JP2008016287A - Ion conductive electrolyte membrane, energy device and cell of fuel cell using this - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ion conductive electrolyte membrane capable of preventing loss by flow out of a liquid electrolyte to the outside of a line from a porous body, and holding the performance of the electrolyte membrane for a long time; and to provide an energy device and a cell of a fuel cell using the ion conductive electrolyte membrane. <P>SOLUTION: The ion conductive electrolyte membrane is formed by filling a liquid electrolyte material having a contact angle of 0°-90° in pores of a porous material. The porous material has a hydrophilic group on the inside of the pores. The hydrophilic group has an unshared electron pair in molecular structure. The hydrophilic group is a hydroxyl group, an aldehyde group, a carbonyl group, a sulfonic acid group, a phosphorous acid group, a carboxylic acid group, an amino group, an ether group, an ester group, and the like. The energy device or the cell of the fuel cell uses the ion conductive membrane. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ion conductive electrolyte membrane, an energy device using the same, and a fuel cell, and more specifically, an ion conductive electrolyte capable of suppressing dissipation due to outflow of a liquid electrolyte from a porous body to the outside of the system. The present invention relates to a membrane, an energy device using the same, and a fuel cell.

  For example, when an electrolyte membrane in which a porous material is impregnated with a liquid electrolyte is used in a fuel cell system, a pinhole is generated in the electrolyte membrane of each cell due to the outflow of the liquid electrolyte from the porous membrane. This leads to gas cross-leakage and greatly affects the performance and life of the fuel cell.

As an example of a method for detecting a gas leak in such a fuel cell stack, there has been proposed an apparatus for detecting a leaked gas by attaching a gas sampling port for each cell to a downstream gas manifold in the fuel cell stack (patent) Reference 1).
JP-A-3-40378

  However, it is generally difficult to detect a gas leak in each cell stacked as a fuel cell stack, and there are problems with the detection limit and detection accuracy, even if the cell causing the gas leak can be identified. There is only a measure to remove or electrically bypass, and it is impossible to avoid deterioration of the overall power generation performance as a system.

On the other hand, as an example of a method for suppressing the outflow of the liquid electrolyte from the electrolyte membrane impregnated with the liquid electrolyte in the porous membrane, a crosslinkable protective film is obtained by attaching a crosslinkable polymer together with a crosslinking agent to the surface of the electrolyte membrane. There has been proposed a method of suppressing elution of the liquid electrolyte by forming the liquid electrolyte (see Patent Document 2).
JP 2001-338657 A

  However, when forming a protective layer on the surface of a porous membrane impregnated with a liquid electrolyte, it is difficult to form the protective layer itself, and even when a protective layer is formed, the thickness of the protective layer is reduced. Difficult to do. When a thick protective layer is formed, the protective layer has a low ionic conductivity, which causes a problem that the conductivity of the ion conductive electrolyte film including the protective layer is lowered.

  The present invention has been made in view of such problems of the prior art, and the object of the present invention is to suppress dissipation based on the outflow of the liquid electrolyte from the porous body to the outside of the system, and as an electrolyte membrane It is an object to provide an ion conductive electrolyte membrane capable of maintaining the above performance for a long period of time, an energy device using the same, and a fuel cell.

  As a result of intensive studies to solve the above problems, the present inventors have arranged the liquid electrolyte material having a contact angle of more than 0 ° and not more than 90 ° in the pores of the porous body material. As a result, the present invention has been completed.

That is, the ion conductive electrolyte membrane of the present invention is an ion conductive electrolyte membrane formed by disposing a liquid electrolyte material in the pores of a porous body material,
The porous body material and the liquid electrolyte material have a contact angle of more than 0 ° and not more than 90 °.

  Moreover, the suitable form of the ion conductive electrolyte membrane of this invention is characterized by the said porous body material having a hydrophilic group in the surface in a hole.

  Furthermore, another preferred embodiment of the ion conductive electrolyte membrane of the present invention is characterized in that the hydrophilic group has one or more elements having unshared electron pairs in the molecular structure.

  Furthermore, the energy device or the fuel battery cell of the present invention is characterized in that the ion conductive electrolyte membrane is applied.

  According to the present invention, since the liquid electrolyte material having a contact angle of more than 0 ° and not more than 90 ° is disposed in the pores of the porous material, it is based on the outflow of the liquid electrolyte from the porous material to the outside of the system. Dissipation can be suppressed, and the performance as an electrolyte membrane can be maintained over a long period of time.

  Hereinafter, the ion conductive electrolyte membrane of the present invention will be described in detail. In the present specification and claims, “%” for concentration, content, filling amount and the like represents a mass percentage unless otherwise specified.

  As described above, the ion conductive electrolyte membrane of the present invention is formed by disposing a liquid electrolyte material in the pores of the porous material. The porous body material and the liquid electrolyte material have a contact angle of more than 0 ° and not more than 90 °.

As a result, the holding power of the liquid electrolyte material is high and the outflow of the liquid electrolyte material is suppressed, so that the battery characteristics are stabilized for a long time when applied to a fuel cell.
Moreover, since a protective layer is not required, the liquid electrolyte material can be retained without lowering the proton conductivity.
Furthermore, since the wettability (low contact angle) between the porous material and the liquid electrolyte material is high, the porous material can be easily impregnated with the liquid electrolyte material, and the manufacturing cost of the electrolyte membrane can be reduced.

Here, the porous material preferably has a hydrophilic group on the surface in the pores.
The surface energy of the porous material is increased by chemically modifying the surface (inner wall surface) in the pores of the porous material with a hydrophilic functional group. Thereby, since the wettability with a porous body material and electrolyte material increases, higher holding power is obtained.

For example, as shown in FIG. 1, when a hydrophilic treatment with a hydroxyl group is performed in the pores of the porous material, the liquid electrolyte material is easily held in the pores.
Further, the holding force of the liquid electrolyte material in the pores of the porous body material is expressed by the following general formula (A) as shown in FIG.
F = 2 · γILs · cosθ / r (A)
(Where F is the holding force, θ is the contact angle, r is the pore radius, and γILs is the surface energy of ILs.)
More demanded.
Furthermore, the graph of FIG. 3 shows the relationship between the holding force at the contact angle of 0 ° to 90 ° between the porous material and the liquid electrolyte material.

Such a hydrophilic group preferably has one or more elements having an unshared electron pair in the molecular structure. For example, the functional group may include oxygen (O), nitrogen (N), sulfur (S), phosphorus (P), and any combination thereof.
Specifically, a hydroxyl group (—OH), an aldehyde group (—CHO), a carbonyl group (> C═O), a sulfonic acid group (—SO 3 H), a nitro group (—NO 2), a phosphoric acid group (—H 2 PO 3), Examples of the functional group include a carboxylic acid group (—COOH), an amino group (—NH 2), an ether group (—O—), an ester group (— (C═O) O—), and any combination thereof. With such a functional group, the surface modification is relatively easy and the manufacturing cost can be reduced.

As the porous material, for example, a sintered body containing a metal oxide can be used from the viewpoint of high stability and low cost.
Examples of such metal oxides include alumina (Al 2 O 3), silica (SiO 2), titania (TiO 2), zirconia (ZrO 2), and any combination thereof.

The porosity of the porous material is preferably 30 to 90%.
At this time, the filling rate of the electrolyte material into the porous material can be increased, and high ion conductivity can be obtained.
Furthermore, the pore diameter of the porous material can be designed to be 100 to 1500 nm from the balance between ion conductivity and ease of introduction of the electrolyte material.

In the ion conductive electrolyte membrane of the present invention, in the liquid electrolyte material, all or part of the cation component is preferably a molecular cation, and all or part of the anion component is preferably a molecular anion.
By adopting such a configuration, it becomes possible to form a complex ion or the like with a polar substance, and proton conductivity can be further improved. In addition, the range of the material selectivity is wider than that of the atomic cation and the atomic anion, and the configuration can be optimized according to the target energy device.
In particular, it is more desirable that all of the cation components are molecular cations and that all of the anion components are molecular anions from the viewpoint of easy formation of a polar substance and complex ions.
“Molecular cation” and “molecular anion” mean a polyatomic cation and a polyatomic anion, respectively.

Furthermore, in this invention, it is suitable to contain the normal temperature molten salt which contains a molecular cation and a molecular anion, and these form.
By containing such a room temperature molten salt, it has the following properties as a room temperature molten salt, and further has high ionic conductivity, whereby proton conductivity can be further improved.
1. 1. Very low vapor pressure 2. Flame resistance 3. High pyrolysis temperature Low freezing point

On the other hand, if it is a room temperature molten salt, it is not necessary that both the cation component and the anion component to be formed are a molecular cation and a molecular anion, respectively.
Here, “room temperature molten salt” refers to a salt that melts at room temperature and does not evaporate at a high temperature and is a stable medium with high polarity and specific heat.
A typical example of such a room temperature molten salt is a Bronsted acid-base type. Details will be described later.

The molecular cation preferably has at least one heteroatom.
Such a molecular cation containing a heteroatom has high ionic conductivity and can further improve proton conductivity. Moreover, the beagle mechanism of a cation molecule can be utilized as carrier ion (especially proton) conductive substance in electrolyte.

  In addition, a hetero atom is an atom other than a carbon atom (C) and a hydrogen atom (H), and typically an oxygen atom (O), a nitrogen atom (N), a sulfur atom (S), a phosphorus atom (P ), Fluorine atom (F), chlorine atom (Cl), bromine atom (Br), iodine atom (I), boron atom (B), cobalt atom (Co), antimony atom (Sb), and the like. .

Here, the cation component and the anion component used in the ion conductor of the present invention will be described in detail with specific examples.
In the present invention, the following cation component and anion component can be used in appropriate combination.

  Examples of the molecular cation which is a kind of the cation component include, for example, an imidazolium derivative cation, more specifically, a monosubstituted imidazolium derivative cation represented by the following formula (1):

(R11 in the formula represents a monovalent organic group, preferably a monovalent hydrocarbon group, more preferably an alkyl group or arylalkyl group having 1 to 20 carbon atoms).

  Specific examples of the hydrocarbon group include a methyl group and a butyl group.

  In addition, a disubstituted imidazolium derivative cation represented by the following formula (2) (Distributed Imidazol Derivatives Cation);

(R21 and R22 in the formula may be the same or different and each represents a monovalent organic group, preferably a monovalent hydrocarbon group, more preferably an alkyl group having 1 to 20 carbon atoms or an arylalkyl group.) Can be mentioned.

  And as R21 and R22, what combined arbitrarily the thing similar to R11 mentioned above can be mentioned, In addition, an ethyl group, a pentyl group, a hexyl group, an octyl group, a decyl group, a dodecyl group, a tetradecyl group , Hexadecyl group, octadecyl group, benzyl group, γ-phenylpropyl group and the like.

  Specific examples of typical combinations of these groups include: R21 is a methyl group, and R22 is a methyl group, ethyl group, butyl group, pentyl group, hexyl group, octyl group, decyl group, dodecyl group, tetradecyl group. Group, hexadecyl group, octadecyl group, benzyl group, γ-phenylpropyl group, and those in which R21 is an ethyl group and R22 is a butyl group.

  Furthermore, a trisubstituted imidazolium derivative cation represented by the following formula (3) (Tristubulated Imidazol Derivatives Cation);

(R31 to R33 in the formula may be the same or different and each represents a monovalent organic group, preferably a monovalent hydrocarbon group, more preferably an alkyl group or arylalkyl group having 1 to 20 carbon atoms.) Can be mentioned.

  And as R31-R33, what combined arbitrarily the thing similar to R11 mentioned above can be mentioned, In addition, an ethyl group, a propyl group, a hexyl group, a hexadecyl group etc. can be mentioned.

  Specific examples of typical combinations of these groups include those in which R31 is an ethyl group, R32 and R33 are methyl groups, R31 is a propyl group, and R32 and R33 are methyl groups, R31 is a butyl group, R32 and R33 are methyl groups, R31 is a hexyl group, R32 and R33 are methyl groups, R31 is a hexadecyl group, and R32 and R33 are methyl groups And so on.

  Moreover, the pyridinium derivative cation (Pyridinium Derivatives Cation) represented by following formula (4);

(In the formula, R41 to R44 may be the same or different and each represents hydrogen or a monovalent organic group, preferably a monovalent hydrocarbon group, more preferably an alkyl group or arylalkyl group having 1 to 20 carbon atoms. .).

  And as R41-R44, what combined arbitrarily the thing similar to R11 mentioned above can be mentioned, In addition, hydrogen, an ethyl group, a hexyl group, an octyl group etc. can be mentioned.

  Specific examples of typical combinations of these groups include those in which R41 is an ethyl group, R42 to R44 are hydrogen, R41 is a butyl group, R42 to R44 is hydrogen, R42 and R43 is hydrogen and R44 is a methyl group, R42 and R44 are hydrogen and R43 is a methyl group, R42 and R43 are methyl groups and R44 is hydrogen, R42 and R44 are methyl groups R43 is hydrogen, R42 and R43 are hydrogen and R44 is an ethyl group, R41 is a hexyl group, R42 to R44 are hydrogen, R42 and R43 are hydrogen, and R44 is a methyl group R42 and R44 are hydrogen and R43 is a methyl group, R41 is an octyl group, and R42 to R44 are hydrogen. Objects or R42 and R43 are hydrogen R44 is a methyl group, R42 and R44 are hydrogen R43 can be exemplified such as a methyl group.

  Further, a pyrrolidinium derivative cation represented by the following formula (5) (Pyrrolidinium Derivatives Cation);

(R51 and R52 in the formula may be the same or different and each represents a monovalent organic group, preferably a monovalent hydrocarbon group, more preferably an alkyl group having 1 to 20 carbon atoms or an arylalkyl group.) Can be mentioned.

  And as R51 and R52, what combined arbitrarily the thing similar to R11 mentioned above can be mentioned, In addition, an ethyl group, a propyl group, a hexyl group, an octyl group etc. can be mentioned.

  Specific examples of typical combinations of these groups include those in which R51 is a methyl group, R52 is a methyl group, an ethyl group, a butyl group, a hexyl group, an octyl group, And those in which R51 is an ethyl group and R52 is a butyl group, and those in which R51 and R52 are a propyl group, a butyl group, and a hexyl group.

  Moreover, the ammonium derivative cation (Ammonium Derivatives Cation) represented by following formula (6);

(R61 to R64 in the formula may be the same or different and each represents a monovalent organic group, preferably a monovalent hydrocarbon group, more preferably an alkyl group having 1 to 20 carbon atoms or an arylalkyl group.) Can be mentioned.

  And as R61-R64, what combined arbitrarily the thing similar to R11 mentioned above can be mentioned, In addition, an ethyl group, an octyl group, etc. can be mentioned.

  Specific examples of typical combinations of these groups include those in which R61 to R64 are methyl groups, ethyl groups, butyl groups, R61 is a methyl group, and R62 to R64 are octyl. The thing etc. which are groups can be mentioned.

  Furthermore, a phosphonium derivative cation represented by the following formula (7) (Phosphonium Derivatives Cation);

(R71 to R74 in the formula may be the same or different and each represents a monovalent organic group, preferably a monovalent hydrocarbon group, more preferably an alkyl group or arylalkyl group having 1 to 20 carbon atoms.) Can be mentioned.

  And as R71-R74, what combined arbitrarily the thing similar to R11 mentioned above can be mentioned, In addition, an ethyl group, an isobutyl group, a hexyl group, an octyl group, a tetradecyl group, a hexadecyl group, a phenyl group And benzyl group.

  Specific examples of typical combinations of these groups include those in which R71 is a methyl group, R72 to R74 are butyl groups or isobutyl groups, R71 is an ethyl group, and R72 to R74 are A butyl group, R71 to R74 are butyl groups or octyl groups, R71 is a tetradecyl group, R72 to R74 are butyl groups or hexyl groups, R71 is a hexadecyl group And R72 to R74 are butyl groups, R71 is a benzyl group, and R72 to R74 are phenyl groups.

  Further, a guanidinium derivative cation represented by the following formula (8) (Guanidinium Derivatives Cation);

(R81 to R86 in the formula may be the same or different and each represents hydrogen or a monovalent organic group, preferably a monovalent hydrocarbon group, more preferably an alkyl group or arylalkyl group having 1 to 20 carbon atoms. .).

  And as R81-R86, what combined arbitrarily the thing similar to R11 mentioned above can be mentioned, In addition, hydrogen, an ethyl group, a propyl group, an isopropyl group etc. can be mentioned.

  Specific examples of typical combinations of these groups include those in which all of R81 to R86 are hydrogen or methyl groups, R81 is an ethyl group, R82 to R85 are methyl groups, and R86 is hydrogen. And those in which R81 is an isopropyl group, R82 to R85 are methyl groups, R86 is hydrogen, R81 is a propyl group, and R82 to R86 are methyl groups.

  Furthermore, an isouronium derivative cation (Isouronium Derivatives Cation) represented by the following formula (9);

(In the formula, R91 to R95 may be the same or different and each represents hydrogen or a monovalent organic group, preferably a monovalent hydrocarbon group, more preferably an alkyl group or arylalkyl group having 1 to 20 carbon atoms. , A9 represents an oxygen atom or a sulfur atom.

  And as R91-R95, what combined arbitrarily the thing similar to R11 mentioned above can be mentioned, In addition, hydrogen, an ethyl group, etc. can be mentioned.

  Specific examples of typical combinations of these groups include those in which A9 is an oxygen atom (O) and all of R91 to R95 are methyl groups, R91 is an ethyl group, and R92 to R95 are methyl groups. And A9 is a sulfur atom (S), R91 is an ethyl group, and R92 to R95 are methyl groups.

  On the other hand, as the molecular anion, for example, a sulfate anion [SO42-], a monohydrogen sulfate anion [HSO4-] or a sulfate ester anion represented by the following formula (10):

(R101 in the formula represents a monovalent organic group, preferably a monovalent hydrocarbon group, more preferably an alkyl group having 1 to 20 carbon atoms or an arylalkyl group).

  And as R101, the thing similar to R11 mentioned above can be mentioned, In addition, an ethyl group, a hexyl group, an octyl group, etc. can be mentioned.

  Further, typical examples include those in which R101 is a methyl group, an ethyl group, a butyl group, a hexyl group, or an octyl group.

  Moreover, the sulfonate ester anion (Sulfonates anion) represented by following formula (11);

(In the formula, R111 represents a monovalent organic group, preferably a monovalent hydrocarbon group, more preferably an alkyl or arylalkyl group having 1 to 20 carbon atoms, and further a fluorine-substituted product thereof). Can do.

  As a typical example, R111 is a fluorine-substituted methyl group (corresponding to a trifluoromethanesulfonate anion), and further a p-tolyl group (corresponding to a p-toluenesulfonic acid anion). Things can be mentioned.

  Further, an amide anion or an imide anion represented by the following formulas (12) to (14);

Can be mentioned.
The amide anion and imide anion are not necessarily limited to these.

  In addition, a methane anion represented by the following formula (15) or (16);

Can be mentioned.
The methane anion is not necessarily limited to these.

  In addition, boron-containing compound anions represented by the following formulas (17) to (23);

Can be mentioned.
Note that the boron-containing compound anion is not necessarily limited thereto.

  Furthermore, phosphorus-containing compound anions represented by the following formulas (24) to (32);

Can be mentioned.
The phosphorus-containing compound anion is not necessarily limited to these.

  And a carboxylate anion represented by the following formula (33) or (34):

Can be mentioned.
The carboxylate anion is not necessarily limited to these.

  And a metal element-containing anion represented by the following formula (35) or (36):

Can be mentioned.
The metal element-containing anion is not necessarily limited to these.

  On the other hand, although it is not a molecular anion, as other anion components, a halide anion (Halogenides Anion) fluorine anion [F−], chlorine anion [Cl−], bromine anion [Br−], iodine anion [I−] Can also be mentioned.

Furthermore, in the present invention, a mixture of an imidazolium derivative cation, a pyridinium derivative cation, a pyrrolidinium derivative cation or an ammonium derivative cation, and a molecular cation according to any combination thereof, a boron tetrafluoride anion, trifluoromethanesulfone, and the like. Nate anion, hydrogen fluoride anion [(HFn) F- (n is preferably a real number of 1 to 3)], monohydrogen sulfate anion or dihydrogen phosphate anion, and molecular anions related to any combination thereof And a mixture of
This is because a combination of these molecular cations and molecular anions is a room temperature molten salt and exhibits good hydrophilicity.

Next, the energy device and fuel cell of the present invention will be described.
The energy device of the present invention is configured by applying the above-described ion conductive electrolyte membrane. In this case, high ionic conductivity can be obtained and performance can be improved.
Moreover, it can also be systematized appropriately in combination with other control means. Typically, a fuel cell (cell or stack), water electrolysis, hydrohalic acid electrolysis, salt electrolysis, oxygen concentrator, humidity sensor, gas sensor, and the like can be given.

  In particular, the use of an ion conductive electrolyte membrane in a fuel cell and its system makes it possible to operate in the middle temperature range (about 120 ° C.), lowering the radiator load relative to the conventional PEM type fuel cell, and the radiator The size can be reduced. As a result, the system volume can be reduced and the system weight can be reduced.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in full detail, this invention is not limited to these Examples.

(Example 1)
(1) Surface hydrophilization treatment of PTFE (polytetrafluoroethylene) porous membrane A PTFE porous membrane having an average pore diameter of 0.2 µm and a thickness of 100 µm was used as the porous membrane. The porous body was subjected to surface treatment by plasma treatment. The plasma processing apparatus used was a Unitika USX low-temperature plasma processing apparatus. Glow discharge was performed using a radio wave having a frequency of 13.56 MHz.
Oxygen was used as a treatment gas, and plasma irradiation was performed for 60 minutes at an inflow rate of 25 ml / min, a discharge output of 1.3 kW, and a tube pressure of 133 Pa. Regarding the generation of functional groups on the surface, an increase in peaks attributed to OH stretching vibration of 3200 to 3550 cm −1 and CO stretching vibration of 1540 to 1870 cm −1 was confirmed by infrared spectrum.

(2) Impregnation of electrolyte material In this example, 2EtIm BF ₄ (2-ethylimidazolium tetrafluoroborate) was used as the liquid electrolyte. The porous membrane subjected to the above-mentioned surface hydrophilization treatment was dipped in the liquid electrolyte, and the electrolyte was impregnated into the porous membrane by allowing it to stand under vacuum for 60 minutes after dipping, thereby producing an ion conductive electrolyte membrane of this example.

(Performance evaluation 1)
(1) Evaluation of Holding Capacity of Liquid Electrolyte Solution Regarding the holding power of the liquid electrolyte in the obtained electrolyte membrane, US Patent Materials, Inc. Measurement was performed using a Perm Porometer. Gas pressure was applied from the primary side of the electrolyte membrane produced above, the pressure for extruding the electrolyte in the electrolyte membrane was measured, and the retention of the liquid in the porous membrane was measured. The result is shown in FIG.

(2) Contact angle between the liquid electrolyte and the porous substrate The surface energy of the liquid electrolyte was calculated by an appropriate solution method (Yamashita Giken free surface tension measuring device). The contact angle between the liquid electrolyte and the porous substrate was calculated from the relational expression (B) between the surface energy of the obtained liquid electrolyte and the retention force of the liquid electrolyte measured in the porous body. The result is shown in FIG.

cos θ = p × r / 2 / γ (B)
(In the formula, θ represents the contact angle between the liquid electrolyte and the porous substrate, p represents the holding force of the liquid electrolyte in the porous body, r represents the pore diameter of the porous body, and γ represents the surface energy of the liquid electrolyte.)

(Comparative Example 1)
An ion-conducting electrolyte membrane of this example was produced by repeating the same method as in Example 1 except that a PTFE membrane not subjected to surface hydrophilization treatment was used as the porous membrane.
The holding power of the liquid electrolyte in the produced electrolyte membrane was measured. The result is shown in FIG.

  From the comparison between Example 1 and Comparative Example 1, the retention capacity of the liquid electrolyte in the porous membrane subjected to the surface hydrophilization treatment was improved by 6 times compared to the retention strength in the untreated porous membrane.

(Example 2)
(1) Surface hydrophilization treatment of P (VdF-HEP) (poly (vinylidene fluoride-hexafluoropropylene copolymer) porous membrane P (VdF) having an average pore diameter of 0.2 μm and a film thickness of 100 μm as a porous membrane The porous body was surface-treated by plasma treatment, and the plasma treatment apparatus was a USX low-temperature plasma treatment apparatus manufactured by Unitika Glow discharge using radio waves with a frequency of 13.56 MHz. I let you.
Oxygen was used as a processing gas, and plasma irradiation was performed at an inflow rate of 25 ml / min, a discharge output of 1.3 kW, and a tube pressure of 133 Pa for 30 minutes.
Regarding the generation of functional groups on the surface, an increase in peaks attributed to OH stretching vibration of 3200 to 3550 cm −1 and CO stretching vibration of 1540 to 1870 cm −1 was confirmed by infrared spectrum.

(2) Impregnation of electrolyte material Using EMI BF ₄ (ethylmethylimidazolium tetrafluoroborate) as the liquid electrolyte, the same method as in Example 1 was repeated to produce an ion conductive electrolyte membrane of this example.

(Performance evaluation 2)
(1) Holding power evaluation of liquid electrolyte solution The holding power of the obtained electrolyte membrane was measured by the same method as in Example 1. The result is shown in FIG.

(2) Contact angle between the liquid electrolyte and the porous substrate The contact angle between the liquid electrolyte and the porous substrate was calculated in the same manner as in Example 1. The result is shown in FIG.

(Comparative Example 2)
An ion-conducting electrolyte membrane of this example was produced by repeating the same method as in Example 2 except that a P (VdF-HEP) membrane not subjected to surface hydrophilization treatment was used as the porous membrane.
The holding power of the liquid electrolyte in the produced electrolyte membrane was measured. The result is shown in FIG.

  From a comparison between Example 2 and Comparative Example 2, the retention strength of the liquid electrolyte in the porous membrane subjected to surface hydrophilization treatment was improved by a factor of 5 relative to the retention strength in the untreated porous membrane.

(Example 3)
(1) Surface hydrophilization treatment of PE (polyethylene) porous membrane A PE membrane having an average pore diameter of 0.2 µm and a thickness of 100 µm was used as the porous membrane. The porous body was surface-treated with a sulfuric acid-chromic acid mixed solution. 88.5% water, 4.4% potassium chromate (K2Cr2O7) and 7.1% sulfuric acid were mixed to prepare a sulfuric acid-chromic acid mixed solution. In this mixed solution, the PE porous membrane was immersed for 1000 seconds, and after the immersion, the porous membrane was washed with ion-exchanged water. Regarding the generation of functional groups on the surface, an increase in peaks attributed to OH stretching vibration of 3200 to 3550 cm-1, CO stretching vibration of 1540 to 1870 cm-1, and SO stretching vibration of 1200 to 1400 cm-1 by infrared spectrum. It was confirmed.

(2) Impregnation of electrolyte material In this example, acetonitrile (20 mM), lithium iodide (40 mM), 1,2-dimethyl-3-hexylimidazolium iodide (1,2-dimethyl-3-hexylimidazo) was added to acetonitrile as a liquid electrolyte. A solution in which (iodium iodide) (500 mM) and 4-tert-butylpyridine (4-tert-butylpyridine) (500 mM) were dissolved was used. The porous membrane subjected to the surface hydrophilization treatment as described above was immersed in the liquid electrolyte, and allowed to stand for 30 minutes to impregnate the porous membrane with the electrolyte, thereby producing the ion conductive electrolyte membrane of this example.

(Performance evaluation 3)
(1) Retention ability evaluation of liquid electrolyte solution About the retention ability of the electrolyte membrane obtained above, it measured by the method similar to Example 1. FIG. The result is shown in FIG.

(2) Contact angle between the liquid electrolyte and the porous substrate The contact angle between the liquid electrolyte and the porous substrate was calculated in the same manner as in Example 1. The result is shown in FIG.

(Comparative Example 3)
An ion-conducting electrolyte membrane of this example was produced by repeating the same method as in Example 3 except that a PE membrane not subjected to surface hydrophilization treatment was used as the porous membrane.
The holding power of the liquid electrolyte in the produced electrolyte membrane was measured. The result is shown in FIG.

  From the comparison between Example 3 and Comparative Example 3, the retention capacity of the liquid electrolyte in the porous membrane subjected to the surface hydrophilization treatment was improved by a factor of 2 relative to the retention strength in the untreated porous membrane.

Example 4
(1) Surface hydrophilization treatment of PP (polypropylene) porous membrane A PP membrane having an average pore diameter of 0.2 µm and a thickness of 100 µm was used as the porous membrane. The porous body was surface-treated with a sulfuric acid-chromic acid mixed solution. 88.5% water, 4.4% potassium chromate (K2Cr2O7) and 7.1% sulfuric acid were mixed to prepare a sulfuric acid-chromic acid mixed solution. The PP porous membrane was immersed in this mixed solution for 10 seconds, and after the immersion, the porous membrane was washed with ion-exchanged water. Regarding the generation of functional groups on the surface, an increase in peaks attributed to OH stretching vibration of 3200 to 3550 cm-1, CO stretching vibration of 1540 to 1870 cm-1, and SO stretching vibration of 1200 to 1400 cm-1 by infrared spectrum. It was confirmed.

(2) Impregnation of electrolyte material and evaluation of holding power of liquid electrolyte In this example, LiPF6 was mixed in a solvent in which propylene carbonate, dimethyl carbonate, and ethyl methyl carbonate were mixed at a volume ratio of 1: 1: 1 as a liquid electrolyte. A 25M dissolved solution was used. The porous membrane subjected to the surface hydrophilization treatment as described above was immersed in the liquid electrolyte, and allowed to stand for 30 minutes to impregnate the porous membrane with the electrolyte, thereby producing the ion conductive electrolyte membrane of this example.

(Performance evaluation 4)
(1) Retention ability evaluation of liquid electrolyte solution About the retention ability of the electrolyte membrane obtained above, it measured by the method similar to Example 1. FIG. The result is shown in FIG.

(2) Contact angle between the liquid electrolyte and the porous substrate The contact angle between the liquid electrolyte and the porous substrate was calculated in the same manner as in Example 1. The result is shown in FIG.

(Comparative Example 4)
An ion conductive electrolyte membrane of this example was produced by repeating the same method as in Example 4 except that a PP membrane that had not been subjected to surface hydrophilization treatment was used as the porous membrane.
The holding power of the liquid electrolyte in the produced electrolyte membrane was measured. The result is shown in FIG.

  From a comparison between Example 4 and Comparative Example 4, the retention strength of the liquid electrolyte in the porous membrane subjected to the surface hydrophilization treatment was improved twice as much as the retention strength in the untreated porous membrane.

(Example 5)
(1) Surface hydrophilization treatment of PI (polyimide) porous film A PI film having an average pore diameter of 0.2 μm and a film thickness of 100 μm was used as the porous film. The porous body was subjected to surface treatment by plasma treatment. The plasma processing apparatus used was a Unitika USX low-temperature plasma processing apparatus. Glow discharge was performed using a radio wave having a frequency of 13.56 MHz.
Oxygen was used as a processing gas, and plasma irradiation was performed at an inflow rate of 25 ml / min, a discharge output of 1.3 kW, and a tube pressure of 133 Pa for 30 minutes. Regarding the generation of functional groups on the surface, an increase in the peak attributed to the OH stretching vibration of 3200 to 3550 cm −1 was confirmed by infrared spectrum.

(2) Impregnation of electrolyte material In this example, EMI TFSI (ethyl methyl imidazolium trifluoromethane sulfonylimide) was used as the liquid electrolyte, and the same method as in Example 1 was repeated to obtain the ion conductivity of this example. An electrolyte membrane was produced.

(Performance evaluation 5)
(1) Retention ability evaluation of liquid electrolyte solution About the retention ability of the obtained electrolyte membrane, it measured by the method similar to Example 1. FIG. The result is shown in FIG.

(2) Contact angle between the liquid electrolyte and the porous substrate The contact angle between the liquid electrolyte and the porous substrate was calculated in the same manner as in Example 1. The result is shown in FIG.

(Comparative Example 5)
An ion-conducting electrolyte membrane of this example was produced by repeating the same method as in Example 5 except that a PI membrane not subjected to surface hydrophilization treatment was used as the porous membrane.
The holding power of the liquid electrolyte in the produced electrolyte membrane was measured. The result is shown in FIG.

  From a comparison between Example 5 and Comparative Example 5, the retention capacity of the liquid electrolyte in the porous membrane subjected to surface hydrophilization treatment was improved by a factor of 2 relative to the retention strength in the untreated porous membrane.

(Example 6)
(1) Surface hydrophilization treatment of porous silica membrane A porous silica membrane having an average pore diameter of 0.2 µm and a thickness of 150 µm was used. The porous body was subjected to hydrothermal treatment at 170 ° C. for 24 hours using an autoclave to effect surface hydrophilization. Regarding the generation of functional groups on the surface, an increase in the peak attributed to 3200 to 3700 cm-1 SiOH was confirmed by infrared spectrum.

(2) Impregnation with electrolyte material In this example, EMI Tf (ethyl methyl imidazolium triflate) was used as the liquid electrolyte, and the same method as in Example 1 was repeated to produce the ion conductive electrolyte membrane of this example. did.

(Performance evaluation 6)
(1) Retention ability evaluation of liquid electrolyte solution About the retention ability of the obtained electrolyte membrane, it measured by the method similar to Example 1. FIG. The result is shown in FIG.

(2) Contact angle between the liquid electrolyte and the porous substrate The contact angle between the liquid electrolyte and the porous substrate was calculated in the same manner as in Example 1. The result is shown in FIG.

(Comparative Example 6)
An ion conductive electrolyte membrane of this example was produced by repeating the same method as in Example 6 except that a silica membrane that had not been subjected to surface hydrophilization treatment was used as the porous membrane.
The holding power of the liquid electrolyte in the produced electrolyte membrane was measured. The result is shown in FIG.

  From a comparison between Example 6 and Comparative Example 6, the retention strength of the liquid electrolyte in the porous membrane subjected to the surface hydrophilization treatment was improved twice as much as the retention strength in the untreated porous membrane.

(Example 7)
(1) Surface hydrophilization treatment of porous silica membrane A porous silica membrane having an average pore diameter of 0.2 µm and a thickness of 150 µm was used. The porous body was hydrothermally treated at 170 ° C. for 24 hours using an autoclave.
Next, mercapto groups were introduced into the porous silica. γ-Mercaptopropyltrimethylsilane was used as a silane coupling agent. A 3.5% silane coupling agent aqueous solution was used. The porous silica membrane was immersed in an aqueous silane coupling agent solution for 20 hours, and then vacuum dried at 100 ° C. for 10 minutes. Thereafter, a 10% hydrogen peroxide solution was used to oxidize the 2 hr mercapto group at 70 ° C. to form a sulfonic acid group. The generation of functional groups on the surface was confirmed by measuring the EDS spectrum.

(2) Impregnation of electrolyte material (ionic liquid) In this example, 2EtIm Tf (2-ethylimidazolium triflate) was used as the liquid electrolyte, and the same method as in Example 1 was repeated to repeat the ion conduction of this example. A negative electrolyte membrane was prepared.

(Performance evaluation 7)
(1) Retention ability evaluation of liquid electrolyte solution About the retention ability of the obtained electrolyte membrane, it measured by the method similar to Example 1. FIG. The result is shown in FIG.

(2) Contact angle between the liquid electrolyte and the porous substrate The contact angle between the liquid electrolyte and the porous substrate was calculated in the same manner as in Example 1. The result is shown in FIG.

(Comparative Example 7)
An ion conductive electrolyte membrane of this example was prepared by repeating the same method as in Example 7 except that a silica membrane that had not been subjected to surface hydrophilization treatment was used as the porous membrane.
The retention strength of the liquid electrolyte in the produced electrolyte membrane was measured. The result is shown in FIG.

  From a comparison between Example 7 and Comparative Example 7, the retention capacity of the liquid electrolyte in the porous membrane subjected to the surface hydrophilization treatment was improved twice as much as the retention strength in the untreated porous membrane.

It is the schematic which shows an example of a hydrophilic treatment. It is the schematic which shows the retention strength of the liquid electrolyte material in the hole of a porous body material. It is a graph which shows the relationship between the contact angle and retention strength of a porous membrane and a liquid electrolyte. It is a graph which shows the retention strength when the inside of a PTFE membrane is hydrophilized. It is a graph which shows the retention strength when hydrophilizing in a P (VdF-HEP) film | membrane. It is a graph which shows the retention strength when the inside of PE film is hydrophilized. It is a graph which shows the retention strength when the inside of PP film | membrane is hydrophilized. It is a graph which shows the retention strength when the inside of PI membrane is hydrophilized. It is a graph which shows the retention strength when the inside of a silica membrane is hydrophilized. It is a graph which shows the retention strength when the inside of a silica membrane is hydrophilized. It is a graph which shows the contact angle of the porous body material and liquid electrolyte material in the electrolyte membrane of Examples 1-7.

Claims (11)

An ion conductive electrolyte membrane comprising a liquid electrolyte material disposed in pores of a porous body material,
An ion-conductive denatured membrane, wherein the porous material and the liquid electrolyte material have a contact angle of more than 0 ° and 90 ° or less.   2. The ion conductive electrolyte membrane according to claim 1, wherein the porous material has a hydrophilic group on the surface in the pores.   The ion conductive electrolyte membrane according to claim 1 or 2, wherein the hydrophilic group has one or more elements having an unshared electron pair in the molecular structure.   The ion conductive electrolyte membrane according to claim 3, wherein the element having an unshared electron pair includes at least one element selected from the group consisting of oxygen, nitrogen, sulfur, and phosphorus.   The hydrophilic group has at least one functional group selected from the group consisting of a hydroxyl group, an aldehyde group, a carbonyl group, a sulfonic acid group, a phosphoric acid group, a carboxylic acid group, an amino group, an ether group, and an ester group. The ion-conducting electrolyte membrane according to any one of claims 2 to 4, wherein   The ion conductive electrolyte membrane according to any one of claims 1 to 5, wherein the porosity of the porous material is 30 to 90%.   The ion according to any one of claims 1 to 6, wherein the liquid electrolyte material includes a cationic species and an anionic species, and the cationic species and the anionic species are a molecular cation and a molecular anion. Conductive electrolyte membrane.   8. The ion conductive electrolyte membrane according to claim 7, wherein the molecular cation contains at least one heteroatom.   The ion conductive electrolyte membrane according to any one of claims 1 to 8, wherein the liquid electrolyte material is a room temperature molten salt.   An energy device to which the ion conductive electrolyte membrane according to any one of claims 1 to 9 is applied.   A fuel cell comprising the ion conductive electrolyte membrane according to any one of claims 1 to 9.

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