WO2016208486A1

WO2016208486A1 - Solid electrolyte reinforcement member and solid electrolyte film including reinforcement member

Info

Publication number: WO2016208486A1
Application number: PCT/JP2016/067948
Authority: WO
Inventors: 仁興梠; 澤　春夫; 和哉志村
Original assignee: ユニチカ株式会社; ニッポン高度紙工業株式会社
Priority date: 2015-06-24
Filing date: 2016-06-16
Publication date: 2016-12-29
Also published as: JPWO2016208486A1; TW201711263A

Abstract

The purpose of the present invention is to provide a solid electrolyte reinforcement member exhibiting exceptional tensile strength and low swelling characteristics when containing water, and exceptional ion conductivity. For the solid electrolyte reinforcement member, a glass yarn having a specific count is selected, and a fabric in which the weaving density of the glass yarn satisfies a specific range is employed, thereby making it possible to obtain exceptional tensile strength and low swelling characteristics when containing water, and exceptional ion conductivity.

Description

Solid electrolyte reinforcing material and solid electrolyte membrane including the reinforcing material

The present invention relates to a solid electrolyte reinforcing material applicable to a fuel cell and the like, and a solid electrolyte membrane including the reinforcing material.

Fuel cells are attracting attention as environmentally friendly energy sources because of their high power generation efficiency and low environmental impact. Fuel cells are generally classified into several types according to the type of electrolyte. Among them, the polymer electrolyte fuel cell (PEFC) can be easily reduced in size and weight with high output and can be expected to be reduced in cost due to mass production effects.

The most representative hydrogen-oxygen fuel cell as a PEFC is an electrochemical oxidation reaction of hydrogen supplied to the negative electrode as shown in the following formula (1), and oxygen supplied to the positive electrode as shown in the formula (2). An electric current flows and electric energy is taken out by an electrochemical reduction reaction and a reaction consisting of proton transfer in the electrolyte therebetween.
_{^{^{H 2 → 2H + + 2e -}}} ·········· (1)
_1/2 O ₂ + 2H ⁺ + 2e ⁻ → H ₂ O (2)

Since only water is discharged from the fuel cell itself, it is clean and extremely quiet. In the fuel cell, hydrogen can be produced by electrolysis of water using natural energy such as wind power and sunlight, and there are great advantages in terms of CO ₂ reduction, denuclearization, oil removal, and the like. Therefore, it is applied to automobiles, and sales of fuel cell automobiles have already started. In addition, since fuel cells can be used in combination with waste heat to obtain extremely high energy efficiency, they are also becoming popular as household power generators and water heaters. Furthermore, fuel cells are becoming popular as emergency power sources because they can be continuously fed for a long time and do not require periodic replacement. In addition, unlike a secondary battery, a fuel cell does not require charging for a long time, and thus has attracted attention as a power source for work vehicles in terms of operating efficiency.

Some fuel cells use fuel other than hydrogen, such as a direct methanol fuel cell where the fuel supplied to the negative electrode is methanol, but even in this case, the reaction in which the fuel is electrochemically oxidized at the negative electrode to release protons Is carried out in the same way and can be operated using a proton conducting solid electrolyte.

The same reaction can be caused even when the solid electrolyte is not proton conductive but hydroxide ion conductive, in which case the reaction at each electrode is represented by the following formulas (3) and (4). Thus, hydroxide ions move in the electrolyte in the direction opposite to that of protons. However, when the electrolyte has water molecules, the protons move from the water molecules to the hydroxide ions, so that a state equivalent to the movement of the hydroxide ions in the opposite direction can be realized. In practice, hydroxide ions may move due to movement of protons.
H ₂ + 2OH ⁻ → H ₂ O + 2e ⁻ (3)
_1/2 O ₂ + H ₂ O + 2e ⁻ → 2OH ⁻ (4)

As a solid electrolyte membrane used for PEFC, a fluorine-based polymer membrane having perfluoroalkylene as a main skeleton and having an ion exchange group such as a sulfo group is widely used. In these polymer membranes, by containing water, the sulfo group in the polymer is ionized and becomes proton conductive. In addition, ionized molecules gather to form a cluster, and this cluster forms a path for protons. However, since this polymer film swells with moisture, it causes an increase in size, a decrease in mechanical strength, and a creep during long-time operation, resulting in a decrease in durability after the start of operation. There is.

Therefore, in order to eliminate the drawbacks of the solid electrolyte membrane, attempts have been made to reinforce the solid electrolyte membrane with various reinforcing materials. As a reinforcing material for a solid electrolyte membrane, for example, a reinforcing material for a proton conductive membrane, which is made of a nonwoven fabric mainly composed of glass fibers having a C glass composition and a binder that strengthens the bonding between the glass fibers, The average fiber diameter of the fibers is in the range of 0.1 μm to 20 μm, the average fiber length of the glass fibers is in the range of 0.5 mm to 20 mm, the binder contains a fibrous binder, and the added amount of the fibrous binder is glass Proton conductive membrane reinforcements in the range of 1% to 40% of the mass of the fiber are known. (For example, refer to Patent Document 1). According to the reinforcing material, a proton conductive membrane having excellent mechanical strength, dimensional stability, handleability and durability, and good proton conductivity can be obtained, and further, a fuel cell can be obtained using the proton conductive membrane. It is said that a fuel cell with high power generation efficiency can be obtained.

JP 2011-236429 A

However, the reinforcing material disclosed in Patent Document 1 needs to increase the porosity to obtain good proton conductivity. When the porosity is increased, the resulting reinforcing material contains water. There was a problem that the tensile strength (tensile strength when containing water) and the dimensional stability (low swellability) before and after containing water were not sufficient.

On the other hand, as a result of studies by the present inventors, it has been found that it is preferable to reduce the thickness of the solid electrolyte membrane (for example, 30 μm or less) from the viewpoint of obtaining good proton and other ion conductivity. However, the reinforcing material specifically disclosed as an example in Patent Document 1 has a thickness of 50 μm, and the thickness of the reinforcing material is too large, so that the solid electrolyte membrane to be reinforced is inevitably thick. It has been found that there is a problem that the ion conductivity tends to be limited.

The present invention solves the above-mentioned problems and, for example, when used as a solid electrolyte reinforcing material for fuel cells or the like, the solid electrolyte reinforcing material having excellent tensile strength and low swellability when containing water and excellent ionic conductivity The purpose is to provide. Furthermore, an object of the present invention is to provide a solid electrolyte membrane using the reinforcing material.

As a result of intensive studies by the present inventors to solve the above-mentioned problems, the reinforcing material disclosed in Patent Document 1 has a nonwoven fabric structure. Therefore, the tensile strength and low swellability when containing water, protons, etc. It has been found that it is difficult to achieve both ionic conductivity. Therefore, as a result of further studies by the inventors, as a solid electrolyte reinforcing material, a glass yarn having a specific count is selected as a solid electrolyte reinforcing material, and by adopting a woven fabric having a woven density satisfying a specific range, the water content is excellent. It was found that the tensile strength and low swellability can be combined with excellent ionic conductivity. The present invention has been completed by further studies based on this finding.

That is, this invention provides the invention of the aspect hung up below.
Item 1. Including glass yarn with a count of 1.0 to 3.5 tex as warp and weft,
A solid electrolyte reinforcing material, which is a woven fabric having a weaving density of at least one of the warp and the weft of 30 to 75/25 mm.
Item 2. Item 2. The solid electrolyte reinforcing material according to Item 1, wherein the glass yarn has an average filament diameter of 3.0 to 4.8 μm.
Item 3. Item 3. The solid electrolyte reinforcing material according to

Item

1 or 2, which does not substantially contain a binder component that enhances the binding property with the solid electrolyte to be reinforced.
Item 4. Item 4. The solid electrolyte reinforcement according to any one of Items 1 to 3, wherein the glass composition constituting the glass yarn has a total content of CaO, MgO, Na ₂ O and K ₂ O of 20% by mass or less. Wood.
Item 5. In order to reinforce the solid electrolyte membrane of the fuel cell, a glass yarn having a yarn count of 1.0 to 3.5 tex is included as a warp and a weft. The use of textiles that are.
Item 6. 5. A solid electrolyte membrane comprising a solid electrolyte and the solid electrolyte reinforcing material according to any one of Items 1 to 4.
Item 7. Item 7. The solid electrolyte membrane according to Item 6, wherein the solid electrolyte is an ion conductive inorganic / organic hybrid compound.
Item 8. Item 8. The solid electrolyte membrane according to Item 7, wherein the ion conductive inorganic / organic hybrid compound is an inorganic / organic hybrid compound in which at least one selected from a silicic acid compound and a tungstic acid compound and polyvinyl alcohol are chemically bonded. .
Item 9. Use of a solid electrolyte as a solid electrolyte membrane of a fuel cell and a membrane comprising the solid electrolyte reinforcing material according to any one of Items 1 to 4.
Item 10. Item 9. A fuel cell comprising the solid electrolyte membrane according to any one of Items 6 to 8.

According to the solid electrolyte reinforcing material of the present invention, by employing a woven fabric that includes glass yarn of a specific count and has a woven density within a specific range, the solid electrolyte membrane has a water content that could not be obtained by the prior art. It is possible to combine the tensile strength and low swellability of ionic conductivity with protons and the like. Therefore, the solid electrolyte membrane containing the solid electrolyte reinforcing material of the present invention, when used in a fuel cell, for example, has good tensile strength and low swellability when containing water, and can have excellent output characteristics.

It is a schematic diagram explaining the evaluation method of the ionic conductivity of the solid electrolyte in an Example of this application.

<Solid electrolyte reinforcement>
The solid electrolyte reinforcing material of the present invention includes a glass yarn having a yarn count of 1.0 to 3.5 tex as a warp and a weft, and a woven fabric having a woven density of 30 to 75 yarns / 25 mm of at least one of the warp and the weft. It is characterized by being. Hereinafter, the solid electrolyte reinforcing material of the present invention will be described in detail.

In the woven fabric used for the solid electrolyte reinforcing material of the present invention, a known glass material can be used depending on the usage environment of the solid electrolyte to be reinforced for the glass material constituting the glass yarn. Specific examples of the glass material include E glass, C glass, S glass, T glass, and AR glass.

Proton conducting solid electrolytes are usually strong acids. Therefore, when a solid electrolyte is used in, for example, a fuel cell, if the acid resistance of the glass material is excellent, a decrease in tensile strength at the time of water content accompanying the elution of the glass component is less likely to occur, and the cation component eluted from the glass material Decrease in the ionic conductivity of the solid electrolyte due to is more difficult. Therefore, the glass composition constituting the glass yarn has a total content of CaO, MgO, Na ₂ O and K ₂ O of 20% by mass or less from the viewpoint of further improving the tensile strength and output characteristics. preferable. In particular, SiO ₂ is 60 to 70 mass%, Al ₂ O ₃ is 20 to 30 mass%, and the total content of CaO, MgO, Na ₂ O and K ₂ O is 20 mass% or less. More preferably: SiO ₂ is 60 to 70% by mass, Al ₂ O ₃ is 20 to 30% by mass, and the total content of CaO, MgO, Na ₂ O and K ₂ O is 10 to 20% by mass. It is particularly preferable that the total content of Na ₂ O and K ₂ O is 2% by mass or less.

When the solid electrolyte to be reinforced is an inorganic / organic hybrid compound described later, the glass composition constituting the glass yarn is particularly 60 to 70% by mass of SiO _{2 and} 20 to 20% of Al ₂ O _3. 30% by mass, the total content of CaO, MgO, Na ₂ O and K ₂ O is 10 to 20% by mass, and the total content of Na ₂ O and K ₂ O is 2% by mass or less It is particularly preferable that the tensile strength and ionic conductivity at the time of hydration can be made more compatible.

A solid electrolyte membrane using an inorganic / organic hybrid compound as the solid electrolyte can also be used as a separator for an alkaline water electrolysis type hydrogen generator. When the solid electrolyte reinforcing material of the present invention is applied to the solid electrolyte membrane used as such a separator, the glass composition constituting the glass yarn is ZrO ₂ from the viewpoint of further improving the hydrogen generation efficiency. Is preferably 10 to 30% by mass; SiO ₂ is 55 to 62% by mass, Al ₂ O ₃ is 1 to 5% by mass, and the total content of CaO and MgO is 0 to 12% by mass; More preferably, B ₂ O ₃ is 0 to 4% by mass, the total content of Na ₂ O and K ₂ O is 13 to 18% by mass, and the content of ZrO ₂ is 12 to 21% by mass. .

The count of the glass yarn needs to be 1.0 to 3.5 tex from the viewpoint of minimizing the interference of ionic conduction by the glass yarn when it is contained in the solid electrolyte membrane. 4 tex is preferred, 1.0 to 2.0 tex is more preferred, and 1.5 to 1.97 tex is even more preferred. In the present invention, the count of the glass yarn is a value obtained according to a method defined in Japanese Industrial Standard “JIS R 3420 2013 7.1”.

The glass yarn is preferably a glass yarn in which a plurality of single fibers (filaments), which are long glass fibers, are twisted together. The number of filaments in the glass yarn is not particularly limited, but is preferably about 20 to 120 from the viewpoint of further improving the balance between tensile strength and low swellability when containing water and ion conductivity. ~ 70 are more preferred, and 20 to 55 are particularly preferred. From the same viewpoint, the average diameter of the filament in the glass yarn is preferably about 3.0 to 4.8 μm, particularly preferably 3.0 to 4.5 μm. Here, the number of filaments in the glass yarn was determined by embedding the fabric in an epoxy resin and curing it, polishing it to such an extent that the glass yarn could be observed, and observing it at a magnification of 500 times using a scanning electron microscope (SEM). It is required by doing. The average diameter of the filaments in the glass yarn is the same as described above, and the diameters of all filaments contained in one glass yarn are measured at a magnification of 500 times using a scanning electron microscope (SEM). The average value is calculated.

In the woven fabric used for the solid electrolyte reinforcing material of the present invention, the woven density of at least one of warp and weft needs to be 30 to 75/25 mm, and particularly preferably 50 to 60/25 mm. Thereby, the obtained solid electrolyte can have excellent tensile strength and low swellability at the time of water content, and excellent ionic conductivity. It is preferable that both the warp and the weft satisfy the range of the weave density from the viewpoint of further combining the tensile strength and low swellability with water and ionic conductivity when containing water. In the present invention, the weave density of the warp and the weft is a value determined according to a method defined in Japanese Industrial Standard “JIS R 3420 2013 7.9”.

In the woven fabric used for the solid electrolyte reinforcing material of the present invention, the mixing ratio of the glass yarn in the woven fabric is not particularly limited as long as the effect of the present invention is achieved, but is preferably 70% by mass or more, and 80% by mass. The above is more preferable, and 100% by mass (woven fabric made only of glass yarn) is particularly preferable.

The woven structure of the woven fabric used for the solid electrolyte reinforcing material of the present invention is not particularly limited, and examples thereof include plain weave, satin weave, twill weave, oblique weave, and woven weave.

Regarding the thickness of the woven fabric used for the solid electrolyte reinforcing material of the present invention, the viewpoint of making the tensile strength and low swellability at the time of water inclusion and the ionic conductivity even better when contained in the solid electrolyte membrane Therefore, 8 to 30 μm is preferable, and 8 to 20 μm is more preferable. In the present invention, the thickness of the woven fabric is a value determined according to a method defined in Japanese Industrial Standard “JIS R 3420 2013 7.10.1A method”.

In the solid electrolyte reinforcing material of the present invention, the mass of the woven fabric is not particularly limited, but the viewpoint of making the tensile strength and low swellability and ionic conductivity at the time of water content more effective both compatible with each other more effectively. Therefore, 5 to 30 g / m ² is preferable, 5 to 20 g / m ² is more preferable, and 5 to 10 g / m ² is particularly preferable. In the present invention, the mass of the woven fabric is a value determined according to a method defined in Japanese Industrial Standard “JIS R 3420 2013 7.2”.

It is preferable that the solid electrolyte reinforcing material of the present invention does not substantially contain a binder component that enhances the binding property with the solid electrolyte to be reinforced. Thereby, the obtained solid electrolyte membrane has a better film formation state, and for example, the output characteristics when used in a fuel cell can be further improved. Here, “substantially no binder component” means that the binder component is not actively applied to the fabric constituting the solid electrolyte reinforcing material, or the binder component is removed by heat cleaning treatment (heating treatment). As a result, it means that these are not contained. Such a binder component is particularly preferably zero in content, but within a range not impairing the effects of the present invention, it is about 0.1% by mass or less, more preferably 0.05% by mass or less in the solid electrolyte reinforcing material. Even if it is included, there is no problem.

Specific examples of the binder component that enhances the binding property with the solid electrolyte to be reinforced include silane coupling agents, starch and synthetic resins (for example, acrylic resins, urethane resins, fluororesins, silicone resins, epoxy resins, polyesters). Resin) and the like, and inorganic binders such as silica and alkyl silicate. Further, similarly to the binder component, the content of the surfactant is particularly preferably zero, but within a range not impairing the effects of the present invention, the solid electrolyte reinforcing material has a content of about 0.1% by mass or less. Preferably about 0.05 mass% or less may be contained.

When the solid electrolyte reinforcing material of the present invention does not substantially contain the binder component, when an inorganic / organic hybrid compound described later is used as the solid electrolyte to be reinforced, the binding property between the reinforcing material and the solid electrolyte is particularly good. As a result, the film formation state becomes even better, and the output characteristics when used in a fuel cell can be further effectively improved.

Examples of a method for producing a solid electrolyte reinforcing material substantially not containing the binder component include a method of subjecting a woven fabric made of glass yarn to a heat cleaning treatment (heating treatment). Examples of the heat cleaning treatment conditions include a temperature of 350 to 450 ° C. and a time of 20 to 60 hours.

<Solid electrolyte membrane>
The solid electrolyte membrane of the present invention is characterized by including the solid electrolyte reinforcing material and the solid electrolyte. Since the solid electrolyte membrane of the present invention is reinforced by the solid electrolyte reinforcing material, it becomes possible to combine ion conductivity while improving the tensile strength and low swellability when containing water.

The solid electrolyte used in the solid electrolyte membrane of the present invention is not particularly limited as long as it conducts ions such as protons. For example, a polymer electrolyte, an ion conductive inorganic substance, an ion conductive inorganic / organic A hybrid compound etc. are mentioned.

Examples of the polymer electrolyte include a fluorine-based polymer electrolyte, a hydrocarbon-based polymer electrolyte, and a chemically modified fullerene ion conductor. Examples of the fluorine-based polymer electrolyte include perfluoroalkylene as a main skeleton, and sulfo And those having an ion exchange group such as a group or a carboxyl group. Examples of the hydrocarbon polymer electrolyte include sulfonated aromatic polymers such as polystyrene, polyarylene ether, polyimide, polyphosphazene, polybenzimidazole.

Examples of the ion conductive inorganic / organic hybrid compound include those containing an organic part and an inorganic part containing one or more elements selected from Si, Al, Ti, Sn, Zr, Mo, and W and O. Specifically, a hybrid compound in which at least one selected from a silicic acid compound, a tungstic acid compound, and a zirconic acid compound and polyvinyl alcohol are chemically bonded (hereinafter sometimes referred to as a hybrid compound A), etc. Can be mentioned. In particular, the hybrid compound A has particularly good binding properties between the solid electrolyte reinforcing material and the solid electrolyte, and the film-forming state becomes even better. For example, the output characteristics when used in a fuel cell are further improved. It becomes easy to improve.

The solid electrolyte membrane of the present invention only needs to contain the solid electrolyte reinforcing material as a membrane matrix.

In the solid electrolyte membrane of the present invention, the ratio between the solid electrolyte and the solid electrolyte reinforcing material may be appropriately set according to the use of the solid electrolyte membrane, the type of the solid electrolyte to be used, etc. For example, the solid electrolyte 100 The solid electrolyte reinforcing material is 10 to 70 parts by weight, preferably 20 to 50 parts by weight, and more preferably 20 to 40 parts by weight per part by weight.

In addition, the thickness of the solid electrolyte membrane of the present invention may be appropriately set according to the use of the solid electrolyte membrane, and is, for example, 20 to 200 μm, preferably 20 to 50 μm, more preferably 20 to 30 μm. Can be mentioned.

The method for producing the solid electrolyte membrane of the present invention is not particularly limited. For example, the solid electrolyte membrane may be produced by impregnating the solid electrolyte reinforcing material with a liquid in which the solid electrolyte is dispersed or dissolved and then drying. Is mentioned.

The solid electrolyte membrane of the present invention can achieve both the tensile strength and low swellability that could not be obtained by the prior art, and ion conductivity such as protons. For example, solid electrolyte fuel cells, solid electrolyte hydrogen generation It can be suitably used for an apparatus or the like. In addition, since the solid electrolyte membrane of the present invention is excellent in hydroxide ion permeability, it can also be applied as a separator for an alkaline water electrolysis type hydrogen generator.

In the fuel cell using the solid electrolyte membrane of the present invention, portions other than the solid electrolyte are not particularly limited, and the same configuration as that of a known fuel cell can be applied. For example, a known fuel electrode is provided on both sides of the solid electrolyte. A known air electrode is arranged.

Hereinafter, the present invention will be described in detail by way of examples. However, the present invention is not limited to the following examples.

1. Evaluation method (1) Count of glass yarn (tex)
It was measured and calculated according to the method described in Japanese Industrial Standard “JIS R 3420 2013 7.1”.

(2) Glass filament average filament diameter (μm), average filament number (pieces)
Two pieces of the resulting woven fabric cut into 30 cm squares are prepared, one for warp observation and the other for weft observation, and each is embedded in an epoxy resin (trade name 3091 manufactured by Marumoto Struers Co., Ltd.). It was hardened, polished to such an extent that warps and wefts could be observed, and observed and measured at a magnification of 500 times using SEM (trade name JSM-6390A, manufactured by JEOL Ltd.).

(3) Weaving density (main / 25mm)
According to the method described in Japanese Industrial Standard “JIS R 3420 2013 7.9”, the weave density of warp and weft was measured and calculated.

(4) Thickness of fabric (μm)
It was measured and calculated according to the method described in Japanese Industrial Standard “JIS R 3420 2013 7.10.1A Method”.

(5) Mass of fabric (g / m ² )
It was measured and calculated according to the method described in Japanese Industrial Standard “JIS R 3420 2013 7.2”.

(6) Composition and mass ratio (mass%) of the glass composition constituting the glass yarn
It was measured by alkali melting-ICP emission spectrometry and atomic absorption spectrophotometry.

(7) Tensile strength (MPa) of the solid electrolyte membrane when it contains water
A test piece was prepared by cutting the solid electrolyte membrane into a size of 20 mm × 40 mm. After the test piece is immersed in pure water at 20 to 25 ° C. for 1 hour to absorb water, the strength until the solid electrolyte membrane breaks is measured using a weighted measuring instrument, and the tensile strength is calculated by the following formula (a). Was calculated.
Tensile strength (MPa) = measurement load (N) / membrane cross-sectional area (width mm × thickness mm) (a)

(8) Swellability of solid electrolyte membrane (%)
A test piece was prepared by cutting the solid electrolyte membrane into a size of 20 mm × 40 mm. The test piece was immersed in pure water at 20 to 25 ° C. for 1 hour, the area of the test piece before and after immersion was measured, and the degree of swelling was calculated by the following formula (b).
Swelling degree (%) = [(Area after immersion−Area before immersion) / (Area before immersion)] × 100 (b)

(9) Ionic conductivity (mW / cm ² )
Ion conductivity was evaluated by the following method using the maximum output density in the case of a fuel cell as an index. When the maximum output density was 500 mW / m ² or more, it was determined to be acceptable as having excellent ion conductivity.

(Production of membrane electrode assembly (MEA))
In order to evaluate the fuel cell, an electrode was attached to the solid electrolyte membrane to produce a membrane electrode assembly (MEA). As shown in FIG. 1, the produced membrane electrode assembly has catalyst electrode layers 2 and 3 laminated on both sides of a solid electrolyte membrane 1 and gas diffusion layers 4 and 5 laminated on the outermost layer. The catalyst electrode layers 2 and 3 were formed using a 50 wt% platinum-supported carbon catalyst (Tanaka Kikinzoku Kogyo Co., Ltd.) and a Nafion ionomer (5% Solution DE520 CS type). Further, the gas diffusion layer is formed of carbon paper (22.4 × 22.4 mm, thickness 195 μm), and on the inner side (catalyst electrode layers 2 and 3 side), a microporous layer has a thickness of about A layer composed of 10 μm carbon black powder (acetylene black manufactured by Denki Kagaku Kogyo Co., Ltd.) and Teflon (Aldrich) is applied.

(Evaluation of fuel cell output characteristics)
The MEA was set in a commercial fuel cell single cell (manufactured by Electrochem) to constitute a general hydrogen-oxygen fuel cell. Specifically, as shown in FIG. 1, the MEA (members 1 to 5 in FIG. 1) is connected to the conductive separators 6 and 7 which also serve as the chamber separation and the gas supply flow path to the electrodes. A predetermined flow rate of hydrogen 8 and oxygen 9 was passed through the flow path. The maximum power density (mW / cm ² ) was measured by controlling the single cell for fuel cell thus set so that the cell temperature was 80 ° C. and the relative humidity of the supply gas was 100%.

2. Production of solid electrolyte reinforcement and solid electrolyte membrane
Example 1
(1) Production of solid electrolyte reinforcing material As warp and weft, the glass composition is 60 to 70% by mass of SiO _{2 and} 20 to 30% by mass of Al ₂ O ₃ , CaO, MgO, Na ₂ O and K Glass yarn having a total content of ₂ O of 10 to 20% by mass and a total content of Na ₂ O and K ₂ O of 2% by mass or less (glass composition A) (number 1.7 tex, average) Weaving with an air jet loom using a filament diameter of 4.1 μm, 51 filaments, and 0.5 Z twist, a plain weave glass cloth having a warp density of 55/25 mm and a weft density of 55/25 mm was obtained. . Subsequently, the spinning sizing agent and the weaving sizing agent adhering to the obtained glass cloth were removed by heating (heat cleaning) at 400 ° C. for 30 hours to obtain a solid electrolyte reinforcing material. Since the obtained solid electrolyte reinforcing material was subjected to a heat cleaning treatment, it did not substantially contain a binder component that enhances the binding property with the solid electrolyte to be reinforced.

(2) Manufacture of a solid electrolyte membrane A raw material solution of an inorganic / organic hybrid membrane (registered trademark iO-plane, manufactured by Nippon Kogyo Paper Co., Ltd.) in which a silicate compound and a tungstate compound are chemically bonded to polyvinyl alcohol is adjusted to a predetermined thickness with an applicator. Then, it was coated on a polyester film substrate. The solid electrolyte reinforcing material obtained above was placed on the solution, heated to 70 to 130 ° C. and dried. When the applied raw material solution was almost dried, the raw material solution was further applied thereon and dried to produce a solid electrolyte membrane. In the obtained solid electrolyte membrane, the ratio of the solid electrolyte reinforcing material per 100 parts by mass of the solid electrolyte was 30 parts by mass. Moreover, the thickness of the obtained solid electrolyte membrane was 25 micrometers.

Example 2
(1) Production of Solid Electrolyte Reinforcing Material As warp and weft, a glass yarn composed of glass composition B shown in Table 1 (number 1.7 tex, average filament diameter 4.1 μm, number of filaments 51, number of twists 0.5 Z) Used, weaving with an air jet loom to obtain a plain weave glass cloth having a warp density of 55/25 mm and a weft density of 55/25 mm. Subsequently, the spinning sizing agent and the weaving sizing agent adhering to the obtained glass cloth were removed by heating at 400 ° C. for 30 hours to obtain a solid electrolyte reinforcing material. Since the obtained solid electrolyte reinforcing material was subjected to a heat cleaning treatment, it did not substantially contain a binder component that enhances the binding property with the solid electrolyte to be reinforced.

(2) Production of solid electrolyte membrane Using the obtained solid electrolyte reinforcing material, a solid electrolyte membrane was produced under the same conditions as in Example 1. In the obtained solid electrolyte membrane, the ratio of the solid electrolyte reinforcing material per 100 parts by mass of the solid electrolyte was 30 parts by mass. Moreover, the thickness of the obtained solid electrolyte membrane was 25 micrometers.

Example 3
(1) Production of Solid Electrolyte Reinforcing Material As a warp and a weft, a glass yarn composed of glass composition A (number 1.7 tex, average filament diameter 4.1 μm, number of filaments 51, number of twists 0.5 Z) and air jet By weaving with a loom, a plain weave glass cloth having a warp density of 55/25 mm and a weft density of 55/25 mm was obtained and used as a solid electrolyte reinforcing material. Since the obtained solid electrolyte reinforcing material was not subjected to a heat cleaning treatment, it contained a binder component that enhances the binding property to the solid electrolyte to be reinforced.

(2) Production of solid electrolyte membrane Using the obtained solid electrolyte reinforcing material, a solid electrolyte membrane was produced under the same conditions as in Example 1. In the obtained solid electrolyte membrane, the ratio of the solid electrolyte reinforcing material per 100 parts by mass of the solid electrolyte was 30 parts by mass. Moreover, the thickness of the obtained solid electrolyte membrane was 30 micrometers.

Example 4
(1) Production of solid electrolyte reinforcing material A solid electrolyte reinforcing material was obtained under the same conditions as in Example 3 except that the warp density was changed to 95/25 mm and the weft density was changed to 55/25 mm. Since the obtained solid electrolyte reinforcing material was not subjected to a heat cleaning treatment, it contained a binder component that enhances the binding property to the solid electrolyte to be reinforced.

(2) Production of solid electrolyte membrane Using the obtained solid electrolyte reinforcing material, a solid electrolyte membrane was produced under the same conditions as in Example 1. In the obtained solid electrolyte membrane, the ratio of the solid electrolyte reinforcing material per 100 parts by mass of the solid electrolyte was 35 parts by mass. Moreover, the thickness of the obtained solid electrolyte membrane was 30 micrometers.

Comparative Example 1
(1) Production of Solid Electrolyte Reinforcing Material As a warp and a weft, a glass yarn made of glass composition A (number 4.2 tex, average filament diameter 4.6 μm, number of filaments 100, number of twists 1.0 Z) and air jet Weaving with a loom gave a plain weave glass cloth with a warp density of 69/25 mm and a weft density of 72/25 mm. Subsequently, the spinning sizing agent and the weaving sizing agent adhering to the obtained glass cloth were removed by heating (heat cleaning) at 400 ° C. for 30 hours to obtain a solid electrolyte reinforcing material. Since the obtained solid electrolyte reinforcing material was subjected to a heat cleaning treatment, it did not substantially contain a binder component that enhances the binding property with the solid electrolyte to be reinforced.

(2) Production of solid electrolyte membrane Using the obtained solid electrolyte reinforcing material, a solid electrolyte membrane was produced under the same conditions as in Example 1. In the obtained solid electrolyte membrane, the ratio of the solid electrolyte reinforcing material per 100 parts by mass of the solid electrolyte was 65 parts by mass. Moreover, the thickness of the obtained solid electrolyte membrane was 40 micrometers.

Comparative Example 2
(1) Production of Solid Electrolyte Reinforcing Material As a warp and a weft, a glass yarn composed of glass composition A (number 1.7 tex, average filament diameter 4.1 μm, number of filaments 51, number of twists 0.5 Z) and air jet Weaving with a loom gave a plain weave glass cloth having a warp density of 95/25 mm and a weft density of 95/25 mm. Subsequently, the spinning sizing agent and the weaving sizing agent adhering to the obtained glass cloth were removed by heating (heat cleaning) at 400 ° C. for 30 hours. Thereafter, the surface treatment agent silane coupling agent (S-350 N-vinylbenzyl-aminoethyl-γ-aminopropyltrimethoxysilane (hydrochloride) Chisso Corporation) was adjusted to a concentration of 15 g / L and squeezed with a padder roll. Then, it dried and cured at 120 degreeC for 1 minute, and obtained the solid electrolyte reinforcing material.

(2) Production of solid electrolyte membrane Using the obtained solid electrolyte reinforcing material, a solid electrolyte membrane was produced under the same conditions as in Example 1. In the obtained solid electrolyte membrane, the ratio of the solid electrolyte reinforcing material per 100 parts by mass of the solid electrolyte was 45 parts by mass. Moreover, the thickness of the obtained solid electrolyte membrane was 30 micrometers.

3. The results obtained are shown in Table 2. From this result, it is made of a woven fabric manufactured by using glass yarn having a yarn count of 1.0 to 3.5 tex as warp and weft and setting the weave density of at least one of the warp and weft to 30 to 75 yarns / 25 mm. The solid electrolyte membranes (Examples 1 to 4) using the solid electrolyte reinforcing material had high tensile strength when containing water, low swelling, and excellent ionic conductivity. In particular, when a solid electrolyte reinforcing material substantially not containing a binder component was used (Examples 1 and 2), the ion conductivity was remarkably excellent. On the other hand, in the case of using a solid electrolyte reinforcement made of a woven fabric manufactured using glass yarns exceeding 3.5 tex as warp and weft, the material (Comparative Example 1) has insufficient ion conductivity. In addition, when a glass electrolyte of 1.75 tex is used as the warp and weft, when a solid electrolyte reinforcing material in which the weave density of the warp and weft exceeds 75/25 mm is used (Comparative Example 3), The conductivity was insufficient.

DESCRIPTION OF SYMBOLS 1 Solid electrolyte membrane 2, 3 Catalyst electrode layer 4, 5 Gas diffusion layer 6, 7 Separator 8 Hydrogen 9 Oxygen

Claims

Including glass yarn with a count of 1.0 to 3.5 tex as warp and weft,
A solid electrolyte reinforcing material, which is a woven fabric having a weaving density of at least one of the warp and the weft of 30 to 75/25 mm.
The solid electrolyte reinforcing material according to claim 1, wherein the glass filament has an average filament diameter of 3.0 to 4.8 µm.
The solid electrolyte reinforcing material according to claim 1 or 2, which does not substantially contain a binder component that enhances the binding property with the solid electrolyte to be reinforced.
The solid electrolyte according to any one of claims 1 to 3, wherein the glass composition constituting the glass yarn has a total content of CaO, MgO, Na 2 O and K 2 O of 20% by mass or less. Reinforcement.
In order to reinforce the solid electrolyte membrane of the fuel cell, a glass yarn having a yarn count of 1.0 to 3.5 tex is included as a warp and a weft, and a woven density of at least one of the warp and the weft is 30 to 75/25 mm The use of textiles that are.
A solid electrolyte membrane comprising a solid electrolyte and the solid electrolyte reinforcing material according to any one of claims 1 to 4.
The solid electrolyte membrane according to claim 6, wherein the solid electrolyte is an ion conductive inorganic / organic hybrid compound.
The solid electrolyte according to claim 7, wherein the ion conductive inorganic / organic hybrid compound is an inorganic / organic hybrid compound in which at least one selected from a silicic acid compound and a tungstic acid compound is chemically bonded to polyvinyl alcohol. film.
Use of a membrane containing a solid electrolyte and the solid electrolyte reinforcing material according to any one of claims 1 to 4 as a solid electrolyte membrane of a fuel cell.
A fuel cell comprising the solid electrolyte membrane according to any one of claims 6 to 8.