JP4844864B2 - Ionic conductor and energy device - Google Patents

Description

  The present invention relates to an ion conductor and an energy device, and more particularly to an ion conductor having a specific polymer and a predetermined electrolyte, and an energy device and a fuel cell using the ion conductor.

  Such ion conductors are solid for 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 is useful for use as a polymer electrolyte membrane.

  Fuel cells using proton conductors are attracting attention as an energy source for achieving zero emissions. Among them, polymer electrolyte fuel cells (PEFCs) are stationary power sources, power sources for portable electronic devices for personal use, or mobile Development as a power source for the body is active. The PEFC is basically configured in such a way that both sides of the electrolyte are sandwiched between an anode (fuel electrode) and a cathode (air electrode), and a reducing agent = fuel (hydrogen) is supplied to the anode and an oxidant (oxygen or air) is supplied to the cathode. By doing so, power is generated.

  Currently, perfluorosulfonic acid polymer electrolyte membranes (represented by Nafion (registered trademark)) are used as proton conductors, but these electrolyte membranes have glass transition temperatures that are low, so that they exceed the glass transition temperature. In addition, since the proton conductivity depends on the water content of the membrane, the proton conductivity of the electrolyte membrane extremely decreases due to the evaporation of water as the operating temperature increases. Furthermore, the operation of the fuel cell system is greatly limited because the water in the membrane is frozen below the freezing point. In order to solve such a problem, development of a new proton conductor without water has been attempted.

On the other hand, “salts” having a low melting point having ionic conductivity have been in the limelight as new materials in recent years, and these are called ionic liquids, ionic liquids or room temperature molten salts. Most of them indicate organic onium ions as cations and those having a relatively low melting point obtained by combining organic or inorganic anions as anions. Many of these contain a large amount of proton conductors containing a basic compound containing a heteroatom, and are known to exhibit high proton conductivity without depending on water (for example, Patent Document 1). , 2).
WO 03/083981 Patent Publication No. 2003-123791

  These are expressed in English as Ionic Liquid, and recently, the name “ionic liquid” has been unified by experts, so the term “ionic liquid” is used in this specification. To be unified.

In the techniques described in Patent Documents 1 and 2, the proton conductivity is realized by utilizing a hydrogen atom bonded to a hetero atom of a basic compound containing a hetero atom. Further, their hydrogen mobility (hydrogen mobility: evaluated based on the proton pump principle) shows a value equal to or less than the ionic conductivity obtained by AC impedance measurement.
Therefore, these liquid electrolytes generally exhibit a behavior in which the ionic conductivity is reduced as compared with the original value when the liquid electrolyte is gelled or fixed in a film form using a monomer or the like.

  As a result, when gelation and immobilization is performed for the purpose of applying a liquid electrolyte to various energy devices, the ionic conductivity is lowered, and as a result, in proton conductors with low ionic conductivity, hydrogen mobility is reduced. Sometimes became low.

  Considering the application of these electrolytes to PEFC, it is desirable to immobilize the electrolyte in the membrane shape. However, since the ionic conductivity and proton conductivity of the immobilized electrolyte membrane are reduced, the inherent properties Could not be fully demonstrated.

  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 conductivity that can exhibit good ionic conductivity and proton conductivity even when immobilized in a membrane shape. The present invention provides an energy device and a fuel cell using the body.

  As a result of intensive studies to achieve the above object, the present inventor has found that the above object can be achieved by using a predetermined polymer in combination with an electrolyte containing a cation component and an anion component, thereby completing the present invention. It came.

That is, the ion conductor of the present invention comprises a polymer including a basic officer functional group in the side chain, and an electrolyte coexist containing molecular Kachio down and molecular anion down to form an ionic liquid, said basic The functional group corresponds to a derivative derived from the molecular cation .

  In a preferred embodiment of the ion conductor of the present invention, at least one of the basic functional groups is present in the repeating unit of the polymer.

Furthermore, another preferred embodiment of the ion conductor of the present invention is a structure in which the basic functional group contains —NR ₂ (R: H or an alkyl group) and / or a heteroatom having an unshared electron pair. It is characterized by that.

Furthermore, in another preferred embodiment of the ionic conductor of the present invention, the electrolyte is a room temperature molten salt of a molecular cation and a molecular anion,
The basic functional group present in the side chain of the polymer corresponds to a derivative of a molecular cation constituting the electrolyte,
The following general formula (1)
Molar fraction = (number of moles of molecular cation + number of functional groups contained in the whole polymer) / (number of moles of molecular cation + number of moles of molecular anion + number of functional groups contained in the whole polymer) (1)
Is characterized by being more than 0.5 and not more than 0.9.

  Moreover, the energy device of the present invention is characterized in that it comprises a structural part in which the above-mentioned ion conductor is held between electrodes.

  Furthermore, the fuel cell according to the present invention is characterized in that the ion conductor is used as a solid electrolyte, and a structural portion is provided in which the solid electrolyte is sandwiched between electrodes.

ADVANTAGE OF THE INVENTION According to this invention, the fall of the ionic conductivity which an electrolyte has can be suppressed in the case of fixation of the electrolyte which has ionic liquid as a main body.
Moreover, it can be set as the membrane | film | coat formation form with easy handling of electrolyte, maintaining the form of the conventional PEM type fuel cell.

  Furthermore, by using a polymer matrix having a molecular structure showing the basicity corresponding to the molecular cation species constituting the electrolyte as a side chain and coexisting with the electrolyte, and using it as a matrix for holding the electrolyte, the electrolyte and the polymer side chain A new cooperative ion conduction path can be formed to suppress a decrease in ion conductivity in the immobilized electrolyte.

  Hereinafter, the ion conductor of the present invention will be described in detail. In the present specification, “%” indicates a mass percentage unless otherwise specified.

  As described above, the ionic conductor of the present invention comprises a polymer (A) having a basic functional group in the side chain and an electrolyte (B) containing a cation component and an anion component.

By taking such a form, a new ion conduction path is formed by the cooperative action between the polymer composed of heteroatoms having unshared electron pairs and the electrolyte.
Thereby, the conventional high ionic conductivity can be expressed, and higher energy performance can be obtained by suppressing the IR drop in the energy device.

[1] Polymer having basic functional group in side chain First, the predetermined polymer as the component (A) will be described.
As said polymer, engineering plastics etc. which are excellent in heat resistance can be used, for example. At this time, it is possible to apply up to a high temperature region, and it can be used as an electrolyte for operation in a temperature region of 100 ° C. or higher.

Moreover, as a functional group which shows basicity, what contains the hetero atom which has an unshared electron pair in the frame | skeleton part can be used.
Here, the “heteroatom” means an atom other than a carbon atom and a hydrogen atom, and is not limited to an atom other than a carbon atom constituting a heterocyclic ring (heterocycle).
Moreover, as a hetero atom having an unshared electron pair, an oxygen atom (O), a nitrogen atom (N), a sulfur atom (S), a phosphorus atom (P), a selenium atom (Se), a tin atom (Sn), indium Mention may be made of atoms (In) or antimony atoms (Sb) and any combination thereof.

Further, it is preferable that at least one basic functional group is present in the repeating unit of the polymer.
As will be described later, the present invention is intended to improve the conductivity of carrier ions in an ionic conductor. However, if such a basic functional group is present in a repeating unit, the carrier ions are Lewis acids. (Carrier ions)-Lewis bases (hetero atoms having non-covalent electron pairs) hydrogen bonds and bonding sites that can dissociate them are provided at regular intervals in chemical structure. Therefore, it is effective for improving carrier ion conductivity.
In addition, the said polymer is not limited to the structure in which 1 type or 1 basic functional group exists in the repeating unit of the said polymer, Even if 2 or more types or 2 or more basic functional groups exist Good.

Furthermore, it is preferable that the basic functional group has a structure including a hetero atom having either or both of —NR ₂ (R: H, one or both of alkyl groups) and an unshared electron pair. is there. Examples of the alkyl group include a methyl group (—CH ₃ ) and an ethyl group (—C ₂ H ₅ ).

In particular, when the basic functional group is composed of a skeleton having a hetero atom, it is preferable to form a heterocycle.
Since such a polymer having a hetero ring generally has excellent heat resistance, not only the carrier ion conductivity of the ion conductor can be improved, but also high-temperature stability can be improved.
Therefore, if the ionic conductor of the present invention including such a polymer having a heterocycle is applied to, for example, an electrolyte of a fuel cell, there is a possibility that power generation can be performed even at about 100 to 150 ° C. where power generation is difficult with a conventional PEFC. .

Specific examples of the basic functional group described above include compounds having a —NR ₂ group (R is H, CH ₃ , C ₂ H _5, etc.) and heterocyclic compounds as shown in FIGS. .

[2] Electrolyte containing a cation component and an anion component The electrolyte as the component (B) will be described.
The cation component and the anion component contained in the electrolyte are monoatomic (atomic) formed from a single atom and polyatomic (for example, molecular) formed from a plurality of atoms. Any of them can be used in the present invention.

As an electrolyte containing an atomic cation component and an anion component, sodium chloride (NaCl) is typically cited, and these become molten salts at high temperatures and exhibit ionic conductivity.
As the atomic anion component, typically a halide ion, e.g. ^Cl -, Br ^- and I ^- I may be mentioned.

On the other hand, examples of the electrolyte containing a molecular cation component and an anion component include those containing specific examples of the cation component and the anion component shown below.
In the present invention, it is preferable to use a molecular cation and a molecular anion in any combination.
At this time, the selectivity of the material is widened as compared with the atomic cation and the atomic anion. In addition, the configuration can be optimized according to the target energy device.

  First, as the cation component, for example, imidazolium derivatives represented by the following chemical formulas 1 to 3 (Imidazolium Derivatives, 1 to 3 substitutes), pyridinium derivatives represented by the chemical formula 4 (Pyridinium Derivatives), and pyrrolidinium derivatives (Pyrrolidinium represented by the chemical formula 5). Derivatives), ammonium derivatives represented by Chemical Formula 6 (Ammonium Derivatives), phosphonium derivatives represented by Chemical Formula 7 (Phosphonium Derivatives), guanidinium derivatives represented by Chemical Formula 8 (Guidinium Derivatives), Show Urea derivatives (Thiourea Derivatives), and the like.

R in the formula represents an alkyl group, alkenyl group, alkynyl group, cycloalkyl group, aryl group, aralkyl group, acyl group, alkoxyalkyl group or heterocyclic group having 1 to 18 carbon atoms.
In particular, those in which R is a methyl group, an ethyl group, a propyl group, an isopropyl group, or a butyl group can be preferably used.

R ¹ and R ² in the formula are each independently an alkyl group, alkenyl group, alkynyl group, cycloalkyl group, aryl group, aralkyl group, acyl group, alkoxyalkyl group or heterocyclic group having 1 to 18 carbon atoms. Indicates a group.
Particularly preferred are those in which R is a hydrogen atom, methyl group, ethyl group, propyl group, isopropyl group, butyl group, pentyl group, nonyl group, hexyl group, octyl group, decyl group, tetradecyl group, octadecyl group or benzyl group. Can be used.

R ¹ , R ² and R ³ in the formula are each independently a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an aryl group, an aralkyl group, an acyl group, an alkoxy group having 1 to 18 carbon atoms. An alkyl group or a heterocyclic group is shown.
In particular, those in which R ¹ and R ² are a methyl group and R ³ is a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group, or a hexyl group can be preferably used.

R ¹ in the formula represents an alkyl group, alkenyl group, alkynyl group, cycloalkyl group, aryl group, aralkyl group, acyl group, alkoxyalkyl group or heterocyclic group having 1 to 18 carbon atoms. R ² , R ³ , and R ⁴ in the formula are each an alkyl group, an alkenyl group, an alkynyl group, wherein at least one R is hydrogen (H), and the remaining Rs are each independently having 1 to 18 carbon atoms. A cycloalkyl group, an aryl group, an aralkyl group, an acyl group, an alkoxyalkyl group or a heterocyclic group;
In particular, R ¹ is preferably an ethyl group, a butyl group, a hexyl group or an octyl group, and all of R ² , R ³ and R ⁴ are hydrogen-oriented, or one or two are methyl groups. Can be used.

R ¹ and R ² in the formula are each independently an alkyl group, alkenyl group, alkynyl group, cycloalkyl group, aryl group, aralkyl group, acyl group, alkoxyalkyl group or heterocyclic group having 1 to 18 carbon atoms. Indicates a group.
In particular, those in which R ¹ and R ² are a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group or an octyl group can be preferably used. Furthermore, even if one of R is a hydrogen atom, it can be preferably used.

R ⁹ , R ² , R ³ and R ⁴ in the formula are each independently an alkyl group, alkenyl group, alkynyl group, cycloalkyl group, aryl group, aralkyl group, acyl group, alkoxyalkyl having 1 to 18 carbon atoms. A group or a heterocyclic group;
In particular, all of R ¹ , R ² , R ³ and R ⁴ are methyl groups or butyl groups, and further those in which at least one or two functional groups are ethyl groups, butyl groups or methoxyethyl groups. It can be suitably used.

R ¹ , R ² , R ³ and R ⁴ in the formula are each independently an alkyl group, alkenyl group, alkynyl group, cycloalkyl group, aryl group, aralkyl group, acyl group, alkoxyalkyl having 1 to 18 carbon atoms. A group or a heterocyclic group;
In particular, those in which all of R ¹ , R ² , R ³ and R ⁴ are butyl groups, and those having a hexyl group and at least one tetradecyl group can be suitably used.

R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ in the formula are each independently a hydrogen atom, a C 1-18 alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an aryl group. , An aralkyl group, an acyl group, an alkoxyalkyl group or a heterocyclic group.
In particular, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ are all hydrogen atoms, or any of R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ Those in which one of them is a methyl group, an isopropyl group, or a phenyl group can be preferably used.

R ¹ , R ² , R ³ , R ⁴ , and R ⁵ in the formula are each independently a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an aryl group, an aralkyl group having 1 to 18 carbon atoms. Represents an acyl group, an alkoxyalkyl group or a heterocyclic group.
In particular, R ¹ , R ² , R ³ , R ⁴ , R ⁵ are all methyl groups, R ¹ , R ² , R ³ , R ⁴ are methyl groups, and R ⁵ is an ethyl group Can be suitably used.

R ¹ , R ² , R ³ , R ⁴ , R ⁵ in the formula are a hydrogen atom, a C 1-18 alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an aryl group, an aralkyl group, an acyl A group, an alkoxyalkyl group or a heterocyclic group;
In particular, those in which R ¹ , R ² , R ³ and R ⁴ are methyl groups and R ⁵ is an ethyl group can be suitably used.

  On the other hand, examples of the anion component include sulfates and sulfonates represented by the following chemical formulas 11 and 12, amides and imides represented by the chemical formula 13, and methanes represented by the chemical formula 14 ( Methanes), borates represented by chemical formulas 15 to 20 (Borates), phosphates and antimonies represented by chemical formulas 21 and 22, and other salts represented by chemical formula 23, and the like.

  Moreover, as a polyvalent anion, for example, one represented by the following chemical formula 24 can be used.

If an electrolyte containing a molecular ion component as described above is employed, the degree of freedom of combination of the cation component and the anion component is large, and the range of material selection can be expanded.
Moreover, it becomes easy to optimize the said electrolyte according to the energy device to which an ion conductor is applied, and the actual applicability to an energy device can be improved.

When the predetermined electrolyte (B) is a room temperature molten salt composed of a molecular cation and a molecular anion as described above, the treatment for dissolving the electrolyte can be omitted, and the handling and manufacturing process can be simplified. is there.
Such a room temperature molten salt is generally called an ionic liquid, and since it is a room temperature molten salt, its vapor pressure is extremely low and it is difficult to evaporate. In addition, it is a flame retardant material having a high thermal decomposition temperature of typically 250 ° C. or higher and a freezing point of typically −20 ° C. or lower, which is excellent in stability.

  In the present invention, the predetermined electrolyte (B) can be composed only of the ionic liquid as described above. However, by adding a polar solvent such as water, the proton conductivity in the ionic liquid can be improved. It is also possible to improve carrier ion conductivity by forming an ionic conductor using an ionic liquid to which such a polar solvent is added for the electrolyte (B).

Here, the “carrier ion” means a proton (H ⁺ ) or an alkali metal ion.
When the ion conductor of the present invention is applied to a PEFC electrolyte membrane, proton conductivity is a direct technical object.
In addition, if this becomes another energy device, for example, a lithium ion battery, the carrier ion becomes Li ⁺ and the carrier ion can be appropriately changed depending on the form of the target energy device.

In the present invention, it is preferable that the molecular cation includes a heteroatom having an unshared electron pair.
It is known that an ionic liquid containing a molecular cation having a specific heteroatom exhibits good proton conductivity due to the Grotus mechanism shown in the following chemical formula 25 and the vehicle mechanism shown in the chemical formula 26. ing.

By using a molecular cation having a specific heteroatom, the ion (especially proton) conducting material in the electrolyte (B) is a ionic molecule that can become an ion carrier, the vehicle mechanism of anion molecules, and carrier ions hop between the ion carriers Thus, it is possible to utilize both of the Grotus mechanism that conducts ions. The contribution ratio between the Grotus mechanism and the vehicle mechanism varies greatly depending on the selected cation molecule and anion molecule, but the vehicle mechanism is generally considered to be dominant.
In the system of the present invention, since the cooperative action of ionic conduction with the electrolyte can be exhibited by utilizing unshared electrons present at the interface between the support and the electrolyte (B) coexisting in the system, Grotus has faster ionic conductivity. Since the contribution of the mechanism can be increased, it is possible to suppress a decrease in ionic conductivity accompanying immobilization.

[3] Coexistence of the predetermined polymer (A) and the predetermined electrolyte (B) As described above, the ionic conductor of the present invention is a mixture of the predetermined polymer (A) and the predetermined electrolyte (B) described above. It is excellent in carrier ion conductivity by the mechanism shown in FIG.

  That is, since the basic functional group of the polymer (A) and the heteroatom of the electrolyte (B) are present at a short distance from each other, carrier ions (particularly protons) are ion-conducted by the aforementioned Grotus mechanism or vehicle mechanism. However, by taking the form of the present invention, carrier ions can easily move between the basic functional groups and heteroatoms, and in particular, the contribution of Grotus mechanism with faster ion conductivity can be increased. Therefore, good proton conductivity is exhibited.

From the viewpoint of improving proton conductivity, the basic functional group of the polymer (A) preferably corresponds to a derivative derived from a molecular cation.
In this case, since the steric structures of the two can be approximated, proton conductivity can be further improved by bringing the basic functional group of the polymer closer to the cationic molecule.

Specifically, the following general formula (1)
Molar fraction = (number of moles of molecular cation + number of functional groups contained in the whole polymer) / (number of moles of molecular cation + number of moles of molecular anion + number of functional groups contained in the whole polymer) (1)
Is preferably more than 0.5 and not more than 0.9.
Further, FIG. 5 shows the relationship between the molar fraction of the imidazole group and the ionic conductivity.

  In addition, such an ionic conductor first defines a predetermined molecular cation, and if the polymer (A) is synthesized so that the polymer (A) includes a derivative of the same kind as the molecular cation as a basic functional group. Good. Moreover, the polymer (A) used as a support body is prescribed | regulated first, and the molecular cation which has the same kind of structure as the basic functional group with which this polymer (A) is provided as a side chain may be selected suitably.

Typically, the predetermined polymer (A) can be used as a support, and the predetermined electrolyte (B) can be immobilized thereon.
In this case, the support for holding the electrolyte can be used in combination with a substance for forming a new ion conduction field. Further, when viewed from the electrolyte (B) side, it is possible to realize the immobilization and film formation of the electrolyte capable of exhibiting excellent carrier ion conductivity.
Therefore, according to the present invention, an ion conductor excellent in applicability to a polymer electrolyte fuel cell (PEFC) can be provided.

  From the viewpoint of effectively immobilizing the electrolyte (B) to the polymer (A), it is preferable to form the polymer (A) into a film, which facilitates molding and easily functions as a support. . In addition, it is easy to form a homogeneous support, and the range of application of the electrolyte held on the support to the energy device is expanded.

  A film having a thickness of 10 to 500 μm can be applied. The resistance detected as electrical resistance due to ionic conduction in the device is increased with the film thickness, and if it is too thin, the handling property is reduced. Therefore, the resistance is preferably 15 to 200 μm, especially 20 to 150 μm. It is preferable to do.

In addition, the polymer (A) may be made porous, which makes it possible to immobilize a large amount of the electrolyte (B) using the pores (pores) of the polymer (A) which is a porous body. As a result, carrier ion conductivity can be further improved.
In addition, when making the polymer (A) porous, it is possible to adjust the porosity, pore diameter and pore distribution of the porous polymer, and thereby, the carrier ion conductivity and the electrolyte holding power can be designed. A desired ionic conductor according to the application can be obtained.

  Since the amount of electrolyte retained increases, the higher the porosity, the better, and 50 to 90% is desirable. The higher the porosity, the lower the strength of the support, and preferably 60 to 85%, more preferably 65 to 80%, which easily balances the amount of electrolyte retained and the strength of the support.

  A porous body having a pore diameter of 0.01 to 50 μm can be used. From the standpoint of improving the electrolyte retention capacity, the pore diameter is preferably as small as possible, and is 0.02 to 20 μm, more preferably 0.05 to 10 μm.

Next, the energy device of the present invention will be described.
As described above, the energy device of the present invention has a structural portion in which the above ionic conductor is sandwiched between electrodes.
Since the ionic conductor is excellent in carrier ionic conductivity, this energy device has a small energy loss due to a voltage drop (IR drop), and thus can exhibit high energy performance.

Specific examples of such energy devices include fuel cells, lithium ion batteries, electric double layer capacitors, and dye-sensitized solar cells.
In addition, it can apply also to the solid polymer electrolyte membrane used for water electrolysis, hydrohalic acid electrolysis, salt electrolysis, an oxygen concentrator, a humidity sensor, and a gas sensor.

Next, the fuel cell of the present invention will be described.
This fuel cell uses the above-mentioned energy device as a single cell, and exhibits high power generation due to the above-described IR drop suppression ability.

This enables operation at 100 ° C. or higher, which is difficult to operate with conventional PEM electrolytes.
In addition, since the temperature difference from the outside air becomes large, the heat discharge load generated during fuel cell power generation can be reduced, and therefore the radiator load can be reduced as compared with the conventional PEFC type fuel cell. As a result, the radiator size can be reduced, and the volume can be reduced and the weight can be reduced.

  Furthermore, when the electrolyte is composed of molecular ions, water is not required to express high ionic conductivity as in the conventional PEFC, so it is not necessary to provide water in the mobile body itself. If applied to the body, it can be reduced.

  It is possible to construct a fuel cell (power generation) system by stacking the fuel cells, but it goes without saying that this system exhibits high power generation.

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

1. Preparation of ionic conductor (Example 1)
An ion conductor prepared by compositing with 1-ethyl-3-methylimidazolium triflate (EMImOTf) as an electrolyte was prepared by the following procedure using poly-N-vinylimidazole as a support.

  N-vinylimidazole monomer, methyl methacrylate (MMA), and EMImOTf are dissolved in acetone so that the molar ratio is 1: 4: 2, and 2,2-azobisisobutyronitrile is used as a polymerization initiator for the vinyl unit. After adding to 5 mol% and casting on a thin film, a polymerization reaction was carried out at 70 ° C. for 12 hours to obtain a film-like ion conductor after drying.

  EMImOTf used here is a mixture of commercially available 1-ethyl-3-methylimidazolium chloride and trifluoromethanesulfonic acid mixed in an equimolar amount, and mixed and stirred at room temperature for 12 hours to dry under reduced pressure. Preliminary drying was performed, and the obtained product was washed with a hexane / ethyl acetate mixed solvent (volume ratio 1/1) and then dried under reduced pressure.

(Example 2)
Example 1 The N-vinylimidazole monomer, 2-hydroxyethyl methacrylate (HEMA), and EMImOTf used were in a molar ratio of 1: 8: 4, and benzoyl peroxide as a polymerization initiator was 5% based on the polymer weight. The added and cast product was subjected to a polymerization reaction at 80 ° C. for 24 hours, and after drying, a film-like ion conductor was obtained. Otherwise, the same operation as in Example 1 was repeated to produce an ion conductor.

(Example 3)
Example 1 An N-vinylimidazole monomer and EMImOTf used were made to have a molar ratio of 4: 1, and the same operation as in Example 1 was repeated except that a ionic conductor was produced.

Example 4
Silica fine particles having an average particle diameter of about 70 to 100 nm were added to the N-vinylimidazole monomer used in Example 3 so as to have a weight ratio of 4: 1 with respect to the polymer, and cast and molded, followed by polymerization and drying according to Example 1. To obtain a film shape. After forming the film, it is treated with a 10 wt% hydrofluoric acid aqueous solution to remove silica fine particles contained therein, and the silica fine particles are dissolved and made porous by hydrofluoric acid (HF) treatment, and then impregnated with EMImOTf. Thus, an ionic conductor was produced.

(Comparative Example 1)
An ion conductor was produced by repeating the same operation as in Example 1 except that the monomer of the electrolyte membrane produced in Example 1 was replaced with polymethacrylate (MMA) from poly-N-vinylimidazole.

2. Measurement of ion conductivity For ion conductivity, a dedicated cell provided with a Pt electrode having platinum black formed on the surface thereof was used. The sol electrolyte was poured into the electrolyte container, naturally cooled while standing at room temperature, and the gelled material was used to measure the ionic conductivity of the electrolyte by the AC impedance method.
The results are shown in Table 1. Moreover, about the ion conductor obtained by Example 1 and the comparative example 1, the change of the ion conductivity with respect to a temperature change is shown in FIG.

  As shown in Table 1, in Examples 1 to 4, good ionic conductivity was exhibited in any case, and thus the effect of the present invention was recognized. On the other hand, Comparative Example 1 showed a value of 0.085 mS / cm at 40 ° C., and the ionic conductivity was significantly reduced as compared with Examples 1 to 4 to which the present invention was applied.

In addition, FIG. 5 is a graph which shows the ionic conductivity change with respect to the imidazole group molar fraction in an electrolyte solution by adding N-ethylimidazole to EMImOTf.
Thus, the fact that the ionic conductivity is improved when the imidazole component in the system is increased is consistent with the announcement by Watanabe et al. (See “Chem. Commun, p. 938, 2003”).

As mentioned above, although this invention was demonstrated in detail by the preferred Example and the comparative example, this invention is not limited to these Examples, A various deformation | transformation is possible within the range of the summary of this invention.
For example, although an ionic liquid having a single composition is used as the electrolyte here, two or more kinds of ionic liquids may be mixed and used.
Moreover, you may mix what is not onium salt like imidazole. In this case, N having a specific covalent bond electron pair of imidazole can also contribute to ionic conduction.

It is a chemical formula which shows an example of the basic side chain with which the polymer used by this invention is provided. It is a chemical formula which shows the other example of the basic side chain with which the polymer used by this invention is equipped. It is a chemical formula which shows the further another example of the basic side chain with which the polymer used by this invention is equipped. It is a conceptual diagram which shows an example of the flow of carrier ion. It is a graph which shows the relationship between a molar fraction and ionic conductivity. It is a graph which shows the ionic conductivity in each temperature range about the ion conductor of Example 1 and Comparative Example 1.

Claims (11)

A polymer comprising a basic officer functional group in the side chain, and an electrolyte coexist containing molecular Kachio down and molecular anion down to form an ionic liquid,
An ionic conductor , wherein the basic functional group corresponds to a derivative derived from the molecular cation .   The ionic conductor according to claim 1, wherein at least one of the basic functional groups is present in a repeating unit of the polymer. 3. The ion conduction according to claim 1, wherein the basic functional group has a structure containing a hetero atom having —NR ₂ (R: H or an alkyl group) and / or a lone pair of electrons. body. The ionic conductor according to any one of claims 1 to 3, wherein the molecular cation contained in the electrolyte contains a heteroatom having an unshared electron pair. The molecular cation is at least one selected from the group consisting of imidazolium derivatives, pyridinium derivatives, pyrrolidinium derivatives, ammonium derivatives, phosphonium derivatives, guanidinium derivatives, isouronium derivatives, and thiourea derivatives,
The molecular anions include sulfates and sulfonic acids, amides and imides, methanes, borates, phosphates and antimony, and chemical formula 23

The ion conductor according to any one of claims 1 to 4, wherein the ion conductor is at least one selected from the group consisting of other salts. The ion conductor according to claim 1 , wherein the polymer functions as a support material for the electrolyte. The ionic conductor according to any one of claims 1 to 6, wherein the polymer forms a film. The ion conductor according to any one of claims 1 to 7, wherein the polymer forms a porous body. The ion conductor according to any one of claims 1 to 8, wherein the carrier ion is a proton. An energy device comprising a structural part in which the ionic conductor according to any one of claims 1 to 9 is sandwiched between electrodes. A fuel cell comprising: a structural portion in which the ionic conductor according to any one of claims 1 to 9 is used as a solid electrolyte and the solid electrolyte is sandwiched between electrodes.

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