JP4713861B2 - Proton conducting solid electrolyte membrane - Google Patents

Description

  The present invention relates to a proton conductive solid electrolyte membrane, and more particularly to a proton conductive solid electrolyte membrane having performance suitable as a solid electrolyte membrane for a fuel cell using hydrogen, methanol or the like as a fuel.

  In recent years, various fuel cells have attracted attention as power generation devices with high power generation efficiency and low environmental load. Among these fuel cells, polymer electrolyte fuel cells (PEFC), direct methanol fuel cells (DMFC), etc. use proton-conducting electrolyte membranes mainly composed of polymer compounds. As an electrolyte membrane having excellent stability, a perfluorocarbon sulfonic acid membrane represented by Nafion (registered trademark of Nafion, DuPont, the same applies hereinafter) is often used.

  However, although these perfluorocarbon sulfonic acid membranes are excellent in proton conductivity and oxidation resistance, they are very expensive due to the complicated manufacturing process, and fluorine-containing compounds are burdened on the environment during synthesis and disposal. However, when considering future environmental problems, it is not necessarily the optimum material for a fuel cell or the like.

  Against this background, various non-perfluorocarbon sulfonated proton conducting membranes such as sulfonated partially fluorinated membranes or sulfonated aromatic polymer membranes with reduced fluorine content have been proposed. Typical examples include sulfonated polyetheretherketone, sulfonated products of heat-resistant aromatic polymers such as sulfonated polyethersulfone and sulfonated polysulfone, and a copolymer consisting of a fluorocarbon vinyl monomer and a hydrocarbon vinyl monomer. Examples thereof include a sulfonated polystyrene-graft-ethylene-tetrafluoroethylene copolymer film composed of a combined structure and an aromatic hydrocarbon structure having a sulfonic acid group. Also, an inexpensive, mechanically and chemically stable SEBS ( Proton conducting membranes composed of sulfonated styrene- (ethylene-butylene) -styrene) have been proposed.

  However, these electrolyte membranes have a large dimensional change due to swelling due to water content during power generation, and chemical stability (oxidation resistance) tends to be insufficient. In addition, when applied to an electrolyte membrane of a methanol fuel cell, there is a problem in that the power generation output is greatly reduced due to dissolution of the electrolyte membrane in methanol and crossover in which methanol permeates the electrolyte membrane at a high ratio.

  In order to solve the various problems of these polymer electrolyte membranes, electrolyte membranes made of inorganic compounds have been made, but generally they have poor processability and flexibility, are difficult to handle, and are self-supporting. It is difficult to form a film having a certain practical strength and flexibility. (For example, Patent Document 1 and Non-Patent Document 1)

  As described above, in general, an electrolyte membrane made of an inorganic compound alone is very difficult to form a continuous membrane having sufficient mechanical strength as a self-supporting membrane for use in a solid electrolyte membrane of a fuel cell. This is because, in general, solid electrolyte membranes made of polymer materials can realize mechanical strength as a self-supporting membrane by spatially spreading molecular chains having molecular weights and molecular chain lengths that are entangled with each other. This is because it is difficult to sufficiently entangle the molecular weight and molecular chain.

  Therefore, as an attempt to secure high proton conductivity of an electrolyte made of an inorganic compound while maintaining the workability and flexibility of a polymer electrolyte membrane, Proton-conducting thin film electrolytes that hold a proton-conducting solid electrolyte have been proposed. (Patent Document 2)

The method used here is that the pores of the microporous polymer membrane are filled with an inorganic carrier and then solidified in the pores of the microporous polymer membrane by filling and immobilizing a proton conductive solid electrolyte solution. This is a method of supporting an electrolyte.
However, in addition to the complexity of such a manufacturing method, the ionic conductivity realized with this membrane is on the order of 10 to the third power, and a proton conductive fixed electrolyte membrane having a further easier manufacturing method and high ionic conductivity. The appearance of is desired.

JP 2001-307545 A JP 7-65624 A “Chemistry Letters”, 2000, p. 1314

  As a solid electrolyte membrane for a fuel cell, a solid electrolyte membrane having sufficient mechanical strength and flexibility as a self-supporting membrane and having high proton conductivity and a method for producing the same are provided.

The inventor of the present invention provides an inorganic oxide solid electrolyte, particularly ( D) titanium alkoxide or aluminum, which is difficult to form into a film due to insufficient mechanical strength alone due to insufficient mechanical strength or fracture due to internal stress. A metal alkoxide which is an alkoxide, and / or (F) a condensate of silicon alkoxide and / or silicon chloride, and the condensate is suitable for (E) a solid electrolyte having a sulfone group or a sulfone group and a phosphonic acid group. Focusing on the fact that a solid electrolyte membrane can be manufactured by impregnating and compositing into the voids of a reinforcing substrate having a large number of voids, it has mechanical strength and high proton conductivity that can be used as a free-standing membrane. The solid electrolyte membrane is realized.

That is, the present invention
1. A solid electrolyte membrane comprising a reinforcing substrate having voids and a solid electrolyte carried in the voids of the reinforcing substrate,
(1) The reinforcing substrate is a porous organic polymer film,
(2) The porous organic polymer film has (A) a thickness of 5 to 300 μm, (B) an average pore diameter of 0.1 to 10 μm, a maximum pore diameter of 100 μm or less, and (C) air permeability (JIS P8117). ) Is a porous organic polymer film within 20 seconds, and (3) the solid electrolyte is (D) a metal alkoxide that is titanium alkoxide or aluminum alkoxide, and / or (F) silicon alkoxide and / or silicon chloride It consists condensates of goods, and the fused Gobutsu has (E) a sulfone group or a sulfone group and a phosphonic acid group,
(4) The proton conductive solid electrolyte membrane, wherein the solid electrolyte membrane contains 60 to 90 parts by volume of the solid electrolyte.

Furthermore, the following aspects are also included in the present invention.
2. 2. The proton conductive solid electrolyte membrane according to the invention 1, wherein the porous organic polymer film is a porous film made of ultrahigh molecular weight polyethylene having a molecular weight of 1 × 10 ⁵ to 1 × 10 ⁷ .
3. (D) Titanium alkoxide or aluminum alkoxide metal alkoxide and / or (F) silicon alkoxide and / or silicon chloride, and silicon having a sulfonic group on one side of the porous organic polymer film A state in which a liquid containing an alkoxide and / or silicon chloride, or a liquid or liquid stream containing a condensate of the precursor is brought into contact with a gas or gas stream having moisture on the other surface of the porous organic polymer film in the above invention 1 or 2 work made process for the proton conductive solid electrolyte membrane according to comprising the step of infiltrating the solvent solution containing a precursor material of the solid electrolyte pores inside the porous organic polymer film.

Hereinafter, the present invention will be described in more detail.
The solid electrolyte used in the present invention is a solid electrolyte mainly composed of an inorganic oxide, which will be described later, and has excellent performance in proton conductivity, chemical stability, etc. And the mechanical strength against tension, etc.) is insufficient, and film breakage, breakage, cracks, etc. are likely to occur.

However, when the solid electrolyte is supported on a reinforcing substrate having voids, that is, when it is supported in a state of being divided into domains having a suitable size, the domain made of the solid electrolyte is resistant to some external force. It shows great resistance, and domain destruction is unlikely to occur. This is explained as a result of avoiding stress and strain energy concentration by being divided into relatively small domains.
Thus, there is an upper limit on the size of the domain, that is, the size of the gap, in order to sufficiently obtain the effect of avoiding stress energy concentration and making it difficult to cause breakage.

On the other hand, there is a lower limit on the size of the void in order to sufficiently penetrate the solid electrolyte precursor material liquid into the void.
In order to satisfy these requirements, the reinforcing substrate used in the present invention is preferably a porous organic polymer film having an average pore diameter of 0.1 to 10 μm and a maximum pore diameter of 100 μm or less, more preferably an average pore diameter of 0. .1 to 5 μm and the maximum pore size is 20 μm or less.

In the present invention, since the porous organic polymer film is used, the size of the void is represented by the size of the pores of the porous organic polymer film.
For the measurement of the average pore size and the maximum pore size, see U.S. Pat. S. Patent No. No. 4,489,593, measurement is performed based on the continuous capacity gas adsorption / desorption measurement method (OMNISORP method) described in No. 4,489,593, and an apparatus manufactured by BECKMAN COULTER is used as the measurement apparatus.

The void ratio of the porous organic polymer film, that is, the porosity is preferably in the range of 60 to 90 parts by volume. If the porosity is less than 60 parts by volume, the amount of the solid electrolyte supported is absolutely insufficient, and it is difficult to obtain sufficient proton conductivity, and if it is 90 parts by volume or more, the mechanical strength of the porous organic polymer film Is not preferable because it becomes insufficient.
The porous organic polymer film preferably has an air permeability based on JIS P8117 of 20 seconds / 100 cc or less, more preferably 10 or less, still more preferably 5 or less.

  The thickness of the porous organic polymer film is preferably in the range of 5 to 300 μm. If it is less than 5 μm, the mechanical strength as a substrate tends to be insufficient, and if it exceeds 300 μm, the proton conductivity is remarkably lowered, which is not preferable.

Preferred examples of the material for such a porous organic polymer film include organic polymers such as polytetrafluoroethylene, polysulfone, high molecular weight polyethylene, and polypropylene. Here, the porosity is calculated based on the following formula from the density (ρ ₀ ) of the raw material and the density (ρ) of the porous film.
Porosity (%) = (1−ρ / ρ ₀ ) × 100

Among these porous films made of organic polymers, in particular, it is made of ultra high molecular weight polyethylene having a molecular weight of 1 × 10 ⁵ to 1 × 10 ⁷ , more preferably 5 × 10 ^{5 to} 5 × 10 ⁶ , and a thickness of 10 to 10. An ultra-high molecular weight polyethylene film having a tensile strength in at least one of the in-plane directions of about 70 μm and an elongation rate of 10% or more is in view of its mechanical strength, pore diameter controllability, price, etc. Most preferably used.
Here, when the molecular weight of ultrahigh molecular weight polyethylene exceeds 1 × 10 ⁷ , film molding becomes difficult, and when it is less than 1 × 10 ⁵ , the mechanical strength decreases, which is not preferable.

  The ultra high molecular weight polyethylene may be a copolymer of a small amount, preferably 5 mol% or less of propylene, butene, pentene, hexane, 4-thympentene-1, octene, etc., and a small amount, for example, 25% by weight. The following polypropylene, polybutylene, ethylene-propylene copolymer and the like may be included. The ultra high molecular weight polyethylene may contain commonly used additives such as a stabilizer, a colorant, a flame retardant, and an antistatic agent.

  Such a porous ultra-high molecular weight polyethylene film having a large number of micropores can be obtained by, for example, the methods described in JP-A-2-232242, JP-A-5-98065, JP-A-5-239246, and the like. Can be manufactured in compliance. For example, a solution (concentration 2 to 30% by weight) of ultra high molecular weight polyethylene having a molecular weight of 5 million dissolved in a solvent such as decalin is extruded from a slit die to form a gel film, and then the solvent in the gel film is evaporated. After that, a method of stretching at a high magnification, or a polyethylene film in which inorganic fine particles and organic fine particles having appropriate particle diameters are similarly drawn and formed into a film, and then these fine particles are used with an appropriate acid, alkali, organic solvent, etc. Thus, it can be preferably produced by a method of dissolution extraction.

  Furthermore, these ultra high molecular weight polyethylene porous films often have a fibrillated nonwoven shape in the thickness direction, but the tear strength in at least one direction in the plane may be 0.05 N or more. preferable.

In addition, the porous film made of ultra high molecular weight polyethylene produced by the method as described above may be further perforated as necessary. As the drilling process, for example, mechanical punching, laser beam, processing by water pressure, or the like can be used.
For the purpose of improving the mechanical strength, it is also possible to improve the interlaminar strength of the fibrillated nonwoven fabric by using thermal calendaring or the like.

The solid electrolyte used in the present invention is mainly composed of an inorganic oxide, and more specifically, a sulfone group , or a silicon alkoxide and / or silicon in which a sulfonic acid group and a phosphonic acid group are covalently bonded. the need use a solid electrolyte comprising fused with de alkoxide of or dechlorination of chloride and or metal alkoxide.

  Suitable silicon alkoxides for this application include, for example, tetramethoxysilane, tetraethoxylane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, diphenyldimethoxysilane. , Diphenyldiethoxysilane, phenylmethyldimethoxysilane, phenylmethyldiethoxysilane, phenylmethyltrimethoxysilane, phenylmethyltriethoxysilane, phenylethyltrimethoxysilane, phenylethyltriethoxysilane, phenylpropyltrimethoxysilane, phenylpropyltriethoxysilane , Mercaptomethyltrimethoxysilane, mercaptomethyltriethoxysilane, mercaptoethyltri Toxisilane, mercaptoethyltriethoxysilane, mercaptopropyltrimethoxysilane, mercaptopropyltriethoxysilane, glycidoxypropyltrimethoxysilane, glycidoxypropyltriethoxysilane, aminopropyltrimethoxysilane, aminopropyltriethoxysilane, vinyltri Examples include methoxysilane, vinyltriethoxysilane, chlorotrimethoxysilane, and chlorotriethoxysilane. In addition, you may use these 1 type or in mixture of 2 or more types as needed.

Moreover, as a silicon chloride, the compound which substituted the alkoxy group of the said various silicon alkoxide by the chlorine group is mentioned preferably, for example.
Examples of the metal alkoxide include titanium alkoxides such as tetraisopropoxy titanium, tetra-n-butoxy titanium, and tetra-t-butoxy titanium, aluminum alkoxides such as tri-isopropoxy aluminum and tri-n-butoxy aluminum, and tetra-n-butoxy. Zirconium etc. can be mentioned preferably.

These silicon alkoxides, silicon chlorides, and metal alkoxides are subjected to condensation through dealkoxylation or dechlorination by a known method and used as condensates. In the present invention, these condensates have sulfone groups or phosphorous groups. A step of chemically bonding and introducing an acid group is required.
This step may be performed at the stage of the raw material monomer before dealkoxide and dechlorination, may be performed in the process of condensation, or may be performed after condensation.

  The introduction of the sulfone group can be realized, for example, by mixing chlorosulfuric acid and / or sulfuric acid, fuming sulfuric acid, etc. with silicon alkoxide or silicon chloride having a phenyl group and reacting for a predetermined time, or silicon alkoxide having a mercapto group or This can be realized by mixing hydrogen peroxide with silicon chloride and reacting for a predetermined time.

  In addition, as described above, silicon alkoxides and silicon chlorides having chlorosulfonylphenyl groups obtained by allowing chlorosulfuric acid to act on silicon alkoxides and silicon chlorides having phenyl groups (some of them are commercially available). In the present invention, it can be preferably used.

  On the other hand, the introduction of the phosphonic acid group is preferably carried out at the stage of the raw material monomer before dealkoxide, dechlorination, or the condensation process, but the phosphate group is an alkoxide group or chlorine group or they are hydrolyzed. Since it can enter the network of the condensate and be stably supported by the exchange reaction with the hydroxyl group, it can be efficiently introduced particularly in the condensation process.

For introduction of such a phosphonic acid group, phosphoric acid represented by the general formula (1) or a derivative thereof, or phosphorous acid represented by the following general formula (2) or a derivative thereof is preferably used. Polyphosphoric acid obtained by condensing an acid can also be used.
PO (OR) _3-y (OH) _y (1)
[In the formula, R represents a monovalent organic group having 1 to 6 carbon atoms, and y is an integer of 0 to 3. ]
P (OR) _3-z (OH) _z (2)
[In the formula, R represents a monovalent organic group having 1 to 6 carbon atoms, and z represents an integer of 0 to 3. ]

Examples of the monovalent organic group having 1 to 6 carbon atoms in the general formula (1) include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a sec-butyl group, and a t-butyl group. Group, n-pentyl group, phenyl group and the like.
In general formula (1), y is 0 to 3, and specific examples of y being 0 are phosphoric acid trimethyl ester, phosphoric acid triethyl ester, phosphoric acid tripropyl ester, phosphoric acid tributyl ester, phosphoric acid. A triphenyl ester etc. can be mentioned.

In the general formula (1), specific examples of y being 1 or 2 include phosphoric acid dimethyl ester, phosphoric acid diethyl ester, phosphoric acid dipropyl ester, phosphoric acid dibutyl ester, phosphoric acid diphenyl ester, phosphoric acid. Prepared by dissolving P ₂ O ₅ in methanol, ethanol, propanol, butanol, pentanol, phenol, etc. in addition to methyl ester, phosphoric acid ethyl ester, phosphoric acid propyl ester, phosphoric acid butyl ester, phosphoric acid phenyl ester, etc. What is done. Further, as a specific example where y is 3, orthophosphoric acid can be mentioned.

Examples of the monovalent organic group having 1 to 6 carbon atoms in the general formula (2) include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, sec-butyl group, and t-butyl. Group, n-pentyl group, phenyl group and the like.
In the general formula (2), z is 0 to 3, and specific examples of z being 0 are trimethyl phosphite, triethyl phosphite, tripropyl phosphite, tributyl phosphite. Examples thereof include esters and triphenyl phosphite.

  In the general formula (2), specific examples of z = 1 are dimethyl phosphite, diethyl phosphite, dipropyl phosphite, dibutyl phosphite, diphenyl phosphite. In addition, as specific examples of z being 2, phosphorous acid methyl ester, phosphorous acid ethyl ester, phosphorous acid propyl ester, phosphorous acid butyl ester, phosphorous acid phenyl ester, and z being 3 Specific examples include phosphorous acid.

  In the present invention, as described above, silicon alkoxide, silicon chloride, and metal alkoxide condensate covalently bonded to sulfonic acid and / or phosphonic acid are preferably used. In addition, inorganic typified by tungstophosphoric acid or the like is used. It is also preferable to use a solid acid in combination and use the inorganic solid acid substantially fixed to the condensate by a strong adsorption action based on a covalent bond or an ionic interaction.

  Further, as a method of infiltrating the pores of the porous organic polymer film with these solid electrolyte precursor material liquid, for example, the liquid or liquid flow of the solid electrolyte precursor material is brought into contact with one side of the porous organic polymer film, A preferred method is to allow the solid electrolyte precursor material liquid to penetrate into the pores of the porous organic polymer film in a state where a gas or a gas flow is in contact with the other surface of the porous organic polymer film.

  It should be noted that the precursor liquid or liquid stream is preferably supplied with its temperature, pressure and / or flow rate controlled, and the gas or gas stream also preferably has its temperature, pressure and / or flow rate, and It is preferable to supply by controlling the moisture content (humidity).

  By the above means, the proton conductive solid electrolyte membrane of the present invention can have sufficient mechanical strength, proton conductivity, and oxidation resistance to withstand practical use as a solid electrolyte membrane for fuel cells and the like. .

Examples of the best mode for carrying out the present invention will be described below. However, the invention is not limited to the examples described.
The performance evaluation of the proton conductive solid electrolyte membrane according to this example was performed as follows.

Next, examples and comparative examples of the present invention will be described in detail. Various performance evaluations of the proton conductive solid polymer membranes described in Examples and Comparative Examples were performed as follows.
<Bending resistance>
As an evaluation of the mechanical strength and handling property of the sample, when a sample was wound around a metal roll with a diameter of 30 mm, if the sample showed cracks or other abnormalities, it was judged as bad or not. evaluated.
<Proton conductivity>
Impedance measurement was performed by sandwiching a sample between a pair of platinum-plated electrodes (electrode surface area of about 0.0314 cm ² ). For impedance measurement, use a Solartron impedance analyzer, perform frequency sweep within the range of amplitude 10mV, 10k to 100Hz, obtain the resistance component value of the membrane from the obtained colle-core plot, and convert it according to the following relational expression. The proton conductivity in the thickness direction of the electrolyte membrane was determined.
Proton conductivity (S / cm) = sample thickness (cm) / [resistance (Ω) × electrode area (cm ² )]
<Methanol aqueous solution solubility, swellability>
A sample cut to a size of 4 cm × 4 cm was treated in a vacuum drying oven at 90 ° C. for 3 hours and then immersed in a 50 mol% aqueous methanol solution at 25 ° C. for 3 days. ) As well as the rate of change in area of the sample (area after immersion / area before immersion,%).
In addition, the measurement of the sample weight before and after immersion was performed in a state where each sample was heat-treated in a vacuum drying furnace at 90 ° C. for 3 hours to sufficiently remove moisture contained in the sample.

[ Reference Example 1 ]
After slowly mixing 4 mol% of phosphoric acid with 1 mol% of titanium isopropoxide at 30 ° C. and stirring for 3 hours, 1 mol% of tetraethoxysilane, 3 mol% of methyltrimethoxysilane, 1 mol% of dimethyldimethoxysilane, 10 mol of methyl alcohol % Was mixed and stirred at room temperature for 24 hours to obtain a precursor material solution of a solid electrolyte.
As a reinforcing base material, a porous film of ultra high molecular weight polyethylene (trade name “Solupoor 8P07A”, DSM, Netherlands) having a molecular weight in the range of 1 × 10 5 to 1 × 10 7, an average pore size of 0.7 μm, a maximum pore size of 1. 4 μm, porosity 84%, thickness 50 μm, tensile strength 15 MPa, elongation 15%, air permeability 4 sec / 100 cc or less).

  First, the film was subjected to a surface treatment using oxygen plasma. That is, the surface of the gas phase / solid phase interface in the film in oxygen plasma generated by applying oxygen at a partial pressure of 2 Pa into a vacuum chamber reduced to 0.2 Pa by a vacuum pump and applying a high frequency electric field of 13.56 MHz. Treatment was performed to make the surface hydrophilic.

  Next, in the arrangement schematically shown in FIG. 2, the reinforcing base material is arranged in a state where the end face is held and the tension in the plane direction is maintained, and the precursor material liquid of the solid electrolyte is supplied to one side while applying a slight pressure. Then, the film and the liquid phase are brought into contact with each other, and an air flow controlled at 30 ° C. and 75% RH is supplied to the other side to keep the film and the air phase in contact with each other while the precursor is formed in the gap of the base material. The material liquid was infiltrated and left for a predetermined time.

  By this method, the alkoxide of titanium and silicon in the solid electrolyte precursor material that has penetrated into the voids of the reinforcing substrate is gradually hydrolyzed by moisture contained in the air in contact with one side, and solidified by dealkoxide / condensation reaction. A composite membrane comprising a reinforcing substrate and a solid electrolyte was formed.

Next, the composite membrane was subjected to heat treatment in the order of 70 ° C. for 1 hour, 100 ° C. for 1 hour, and 130 ° C. for 5 minutes to prepare a target proton conductive solid electrolyte membrane.
The appearance of the sample thus obtained was good and no cracks or other abnormalities were observed. The performance evaluation results of this sample are shown in Table 1.

[Example 2]
The precursor material for the solid electrolyte was prepared as follows.
That is, a 50% solution of chlorosulfonylphenylethyltrimethoxysilane in methylene chloride (manufactured by Azomax) was placed in a reaction vessel equipped with a reflux tube and stirred while blowing air controlled at 30 ° C. and 75% RH into the solution. Then, partial conversion from chlorosulfone group to sulfone group and hydrolysis / dealkoxide reaction of alkoxide proceeded by contact of the liquid with moisture in the air to obtain a solid condensate.

Next, the solid condensate is placed in a 1N aqueous sodium hydroxide solution, and the condensate is atomized and dispersed using a high-speed mixer, followed by stirring at 30 ° C. for 24 hours, and then 1N sulfuric acid is slowly added. The system was neutralized and stirred at 30 ° C. for 24 hours.
Next, the solid obtained by filtering this dispersion was repeatedly washed with water and filtered several times, dehydrated and dissolved in acetone to obtain a solid electrolyte precursor material liquid of Example 2.

The same material as used in Reference Example 1 was used as the reinforcing base material, and the precursor material was the same as in Reference Example 1 except that the air flow to be supplied was changed to an air flow controlled at 30 ° C. and 30% RH. After the liquid is left in contact with and infiltrated the reinforcing substrate for about 1 hour to form a composite membrane, heat treatment is performed at 70 ° C. for 1 hour, 100 ° C. for 1 hour, and further at 130 ° C. for 5 minutes. Proton conducting solid electrolyte membrane was prepared.
The appearance of the sample thus obtained was good, and no cracks or other abnormalities were observed. The performance evaluation results of this sample are shown in Table 1.

The film formability and bending resistance obtained in Reference Example 1 and Example 2 are good, the solubility / swellability in aqueous methanol solution is low, and the proton conductivity is 7.9 × 10 ⁻² and 4.8 ×, respectively. ^10-2 , which indicates a higher proton conductivity than the proton conductive fixed electrolyte membrane of Patent Document 1.

  In addition, as in Patent Document 1, the manufacturing method is such that the solid electrolyte is filled without taking the complicated steps of filling the pores of the polymer microporous membrane with an inorganic carrier and then filling and immobilizing the proton conductive solid electrolyte solution. It is an easy manufacturing method comprising a series of processes of application of precursor material liquid and hydrolysis, condensation and solidification.

  The proton conductive solid electrolyte membrane of the present invention has excellent characteristics such as oxidation resistance and mechanical strength, and is considered to be extremely useful as a solid electrolyte membrane for fuel cells using hydrogen, methanol or the like as fuel. It is done.

In an Example, it is explanatory drawing which shows typically the method of making the precursor material liquid of a solid electrolyte contact and osmose | permeate a reinforcement base material.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Space | gap of reinforcement base material 2 Reinforcement base material 3 Precursor liquid of solid electrolyte 4 Air layer (air flow) in which temperature and humidity were controlled

Claims (3)

A solid electrolyte membrane comprising a reinforcing substrate having voids and a solid electrolyte carried in the voids of the reinforcing substrate,
(1) The reinforcing substrate is a porous organic polymer film,
(2) The porous organic polymer film has (A) a thickness of 5 to 300 μm, (B) an average pore diameter of 0.1 to 10 μm, a maximum pore diameter of 100 μm or less, and (C) air permeability (JIS P8117). ) Is a porous organic polymer film within 20 seconds, and (3) the solid electrolyte is (D) a metal alkoxide that is titanium alkoxide or aluminum alkoxide, and / or (F) silicon alkoxide and / or silicon chloride It consists condensates of goods, and the fused Gobutsu has (E) a sulfone group or a sulfone group and a phosphonic acid group,
(4) The proton conductive solid electrolyte membrane, wherein the solid electrolyte membrane contains 60 to 90 parts by volume of the solid electrolyte. 2. The proton conductive solid electrolyte membrane according to claim 1, wherein the porous organic polymer film is a porous film made of ultrahigh molecular weight polyethylene having a molecular weight of 1 × 10 ⁵ to 1 × 10 ⁷ . (D) Titanium alkoxide or aluminum alkoxide metal alkoxide and / or (F) silicon alkoxide and / or silicon chloride, and silicon having a sulfonic group on one side of the porous organic polymer film A state in which a liquid containing an alkoxide and / or silicon chloride, or a liquid or liquid stream containing a condensate of the precursor is brought into contact with a gas or gas stream having moisture on the other surface of the porous organic polymer film in, work made process for the proton conductive solid electrolyte membrane according to claim 1 or 2 comprising the step of infiltrating the solvent solution containing a precursor material of the solid electrolyte pores inside the porous organic polymer film.

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