JP2010040252A - Ionic conductor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ionic conductor capable of exhibiting high ionic conductivity and excellent durability, as well as an electrochemical cell and a fuel cell using the same. <P>SOLUTION: The ionic conductor contains two or more kinds of electrolyte with different compatibility with water. At least a part of the electrolyte forming a surface of the ionic conductor is to be one other than that with the highest compatibility with water, out of the two kinds of electrolyte with different compatibility with water. The electrochemical cell is made up by adopting the ionic conductor. The fuel cell is made up by adopting the ionic conductor. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to an ionic conductor, and more specifically, an ionic conductor having two or more electrolytes having different compatibility with water and having a predetermined structure, an electrochemical cell to which the ionic conductor is applied, and The present invention relates to a fuel cell.
Such ionic conductors include, for example, fuel cells, lithium ion batteries, electric double layer capacitors, dye-sensitized solar cells, water electrolysis, hydrohalic acid electrolysis, salt electrolysis, oxygen concentrators, humidity sensors, gas sensors, etc. It can be suitably used as an electrolyte.

In recent years, in countries that consume a lot of energy, solving environmental problems and energy problems has become a major issue.
The fuel cell is a next-generation energy supply device that has high power generation efficiency and excellent environmental load suppression, and is expected to contribute to solving these problems.
Fuel cells are classified according to the type of electrolyte. Among them, polymer electrolyte fuel cells are small and can provide high output. For this reason, research and development are underway for application as an energy supply source for small stationary devices, mobile objects, and portable terminals.

  In such a polymer electrolyte fuel cell, the polymer electrolyte responsible for ion conduction generally includes a perfluorosulfonic acid polymer electrolyte having a perfluorocarbon main chain and a side chain having a sulfonic acid group. in use.

Such a perfluorosulfonic acid polymer electrolyte is considered to be microphase-separated into a region mainly composed of a sulfonic acid group and a region mainly composed of a perfluorocarbon-based main chain. In addition, in the phase containing a sulfonic acid group, the sulfonic acid group is considered to form a cluster.
The site where the perfluorocarbon-based main chain aggregates contributes to the chemical stability of the perfluorosulfonic acid-based polymer electrolyte membrane, and the site where the sulfonic acid groups gather to form a cluster However, it is thought that it contributes to the ionic conduction of the perfluorosulfonic acid polymer electrolyte membrane.

  Even with such a perfluorosulfonic acid polymer electrolyte membrane having both excellent chemical stability and ionic conductivity, it can be applied to, for example, a solid polymer fuel cell that is expected to be a power source for moving objects. There are various restrictions on application. There is also a problem of high cost.

For example, current polymer electrolyte fuel cells are operated in a relatively low temperature range from room temperature to about 80 ° C.
The reason why the operation temperature is limited is as follows (1) and (2).
(1) The perfluorosulfonic acid polymer used has a glass transition point in the vicinity of 120 to 130 ° C., and it becomes difficult to maintain an ion channel structure that contributes to proton conduction at higher temperatures. In practice, it is desirable to use at 100 ° C or lower.
(2) Since water is used as a proton conduction medium, pressurization is required when the boiling point of water exceeds 100 ° C., and the apparatus becomes large.

  Further, when the operating temperature of the fuel cell is low, the power generation efficiency of the fuel cell is lowered, and carbon monoxide (CO) poisoning may occur remarkably in the catalyst.

  On the other hand, when the operating temperature of the fuel cell is 100 ° C. or higher, the power generation efficiency of the fuel cell is improved. Furthermore, since exhaust heat can be used, energy can be utilized more efficiently.

  When the operating temperature can be raised to 120 ° C. when the fuel cell is applied to a moving body such as an automobile, for example, not only the power generation efficiency can be improved, but also the radiator load required for exhaust heat can be reduced. Further, for example, a system having the same specifications as the radiator used in the current mobile body can be applied, so that the system can be made compact.

Therefore, as one of solutions to such problems, it has been proposed to use an ionic liquid as an electrolyte as a proton conductor (see Patent Document 1).
Further, it has been disclosed that an ionic liquid composed of a fluorine-based anion having a hydrophilic anion component exhibits excellent power generation characteristics as a fuel cell electrolyte (see Non-Patent Document 1).
Furthermore, it is disclosed that an ionic liquid composed of a neutralized salt of diethylmethylamine and trifluoromethanesulfonic acid exhibits excellent power generation characteristics as an electrolyte for fuel cells (see Non-Patent Document 2).

International Publication No. 03/083981 Pamphlet “The 46th Battery Symposium Abstracts”, 2005, p. 808 “Chemical Communications”, 2007, p. 2539-2541

However, the use of the hydrophobic ionic liquid described in Patent Document 1 as an electrolyte enables power generation of the fuel cell at a high temperature (120 ° C.). However, the fuel cell has sufficient performance such as IV characteristics. There was a problem that it was not obtained.
In addition, the hydrophilic ionic liquid described in Non-Patent Document 1 and Non-Patent Document 2 described above can be used for the water generated during fuel cell power generation even when the hydrophilic ionic liquid is formed into a film by fixing it in a gel form. Since it melt | dissolves and an ionic liquid will escape from a film | membrane, it was difficult to obtain a durable ionic conductor.

  The present invention has been made in view of such problems of the prior art, and an object of the present invention is to provide an ionic conductor that can exhibit high ionic conductivity and excellent durability, and electricity using the ionic conductor. It is to provide a chemical cell and a fuel cell.

  The inventors of the present invention have made extensive studies in order to achieve the above object. As a result, the inventors have found that the above object can be achieved by containing two or more kinds of electrolytes having different compatibility with water and having an ionic conductor having a predetermined structure, thereby completing the present invention.

  That is, the ionic conductor of the present invention is an ionic conductor containing two or more kinds of electrolytes having different compatibility with water, and at least a part of the electrolyte forming the surface of the ionic conductor is incompatible with the water. It is an electrolyte other than the electrolyte having the highest compatibility with water among two or more electrolytes having different compatibility.

  The electrochemical cell of the present invention is characterized by applying the ionic conductor of the present invention.

  Furthermore, the fuel cell of the present invention is characterized by applying the ionic conductor of the present invention.

  According to the present invention, two or more kinds of electrolytes having different compatibility with water are used to form an ionic conductor having a predetermined structure. Therefore, ions that can exhibit high ionic conductivity and excellent durability. A conductor, an electrochemical cell using the same, and a fuel cell can be provided.

Hereinafter, the ion conductor of the present invention will be described in detail.
The ionic conductor of the present invention contains two or more electrolytes having different compatibility with water.
Further, at least a part of the electrolyte forming the surface of the ion conductor is an electrolyte other than the electrolyte having the highest compatibility with water among two or more electrolytes having different compatibility with water.
By adopting such a configuration, high ion conductivity and excellent durability can be exhibited.

Here, the “compatibility with water” indicates the degree of compatibility with water.
For example, the electrolyte is fixed with a gelling agent to form a membrane shape, the membrane is immersed in water for a certain period of time, the change in mass of the membrane before and after immersion is measured, and the rate of change (electrolyte retention) is calculated. Based on this electrolyte retention, compatibility with water can be defined.
Specifically, the electrolyte retention rate can be calculated by the following equation [1].
Moreover, a high electrolyte retention means that the compatibility with water is low, and a low electrolyte retention means that the compatibility with water is high.

  In the present invention, the two or more kinds of electrolytes contained in the ionic conductor may be different if they have different compatibility with water.

  Hereinafter, some embodiments of the ion conductor of the present invention will be described with reference to the drawings. In all the drawings of the following embodiments, the same or corresponding parts are denoted by the same reference numerals.

(1) 1st Embodiment FIG. 1: is the top view (a) and sectional drawing (b) which show an example of the schematic structure of 1st Embodiment of the ion conductor of this invention. FIG. 2B is a cross-sectional view taken along line I-I in FIG.
As shown in the figure, the ionic conductor 10 contains two types of electrolytes 11 and 13 having different compatibility with water.
In the present embodiment, the electrolyte 11 is the electrolyte having the highest compatibility with water among the electrolytes included in the ion conductor 10. On the other hand, the electrolyte 13 is an electrolyte other than the electrolyte having the highest compatibility with water among the electrolytes included in the ion conductor 10. That is, when the compatibility of the electrolyte 11 and the electrolyte 13 with water is compared, the result shows that the electrolyte 11 has a relatively high compatibility with water.
The ion conductor 10 is an electrolyte 13 other than the electrolyte 11 having the highest compatibility with water among two types of electrolytes having different compatibility with water, at least a part of the electrolyte forming the surface thereof. The electrolyte 13 is scattered and scattered on the surface of the ion conductor 10.

By adopting such a configuration, high ion conductivity and excellent durability can be exhibited.
As another example of the present embodiment, although not shown, not only the electrolyte that forms the surface of the ionic conductor, but also the electrolyte that forms the interior is compatible with water among the electrolytes contained in the ionic conductor. What is electrolyte other than the highest electrolyte can be mentioned.
The electrolyte 13 is not limited to the case where the electrolyte 13 is dispersed and scattered on the surface of the ion conductor 10, and can take various forms. For example, the following second embodiment can be given.

(2) Second Embodiment FIG. 2 is a plan view (a) and a cross-sectional view (b) showing an example of a schematic configuration of a second embodiment of the ion conductor of the present invention. In addition, the figure (b) is sectional drawing along the II-II line of the figure (a).
As shown in the figure, the ionic conductor 10 contains two types of electrolytes 11 and 13 having different compatibility with water. Also in the present embodiment, the electrolyte 11 is the electrolyte having the highest compatibility with water among the electrolytes included in the ion conductor 10. On the other hand, the electrolyte 13 is an electrolyte other than the electrolyte having the highest compatibility with water among the electrolytes included in the ion conductor 10.
The ion conductor 10 is an electrolyte 13 other than the electrolyte 11 having the highest compatibility with water among two types of electrolytes having different compatibility with water, at least a part of the electrolyte forming the surface thereof. The electrolyte 13 is localized on the surface of the ion conductor 10 by forming a large lump to some extent.

By adopting such a configuration, high ion conductivity and excellent durability can be exhibited.
As another example of the present embodiment, although not shown, not only the electrolyte that forms the surface of the ionic conductor, but also the electrolyte that forms the interior is compatible with water among the electrolytes contained in the ionic conductor. What is electrolyte other than the highest electrolyte can be mentioned.

In the first and second embodiments, the case where the ion conductor contains two types of electrolytes having different compatibility with water has been described. However, the ion conductor contains three or more types of electrolytes. It can also be applied to cases.
And when it contains three or more types of electrolytes with different compatibility with water, electrolytes other than the electrolyte with the highest compatibility with water among the three or more types of electrolytes with different compatibility with water Of the three or more electrolytes having different compatibility, the electrolyte is not necessarily the one having the lowest compatibility with water.
In such a case, it is preferable that at least a part of the electrolyte forming the surface of the ionic conductor is an electrolyte having the lowest compatibility with water among three or more electrolytes having different compatibility with water.
However, the present invention is not limited to this, and the case where at least a part of the electrolyte forming the surface of the ionic conductor is an electrolyte having the second lowest compatibility with water, for example, is also included in the scope of the present invention.

(3) Third Embodiment FIG. 3 is a plan view (a) and a sectional view (b) showing an example of a schematic configuration of a third embodiment of the ion conductor of the present invention. In addition, the figure (b) is sectional drawing along the III-III line of the figure (a).
As shown in the figure, this ionic conductor 10 contains two types of membrane electrolytes 11 and membrane electrolytes 13 having different compatibility with water, and the thickness direction of the membrane electrolyte 11 (13). Has a layer structure. Also in this embodiment, the membrane electrolyte 11 is a membrane electrolyte having the highest compatibility with water among the membrane electrolyte contained in the ion conductor 10. On the other hand, the membrane electrolyte 13 is a membrane electrolyte other than the membrane electrolyte having the highest compatibility with water among the membrane electrolytes contained in the ion conductor 10.
The ion conductor 10 has a part of the membrane electrolyte that forms at least one surface in the thickness direction of the membrane electrolyte 11 (13). Of the two types of electrolytes having different compatibility with water, It is an electrolyte 13 other than the electrolyte 11 having the highest compatibility. The electrolyte 13 is unevenly distributed on the surface of the ion conductor 10.

By adopting such a configuration, high ion conductivity and excellent durability can be exhibited.
Further, as another example of the present embodiment, although not shown, not only the membrane electrolyte that forms the surface of the ion conductor, but also the membrane electrolyte that forms the inside includes the membrane electrolyte that is included in the ion conductor. Among these electrolytes, those having a membrane-like electrolyte other than the membrane-like electrolyte having the highest compatibility with water can be mentioned.

In the third embodiment, the case where the ionic conductor contains two kinds of membrane-like electrolytes having different compatibility with water has been described. However, three or more kinds of membrane-like electrolytes are contained. It can also be applied when
For example, as another example of this embodiment, although not shown, in the ion conductor, a part of the membrane electrolyte that forms at least one surface in the thickness direction of the membrane electrolyte is included in the ion conductor. Among the electrolytes that can be used, there can be mentioned membrane electrolytes other than the membrane electrolyte having the highest compatibility with water, wherein the membrane electrolyte contains two or more types of membrane electrolytes. .
In addition, when three or more kinds of membrane electrolytes having different compatibility with water are contained, among the three or more kinds of membrane electrolytes with different compatibility with water, the film shape having the highest compatibility with water A membrane electrolyte other than the electrolyte is not necessarily a membrane electrolyte having the lowest compatibility with water among three or more types of membrane electrolytes having different compatibility with water.
In such a case, at least a part of the membrane electrolyte forming the surface of the ion conductor is a membrane electrolyte having the lowest compatibility with water among three or more membrane electrolytes having different compatibility with water. It is preferable that
However, the present invention is not limited to this, and in the ionic conductor, at least a part of the membrane electrolyte forming at least one surface in the thickness direction of the membrane electrolyte has, for example, the second compatibility with water. A low membrane electrolyte is also included in the scope of the present invention.

(4) Fourth Embodiment FIG. 4 is a plan view (a) and a sectional view (b) showing an example of a schematic configuration of a fourth embodiment of the ion conductor of the present invention. FIG. 2B is a cross-sectional view taken along the line IV-IV in FIG.
As shown in the figure, this ionic conductor 10 contains two types of membrane electrolytes 11 and membrane electrolytes 13 having different compatibility with water, and the thickness direction of the membrane electrolyte 11 (13). Has a layer structure. Also in this embodiment, the membrane electrolyte 11 is a membrane electrolyte having the highest compatibility with water among the membrane electrolyte contained in the ion conductor 10. On the other hand, the membrane electrolyte 13 is a membrane electrolyte other than the membrane electrolyte having the highest compatibility with water among the membrane electrolytes contained in the ion conductor 10.
And the ion conductor 10 is a phase with respect to water among two types of electrolytes in which all of the membrane electrolyte forming at least one surface in the thickness direction of the membrane electrolyte 11 (13) has different compatibility with water. It is an electrolyte 13 other than the electrolyte 11 having the highest solubility.

By adopting such a configuration, high ion conductivity and excellent durability can be exhibited.
Further, as another example of the present embodiment, although not shown, in the ion conductor, a part of the membrane electrolyte that forms at least one surface in the thickness direction of the membrane electrolyte is included in the ion conductor. Among the electrolytes that can be used, there can be mentioned membrane electrolytes other than the membrane electrolyte having the highest compatibility with water, wherein the membrane electrolyte contains two or more types of membrane electrolytes. .

(5) Fifth Embodiment FIGS. 5A and 5B are a plan view and a cross-sectional view showing an example of a schematic configuration of a fifth embodiment of the ion conductor of the present invention. FIG. 2B is a cross-sectional view taken along the line V-V in FIG.
As shown in the figure, the ionic conductor 10 includes three kinds of membrane electrolytes 11 having different compatibility with water, a membrane electrolyte 13, and a membrane electrolyte 15, and the membrane electrolyte 11. It has a layer structure with respect to the thickness direction of (13, 15). Also in this embodiment, the membrane electrolyte 11 is a membrane electrolyte having the highest compatibility with water among the membrane electrolyte contained in the ion conductor 10. On the other hand, the membrane electrolyte 13 and the membrane electrolyte 15 are membrane electrolytes other than the membrane electrolyte having the highest compatibility with water among the membrane electrolytes contained in the ion conductor 10.
The ionic conductor 10 is composed of two electrolytes having different compatibility with water in which all of the membrane electrolyte forming at least one surface in the thickness direction of the membrane electrolyte 11 (13, 15) is water. This is an electrolyte 13 other than the electrolyte 11 having the highest compatibility with respect to.

By adopting such a configuration, high ion conductivity and excellent durability can be exhibited.
Although not particularly limited, the membrane-like electrolyte 13 forming the surface of the ion conductor is a membrane having the lowest compatibility with water among three or more types of membrane-like electrolytes having different compatibility with water. It is preferable that the electrolyte be in the form of a liquid.
In addition, as a typical example of such a case, although not shown, a plurality of kinds of membrane-like electrolytes having different compatibility with water are contained, and a membrane-like electrolyte having the highest compatibility with water in the thickness direction. Examples include those having a gradient structure with respect to water compatibility, from the membrane electrolyte having the lowest water compatibility.

Moreover, in the said 4th and 5th embodiment, although it does not specifically limit, For example, the ratio of the thickness of the electrolyte with the highest compatibility with water among 2 or more types of electrolytes with which compatibility with water differs is shown. When the total thickness of the membrane electrolyte is 1, it is preferably 0.3 to 0.99, more preferably 0.5 to 0.99.
The ratio of the thickness of the electrolyte may be adjusted as appropriate depending on the form of the ionic conductor, and is included in the scope of the present invention even when the value is not within the above-described range.

(6) Sixth Embodiment FIG. 6 is a plan view (a) and a cross-sectional view (b) showing an example of a schematic configuration of a sixth embodiment of the ion conductor of the present invention. FIG. 2B is a cross-sectional view taken along line VI-VI in FIG.
As shown in the figure, the ion conductor 10 is sandwiched between a cathode 20 and an anode 30 and used for a fuel cell.
And this ion conductor 10 contains two types of membrane-like electrolytes 11 and membrane-like electrolytes 13 having different compatibility with water, and has a layer structure with respect to the thickness direction of the membrane-like electrolyte 11 (13). have. Also in the present embodiment, the electrolyte 11 is the electrolyte having the highest compatibility with water among the electrolytes included in the ion conductor 10. On the other hand, the electrolyte 13 is an electrolyte other than the electrolyte having the highest compatibility with water among the electrolytes included in the ion conductor 10.
In addition, the ion conductor 10 has a membrane-like electrolyte that forms at least one surface in the thickness direction of the membrane-like electrolyte 11 (13), and is compatible with water among two types of electrolytes having different compatibility with water. It is an electrolyte 13 other than the highest electrolyte 11.
Furthermore, an electrolyte 13 other than the electrolyte having the highest compatibility with water among the electrolytes included in the ion conductor 10 is disposed on the cathode 20 side.
The cathode 20 and the anode 30 are each composed of a catalyst layer 21 (31) and a gas diffusion layer 23 (33).
In the technical field of fuel cells, generally, a membrane-shaped ion conductor sandwiched between a cathode and an anode is called a membrane electrode assembly (MEA).

By adopting such a configuration, high ion conductivity and excellent durability can be exhibited.
Specifically, a membrane electrolyte having low compatibility with water is disposed on the cathode side. By setting it as such an arrangement | positioning, it can be made hard to receive the influence of the produced water produced | generated by the cathode side, and the elution to the water of an electrolyte can be suppressed effectively. Thereby, durability with respect to the melt | dissolution to the water of an ion conductor improves. Furthermore, by disposing a membrane-like electrolyte that has excellent power generation performance as an electrolyte for fuel cells and is highly compatible with water on the anode side, it is possible to obtain its power generation performance as a fuel cell by drawing out its characteristics. .

(7) Seventh Embodiment FIG. 7 is a plan view (a), a sectional view (b), and a sectional view (c) showing an example of a schematic configuration of a seventh embodiment of the ion conductor of the present invention. It is. 2B is a sectional view taken along line VII-VII in FIG. 1A, and FIG. 2C is a sectional view taken along line VII′-VII ′ in FIG. FIG.
As shown in the figure, the ion conductor 10 is sandwiched between a cathode 20 and an anode 30 and further sandwiched between separators and used for a fuel cell.
And this ion conductor 10 contains two types of membrane-like electrolytes 11 and membrane-like electrolytes 13 having different compatibility with water, and has a layer structure with respect to the thickness direction of the membrane-like electrolyte 11 (13). have. Also in the present embodiment, the electrolyte 11 is the electrolyte having the highest compatibility with water among the electrolytes included in the ion conductor 10. On the other hand, the electrolyte 13 is an electrolyte other than the electrolyte having the highest compatibility with water among the electrolytes included in the ion conductor 10.
In addition, the ion conductor 10 has a part of the membrane electrolyte that forms at least one surface in the thickness direction of the membrane electrolyte 11 (13). It is an electrolyte 13 other than the electrolyte 11 having the highest compatibility.
Further, an electrolyte 13 other than the electrolyte having the highest compatibility with water among the electrolytes included in the ion conductor 10 is disposed on the cathode 20 side and in detail on the downstream side in the cathode gas flow direction, which will be described later. Yes.
The cathode 20 and the anode 30 are each composed of a catalyst layer 21 (31) and a gas diffusion layer 23 (33).
In the separator 40, a cathode gas channel 41 and an anode gas channel 43 are formed on the cathode 20 side and the anode 30 side, respectively. For example, the cathode gas introduced from the cathode gas inlet 41a flows in the cathode gas channel 41 as indicated by an arrow, and is discharged from the cathode gas outlet. In the present embodiment, the cathode gas channel 41 forms a so-called serpentine channel.

By adopting such a configuration, high ion conductivity and excellent durability can be exhibited.
Specifically, a membrane electrolyte having a high compatibility with water is arranged on the upstream side in the flow direction of the cathode gas, and a membrane electrolyte having a low compatibility with water is arranged on the downstream side. By adopting such an arrangement, it is possible to effectively suppress the elution of the electrolyte into the water on the downstream side that is susceptible to the generated water generated on the cathode side. Thereby, durability with respect to the melt | dissolution to the water of an ion conductor improves. Furthermore, by arranging a membrane-like electrolyte having excellent power generation performance as a fuel cell electrolyte and having high compatibility with water on the upstream side, it is possible to obtain its power generation performance as a fuel cell by drawing out its characteristics. .

In the sixth and seventh embodiments, the case where the ion conductor contains two kinds of membrane-like electrolytes having different compatibility with water has been described. However, three or more kinds of membrane-like electrolytes have been described. It can also be applied when an electrolyte is contained.
For example, as another example of the present embodiment, although not shown, in the ion conductor, all or part of the membrane electrolyte forming at least one surface in the thickness direction of the membrane electrolyte is an ion conductor. A membrane electrolyte other than the membrane electrolyte having the highest compatibility with water among the electrolytes contained in the electrolyte, wherein the membrane electrolyte contains two or more types of membrane electrolytes Can do.
Further, for example, as still another example of the present embodiment, although not shown, in the ion conductor, all or part of the membrane electrolyte forming at least one surface in the thickness direction of the membrane electrolyte is water. Among the three or more kinds of membrane-like electrolytes having different compatibility with respect to water, those having the lowest membrane-like electrolyte with respect to water can be mentioned.

Moreover, in the said ion conductor, the thing whose 2 or more types of electrolyte from which compatibility with water differs, for example is a gel-like electrolyte is employable.
By adopting such a configuration, high ion conductivity and excellent durability can be exhibited.
Specifically, two or more types of electrolytes having different compatibility with water can be prevented from being substantially compatible with each other by gelling and semi-fixing or fixing. Thereby, for example, an electrolyte having low compatibility with water can be continuously disposed on the cathode side, and durability is improved.

The gel electrolyte contains an electrolyte and a polymer that holds the electrolyte.
Examples of the polymer include polymethyl methacrylate (PMMA), polyhydroxyethyl methacrylate, polymethacrylonitrile, poly-4-vinylpyridine, polystyrene, and polyimide. These may be used alone or in combination. When they are combined, they may be used in combination, or may be appropriately selected according to the electrolyte.

An example of a method for manufacturing the above-described ion conductor will be described.
First, two types of electrolytes having different compatibility with water are prepared.
Subsequently, one electrolyte and the monomer which is a raw material of a polymer are mixed, a monomer is polymerized and gelatinized, and one membrane-like electrolyte is produced. The other membrane-like electrolyte is produced by the same process.
Thereafter, by superimposing these, a desired ionic conductor can be produced.
Moreover, it is not limited to this, For example, two types of electrolytes with which water compatibility differs are prepared. Next, one electrolyte and polymer are dissolved in a solvent, the solution is cast on a flat plate, and dried to produce one membrane-like electrolyte. The other membrane-like electrolyte is produced by the same process.
Thereafter, by superimposing these, a desired ion conductor can be produced.

In the ionic conductor, for example, it is desirable that two or more types of electrolytes having different compatibility with water are not substantially compatible with each other.
Here, “two or more types of electrolytes are not compatible with each other” means that when two or more types of electrolytes are not compatible with each other or in other words, even if they are mixed, the generated mixed portion is This is only a part.

  In order to prevent two or more types of electrolytes having different compatibility with water from being mutually compatible, in addition to the method realized by using other components such as the above-described gelation, they are mutually compatible. There is a method of selecting and using an electrolyte that does not dissolve.

In the ionic conductor, for example, an electrolyte having the lowest compatibility with water among two or more electrolytes having different compatibility with water preferably includes an onium cation as a cation component.
Moreover, as a suitable example of this onium cation, for example, it has a monovalent substituent directly bonded to the central atom, and the monovalent substituent is represented by the following general formula (1) or general formula (2). Things can be mentioned.

(In the formula, R ¹ is a hydrogen atom, a halogen atom, or an unsubstituted or substituted hydrocarbon group, Z ¹ is an oxygen atom (O), a sulfur atom (S), an NR ² group (R ² is a hydrogen atom, a halogen atom) Or an unsubstituted or substituted hydrocarbon group) or a PR ³ group (R ³ represents a hydrogen atom, a halogen atom or an unsubstituted or substituted hydrocarbon group).

(In the formula, R ⁴ represents a hydrogen atom, a halogen atom, or an unsubstituted or substituted hydrocarbon group, and Z ² represents a carbonyl group (CO), a sulfonyl group (SO ₂ ), or a difluoromethylene group (CF ₂ ).)

For example, when the onium cation has the structural formula represented by the general formula (1) or (2), water generated by the reaction at the cathode can be effectively utilized.
Specifically, a hydrogen bond is formed between the onium cation and water, and the proton source is effectively released from the water. This increases the proton concentration in the ionic conductor. Furthermore, the proton mobility increases because protons are transmitted (hopped) through water.
In addition, it is also possible to contain polar substances other than water in an ionic conductor, and to form a hydrogen bond with this polar substance.
Examples of such polar substances include urea, melamine, thiourea, guanidine, ammonia, hydrogen sulfide and the like.
Such an effect improves proton conduction in the ion conduction pair. Furthermore, also about the oxygen reduction reaction at a cathode, high reactivity can be acquired by utilizing produced | generated water.

  Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom.

  Examples of the unsubstituted hydrocarbon group include an aliphatic hydrocarbon group and an aromatic hydrocarbon group.

  Examples of the unsubstituted hydrocarbon group include linear or branched alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, and t-butyl group. Preferred examples include linear alkyl groups. Further, the linear or branched alkyl group preferably has 1 to 16 carbon atoms, and more preferably 1 to 10 carbon atoms.

  Examples of the unsubstituted hydrocarbon group include a cycloalkyl group such as a cyclohexyl group. The cycloalkyl group preferably has 3 to 8 carbon atoms, more preferably 3 to 6 carbon atoms.

  Furthermore, examples of the unsubstituted hydrocarbon group include linear or branched alkenyl groups such as vinyl group, 1-propenyl group, and isopropenyl group, preferably linear alkenyl groups. Further, the linear or branched alkenyl group preferably has 2 to 16 carbon atoms, and more preferably 2 to 10 carbon atoms.

  Examples of the unsubstituted hydrocarbon group include cycloalkenyl groups such as 1-cyclohexenyl. The cycloalkenyl group preferably has 3 to 8 carbon atoms, more preferably 3 to 6 carbon atoms.

  Furthermore, examples of the unsubstituted hydrocarbon group include aryl groups such as a phenyl group and a naphthyl group. The aryl group preferably has 6 to 10 carbon atoms.

On the other hand, as the substituted hydrocarbon group, a group in which all or a part of the hydrogen atoms of the unsubstituted hydrocarbon group include a hetero atom or hetero atom such as an oxygen atom, a nitrogen atom, a sulfur atom, or a silicon atom. And a group substituted with a halogen atom, the above-mentioned unsubstituted hydrocarbon group, and the like.
In addition, a group in which a part of carbon atoms of the unsubstituted hydrocarbon group is substituted with a hetero atom or a group containing a hetero atom can be exemplified.

  More specifically, examples of the group in which part of the hydrogen atoms of the unsubstituted hydrocarbon group is substituted with a heteroatom, a group containing a heteroatom, a halogen atom, etc. include, for example, a hydrogen atom of an unsubstituted hydrocarbon group A part of oxo group, sulfide group, hydroxyl group, thiol group, amino group, alkylamino group, ether group, ester group, thioether group, thioester group, amide group, alkylsilyl group, fluorine atom, chlorine atom, bromine atom And hydrocarbon groups substituted by the above. In addition, as a group in which all of the hydrogen atoms of the unsubstituted hydrocarbon group are substituted with halogen atoms, more specifically, for example, a carbon atom in which all of the hydrogen atoms of the unsubstituted hydrocarbon group are substituted with fluorine atoms. A hydrogen group etc. can be mentioned. For example, a perfluoroalkyl group is a typical example.

  More specifically, examples of the group in which part of the carbon atoms of the unsubstituted hydrocarbon group is substituted with a hetero atom or a group containing a hetero atom include straight-chain or branched groups such as a butoxy group and a t-butoxy group. Can be mentioned. Further, the linear or branched alkoxy group preferably has 1 to 16 carbon atoms, and more preferably 1 to 10 carbon atoms.

  More specifically, examples of the group in which part of the carbon atoms of the unsubstituted hydrocarbon group is substituted with a heteroatom or a group containing a heteroatom include a cycloalkyloxy group such as a cyclohexyloxy group. be able to. The cycloalkyloxy group preferably has 3 to 8 carbon atoms, more preferably 3 to 6 carbon atoms.

  Furthermore, as a group in which a part of the carbon atoms of the unsubstituted hydrocarbon group is substituted with a heteroatom or a group containing a heteroatom, more specifically, for example, a linear or branched group such as a butylthiolate group An alkylthiolate group can be exemplified, and the linear or branched alkylthiolate group preferably has 1 to 16 carbon atoms, and more preferably 1 to 10 carbon atoms.

  More specifically, examples of the group in which part of the carbon atoms of the unsubstituted hydrocarbon group is substituted with a hetero atom or a group containing a hetero atom include an alkylamino group such as an N, N-diethylamino group. Can be mentioned. The alkylamino group preferably has 1 to 16 carbon atoms, more preferably 1 to 10 carbon atoms.

  Furthermore, as a group in which a part of carbon atoms of the unsubstituted hydrocarbon group is substituted with a hetero atom or a group containing a hetero atom, more specifically, for example, a phenoxy group, a p-methylphenoxy group, etc. An aryloxy group can be mentioned. The aryloxy group preferably has 6 to 10 carbon atoms.

  The onium cation may have at least one monovalent substituent directly bonded to the central atom described above, but may have a plurality of monovalent substituents directly bonded to the central atom. Moreover, when it has two or more monovalent substituents couple | bonded directly with the central atom, they may be the same or different.

The onium cation has a hydrogen atom, a halogen atom, an unsubstituted hydrocarbon group or a substituted hydrocarbon group directly bonded to the central atom, in addition to the monovalent substituent directly bonded to the central atom. It may be.
Here, the halogen atom, the unsubstituted hydrocarbon group, or the substituted hydrocarbon group may be the same as those described in the above-described monovalent substituent.

  Further, the onium cation has a plurality of hydrogen atoms, halogen atoms, or unsubstituted or substituted hydrocarbon groups directly bonded to the central atom, in addition to the monovalent substituent directly bonded to the central atom. In this case, they may be the same or different.

  Examples of the onium cation include an ammonium cation having a nitrogen atom (N) as a central atom, a phosphonium cation having a phosphorus atom (P) as a central atom, and a sulfonium cation having a sulfur atom (S) as a central atom. .

  More specifically, the onium cation can be represented by, for example, the following general formulas (3) to (5).

(Wherein R ¹ , R ⁴ and R ⁵ are each independently a hydrogen atom, a halogen atom, or an unsubstituted or substituted hydrocarbon group, Z ¹ is independently an oxygen atom (O) or a sulfur atom) (S), an NR ² group (R ² independently represents a hydrogen atom, a halogen atom or an unsubstituted or substituted hydrocarbon group) or a PR ³ group (R ³ is independently a hydrogen atom, A halogen atom or an unsubstituted or substituted hydrocarbon group.), Z ² each independently represents a carbonyl group (CO), a sulfonyl group (SO ₂ ) or a difluoromethylene group (CF ₂ ), and a and b Each represents an integer of 0 to 4 and satisfies the relationship of 0 ≦ a ≦ 4, 0 ≦ b ≦ 4, 1 ≦ a + b ≦ 4.)

(Wherein R ¹ , R ⁴ and R ⁵ are each independently a hydrogen atom, a halogen atom, or an unsubstituted or substituted hydrocarbon group, Z ¹ is independently an oxygen atom (O) or a sulfur atom) (S), an NR ² group (R ² independently represents a hydrogen atom, a halogen atom or an unsubstituted or substituted hydrocarbon group) or a PR ³ group (R ³ is independently a hydrogen atom, A halogen atom or an unsubstituted or substituted hydrocarbon group.), Z ² each independently represents a carbonyl group (CO), a sulfonyl group (SO ₂ ) or a difluoromethylene group (CF ₂ ), and c and d Each represents an integer of 0 to 4, and satisfies the relationship of 0 ≦ c ≦ 4, 0 ≦ d ≦ 4, 1 ≦ c + d ≦ 4.)

(Wherein, R ^1, R ⁴ and R ⁵ are each independently a hydrogen atom, a halogen atom, or an unsubstituted or substituted hydrocarbon group, Z ¹ is independently oxygen atom (O), sulfur atom (S), an NR ² group (R ² independently represents a hydrogen atom, a halogen atom or an unsubstituted or substituted hydrocarbon group) or a PR ³ group (R ³ is independently a hydrogen atom, A halogen atom or an unsubstituted or substituted hydrocarbon group.), Z ² each independently represents a carbonyl group (CO), a sulfonyl group (SO ₂ ) or a difluoromethylene group (CF ₂ ), and e and f Each represents an integer of 0 to 4, and satisfies the relationship of 0 ≦ e ≦ 3, 0 ≦ f ≦ 3, and 1 ≦ e + f ≦ 3.)

In addition, examples of the halogen atom, the unsubstituted hydrocarbon group, or the substituted hydrocarbon group in the formula include the same ones as described above.
Moreover, the said onium cation can be used individually or in mixture, respectively.

In the above onium cation, the phosphorus atom of the phosphonium cation has a larger positive charge bias than the nitrogen atom of the ammonium cation, and it is easy to form a hydrogen bond with water, and it is easy to release protons from the water. It is preferable to apply a phosphonium cation because conductivity is improved.
A phosphonium cation is preferable because it is chemically stable and can be combined with any anion component. Furthermore, phosphonium cations are preferred because they are widely used industrially and are low in cost.

Z ^{1 in} the formulas such as the general formula (1) is an oxygen atom (O) or a sulfur atom (S) from the viewpoint of the steric structure of the cation component and the ease of forming a hydrogen bond with water. It is desirable that
In particular, when Z ¹ is an oxygen atom (O), the electronegativity is large, a hydrogen bond is formed with water, protons are easily released from water, and ion conductivity is improved, so that Z ¹ is an oxygen atom ( O) is preferred.
In addition, water should just be contained at the time of use of an ion conductor, and when making it contain, it does not specifically limit about the method, A conventionally well-known method can be utilized. Specifically, when an ionic conductor is used as an electrolyte for a fuel cell, the supplied gas may contain water, for example. Further, the ion conductor may contain water in advance. Furthermore, you may contain the produced water produced | generated during fuel cell electric power generation.
On the other hand, Z ² in the formula (2) is a carbonyl group (CO) or a sulfonyl group (SO) from the viewpoint of the steric structure of the cation component and the ease of forming a hydrogen bond with water. ₂ ) is desirable.

Furthermore, in the ionic conductor, for example, an electrolyte other than an electrolyte having the lowest compatibility with water among two or more kinds of electrolytes having different compatibility with water is a primary onium cation, a secondary onium cation, or It is desirable to include a tertiary onium cation or any combination thereof.
Here, the primary onium cation is one in which one of the hydrogens of the onium cation is replaced by another element or the like, and the secondary onium cation and the tertiary onium cation are two hydrogens of the onium cation, respectively. And three are substituted by other elements.
By adopting such a configuration, high ion conductivity and excellent durability can be exhibited.
Specifically, when the proton conducting species is a primary, secondary or tertiary onium cation, high proton conductivity and high reactivity with respect to hydrogen oxidation reaction and oxygen reduction reaction as fuel cell reactions can be obtained. it can. Further, for example, when the anion component is an imido acid anion, it becomes easy to lower the compatibility with water, and high durability can be obtained against the elution of the electrolyte by water.

In the ionic conductor, for example, an electrolyte having the lowest compatibility with water among two or more electrolytes having different compatibility with water includes an oxo acid type anion, an imido acid type anion, and a thio acid type. It is desirable to include those related to anions or hydrohalic acid type anions or any combination thereof.
When the anion component is used, the chemical stability and heat resistance are excellent.

Specific examples of the anion component include imido acid type anions such as bis (trifluoromethanesulfonyl) imidate anion ((CF ₃ SO ₂ ) ₂ N ⁻ ), trifluoromethanesulfonate anion (CF ₃ SO ₃ ⁻ ), Alkyl sulfate anions (ROSO ₃ ⁻ ), hydrogen sulfate anions (HSO ₄ ⁻ ), and dihydrogen phosphate anions (H ₂ PO ₄ ⁻ ). These can be used alone or in combination.
When the anion component is used, excellent ionic conductivity is obtained, and the reactivity with respect to a hydrogen oxidation reaction or an oxygen reduction reaction is further improved.

Next, the electrochemical cell of the present invention will be described in detail.
The electrochemical cell of the present invention uses the above-described ion conductor of the present invention. For example, the fuel cell, lithium ion battery, electric double layer capacitor, dye-sensitized solar cell, water electrolysis, hydrohalic acid Examples include electrolysis, salt electrolysis, oxygen concentrators, humidity sensors, and gas sensors.
In such an electrochemical cell, ion conductivity of, for example, protons in the ion conductor is improved, and the internal resistance of the cell can be reduced.
A typical example of these is a fuel cell.

Next, the fuel cell of the present invention will be described in detail.
The fuel cell of the present invention uses the above-described ionic conductor of the present invention, and includes, for example, a fuel cell having an operating temperature in the range of low temperature to medium temperature.
Such a fuel cell can improve the proton conductivity in the ionic conductor and reduce the internal resistance of the cell, thereby improving the output of the fuel cell.

[Preparation of component materials]
(1) Synthesis of electrolyte (1-1) Synthesis of ethoxymethyl (tri-n-butyl) phosphonium bis (trifluoromethanesulfonyl) imide Chloromethyl ethyl ether was dissolved in 5 times the amount of ethanol to obtain an ethanol solution. . Chloromethyl ethyl ether and equimolar amount of tri-n-butylphosphine were added to the ethanol solution to obtain a mixture. The mixture was stirred at 80 ° C. for 22 hours to obtain a reaction solution.
After cooling the reaction solution to room temperature, hexane was added to the reaction solution to cause precipitation. The precipitate was collected by filtration and dried under reduced pressure to obtain a chlorine salt.
The chlorine salt was dissolved in ethanol, and chloromethyl ethyl ether and an equimolar amount of lithium bis (trifluoromethanesulfonyl) imide were added to obtain a mixture. The mixture was stirred at room temperature for 17 hours to obtain a reaction solution.
A precipitate of lithium chloride formed in the reaction solution was removed by filtration. The filtrate was lyophilized and the solvent was removed to give an oily compound.
The compound was dissolved in acetone, treated with activated carbon, and the activated carbon was removed by filtration. The filtrate was purified by an alumina column and dried under reduced pressure at 50 ° C. to obtain ethoxymethyl (tri-n-butyl) phosphonium bis (trifluoromethanesulfonyl) imide (hereinafter referred to as “electrolyte α”).

(1-2) Synthesis of diethylmethylammonium trifluoromethanesulfonate Diethylmethylamine and trifluoromethanesulfonic acid were weighed in equimolar amounts in a glove box under an argon atmosphere. After weighing, while cooling with liquid nitrogen, weighed diethylmethylamine and trifluoromethanesulfonic acid were mixed and stirred to obtain diethylmethylammonium trifluoromethanesulfonate (hereinafter referred to as “electrolyte β”).

(2) Preparation of gel electrolyte (2-1) Preparation of gel electrolyte α First, electrolyte α is added to methyl methacrylate (MMA) so that MMA: electrolyte 1 = 7: 3 (molar ratio). In addition, a mixed solution was prepared.
Next, azobisisobutyronitrile, which is a radical polymerization initiator, was added to the prepared mixed solution so as to be 0.5% by mass to prepare a gel electrolyte precursor solution.
Thereafter, the prepared gel electrolyte precursor solution was cast on a glass petri dish and polymerized at 80 ° C. for 12 hours.
After completion of the reaction, drying was performed at room temperature for 3 hours, and further, vacuum drying was performed at 100 ° C. for 12 hours to produce a gel electrolyte membrane α.
The film thicknesses were 10 μm and 100 μm.

(2-2) Production of Gelled Electrolyte β First, electrolyte β was added to methyl methacrylate (MMA) so as to be (MMA: electrolyte 2 = 7: 3 (molar ratio)) to prepare a mixed solution.
Next, azobisisobutyronitrile, which is a radical polymerization initiator, was added to the prepared mixed solution so as to be 0.5% by mass to prepare a gel electrolyte precursor solution.
Thereafter, the prepared gel electrolyte precursor solution was cast on a glass petri dish and polymerized at 80 ° C. for 12 hours.
After completion of the reaction, drying was performed at room temperature for 3 hours, and further, vacuum drying was performed at 100 ° C. for 12 hours to produce a gel electrolyte membrane β. The film thicknesses were 90 μm and 100 μm.

(3) Evaluation of compatibility with water (3-1) Measurement of retention rate of electrolyte α in gel electrolyte membrane α A test piece (1 cm × 3 cm × 100 μm) was cut out from the gel electrolyte membrane α, The mass of the electrolyte membrane α was measured.
Next, the gel electrolyte membrane α was immersed in ion-exchanged water for 24 hours, taken out, dried at 100 ° C. for 12 hours, and the mass of the gel electrolyte membrane α was measured. The retention rate of the electrolyte can be calculated by the following formula [1]. The obtained result is shown in FIG.

(3-2) Measurement of retention rate of electrolyte β in gel electrolyte membrane β A test piece (1 cm × 3 cm × 100 μm) was cut out from the gel electrolyte membrane β, and the mass of the gel electrolyte membrane β was measured.
Next, the gel electrolyte membrane β was immersed in ion-exchanged water for 24 hours, taken out, dried at 100 ° C. for 12 hours, and the mass of the gel electrolyte membrane β was measured. The retention rate of the electrolyte was calculated by the formula [1]. The obtained result is shown in FIG.

(3-3) Evaluation of Compatibility of Electrolyte α and Electrolyte β with Water FIG. 8 shows that the retention rate of the electrolyte is higher in the gel electrolyte membrane α than in the gel electrolyte membrane β. From this, it can be seen that the electrolyte β is more compatible with water than the electrolyte α.
In the gel electrolyte α, almost no elution of the electrolyte into water was observed even after a certain time from the immersion test in ion-exchanged water.
On the other hand, in the gel electrolyte β, it was found that almost all of the electrolyte was released into the water after a certain time from the immersion test in ion-exchanged water.
From these results, it was found that the cathode in the fuel cell power generation test was formed by disposing a gel having low compatibility with water (gel of ethoxymethyl (tri-n-butyl) phosphonium bis (trifluoromethanesulfonyl) imide) on the cathode side. It can be seen that it shows high durability against the generated water.

Example 1
[Production of ion conductor]
The gel electrolyte membrane α (film thickness: 10 μm) and the gel electrolyte membrane β (film thickness: 90 μm) were brought into contact with each other to obtain an ion conductor (film thickness: 100 μm) of this example.

[Fabrication of fuel cell]
Using the obtained ion conductor, a single cell of the fuel cell of this example as shown in FIG. 6 was obtained.
Specifically, first, 150 parts by mass of 40% by mass platinum-supported carbon (manufactured by Tanaka Kikinzoku Kogyo Co., Ltd.) as an electrode catalyst, 1 part by mass of glycerol, and 5% by mass Nafion (registered trademark) solution (manufactured by DuPont) 1) was added to 750 parts by weight of water and dispersed by ultrasonic treatment to prepare a cathode-side catalyst layer forming slurry and an anode-side catalyst layer forming slurry.
Next, the cathode-side catalyst layer forming slurry and the anode-side catalyst layer were respectively applied to water-repellent treated carbon paper (TGP-H090, manufactured by Toray Industries, Inc.) as a cathode-side gas diffusion layer and an anode-side gas diffusion layer. The slurry for formation is applied using a spray coater so that the amount of platinum is 2 mg / cm ^2, and calcined in an air atmosphere at 350 ° C. for 30 minutes using a firing furnace to form a catalyst layer and a gas diffusion layer. An anode and a cathode were prepared.
The electrode area was 4 cm ² .
Thereafter, the MEA is held in contact with the anode and the cathode so that the gel electrolyte membrane of ethoxymethyl (tri-n-butyl) phosphonium bis (trifluoromethanesulfonyl) imide is disposed on the cathode side. It was fabricated (this was a single cell).

(Comparative Example 1)
[Production of ion conductor]
The gel electrolyte β (film thickness: 100 μm) was used as the ion conductor (film thickness: 100 μm) of this example.

  Except that the obtained ionic conductor was used, the same operation as in Example 1 was repeated to obtain a single cell of the fuel cell of this example as shown in FIG.

(Comparative Example 2)
[Production of ion conductor]
The gel electrolyte α (film thickness: 100 μm) was used as the ion conductor (film thickness: 100 μm) of this example.

  Except that the obtained ionic conductor was used, the same operation as in Example 1 was repeated to obtain a single cell of the fuel cell of this example as shown in FIG.

[Performance evaluation]
As shown in FIG. 11, a power generation test was performed by flowing hydrogen and oxygen into the cell with an electrolyte membrane having low compatibility with water as the air electrode side. FIG. 12 shows the result of comparing cell voltages at a constant current value.
The cell voltage is immediately after the start of power generation, and is a relative value based on the cell voltage value of Example 1.

From FIG. 12, it can be seen that Example 1 included in the scope of the present invention can realize substantially the same generated voltage as that of Comparative Example 1 outside the present invention. Moreover, it turns out that Example 1 can implement | achieve a remarkably high power generation voltage compared with the comparative example 2 outside this invention. Although not shown, Example 1 was able to maintain the generated voltage shown in FIG. 12 for a long time, while Comparative Example 1 was able to maintain the generated voltage shown in FIG. 12 for only a very short time. I couldn't.
This is because, in Example 1, the compatibility with water generated by fuel cell power generation is extremely low, so that the escape of the electrolyte due to dissolution in the generated water is suppressed, and the durability of the ionic conductor to water is large. This is thought to be due to the improvement. Furthermore, since almost the same power generation performance as when using an electrolyte highly compatible with water is obtained, the fuel cell power generation characteristics are excellent under the high-temperature and non-humidified conditions of the present invention. It turns out that it is useful as an ion conductor for fuel cells excellent in durability.

  As mentioned above, although this invention was demonstrated with some embodiment and an Example, this invention is not limited to these, A various deformation | transformation is possible within the range of the summary of this invention.

  For example, in the above-described embodiments and examples, the case where an ion conductor is used as an electrolyte of a fuel cell has been described. However, for example, a lithium ion battery, an electric double layer capacitor, a dye-sensitized solar cell, water It can also be used as an electrolyte for electrolysis, hydrohalic acid electrolysis, salt electrolysis, oxygen concentrator, humidity sensor, gas sensor and the like.

  For example, when applied to water electrolysis, hydrohalic acid electrolysis, salt electrolysis, etc., a membrane electrolyte having low compatibility with water is disposed on the anode side. By adopting such an arrangement, it can be made less susceptible to the water supplied to the anode side, can effectively suppress the elution of the electrolyte into the water, and exhibits excellent durability Can do. That is, the electrolysis apparatus is excellent in durability.

It is the top view (a) and sectional drawing (b) which show an example of the schematic structure of 1st Embodiment of the ion conductor of this invention. It is the top view (a) and sectional drawing (b) which show an example of the schematic structure of 2nd Embodiment of the ion conductor of this invention. It is the top view (a) and sectional drawing (b) which show an example of the schematic structure of 3rd Embodiment of the ion conductor of this invention. It is the top view (a) and sectional drawing (b) which show an example of the schematic structure of 4th Embodiment of the ion conductor of this invention. It is the top view (a) and sectional drawing (b) which show an example of the schematic structure of 5th Embodiment of the ion conductor of this invention. It is the top view (a) and sectional drawing (b) which show an example of the schematic structure of 6th Embodiment of the ion conductor of this invention. It is the top view (a), sectional drawing (b), and sectional drawing (c) which show an example of the schematic structure of 7th Embodiment of the ion conductor of this invention. It is a graph which shows the result of compatibility evaluation with respect to water. It is the top view (a) and sectional drawing (b) which show the schematic structure of the ion conductor of the comparative example 1. It is the top view (a) and sectional drawing (b) which show the schematic structure of the ion conductor of the comparative example 2. It is a schematic sectional drawing which shows the point of a power generation test. It is a graph which shows the result of a power generation test.

Explanation of symbols

10 Ionic conductor 11, 13, 15 Electrolyte 20 Cathode (air electrode)
21, 31 Catalyst layer 23, 33 Gas diffusion layer 30 Anode (fuel electrode)
40 Separator 41 Cathode gas flow path 41a Cathode gas inlet 41b Cathode gas outlet 43 Anode gas flow path

Claims (12)

An ionic conductor containing two or more electrolytes having different compatibility with water,
Ion characterized in that at least a part of the electrolyte forming the surface of the ionic conductor is an electrolyte other than the electrolyte having the highest compatibility with water among the two or more electrolytes having different compatibility with water. Conductor. The ion conductor contains two or more kinds of membrane electrolytes having different compatibility with water, and has a layer structure with respect to the thickness direction of the membrane electrolyte,
At least a part of the membrane electrolyte that forms at least one surface of the ion conductor in the thickness direction of the ion conductor is in water among two or more membrane electrolytes having different compatibility with water. 2. The ion conductor according to claim 1, wherein the ion conductor is a membrane electrolyte other than the membrane electrolyte having the highest compatibility. An ionic conductor used in a fuel cell sandwiched between a cathode and an anode,
3. The ion conduction according to claim 1, wherein an electrolyte other than the electrolyte having the highest compatibility with water among the two or more electrolytes having different compatibility with water is disposed on at least the cathode side. body. An ionic conductor used in a fuel cell sandwiched between a cathode and an anode,
The electrolyte other than the electrolyte having the highest compatibility with water among the two or more electrolytes having different compatibility with water is disposed at least on the cathode side and on the downstream side in the cathode gas flow direction. The ionic conductor according to any one of claims 1 to 3, wherein An ionic conductor used in a fuel cell sandwiched between a cathode and an anode,
5. The electrolyte according to claim 1, wherein the electrolyte having the lowest compatibility with water among the two or more electrolytes having different compatibility with water is disposed on at least the cathode side. 6. Ionic conductor.   The ion conductor according to any one of claims 1 to 5, wherein the two or more kinds of electrolytes having different compatibility with water are gel electrolytes.   The ion conductor according to any one of claims 1 to 6, wherein the two or more types of electrolytes having different compatibility with water are not substantially compatible with each other. Among the two or more electrolytes having different compatibility with water, the electrolyte having the lowest compatibility with water contains an onium cation as a cation component,
The onium cation has a monovalent substituent directly bonded to the central atom,
The monovalent substituent is represented by the following general formula (1)

(Wherein, ^{R 1} represents a hydrogen atom, a halogen atom, or an unsubstituted or substituted hydrocarbon group, ^{Z 1} is an oxygen atom (O), sulfur atom (S), NR ² group ^{(R 2} is a hydrogen atom, a halogen atom Or an unsubstituted or substituted hydrocarbon group) or a PR ³ group (R ³ represents a hydrogen atom, a halogen atom or an unsubstituted or substituted hydrocarbon group), or the following general formula (2 )

(In the formula, R ⁴ represents a hydrogen atom, a halogen atom, or an unsubstituted or substituted hydrocarbon group, and Z ² represents a carbonyl group (CO), a sulfonyl group (SO ₂ ), or a difluoromethylene group (CF ₂ ).) It is represented by these, The ion conductor as described in any one of Claims 1-7 characterized by the above-mentioned.   Among the two or more electrolytes having different water compatibility, the electrolyte other than the one having the lowest water compatibility is selected from the group consisting of a primary onium cation, a secondary onium cation, and a tertiary onium cation as a cation component. The ionic conductor according to claim 1, wherein the ionic conductor includes at least one kind.   Among the two or more types of electrolytes having different compatibility with water, the electrolyte with the lowest compatibility with water includes an oxo acid type anion, an imido acid type anion, a thio acid type anion and a hydrohalic acid type anion. The ionic conductor according to any one of claims 1 to 9, comprising at least one selected from the group consisting of:   An electrochemical cell comprising the ionic conductor according to any one of claims 1 to 10.   A fuel cell comprising the ionic conductor according to any one of claims 1 to 10.

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