JP5162903B2 - Anion exchange type electrolyte composition, solid electrolyte membrane and fuel cell - Google Patents

Description

  The present invention relates to an anion exchange type electrolyte composition that can be used in a fuel cell, a solid electrolyte membrane comprising the anion exchange type electrolyte composition, and an anion exchange type solid polymer using the anion exchange type electrolyte composition as a solid electrolyte membrane Type fuel cell.

  In recent years, along with the development of portable electronic devices such as mobile phones, PDAs (Personal Digital Assistants), notebook personal computers, etc., the batteries used as the driving power source and memory holding power source are also reduced in size, weight, and capacity. Has been demanded. In current portable electronic devices, lithium ion batteries are most commonly used as drive power sources and the like.

  This lithium ion battery has a high driving voltage and a battery capacity from the beginning of practical use, and has been improved in performance to match the progress of portable electronic devices. However, there is a limit to improving the performance of the lithium ion battery, and it is becoming impossible to satisfy the requirement for use as a driving power source for portable electronic devices that are further enhanced in the future.

  Against this background, the development of a new power generation device that replaces lithium-ion batteries has resulted in the proposal of fuel cells that can be expected to have a capacity that is several times higher than lithium-ion batteries. .

  In general, a fuel cell has a structure including a power generation unit including a fuel electrode (negative electrode) and an air electrode (positive electrode) containing a catalyst, and an electrolyte layer that is provided between the electrode and allows movement of predetermined ions. ing. In this fuel cell, when a fuel such as hydrogen or a low molecular weight organic substance is supplied to the negative electrode and oxygen (may be in the form of air) is supplied to the positive electrode, An electrochemical reaction takes place, and the electric current from the electrons can be directly taken out using fuel as a supply source. In a fuel cell that generates electricity by such a mechanism, by supplying fuel to the negative electrode and oxygen to the positive electrode, continuous power generation is possible over a long period of time, and it can be used in the same way as a secondary battery. Application to power sources of electronic devices is expected.

  Fuel cells are classified into phosphoric acid type, solid polymer type, molten carbonate type, solid oxide type, and the like based on the type of electrolyte. As a power source for portable electronic devices, it is possible to operate at low temperatures around room temperature, to be compact, and to be equipped with a solid electrolyte layer that is resistant to vibration and easy to mass-produce. Molecular fuel cells are considered suitable.

  In a polymer electrolyte fuel cell, as a fuel supply method, a method of storing hydrogen gas and supplying the hydrogen gas directly to a fuel electrode, a hydrogen gas generated by storing an organic fuel and reforming the organic fuel There are known a method for supplying the fuel electrode to the fuel electrode (reformed fuel cell), a method for supplying the liquid fuel directly to the fuel electrode (direct fuel cell), and the like. Among these, a battery using hydrogen as a fuel is called a hydrogen fuel cell.

  Among these, the method of directly supplying hydrogen gas is difficult to handle the hydrogen gas, and the method of supplying hydrogen gas generated by reforming organic fuel to the fuel electrode is an apparatus configuration for reforming. Therefore, it is not suitable as a small power source used for portable electronic devices and the like. Therefore, from the viewpoint of configuring a small power source, a fuel cell that employs a system that supplies liquid fuel, particularly a direct-type fuel cell that supplies liquid fuel to the fuel electrode (direct fuel cell) has attracted attention. Collecting.

  To date, a large number of direct fuel cells have been developed (for example, direct methanol fuel cells (DMFC). These fuel cells are classified according to the fuel supply system and fuel condition to the power generation unit. Can do.

  First, as a fuel supply system for DMFC, a system called “active type” in which liquid fuel is forcibly circulated by a device called an auxiliary machine such as a pump, and a liquid fuel is supplied by gravity, capillary action, or natural diffusion. It can be classified into a method called "passive type".

  The most important feature of the “active type” DMFC is that the concentration of the liquid fuel to be supplied can be mechanically controlled by recovering the water generated by the power generation reaction and circulating the recovered water. This makes it possible to supply high-concentration methanol while avoiding the permeation of methanol to the air electrode that passes through the electrolyte layer of the power generation unit, which is a problem of DMFC, and the accompanying performance degradation at the air electrode, so-called methanol crossover. It becomes.

  However, on the other hand, “active” DMFCs have problems such as complicated mechanisms and difficulty in miniaturization, and the need for electric power to move the mechanism. It is not suitable for configuring a small power supply. On the other hand, the “passive type” DMFC is easy to miniaturize because of its simple mechanism.

  Furthermore, the polymer electrolyte fuel cells can be classified according to the chemical properties of the polymer material. For example, a solid polymer fuel cell is called a cation exchange fuel cell if it has a cation exchange group in the chemical structure of the polymer material used, and an anion exchange fuel cell if it has an anion exchange group. The electrode reaction between the cation exchange fuel cell and the anion exchange fuel cell in the case of methanol fuel is shown in FIG.

In the example of the cationic fuel cell of FIG. 1 (using methanol as the fuel), methanol and water react at the fuel electrode to produce protons, electrons, and carbon dioxide, and the carbon dioxide is released to the outside. Along with reaching the air electrode through an external load, protons move through the solid electrolyte to the air electrode, where they react with oxygen and electrons that reach the air electrode through the external load to produce water. This solid electrolyte is an electrolyte that passes protons (proton-type solid electrolyte). Most commonly SO ₃ ^- a solid electrolyte having group is used.

  In the example of the anionic fuel cell in FIG. 1 (using methanol as fuel), methanol, hydroxy ions react with each other at the fuel electrode to produce water, electrons, and carbon dioxide, and the carbon dioxide is released to the outside. Reaches the air electrode through an external load. In the air electrode, oxygen and electrons that have reached the air electrode through an external load react with water to produce hydroxy ions, which move through the solid electrolyte and reach the fuel electrode. This solid electrolyte is an electrolyte (anionic solid electrolyte) that passes hydroxy ions. Most commonly, a solid electrolyte having a tetraalkylammonium cation group is used.

  In the case of DMFC, the theoretical cell voltage is 1.28 V, as in the case of a hydrogen battery. However, in the case of a cationic DMFC that uses a cationic electrolyte / electrode layer, CO, which is an intermediate in the decomposition process of methanol, is platinum. In order to be absorbed by the catalyst and to release its CO in an acidic atmosphere, an overvoltage of 0.4 V is required. Furthermore, it is said that the methanol supplied to the anode (negative electrode) reaches the cathode (positive electrode) through the electrolyte membrane (methanol crossover), thereby lowering the cathode potential. As a result, the actual open circuit voltage (OCV: Open Circuit Voltage) of the DMFC is 0.8 V or less.

  Therefore, in the case of a cation type DMFC, it is difficult to realize a required output density for popularization (for example, by downsizing) of a built-in fuel cell for portable devices. Many studies have been made to reduce this overvoltage, but a sufficient effect has not yet been obtained.

On the other hand, in the case of an anionic fuel cell, CO release in an alkaline atmosphere is easy, so that the overvoltage is almost zero and a cell voltage similar to that of a hydrogen fuel cell can be obtained. Therefore, realization of a high power density DMFC is expected. In the case of an anionic fuel cell, since OH ⁻ ions move from the cathode to the anode, the permeability of water and alcohol from the anode to the cathode is low, the crossover of fuel (for example, methanol) is also reduced, and high performance is achieved. Is possible. Furthermore, since the atmosphere is alkaline, non-platinum catalyst materials (Fe, Co, Ni, etc.) can be used, which is advantageous for cost reduction. As for the fuel, there are many advantages in addition to methanol such that harmless alcohol fuel such as ethanol and ethylene glycol can be applied. On the other hand, in the case of a cation type fuel cell, non-platinum-based catalyst materials (Fe, Co, Ni, etc.) are eroded by acid, and 0.4 V is required to desorb CO generated from the electrodes when methanol is used. In the case of ethanol, there arises a problem that the generated acetaldehyde does not desorb from the electrode.
JP 2000-212306 (Claims) Japanese Patent Laying-Open No. 2005-268044 (Claims) JP2004-206899 (Claims) JP 2002-203568 (Claims) US Pat. No. 4,012,324 (claims) US Pat. No. 5,376,418 (claims) “Journal of Electrochemical Society”, 2003, 150 (3), A398-A402.

The problems with this anion exchange material are: (1) heat resistance and resistance to fuels such as alcohol (properties that dissolve or swell in alcohol and other fuels, and mechanical strength does not decrease), dimensional stability sex, it is insufficient in terms of fuel for the block of such alcohols (property of preventing the permeation of fuel), (2) OH ^- of the low diffusivity at high electrical resistance of the membrane, the membrane electrical resistance In order to reduce this, there is a drawback in that the membrane's resistance to fuel and dimensional stability deteriorate when attempting to obtain a sufficiently high ion exchange capacity (IEC). For this reason, it is essential to develop materials having sufficient fuel resistance and sufficient IEC.

  At present, anion exchange type electrolyte membrane materials for fuel cells have not been widely used. For example, polystyrene resins having quaternary ammonium ions in the side chain (see Patent Documents 1 to 5) have been reported. Further, Patent Document 6 proposes a method of introducing an anion exchange group into a thermoplastic polymer such as polyphenylene ether by a chloromethylation method. However, in the case of these materials, it is known that the IEC of the resin material cannot be freely changed, and it is difficult to achieve both sufficient IEC and sufficient strength of the film in methanol. Furthermore, in the case of these anion exchange conductive membrane materials, no applicability to fuel cells is taught.

  Still other objects and advantages of the present invention will become apparent from the following description.

According to one aspect of the present invention, an anion exchange type electrolyte composition containing a tetraalkylammonium cation group,
An anion exchange type electrolyte composition comprising the structural unit represented by the formula (1) and the structural unit represented by the formula (4) is provided.

In the formula (1), X represents O or S independently of each other, Y represents CH ₂ or CH ₂ O independently of each other, and Ar may have fluorine and may be a heterocyclic ring. Represents one or more aromatic rings which may contain, or a group in which these aromatic rings are bonded by a direct bond, O, S, SO or SO ₂ , and R ¹ , independently of each other, represents an alkyl Z ⁻ represents a counter ion of a tetraalkylammonium cation group, and n represents an integer of 1 to 10 independently of each other. In Formula (4), E may have fluorine, may have a branched aliphatic group, may have fluorine, and may contain a heterocyclic ring Or a divalent to tetravalent group having at least one of a direct bond, a group bonded by O, S, SO or SO ₂ , and these aromatic rings are derived from E A broken line means two to four single bonds depending on the valence, and m represents an integer of 2 to 4.

  It is preferable to further include at least one of the structural unit represented by the formula (2) and the structural unit represented by the formula (3).

In the formula (2), X represents O or S independently of each other, Ar represents one or more aromatic rings which may have fluorine and may contain a heterocyclic ring, or these Represents a group in which the aromatic ring is bonded by a direct bond, O, S, SO or SO ₂ . In the formula (3), B may have fluorine, may have a branched alkylene group, may have fluorine, and may contain one or more heterocyclic rings. Represents an aromatic ring or a divalent group having at least one of a direct bond, a group bonded with O, S, SO or SO ₂ , and R ² represents an alkyl group Z ⁻ represents a counter ion of a tetraalkylammonium cation group.

According to another aspect of the present invention, an anion exchange type electrolyte composition containing a tetraalkylammonium cation group,
An anion exchange type electrolyte composition obtained by a treatment comprising reacting a compound represented by the formula (1 ′) and a compound represented by the formula (4 ′) is provided.

In the formula (1 ′), X represents O or S independently of each other, Y represents CH ₂ or CH ₂ O independently of each other, and Ar may have fluorine and may be complex. One or more aromatic rings optionally containing a ring, or a group in which these aromatic rings are bonded by a direct bond, O, S, SO or SO ₂ , R ¹ independently of each other, Represents an alkyl group, Z ⁻ represents a counter ion of a tetraalkylammonium cation group, and n represents an integer of 1 to 10 independently of each other. In formula (4 ′), E may have fluorine, may have a branched aliphatic group, may have fluorine, and may contain a heterocyclic ring 1 The above aromatic ring or a divalent to tetravalent group having at least one of a direct bond, a group bonded with O, S, SO, or SO ₂ is represented by E, The broken line that comes out means two to four single bonds depending on the valence, and m represents an integer of 2 to 4.

  It is preferably obtained by a treatment comprising further reacting at least one of the compound represented by the formula (2 ′) and the compound represented by the formula (3 ′).

In the formula (2 ′), X represents O or S independently of each other, Ar represents one or more aromatic rings which may have fluorine and may contain a heterocyclic ring, or these Represents a group in which the aromatic ring is bonded by a direct bond, O, S, SO or SO ₂ . In formula (3 ′), B may have fluorine, may have a branched alkylene group, may have fluorine, and may contain a heterocyclic ring Or a divalent group having at least one of a direct bond, a group bonded with O, S, SO or SO ₂ , and R ² represents an alkyl group Z ⁻ represents a counter ion of a tetraalkylammonium cation group.

The reaction is performed by at least one of a heat treatment and an active energy ray irradiation treatment, and the treatment is performed by immersing the product of the reaction in a basic aqueous solution as a counter ion. It is preferable to include a treatment to have OH ⁻ .

Furthermore, in common with the above two embodiments, it is preferable that Z ⁻ is Cl ⁻ or Br ⁻ and m is 2 or 4.

  According to the above two embodiments, a novel anion exchange type electrolyte composition is obtained. By introducing an anion exchange group in the monomer state, IEC can be arbitrarily controlled and high IEC can be realized. The three-dimensional network structure is optimized, and as a result, a solid electrolyte membrane having any one of heat resistance, excellent fuel resistance (for example, high-concentration alcohol resistance), dimensional stability, and fuel blockability can be obtained.

  According to still another aspect of the present invention, a solid electrolyte membrane comprising the above anion exchange electrolyte composition, or an anion exchange solid polymer fuel cell using the above anion exchange electrolyte composition as a solid electrolyte membrane Is provided.

  According to the present invention, a novel anion exchange type electrolyte composition, a solid electrolyte membrane using the anion exchange type electrolyte composition, and an anion exchange type solid polymer fuel cell can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings, formulas, examples and the like. In addition, these figures, formulas, examples, etc., and explanations illustrate the present invention, and do not limit the scope of the present invention. It goes without saying that other embodiments may belong to the category of the present invention as long as they match the gist of the present invention.

  The electrolyte composition according to the present invention is an anion exchange type electrolyte composition containing a tetraalkylammonium cation group, and includes a structural unit represented by the formula (1) and a structural unit represented by the formula (4). An anion exchange type electrolyte composition.

Here, in the formula (1), X represents O or S independently of each other, Y represents CH ₂ or CH ₂ O independently of each other, and Ar may have fluorine and be complex. One or more aromatic rings optionally containing a ring, or a group in which these aromatic rings are bonded by a direct bond, O, S, SO or SO ₂ , R ¹ independently of each other, Represents an alkyl group, Z ⁻ represents a counter ion of a tetraalkylammonium cation group, and n represents an integer of 1 to 10 independently of each other. In Formula (4), E may have fluorine, may have a branched aliphatic group, may have fluorine, and may contain a heterocyclic ring Or a divalent to tetravalent group having at least one of a direct bond, a group bonded by O, S, SO or SO ₂ , and these aromatic rings are derived from E A broken line means two to four single bonds depending on the valence, and m represents an integer of 2 to 4.

  With this structure, an anion exchange type electrolyte composition in which a desired amount of tetraalkylammonium cation group is incorporated according to the ratio of the structural unit represented by formula (1) and the structural unit represented by formula (4). Can be obtained. Further, the amount of the structural unit represented by the formula (4), the size of m in the structural unit represented by the formula (4), and the degree of progress of polymerization with respect to the total amount of the anion exchange electrolyte composition. The desired degree of crosslinking can be realized.

  The anion exchange electrolyte composition may further include at least one of the structural unit represented by the formula (2) and the structural unit represented by the formula (3).

In the formula (2), X independently represents O or S, and Ar represents one or more aromatic rings which may have fluorine or may include a heterocyclic ring, or aromatics thereof. Represents a group in which the ring is connected by a direct bond, O, S, SO or SO ₂ . In the formula (3), B may have fluorine, may have a branched alkylene group, may have fluorine, and may contain one or more heterocyclic rings. Represents an aromatic ring or a divalent group having at least one of a direct bond, a group bonded with O, S, SO or SO ₂ , and R ² represents an alkyl group Z ⁻ represents a counter ion of a tetraalkylammonium cation group.

  By sharing the structural unit represented by the formula (2), it becomes easier to obtain an anion exchange type electrolyte composition having a desired amount of tetraalkylammonium cation group incorporated therein. By sharing the structural unit represented by the formula (3), it becomes easier to adjust the degree of polymerization progress and the degree of crosslinking.

  In the anion exchange electrolyte composition, the structural unit represented by the formula (1) or (2) and the structural unit represented by the formula (3) or (4) are interposed via oxygen (O). (Ie through an ether bond). Therefore, at the terminal in the structural unit represented by the formulas (1) to (4), it can be expressed as O is present or as O is not present. Therefore, for example, combinations of structural units represented by formulas (1 ″) to (4 ″) shown in FIG. 8 may have the same meaning as combinations of structural units represented by formulas (1) to (4). .

  The above anion exchange type electrolyte composition may be produced by any known method.

  The anion exchange type electrolyte composition according to the present invention can be obtained, for example, by a treatment comprising reacting a compound represented by the formula (1 ′) and a compound represented by the formula (4 ′).

In the formula (1 ′), X independently represents O or S, Y independently represents CH ₂ or CH ₂ O, and Ar represents a heterocyclic ring which may have fluorine. One or more aromatic rings which may be contained, or a group in which these aromatic rings are bonded by a direct bond, O, S, SO or SO ₂ , R ¹ is independently of each other an alkyl group Z ⁻ represents a counter ion of a tetraalkylammonium cation group, and n represents an integer of 1 to 10 independently of each other. In formula (4 ′), E may have fluorine, may have a branched aliphatic group, may have fluorine, and may contain a heterocyclic ring 1 The above aromatic ring or a divalent to tetravalent group having at least one of a direct bond, a group bonded with O, S, SO, or SO ₂ is represented by E, The broken line that comes out means two to four single bonds depending on the valence, and m represents an integer of 2 to 4.

  By this treatment, an anion exchange type electrolyte composition in which a desired amount of tetraalkylammonium cation group is incorporated according to the ratio of the compound represented by formula (1 ′) and the compound represented by formula (4 ′). Can be obtained. Further, a desired degree of crosslinking is realized based on the amount of the compound represented by the formula (4), the size of m in the compound represented by the formula (4), and the progress of the polymerization with respect to the total amount of the raw material. be able to.

  Moreover, in addition to said process, said anion exchange type electrolyte composition is made to further react at least any one of the compound represented by Formula (2 '), and the compound represented by Formula (3'). Can also be obtained by a process comprising

In the formula (2 ′), X independently represents O or S, and Ar represents one or more aromatic rings which may have fluorine and may contain a heterocyclic ring, or aromatics thereof. A group ring represents a group in which a direct bond, O, S, SO, or SO ₂ is bonded. In formula (3 ′), B may have fluorine, may have a branched alkylene group, may have fluorine, and may contain a heterocyclic ring Or a divalent group having at least one of a direct bond, a group bonded with O, S, SO or SO ₂ , and R ² represents an alkyl group Z ⁻ represents a counter ion of a tetraalkylammonium cation group.

  By sharing the compound represented by the formula (2 '), it becomes easier to obtain an anion exchange type electrolyte composition incorporating a desired amount of tetraalkylammonium cation group. By sharing the compound represented by the formula (3 '), it becomes easier to adjust the degree of polymerization progress and the degree of crosslinking.

In the above, X is preferably O, Y is preferably CH ₂ O, and Ar is bisphenyl sulfone group, bispentyl sulfoxide group, bisphenyl ketone group, phenyl, bisphenylphosphine oxide group, bisphenyl peroxy group. A fluoroalkyl group, a bisphenyl-1,1,1,3,3,3-hexafluoropropane group, a benzoxazole group, a benzthiazole group, and the like are preferable, and methyl groups are preferable as R ¹ and R ² . n is preferably an integer of 2 to 6. E is preferably an aromatic group, an aliphatic group, or an aromatic group / aliphatic group mixture, and B is preferably an aromatic group, an aliphatic group, or an aromatic group / aliphatic group mixture.

In addition, in the anion exchange type electrolyte composition, the structural unit and the compound represented by the above formula are not one type, and a plurality of types may be included. For example, the thing from which m and n differ may be contained. m is preferably 2 or 4 because it is easily available and a sufficient degree of crosslinking can be obtained. Z ^- may be any ion for halide ion, especially Cl ^- or Br ^- is preferred.

  Preferable examples of the compound represented by the formula (1 ′) are those shown in FIG. 2, and preferred examples of the compound represented by the formula (2 ′) are those shown in FIG. Preferred examples of the compound represented by 3 ′) are those shown in FIG. 4, and preferred examples of the compound represented by formula (4 ′) are those shown in FIGS. 5A, 5B, and 5C. Can be mentioned. Moreover, the structure which removed the hydrogen of the hydroxy group from the compounds listed in FIGS. 2 to 5A, 5B and 5C and the structure where the epoxy group was opened are considered as suitable structural units of the formulas (1) to (4). be able to.

  In the formulas (1) to (4) and the formulas (1 ') to (4'), the same symbols have the same meanings, but are not necessarily related to each other and are independent. That is, in the present invention, it is essential that the anion exchange type electrolyte composition appropriately composed of the structural units of the formulas (1) to (4) is prepared from the compounds of the formulas (1 ′) to (4 ′). On the contrary, the anion-exchange electrolyte composition appropriately prepared from the compounds of formulas (1 ′) to (4 ′) is composed of structural units of formulas (1) to (4). There is no need to prove that.

  The above reaction can be carried out in any known manner, but it is practical and preferred that it is carried out by at least one of heat treatment and active energy ray irradiation treatment. Either the heat treatment alone, the active energy ray irradiation treatment alone, or both may be used simultaneously, or both may be employed at different timings. Although there is no restriction | limiting in particular about the temperature of heat processing, Between 120-150 degreeC is often preferable practically.

  In the above, active energy rays mean ultraviolet rays or electromagnetic waves having a shorter wavelength than ultraviolet rays, and examples thereof include ultraviolet rays, electron beams, X-rays and γ rays. If the reaction of the above compound occurs as a result of irradiation, it can be said that the active energy ray is suitable for the present invention. Among these, ultraviolet rays or electron beams are practical and preferable in many cases. As ultraviolet rays, any of UV-A (wavelength 315 to 400 nm), UV-B (wavelength 280 to 315 nm), and UV-C (wavelength 200 to 280 nm) may be used.

  In many cases, it is preferable to use a catalyst for promoting the reaction of the compound. In general, imidazole, triphenylphosphine, sulfonium salts (cation generator), 2,2'-azobisisobutyronitrile and the like are preferable.

In many cases, the product obtained by the reaction is preferably immersed in a basic aqueous solution and the counter ion is replaced with OH ⁻ . When the reaction product has halogen ions as counter ions, it can be easily ion-exchanged in an aqueous alkali solution such as caustic soda.

  Various other processes can be included in the above-described processing as long as it is not contrary to the gist of the present invention. There is no restriction | limiting in particular about this "other various process", The various process used in order to produce electrolyte composition can be included. For example, a treatment for dissolving in a solvent in order to obtain a sheet or film-like electrolyte composition, and post-cure by heating to further promote crosslinking can be exemplified.

  The novel electrolyte composition obtained as described above can be employed in various anion exchange solid polymer fuel cells as a solid electrolyte membrane of a fuel cell. Specifically, it can be used for a direct fuel cell, a reforming fuel cell, a hydrogen fuel cell, etc. that use methanol, ethanol, ethylene glycol or the like as a fuel. This solid electrolyte membrane is excellent in heat resistance, dimensional stability under high-concentration atmosphere, fuel resistance, and fuel blockability, and can realize high ICE.

  The electrolyte composition itself according to the present invention may be the solid electrolyte membrane according to the present invention or a precursor thereof. That is, at the time of producing the electrolyte composition according to the present invention, or subsequently, the solid electrolyte membrane according to the present invention may be finished.

  In the manufacturing process of the electrolyte composition and the solid electrolyte membrane according to the present invention, other components may be included in addition to the components described above. Specifically, other polymers and solvents, catalysts for the above reaction, additives, and the like can be considered. Examples of the other polymer include polyacrylate and polysiloxane, and examples of the solvent include dimethylacetamide, dimethylformamide, N-methylpyrrolidone, dimethylsulfoxide, and water. The catalyst has already been described above.

  From the thus obtained electrolyte composition of the present invention and its raw material or reaction intermediate composition, for example, in the case of a solution containing a solvent, this solution is applied onto a substrate, and then the solvent is removed. By doing so, a solid electrolyte membrane can be easily manufactured. For this reason, film thickness control is easy.

  Heating and / or active energy ray treatment can also be performed after removal of the solvent. This heating and / or active energy ray treatment may be for inducing the reaction according to the present invention or for further advancing the reaction.

  When a substrate is required to form a film, the substrate may be any substrate as long as it is inert to the electrolyte composition or solvent and can form a film of the electrolyte composition.

  An example of a fuel cell manufactured in this way is shown in FIG. In FIG. 6, 1 is a fuel cell power generation unit, 2 is a fuel electrode catalyst layer (also simply referred to as a fuel electrode), 3 is an anion conductive polymer solid electrolyte, 4 is an air electrode catalyst layer (also simply referred to as an air electrode), and 5 is A fuel cell housing, 6 is an air inlet provided in the housing, 7 is a fuel cartridge containing alcohol, 8 is a liquid feeding system section for injecting fuel from the fuel cartridge to the fuel electrode, 9 is a current collector, 10 Is an electronic circuit such as a booster circuit and supplies power to the outside.

  A fuel cell power generation unit (MEA: Membrane Electrode Assembly) is configured as shown in FIG. 7, for example. In FIG. 7, reference numeral 11 denotes a fuel electrode current collector and an air electrode current collector, which are made of SUS mesh or punching metal, and the surface is plated with a stable metal such as Au. Thereby, substances such as fuel can diffuse in the vertical direction. Reference numeral 12 denotes a fuel electrode catalyst layer, and Ni having a high specific surface area such as Raney nickel can be used. Moreover, Ni powder etc. may be mixed with binders, such as PTFE, and it shape | molded as an electrode body. Reference numeral 13 denotes an anion conductive polymer solid electrolyte membrane according to the present invention. In FIG. 7, 14 is an air electrode catalyst layer, and Ni, Fe, Co, Ag, a phthalocyanine complex or the like can be used as a catalyst metal, and these fine powders are generally used by being supported on carbon or the like. It is. Examples of the catalyst used in this anion exchange type fuel cell are described in Non-Patent Document 1 and the like.

  Next, examples of the present invention will be described in detail.

[Example 1] (Preparation of anion exchange type electrolyte composition)
Monomer 1-1 was synthesized by the following procedure. The reaction route is shown in FIG.

(1) 3,5-dihydroxybenzyl bromide
A 200 mL three-necked flask is charged with 10 mL of anhydrous toluene, 14.0 g (0.1 mol) of 3,5-dihydroxybenzyl alcohol (Chemical Formula 1) and 5.5 mL of pyridine, and the mixture is −5 to −10. Cooled to ° C. To this, 10.8 g (0.04 mol) of PBr ₃ was added dropwise over 1 hour and then the mixture was stirred overnight at room temperature. The mixture was poured into 20% by weight sodium chloride solution and the organic layer was washed with 5% by weight aqueous NaHCO ₃ solution.

Finally, the organic layer was dried over anhydrous Mg ₂ SO ₄ and the solvent was evaporated.
The final product was purified by column chromatography on silica gel using hexane: ethyl acetate (10: 4) as eluent (52% yield).

(2) 6- (3,5-dihydroxybenzyloxy) -1-hexanol (Chemical Formula 3)
11.8 g (0.1 mol) of hexane-1,6-diol was dissolved in anhydrous THF. To this was added a 60 wt% NaH suspension of 4.0 g (0.1 mol) NaH suspended in mineral oil and the mixture was stirred at 0 ° C. for 2 hours. To this was added 21.9 g (0.1 mol) of 3,5-dihydroxybenzyl bromide and the mixture was stirred at room temperature overnight, after which 10 mL of ethanol was added with stirring. The solvent was evaporated and the crude product was washed with distilled water.

  The remaining waxy product was purified by column chromatography on silica gel using hexane: ethyl acetate as eluent (64% yield).

(3) 6- (3,5-dihydroxybenzyloxy) -1-bromohexane
6- (3,5-dihydroxybenzyloxy) -1-hexanol (Chemical Formula 3) was reacted with PBr to give 6- (3,5-dihydroxybenzyloxy) -1-bromohexane (Chemical Formula 4).

(4) 6- (3,5-dihydroxybenzyloxy) hexyl-trimethylammonium bromide
30.3 g (0.1 mol) of 6- (3,5-dihydroxybenzyloxy) -1-bromohexane was dissolved in 200 mL of dioxane. To this was added 15 mL of 50 wt% trimethylamine aqueous solution. The mixture was stirred overnight at 50 ° C. The solvent and excess amine were evaporated and the solid was washed with diethyl ether. Finally, the waxy product was dissolved in water and precipitated with sodium chloride to give 6- (3,5-dihydroxybenzyloxy) hexyl-trimethylammonium bromide.

(5) Monomer 1-1
In a three-necked flask equipped with a Dean-Stark arm and a water-cooled condenser, 36.2 g (0.1 mol) of 6- (3,5-dihydroxybenzyloxy) hexyl-trimethylammonium bromide and 13.8 g (0.1 Mol) of K ₂ CO ₃ was dissolved in a mixture of 300 mL of DMF (dimethylformamide) and 30 mL of xylene. The mixture was refluxed at 90 ° C. for 12 hours under a vacuum of 100 mbar (converted value: 0.01 MPa) and dehydrated. To the dehydrated solution, 12.7 g (0.05 mol) of bis (4-fluorophenyl) sulfone (Chemical 6) was added and the mixture was stirred at 80 ° C. for 12 hours. The mixture was poured into cold water and the solution was saturated with sodium chloride. The precipitate was recrystallized with 90% ethanol to obtain monomer 1-1.

(5) Anion-exchange electrolyte composition 9.5 g (0.01 mol) of monomer 1-1 and 2.52 g (0.016 epoxy equivalent) of Epolite 40E (manufactured by Kyoeisha, n in FIG. 5B (13)) = 1 structure), diepoxide corresponding to the compound of formula (4), epoxy equivalent 140), 0.30 g of Araldite MT0163 (manufactured by Ciba Gaigi Japan, structure of (21) in FIG. 5C), formula (4) Tetraepoxide corresponding to the above compound, epoxy equivalent 154) was dissolved in DMF (10 mL), 0.2 g of imidazole 2E4ME (Cazor made by Shikoku Kasei Co., Ltd.) as a reaction accelerator was added and stirred for 1 hour. The reaction is accelerated by the active hydrogen of imidazole 2E4ME.

  Thereafter, this mixture was applied onto a glass plate using a doctor blade having a gap size of 300 μm, and the solvent was removed at a temperature of 50 ° C., 120 ° C. and 150 ° C. (in vacuum) for 1 hour, polymerized, and the film thickness was reduced. A membrane of about 50 μm was obtained. Next, this membrane was immersed in a 0.5 mol / L NaOH aqueous solution for 24 hours, and then washed with deionized water until no acid could be detected to obtain an anion exchange type electrolyte composition according to the present invention.

  The film was evaluated as follows.

(Methanol permeability measurement)
A 10% by volume methanol aqueous solution and deionized water are separated in a stainless steel container by a sample electrolyte membrane and kept at 30 ° C., and the amount of methanol permeating into the deionized water is determined by GC / MS (gas chromatography / mass Analytical method) was measured at regular time intervals.

The methanol permeability measured for this electrolyte membrane was 6.01 × 10 ⁻⁸ mL / s. cm. On the other hand, the methanol permeability of Nafion 112 is 1.08 × 10 ⁻⁷ mL / s. cm.

(Anion conductivity measurement)
The sample was mounted between platinum electrodes with an electrode distance of 1 cm, and the membrane resistance was measured by the AC impedance method (frequency: 100 Hz to 100 kHz) under a voltage condition of 0.3 V at room temperature, and the anion conductivity was calculated. . The anion conductivity of this electrolyte membrane was 0.62 S / cm. On the other hand, the proton conductivity of Nafion 112 measured in the same manner was 0.112 S / cm.

[Example 2] (Fabrication of fuel cell)
As a catalyst for the fuel electrode, Ni powder was mixed with PTFE (polytetrafluoroethylene) dispersion (Daikin, DE4W), made into a paste, and then applied and pressed onto Ni mesh (100 mesh). . The same Ni catalyst system as the fuel electrode was used for the air electrode catalyst.

The anion exchange membrane was used for the anion conductive polymer solid electrolyte, and was sandwiched between both electrodes to prepare an MEA having an electrode area of 9 cm ² .

  Next, this MEA was sandwiched between SUS punching metal current collectors which were plated with Au to give corrosion resistance, and fixed with a casing to form a power generation unit. The aperture ratio of the current collector was 60%.

Next, a 20% volume MeOH (containing 2 wt% K ₂ CO ₃ ) aqueous solution was supplied from the cartridge.

Experiments on continuous power generation characteristics were performed under the following conditions. That is, the fuel cell was generated with a constant current of 60 mA / cm ² , and the power generation was terminated when the voltage in the fuel cell decreased to 0.1 V after the voltage increased. As a result of this continuous power generation experiment, the average voltage was 0.20 V and the power generation time was 90 minutes.

  As in Example 2, a cation exchange type fuel cell was prepared using Nafion 112 as a polymer solid electrolyte (electrolyte material) and evaluated. As a result, the average voltage was 0.20 V and the power generation time was 50 minutes. .

[Example 3] (Preparation of anion exchange type electrolyte composition and fuel cell)
Instead of using 9.5 g (0.01 mol) of monomer 1-1, 7.60 g (0.008 mol) of monomer 1-1 and 0.460 g (0.002 mol) of bisphenol A were used. Obtained an anion-exchange electrolyte composition according to the present invention in the same manner as in Example 1 (5), and a fuel cell was produced in the same manner as in Example 2.

The methanol permeability measured for this electrolyte membrane was 4.21 × 10 ⁻⁸ mL / s. cm. On the other hand, the methanol permeability of Nafion 112 is 1.08 × 10 ⁻⁷ mL / s. cm.

  The anion conductivity of this electrolyte membrane was 0.52 S / cm. On the other hand, the proton conductivity of Nafion 112 was 0.112 S / cm.

[Example 4]
9.5 g (0.01 mol) of monomer 1-1 and 2.52 g (0.016 epoxy equivalent) of Epolite 40E (manufactured by Kyoeisha, structure of n = 1 in (13) of FIG. 5B), formula (4 Diepoxide corresponding to the compound of), an epoxy equivalent of 140), 0.30 g of Araldite MT0163 (manufactured by Ciba-Gaigi Japan, (structure of (21) in FIG. 5C), tetraepoxide corresponding to the compound of formula (4), Epoxy equivalent 154) is dissolved in DMF (10 mL) and 0.2 g (about 1% by weight) of a reaction accelerator {ADEKA Optomer SP-172 (triphenylsulfonium hexafluoroantimonate) manufactured by Asahi Denka Co., Ltd.}} And stirred for 1 hour.

(Preparation of anion exchange electrolyte composition and fuel cell)
Instead of the heat treatment, an anion exchange type electrolyte composition according to the present invention was obtained in the same manner as (5) of Example 1 except that irradiation with 365 nm ultraviolet rays was performed at 500 mJ / cm ² , and the same as in Example 2. Thus, a fuel cell was produced.

The methanol permeability measured for this electrolyte membrane was 3.51 × 10 ⁻⁸ mL / s. cm. On the other hand, the methanol permeability of Nafion 112 is 1.08 × 10 ⁻⁷ mL / s. cm.

  The anion conductivity of this electrolyte membrane was 0.51 S / cm. On the other hand, the proton conductivity of Nafion 112 was 0.112 S / cm.

  In addition, the invention shown to the following additional remarks can be derived from the content disclosed above.

(Appendix 1)
An anion exchange type electrolyte composition containing a tetraalkylammonium cation group,
An anion exchange electrolyte composition comprising a structural unit represented by formula (1) and a structural unit represented by formula (4);

(In Formula (1), X represents O or S independently of each other; Y represents CH ₂ or CH ₂ O independently of each other; Ar represents a heterocyclic ring which may have fluorine; One or more aromatic rings which may be contained, or a group in which these aromatic rings are bonded by a direct bond, O, S, SO or SO ₂ , R ¹ is independently of each other an alkyl group Z ⁻ represents a counter ion of a tetraalkylammonium cation group, n independently of each other represents an integer of 1 to 10. In formula (4), E may have fluorine, An aliphatic group which may have a branch and one or more aromatic rings which may have a fluorine and may contain a heterocyclic ring, or these aromatic rings may be directly bonded, O, Having at least one of S, SO or a group bonded by SO ₂ And the broken line coming out from E means two to four single bonds depending on the valence, and m represents an integer of 2 to 4.)

(Appendix 2)
The anion exchange electrolyte composition according to appendix 1, further comprising at least one of a structural unit represented by formula (2) and a structural unit represented by formula (3),

(In the formula (2), X represents O or S independently of each other, Ar represents one or more aromatic rings which may have fluorine and may contain a heterocyclic ring, or aromatics thereof. Represents a group in which the group ring is bonded by a direct bond, O, S, SO or SO _{2. In} formula (3), B may have fluorine or may have a branch. An alkylene group and one or more aromatic rings which may have fluorine and may contain a heterocyclic ring, or these aromatic rings are bonded by a direct bond, O, S, SO or SO ₂ R ² represents an alkyl group, and Z ⁻ represents a counter ion of a tetraalkylammonium cation group.

(Appendix 3)
An anion exchange type electrolyte composition containing a tetraalkylammonium cation group,
An anion-exchange electrolyte composition obtained by a treatment comprising reacting a compound represented by the formula (1 ′) and a compound represented by the formula (4 ′);

(In the formula (1 ′), X represents O or S independently of each other, Y represents CH ₂ or CH ₂ O independently of each other, and Ar may have fluorine and may be a heterocyclic ring. Represents one or more aromatic rings which may contain, or a group in which these aromatic rings are bonded by a direct bond, O, S, SO or SO ₂ , and R ¹ , independently of each other, represents an alkyl Z ⁻ represents a counter ion of a tetraalkylammonium cation group, and n independently of each other represents an integer of 1 to 10. In the formula (4 ′), E may have fluorine. In addition, an aliphatic group which may have a branch and one or more aromatic rings which may have a fluorine and may contain a heterocyclic ring, or these aromatic rings are directly bonded, O, S, at least one of a group attached by SO or SO ₂ Yes Represents two to four divalent group that, dashed lines emanating from the E means a single bond four from two depending on the valence, m is an integer of 2-4.).

(Appendix 4)
The anion exchange electrolyte according to appendix 3, obtained by a treatment comprising further reacting at least one of the compound represented by the formula (2 ′) and the compound represented by the formula (3 ′). Composition,

(In the formula (2 ′), X independently represents O or S, Ar represents one or more aromatic rings which may have fluorine and may contain a heterocyclic ring, or these Represents a group in which an aromatic ring is bonded by a direct bond, O, S, SO or SO _{2. In the} formula (3 ′), B may have fluorine or be branched. An alkylene group which may have a fluorine atom and one or more aromatic rings which may contain a heterocyclic ring, or these aromatic rings may be a direct bond, O, S, SO or SO ₂ . A divalent group having at least one of a bonded group, R ² represents an alkyl group, and Z ⁻ represents a counter ion of a tetraalkylammonium cation group).

(Appendix 5)
The anion exchange electrolyte composition according to appendix 3 or 4, wherein the reaction is performed by at least one of heat treatment and active energy ray irradiation treatment.

(Appendix 6)
6. The anion exchange electrolyte composition according to any one of appendices 3 to 5, wherein the treatment includes a treatment of immersing a product of the reaction in a basic aqueous solution to have OH ⁻ as a counter ion.

(Appendix 7)
The anion exchange electrolyte composition according to any one of appendices 1 to 6, wherein Z ⁻ is Cl ⁻ or Br ⁻ .

(Appendix 8)
8. The anion exchange electrolyte composition according to any one of appendices 1 to 7, wherein m is 2 or 4.

(Appendix 9)
A solid electrolyte membrane comprising the anion exchange electrolyte composition according to any one of appendices 1 to 8.

(Appendix 10)
An anion exchange solid polymer fuel cell using the anion exchange electrolyte composition according to any one of appendices 1 to 8 as a solid electrolyte membrane.

It is a figure which shows the electrode reaction of a cation exchange type fuel cell and an anion exchange type fuel cell. It is a figure which shows the suitable example of a compound represented by Formula (1 '). It is a figure which shows the suitable example of a compound represented by Formula (2 '). It is a figure which shows the suitable example of a compound represented by Formula (3 '). It is a figure which shows the suitable example of a compound represented by Formula (4 '). It is a figure which shows the suitable example of a compound represented by Formula (4 '). It is a figure which shows the suitable example of a compound represented by Formula (4 '). It is the schematic of a fuel cell. It is the schematic of a fuel cell power generation part. It is a figure which shows the combination of the structural unit represented by Formula (1 ")-(4") which may have the same meaning as the combination of the structural unit represented by Formula (1)-(4). It is a figure which shows the reaction pathway of the monomer 1-1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel cell power generation part 2 Fuel electrode catalyst layer 3 Anion conductive polymer solid electrolyte 4 Air electrode catalyst layer 5 Fuel cell housing 6 Air inlet 7 Fuel cartridge 8 Liquid supply system part 9 Current collector 10 Electronic circuit 11 Fuel electrode Current collector and air electrode current collector 12 Fuel electrode catalyst layer 13 Anion conductive polymer solid electrolyte membrane 14 Air electrode catalyst layer

Claims (8)

An anion exchange type electrolyte containing a tetraalkylammonium cation group,
An anion-exchange electrolyte comprising a structural unit represented by formula (1) and a compound comprising the structural unit represented by formula (4);

(In Formula (1), X represents O or S independently of each other; Y represents CH ₂ or CH ₂ O independently of each other; Ar represents a heterocyclic ring which may have fluorine; One or more aromatic rings which may be contained, or a group in which these aromatic rings are bonded by a direct bond, O, S, SO or SO ₂ , R ¹ is independently of each other an alkyl group Z ⁻ represents a counter ion of a tetraalkylammonium cation group, n independently of each other represents an integer of 1 to 10. In formula (4), E may have fluorine, An aliphatic group which may have a branch and one or more aromatic rings which may have a fluorine and may contain a heterocyclic ring, or these aromatic rings may be directly bonded, O, Having at least one of S, SO or a group bonded by SO ₂ And the broken line coming out from E means two to four single bonds depending on the valence, and m represents an integer of 2 to 4.) The anion exchange electrolyte according to claim 1, wherein the compound further comprises at least one of a structural unit represented by formula (2) and a structural unit represented by formula (3).

(In the formula (2), X represents O or S independently of each other, Ar represents one or more aromatic rings which may have fluorine and may contain a heterocyclic ring, or aromatics thereof. Represents a group in which the group ring is bonded by a direct bond, O, S, SO or SO _{2. In} formula (3), B may have fluorine or may have a branch. An alkylene group and one or more aromatic rings which may have fluorine and may contain a heterocyclic ring, or these aromatic rings are bonded by a direct bond, O, S, SO or SO ₂ R ² represents an alkyl group, and Z ⁻ represents a counter ion of a tetraalkylammonium cation group. An anion exchange type electrolyte containing a tetraalkylammonium cation group,
An anion exchange electrolyte obtained by a treatment comprising reacting a compound represented by formula (1 ′) and a compound represented by formula (4 ′);

(In the formula (1 ′), X represents O or S independently of each other, Y represents CH ₂ or CH ₂ O independently of each other, and Ar may have fluorine and may be a heterocyclic ring. Represents one or more aromatic rings which may contain, or a group in which these aromatic rings are bonded by a direct bond, O, S, SO or SO ₂ , and R ¹ , independently of each other, represents an alkyl Z ⁻ represents a counter ion of a tetraalkylammonium cation group, and n independently of each other represents an integer of 1 to 10. In the formula (4 ′), E may have fluorine. In addition, an aliphatic group which may have a branch and one or more aromatic rings which may have a fluorine and may contain a heterocyclic ring, or these aromatic rings are directly bonded, O, S, at least one of a group attached by SO or SO ₂ Yes Represents two to four divalent group that, dashed lines emanating from the E means a single bond four from two depending on the valence, m is an integer of 2-4.). The anion exchange type | mold of Claim 3 obtained by the process which comprises making further at least any one of the compound represented by Formula (2 '), and the compound represented by Formula (3') react. Electrolyte ,

(In the formula (2 ′), X independently represents O or S, Ar represents one or more aromatic rings which may have fluorine and may contain a heterocyclic ring, or these Represents a group in which an aromatic ring is bonded by a direct bond, O, S, SO or SO _{2. In the} formula (3 ′), B may have fluorine or be branched. An alkylene group which may have a fluorine atom and one or more aromatic rings which may contain a heterocyclic ring, or these aromatic rings may be a direct bond, O, S, SO or SO ₂ . A divalent group having at least one of a bonded group, R ² represents an alkyl group, and Z ⁻ represents a counter ion of a tetraalkylammonium cation group). The anion exchange electrolyte according to claim 3 or 4, wherein the reaction is performed by at least one of heat treatment and active energy ray irradiation treatment. The process, the product from the reaction was immersed in a basic aqueous solution, OH as a counter ion ^- includes a process to have the anion exchange type electrolyte according to any one of claims 3-5. A solid electrolyte membrane comprising the anion exchange electrolyte according to claim 1. Anion-exchange-type polymer electrolyte fuel cell using an anion-exchange type electrolyte according to any one of claims 1 to 6 as a solid electrolyte membrane.

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