then continuous with acrylic acid or a solution thereof. The grafting reaction can be carried out by immersing the foam and heating at room temperature or below 50 ° C. to carry out the grafting reaction, or by irradiating the sample being immersed with an electron beam. As the solution, an aqueous solution containing 15% by weight or more of acrylic acid can be used.

  The continuous porous body may swell during the grafting reaction, and if it is significant, the required dimensional stability may not be obtained, and the mechanical strength may be impaired. Therefore, the grafting reaction is preferably performed under conditions that suppress swelling. The swelling rate is preferably 30% or less, more preferably 10% or less as a volume change rate.

  When acrylic acid is used as the grafting agent, the grafting reaction is most preferably carried out without a solvent. The base polymer is most preferably high-density polyethylene, and in the case of a polymer blend of polyolefin, the higher the high-density polyethylene content, the lower the swelling ratio and the better polar liquid supply The body is obtained.

  The polar liquid absorptivity of the obtained polar liquid supply body is preferably within 10 seconds, and more preferably within 1 second, using the measurement method of Examples described later.

  When a grafting agent such as glycidyl methacrylate is used, after forming a graft chain, the epoxy ring is opened by an acid ring opening reaction with an acidic aqueous solution such as an aqueous sulfuric acid solution to form two hydroxyl groups. Can be made. The reaction conditions are typically immersed in a 0.5 mol / L sulfuric acid aqueous solution at 75 ° C. for 3 hours.

  The fuel cell of the present invention is a fuel cell using a polar liquid such as alcohol such as methanol or an aqueous solution thereof as a hydrogen source or fuel, and the polar liquid is supplied from the container to the polar liquid supply body of the present invention. To the reformer or the fuel cell. In addition to the above, examples of the polar liquid include ethanol obtained by a fermentation method, an aqueous solution thereof, methanol and / or a liquid containing ethanol together with other components, and the like.

  Taking a fuel cell that uses methanol as a hydrogen source, for example, methanol or an aqueous solution thereof (hereinafter referred to as a methanol-based liquid) is supplied to a reformer, and hydrogen is generated by a reforming reaction such as partial oxidation reaction or steam reforming. The hydrogen is supplied to a fuel chamber in contact with the fuel electrode of the fuel cell. The fuel cell includes an aqueous solution of phosphoric acid, an alkaline solution, a molten carbonate, a solid oxide, a solid polymer, and the like as an electrolyte, and, if necessary, carbon fiber on both sides of an electrolyte layer containing a catalyst and / or an electrolyte holding material. The fuel electrode and the oxygen electrode, which are composed of such a porous conductor, are provided, and the energy generated by the reaction between hydrogen supplied to the fuel electrode and oxygen supplied to the oxygen electrode as air or the like. , And can be taken out as electrical energy from the two electrodes.

  Like a direct methanol fuel cell, a fuel cell that directly uses alcohol as a fuel supplies an alcohol-containing liquid such as a methanol-based liquid directly to the fuel electrode and uses it as a fuel instead of hydrogen. For example, a solid polymer electrolyte membrane is used as an electrolyte layer and is oxidized by a platinum-based catalyst supported on a carrier such as carbon fiber, such as a Ru-Pt catalyst for a fuel electrode or a Pt catalyst for an air electrode, to generate carbon dioxide gas and water. The energy generated by the reaction can be taken out as described above.

  According to the present invention, it is possible to easily obtain a polar liquid supply body for a fuel cell that supplies a polar liquid such as a methanol-based liquid without contaminating it. With the production method of the present invention, the polar liquid supply body can be produced without impairing the physical properties of the foam. Furthermore, by supplying the methanol-based liquid to the reformer or the fuel electrode via the polar liquid supply body of the present invention, the fuel is reduced in size and weight by using methanol as a hydrogen source or using methanol as a fuel. A battery can be obtained. Direct combustion type fuel cells such as direct methanol type fuel cells use a polar liquid such as methanol directly as a fuel, so that they do not require a reformer and are particularly suitable for applications that require miniaturization and weight reduction. .

  The polar liquid supply body of the present invention can be manufactured with good control over the average pore diameter and graft ratio, and will not swell even if the polar liquid is continuously supplied. Therefore, the supply amount of polar liquid such as methanol and its aqueous solution and the discharge amount of generated carbon dioxide gas can be controlled with good control. Further, the fuel cell of the present invention can be designed without considering the dimensional change due to swelling by using such a polar liquid supplier. Furthermore, when a thermoplastic resin such as a polyolefin resin is used as the polar liquid supply body, it is advantageous for recycling.

  Hereinafter, the present invention will be described more specifically with reference to examples. In the examples, “parts” means “parts by weight”, and “concentration / composition”% means “wt%”. The present invention is not limited by these examples.

Production of Open Cell An example is shown in which a high density polyethylene is used as a base polymer and an open cell sample having an average pore diameter of 100 μm and a porosity of 85% is prepared. Other open cells were prepared using similar means by changing the type of base polymer, the average particle diameter of sodium chloride fine powder, and the blending ratio of sodium chloride and base polymer.

  After blending 15 parts of high-density polyethylene with 25 parts of polyethylene glycol having an average molecular weight of 20,000 and 85 parts of sodium chloride fine powder having an average particle diameter of 100 μm, the mixture was stirred and mixed with a kneader, and then 2 mm thick by an extruder. The sheet was extruded and then cut into a length of 50 mm and a width of 50 mm. This was poured into water at room temperature and allowed to stand for 48 hours, whereby the nucleating agent was extracted with water to obtain a sample of the above-mentioned high-density polyethylene open-cell body.

Grafting reaction The open cell sample obtained as described above is placed on a conveyor belt, and the acceleration voltage, current, sample speed, etc. are adjusted so that the absorbed dose of the sample according to the following formula becomes 100 kGy. Then, electron beam irradiation was performed with an electron accelerator at a temperature of 40 ° C. in a nitrogen stream.

However, the loss coefficient K is a coefficient determined by the acceleration voltage, the apparent specific gravity of the sample, and the thickness.

  Immediately after irradiation, the sample was immersed in the grafting agent so that the grafting agent was soaked into the pores. After elapse of a predetermined time at a temperature of 40 ° C., the sample was taken out from the liquid, dried in a constant temperature bath at 40 ° C., and then subjected to evaluation as a polar liquid supplier.

The following evaluation method was used as a polar liquid supplier.
(1) Swelling ratio The ratio of the apparent volume after the grafting reaction to the apparent volume before the grafting reaction was calculated by the following formula to obtain the swelling ratio.
Q (%) = [(v−v ₀ ) / v ₀ ] × 100
(In the formula, Q represents the swelling rate, v ₀ represents the apparent volume before the grafting reaction, and v represents the volume after the grafting reaction.)
(2) Polar liquid absorption time A 10% aqueous solution of methanol was used as a representative polar liquid. Place the sample horizontally, drop one drop of the above polar liquid on the surface from a dropper with a hole diameter of 1 mm, and measure the time until the polar liquid is absorbed in the pores and does not remain on the surface, and the absorption time is taken. .
(3) Breathability Using a Perm Porometer Model CEP-1100-AEXL (product name of Seika Sangyo Co., Ltd.) for a polar liquid supply sample with a thickness of 2mm The air permeability was measured by sandwiching with packing and passing dry air in the thickness direction at a temperature of 25 ° C. and a pressure difference of 1 kPa.

The polyolefins used as the base polymer and their abbreviations are as follows.
HDPE: high density polyethylene LDPE: low density polyethylene PEB: ethylene-α-butene copolymer

Examples 1 to 3, Comparative Examples 1 and 2
Using HDPE as the base polymer and acrylic acid as the grafting agent without solvent, or as an aqueous solution or methanol solution, a grafting reaction was performed to obtain a polar liquid supplier. However, Comparative Example 1 was used for evaluation for comparison without grafting HDPE open-cells. Table 1 shows the evaluation results of the open cell body, the grafting agent, the reaction time, and the obtained polar liquid supplier.

  As is apparent from Table 1, the swelling rate when acrylic acid is used as a grafting agent as it is is 16.0%, excellent in dimensional stability, and excellent in absorbability with a 10% aqueous solution of methanol. It has been found that it has excellent performance as a polar liquid supplier. Using a 20% or more acrylic acid aqueous solution as a grafting agent, a good polar liquid supplier was obtained in the same manner. On the other hand, in a 10% methanol solution, a product that can withstand use as a polar liquid supplier could not be obtained due to swelling.

Examples 4 and 5 and Comparative Examples 3 and 4
A polar liquid supplier was obtained using a polymer blend in which the ratio of HDPE and PEB was changed as a base polymer and acrylic acid as a grafting agent in the absence of a solvent. Table 2 shows the evaluation results of the open cell body, the grafting agent, the reaction time, and the obtained polar liquid supplier.

  As is clear from Table 2 and Example 1 (Table 1), the swelling ratio increases with the blending ratio of PEB in the base polymer. When PEB exceeds about 15%, the swelling ratio exceeds 30% and can be used. A polar liquid supplier could not be obtained.

Example 6 and Comparative Example 5
A polymer blend of PEB and HDPE was used as a base polymer, and a grafting reaction was performed using a methanol solution of acrylic acid as a grafting agent to obtain a polar liquid supplier. The evaluation results of the open cell body, the grafting agent, the reaction time, and the obtained polar liquid supplier were as shown in Table 3.

  As can be seen from Table 3, when methanol was used as the solvent for the grafting agent and a large amount of PEB was used, swelling was significant, but the reaction time was shortened, and a polar liquid supplier with good dimensional stability was obtained. It was.

  The polar liquid supply body of the present invention is particularly useful as a supply device for supplying a polar liquid to a reformer or a fuel electrode of a fuel cell using a polar liquid such as methanol as a hydrogen source or using a polar liquid as a fuel. It is. A fuel cell using such a polar liquid supply body does not require a high-pressure vessel or a pump, and is therefore useful as a safe, small and light fuel cell, particularly a notebook computer, electronic notebook, and mobile phone. It is suitable as a battery that can cope with the high performance of such mobile devices.

Claims (8)

Polar liquid supply for a fuel cell comprising a grafted open cell having a polar liquid affinity pore surface obtained by grafting a compound imparting a hydrophilic group to the pore surface on the pore surface of an open cell made of a hydrophobic polymer A polar liquid supplier for a fuel cell, having a graft ratio of 5 to 100% by weight .   The polar liquid supply body for fuel cells according to claim 1, wherein the hydrophobic polymer is a polyolefin.   The polar liquid supply body for fuel cells according to claim 1 or 2, wherein the average pore diameter is 1 to 200 µm.   The polar liquid supply body for a fuel cell according to any one of claims 1 to 3, wherein the compound providing the hydrophilic group is a vinyl compound or an allyl compound.   The polar liquid supplier for a fuel cell according to claim 4, wherein the compound providing the hydrophilic group is acrylic acid. The polar liquid supply body for a fuel cell according to any one of claims 1 to 5 , wherein the polar liquid to be supplied is methanol or an aqueous solution thereof. The open cells of the hydrophobic polymer, comprising the step of irradiating the electron beam, after the step during or said step, a compound or a solution thereof provide a hydrophilic group on the pore surfaces, is present in the pores, of the open cell foam The method for producing a polar liquid supplier for a fuel cell according to any one of claims 1 to 6 , wherein the grafting reaction is performed while controlling the swelling rate to 30% or less . A fuel cell using a polar liquid as a hydrogen source or fuel, wherein the polar liquid is supplied to a reformer or a fuel electrode via the polar liquid supply body according to any one of claims 1 to 6. Fuel cell.