JP6688837B2 - Electrolyte for electrochemical cell and electrochemical cell - Google Patents

Description

  The present invention relates to an electrolyte for an electrochemical cell and an electrochemical cell.

  Conventionally, in electrochemical cells such as alkaline fuel cells, alkaline secondary batteries, and electrolytic cells, an ion conductor having ion conductivity has been used as an electrolyte (see, for example, Patent Document 1).

JP, 2016-071948, A

  However, in the above-mentioned electrochemical cell, since the electrolyte is used in the presence of water (or steam), the volume of the electrolyte changes depending on the water content in the electrolyte. Therefore, the electrolyte may be separated from the cathode and / or the anode, or the electrolyte itself may be deformed.

  An object of the present invention is to provide an electrolyte for an electrochemical cell capable of suppressing peeling and deformation, and an electrochemical cell capable of suppressing peeling and deformation of the electrolyte.

  The electrolyte for an electrochemical cell according to the present invention includes a porous base material, an ionic conductor, and closed pores. The porous substrate has a three-dimensional network structure and forms continuous pores. The ionic conductor has ionic conductivity and is arranged in the continuous pores. Closed pores are formed in the ion conductor. The porous substrate is composed of at least one selected from ceramic materials and polymer materials.

  ADVANTAGE OF THE INVENTION According to this invention, the electrolyte for electrochemical cells which can suppress peeling and deformation, and the electrochemical cell which can suppress peeling and deformation of an electrolyte can be provided.

Sectional drawing which shows the structure of a solid alkaline fuel cell typically. A partially enlarged view of FIG.

(Solid alkaline fuel cell 10)
Hereinafter, as an example of an electrochemical cell to which the electrolyte for an electrochemical cell according to the present invention is applied, an embodiment of a solid alkaline fuel cell 10 which is a kind of alkaline fuel cell (AFC) using hydroxide ion as a carrier will be described. A description will be given with reference to the drawings.

  FIG. 1 is a cross-sectional view showing the configuration of a solid alkaline fuel cell 10 according to the embodiment. The solid alkaline fuel cell 10 includes a cathode 12, an anode 14, and an electrolyte 16 (an example of “electrolyte for electrochemical cell”). The solid alkaline fuel cell 10 generates power at a relatively low temperature (for example, 50 ° C. to 250 ° C.) based on the following electrochemical reaction formula. However, the following electrochemical reaction formula illustrates the case where methanol is used as an example of fuel.

Cathode 12: 3 / 2O ₂ + 3H ₂ O + 6e ⁻ → 6OH ⁻
Anode 14: CH ₃ OH + 6OH ⁻ → 6e ⁻ + CO ₂ + 5H ₂ O
・ Overall: CH ₃ OH + 3 / 2O ₂ → CO ₂ + 2H ₂ O

The cathode 12 is an anode generally called an air electrode. During power generation of the solid alkaline fuel cell 10, the oxidant containing oxygen (O ₂ ) is supplied to the cathode 12 via the oxidant supply means 13. Air is preferably used as the oxidant, and the air is more preferably humidified. The cathode 12 is a porous body capable of diffusing an oxidant inside. The porosity of the cathode 12 is not particularly limited. The thickness of the cathode 12 is not particularly limited, but may be 10 to 200 μm, for example.

The cathode 12 is not particularly limited as long as it includes a known air electrode catalyst used for AFC. Examples of cathode catalysts include Group 8 elements such as platinum group elements (Ru, Rh, Pd, Ir, Pt) and iron group elements (Fe, Co, Ni) (group 8 in the IUPAC format). Group 10 elements), Group 11 elements such as Cu, Ag, Au (elements belonging to Group 11 in the IUPAC format of the periodic table), rhodium phthalocyanine, tetraphenylporphyrin, Co salen, Ni salen (salen = N, N'-bis (salicylidene) ethylenediamine), silver nitrate, and any combination thereof. The amount of catalyst supported on the cathode 12 is not particularly limited, but is preferably 0.05 to 10 mg / cm ² , and more preferably 0.05 to 5 mg / cm ² . The cathode catalyst is preferably supported on carbon. Preferable examples of the cathode 12 or a catalyst constituting the same include platinum-supporting carbon (Pt / C), platinum-cobalt-supporting carbon (PtCo / C), palladium-supporting carbon (Pd / C), rhodium-supporting carbon (Rh / C). , Nickel-supporting carbon (Ni / C), copper-supporting carbon (Cu / C), and silver-supporting carbon (Ag / C).

  The method for producing the cathode 12 is not particularly limited. For example, the cathode 12 may be formed by mixing the cathode catalyst and, if desired, a carrier with a binder to form a paste, and applying this paste mixture to the cathode side surface 16S of the electrolyte 16. it can.

  The anode 14 is a cathode generally called a fuel electrode. During the power generation of the solid alkaline fuel cell 10, the fuel containing hydrogen atoms (H) is supplied to the anode 14 via the fuel supply means 15. The anode 14 is a porous body capable of diffusing fuel inside. The porosity of the anode 14 is not particularly limited.

The fuel only needs to contain a fuel compound capable of reacting with hydroxide ions (OH ⁻ ) in the anode 14, and may be in the form of either a liquid fuel or a gas fuel. The anode 14 is a porous body capable of diffusing fuel inside. The porosity of the anode 14 is not particularly limited. The thickness of the anode 14 is not particularly limited, but may be 10 to 500 μm, for example.

Examples of the fuel compound include (i) hydrazine (NH ₂ NH ₂ ), hydrazine hydrate (NH ₂ NH ₂ · H ₂ O), hydrazine carbonate ((NH ₂ NH ₂ ) ₂ CO ₂ ), and hydrazine sulfate (NH). ₂ NH ₂ · H ₂ SO ₄ ), hydrazine such as monomethylhydrazine (CH ₃ NHNH ₂ ), dimethylhydrazine ((CH ₃ ) ₂ NNH ₂ , CH ₃ NHNHCH ₃ ), and carvone hydrazide ((NHNH ₂ ) ₂ CO). , (Ii) Urea (NH ₂ CONH ₂ ), (iii) Ammonia (NH ₃ ), (iv) Imidazole, 1,3,5-triazine, 3-amino-1,2,4-triazole, etc. class compounds, (v) hydroxylamine _(NH 2 OH), hydro such as sulfuric hydroxylamine _{(NH 2 OH · H 2 SO} 4) Shiruamin acids, and combinations thereof. Of these fuel compounds, carbon-free compounds (that is, hydrazine, hydrazine hydrate, hydrazine sulfate, ammonia, hydroxylamine, hydroxylamine sulfate, and the like) are particularly preferable because they do not have a problem of catalyst poisoning by carbon monoxide. is there.

  The fuel compound may be used as a fuel as it is, or may be used as a solution dissolved in water and / or alcohol (for example, lower alcohol such as methanol, ethanol, propanol, isopropanol, etc.). For example, among the above fuel compounds, hydrazine, hydrated hydrazine, monomethylhydrazine and dimethylhydrazine are liquids, and thus can be used as they are as liquid fuels. Further, hydrazine carbonate, hydrazine sulfate, carboxylic hydrazide, urea, imidazole, 3-amino-1,2,4-triazole, and hydroxylamine sulfate are solid but soluble in water. 1,3,5-Triazine and hydroxylamine are solid but soluble in alcohol. Ammonia is a gas but soluble in water. Thus, the solid fuel compound can be dissolved in water or alcohol and used as a liquid fuel. When the fuel compound is used by dissolving it in water and / or alcohol, the concentration of the fuel compound in the solution is, for example, 30 to 99.9% by weight, preferably 66 to 99.9% by weight.

  Further, a hydrocarbon-based liquid fuel containing alcohols such as methanol and ethanol or ethers, a hydrocarbon-based gas such as methane, or pure hydrogen can be directly used as a fuel. In particular, methanol is suitable as the fuel used in the solid alkaline fuel cell 10 according to this embodiment. Methanol may be in a gas state, a liquid state, or a gas-liquid mixed state.

  The anode 14 is not particularly limited as long as it includes a known anode catalyst used for AFC. Examples of the anode catalyst include metal catalysts such as Pt, Ni, Co, Fe, Ru, Sn, and Pd. The metal catalyst is preferably supported on a carrier such as carbon, but may be in the form of an organic metal complex having a metal atom of the metal catalyst as a central metal, or the organic metal complex may be supported as a carrier. A diffusion layer made of a porous material or the like may be arranged on the surface of the anode catalyst. Preferred examples of the anode 14 and the catalyst constituting the same include nickel, cobalt, silver, platinum-supporting carbon (Pt / C), platinum-ruthenium-supporting carbon (PtRu / C), palladium-supporting carbon (Pd / C), rhodium-supporting. Examples include carbon (Rh / C), nickel-supporting carbon (Ni / C), copper-supporting carbon (Cu / C), and silver-supporting carbon (Ag / C).

  The method for producing the anode 14 is not particularly limited. For example, the anode 14 may be formed by mixing the anode catalyst and, if desired, a carrier with a binder to form a paste, and applying the paste mixture to the anode-side surface 16T of the electrolyte 16. it can.

  The electrolyte 16 is disposed between the cathode 12 and the anode 14. The electrolyte 16 is connected to each of the cathode 12 and the anode 14. The electrolyte 16 is formed in a film shape, a layer shape, or a sheet shape.

  FIG. 2 is a schematic view showing an enlarged cross section of the electrolyte 16. The electrolyte 16 has a porous base material 20 and an inorganic solid electrolyte body 22.

  The porous substrate 20 has a three-dimensional network structure. The “three-dimensional mesh structure” is a structure in which the constituent materials of the base material are connected in a three-dimensional and mesh shape. The porous substrate 20 forms continuous holes 20a. The continuous holes 20 a are formed by connecting the holes in a three-dimensional and mesh shape, and are exposed on the outer surface of the porous substrate 20. The continuous hole 20a is impregnated with an inorganic solid electrolyte body 22 described later.

  The porous substrate 20 can be composed of at least one selected from a ceramic material and a polymer material. Examples of ceramic materials include alumina, zirconia, titania, magnesia, calcia, cordierite, zeolite, mullite, zinc oxide, silicon carbide, and any combination thereof. Examples of the polymer material include polystyrene, polyether sulfone, polypropylene, epoxy resin, polyphenylene sulfide, fluororesin (tetrafluorinated resin: PTFE, etc.), cellulose, nylon, polyethylene, polyimide, and any combination thereof. When the porous base material 20 is made of a flexible polymer material, since it is easy to reduce the thickness of the continuous pores 20a while increasing the volume, the hydroxide ion conductivity can be improved. As the porous substrate 20 made of a polymer material, a microporous film commercially available as a lithium battery separator can be used.

  The thickness of the porous substrate 20 is not particularly limited, but can be, for example, 200 μm or less, preferably 100 μm or less, more preferably 75 μm or less, further preferably 50 μm or less, particularly preferably 25 μm or less, and 5 μm. The following are the most preferable. The lower limit of the thickness of the porous base material 20 may be appropriately set according to the application, but is preferably 1 μm or more, more preferably 2 μm or more in order to secure a certain degree of hardness.

  The average inner diameter of the continuous holes 20a in the cross section of the porous substrate 20 is not particularly limited, but can be, for example, 0.001 to 1.5 μm, preferably 0.001 to 1.25 μm, and more preferably 0. 001 to 1.0 μm, more preferably 0.001 to 0.75 μm, and particularly preferably 0.001 to 0.5 μm. By setting it as these ranges, the density of the inorganic solid electrolyte body 22 can be improved, giving the porous base material 20 the strength as a support body. The average inner diameter of the continuous holes 20a is obtained by arithmetically averaging the equivalent circle diameters of the continuous holes 20a at 20 locations randomly selected on the observed image when the cross section of the porous substrate 20 is observed with an electron microscope. To be The equivalent circle diameter of the continuous hole 20a is the diameter of a circle having the same area as the cross-sectional area of the continuous hole 20a in the observed image. The magnification of the electron microscope may be appropriately set according to the cross-sectional size of the continuous hole 20a.

  The volume ratio of the continuous holes 20a is not particularly limited, but may be, for example, 10 to 60%, preferably 15 to 55%, more preferably 20 to 50%. By setting it as these ranges, the density of the inorganic solid electrolyte body 22 can be improved, ensuring the strength as a support body in the porous base material 20. The volume ratio of the continuous holes 20a can be measured by the Archimedes method.

  Although not shown in FIG. 2, the porous substrate 20 preferably has a plurality of pores inside itself. The plurality of pores may be connected to each other inside the porous substrate 20. It is more preferable that each of the pores is an open pore that opens on the surface of the porous base material 20, and each of the pores is impregnated with the inorganic solid electrolyte body 22. As a result, a short-distance ion conduction path of continuous pore 20a → pore in porous substrate 20 → continuous pore 20a, continuous pore 20a → pore in porous substrate 20 → second membrane portion 22c, or It is possible to form a long-distance ion conduction path of the first membrane portion 22b → the pores in the porous substrate 20 → the second membrane portion 22c. As a result, the ion-conductive region in the composite portion 22a is expanded, so that the ion conductivity of the electrolyte 16 as a whole can be improved.

The inorganic solid electrolyte body 22 has hydroxide ion conductivity. During the power generation of the solid alkaline fuel cell 10, the inorganic solid electrolyte body 22 conducts hydroxide ions (OH ⁻ ) from the cathode 12 side to the anode 14 side. The hydroxide ion conductivity of the inorganic solid electrolyte body 22 is not particularly limited, but is preferably 0.1 mS / cm or more, more preferably 0.5 mS / cm or more, and further preferably 1.0 mS / cm or more. The higher the hydroxide ion conductivity of the inorganic solid electrolyte body 22, the more preferable, and the upper limit value thereof is not particularly limited, but is, for example, 10 mS / cm.

  The inorganic solid electrolyte body 22 can be made of a ceramic material having hydroxide ion conductivity. As such a ceramic material, a well-known ceramic having hydroxide ion conductivity can be used, but a layered double hydroxide (LDH: Layered Double Hydroxide) described below is particularly suitable.

LDH is M ²⁺ _1−x M ³⁺ _x (OH) ₂ A ⁿ⁻ x / n · mH ₂ O (in the formula, M ²⁺ is a divalent cation, M ³⁺ is a trivalent cation, and A ^n- is an anion of valence, n is an integer of 1 or more, x is 0.1 to 0.4, and m is an arbitrary integer which means the number of moles of water). Have. Examples of M ²⁺ include Mg ²⁺ , Ca ²⁺ , Sr ²⁺ , Ni ²⁺ , Co ²⁺ , Fe ²⁺ , Mn ²⁺ , and Zn ²⁺ , and examples of M ³⁺ include Al ³⁺ , Fe ³⁺ , Ti ³⁺ , ^{Y 3+, Ce 3+, Mo 3+} , and ^{Cr 3+} can be mentioned, An ^- _CO ^{3 2-} and OH- can be cited as examples of. As M ²⁺ and M ³⁺ , one type may be used alone, or two or more types may be used in combination.

The LDH is composed of a plurality of hydroxide basic layers and an intermediate layer interposed between the plurality of hydroxide basic layers. The intermediate layer is composed of anions and H ₂ O. The hydroxide base layer contains Ni, Al, Ti and OH groups when the metal M is Ni, Al or Ti, for example. Hereinafter, a case where the hydroxide basic layer of LDH contains Ni, Al, Ti and OH groups will be described.

Ni in LDH can take the form of nickel ions. The nickel ion in LDH is considered to be typically Ni ²⁺ , but is not particularly limited because it may have other valences such as Ni ³⁺ . Al in LDH can take the form of aluminum ions. The aluminum ion in LDH is considered to be typically Al ³⁺ , but it is not particularly limited because it may have other valences. Ti in LDH can take the form of titanium ions. The titanium ion in LDH is considered to be typically Ti ⁴⁺ , but it is not particularly limited because it may have other valences such as Ti ³⁺ . The hydroxide basic layer preferably contains Ni, Al, Ti and OH groups as main constituent elements, but may contain other elements or ions, or may contain unavoidable impurities. The unavoidable impurities are arbitrary elements that can be unavoidably mixed in the manufacturing method, and can be mixed in LDH due to, for example, a raw material or a base material.

The intermediate layer of LDH is composed of anions and H ₂ O. The anion is a monovalent or more anion, preferably a monovalent or divalent ion. Preferably, the anions in LDH include OH ⁻ and / or CO ₃ ²⁻ .

As described above, since the valences of Ni, Al, and Ti are not always clear, it is impractical or impossible to specify LDH exactly by the general formula. If it is assumed that the hydroxide basic layer is mainly composed of Ni ²⁺ , Al ³⁺ , Ti ⁴⁺ and OH groups, LDH has the general formula: Ni ²⁺ _1−x−y Al ³⁺ _x Ti ⁴⁺ _y (OH _{^{) 2 a n- (x + 2y}} ) / n · mH 2 O ( ^{wherein, a n-n-valent} anion, n is an integer of 1 or more, preferably 1 or 2, 0 <x <1, preferably Is 0.01 ≦ x ≦ 0.5, 0 <y <1, preferably 0.01 ≦ y ≦ 0.5, 0 <x + y <1, and m is 0 or more, typically more than 0 or 1 or more. Is a real number). However, the above general formula should be understood as “basic composition” to the extent that elements such as Ni ²⁺ , Al ³⁺ and Ti ⁴⁺ do not impair the basic characteristics of LDH and other elements or ions (of the same element) (Including elements or ions having other valences and elements or ions which may be unavoidably incorporated in the manufacturing process).

  In the present embodiment, the inorganic solid electrolyte body 22 has a composite portion 22a (an example of “ion conductor”), a first film-shaped portion 22b, and a second film-shaped portion 22c.

  The composite portion 22a is arranged between the first film-shaped portion 22b and the second film-shaped portion 22c. The composite part 22a is arranged in the continuous hole 20a of the porous substrate 20. The composite portion 22a is impregnated in the continuous hole 20a and is integrated with the porous substrate 20. Since the strength of the inorganic solid electrolyte body 22 can be improved by supporting the inorganic solid electrolyte body 22 with the porous base material 20 as described above, the inorganic solid electrolyte body 22 can be made thin. As a result, the resistance of the electrolyte 16 can be reduced.

  In the present embodiment, the composite part 22a is spread over substantially the entire area of the continuous pores 20a of the porous base material 20, but the inorganic solid electrolyte body 22 has at least the first membrane portion 22b and the second membrane portion 22c. When not having one, the composite part 22a may be impregnated only in a part of the porous substrate 20.

  Here, the composite portion 22a has a plurality of closed air holes 24 formed therein. Since the closed pores 24 are formed inside the composite portion 22a, it is possible to reduce the volume change of the electrolyte 16 due to the change in the water content of the composite portion 22a during the operation of the solid alkaline fuel cell 10. it can. As a result, it is possible to prevent stress from being generated at the interface between the cathode 12 and the electrolyte 16 or / and the interface between the anode 14 and the electrolyte 16, so that the electrolyte 16 is separated from the cathode 12 or / and the anode 14. Alternatively, it is possible to suppress the deformation of the electrolyte 16 itself.

  Furthermore, since the closed pores 24 are formed inside the composite portion 22a, flexibility can be imparted to the composite portion 22a. Therefore, due to the temperature distribution in the solid alkaline fuel cell 10, Generation of thermal stress at the interface with the electrolyte 16 and / or the interface between the anode 14 and the electrolyte 16 can be suppressed. Therefore, it is possible to prevent the electrolyte 16 from peeling off from the cathode 12 and / or the anode 14 or the deformation of the electrolyte 16 itself.

  As shown in FIG. 2, the closed pores 24 are preferably separated from the porous substrate 20. That is, it is preferable that the closed air holes 24 are confined inside the composite portion 22a and do not directly contact the inner surface of the continuous hole 20a. As a result, in comparison with the case where the closed pores 24 directly contact the porous base material 20, when the electrolyte 16 undergoes a volume change or deformation, the porous base material 20, the composite portion 22a, and the closed pores 24 are combined. It is possible to prevent the composite portion 22a from peeling off from the porous base material 20 with the corner portion formed in step 1 as the starting point.

  The average equivalent circle diameter of each closed pore 24 is not particularly limited, but may be 0.001 to 1.0 μm, for example. The average equivalent circle diameter of each closed pore 24 is preferably 0.001 μm or more, more preferably 0.002 μm or more. Thereby, the flexibility of the composite part 22a can be further improved. Further, the average equivalent circle diameter of each closed pore 24 is preferably 1.0 μm or less, and more preferably 0.8 μm or less. This can prevent the oxidant supplied to the cathode 12 from permeating to the anode 14 side or the fuel supplied to the anode 14 from permeating to the cathode 12 side.

  The average equivalent circle diameter of each closed pore 24 is calculated by observing the cross section of the electrolyte 16 with an electron microscope of 20,000 to 1,500,000 times and calculating the equivalent circle diameter of 20 randomly selected closed pores 24. Obtained by averaging. The equivalent circle diameter of the closed pores 24 is the diameter of a circle having the same area as the closed pores 24 in the cross section of the electrolyte 16. However, since the closed pores 24 having a circle equivalent diameter of 0.001 μm or less contribute very little to the relaxation of the volume change of the composite portion 22a and the improvement of flexibility, when determining the average circle equivalent diameter of each closed pore 24. Shall be excluded.

  The first film-shaped portion 22b is continuous with the cathode 12 side of the composite portion 22a. The first film-shaped portion 22b is formed in a film shape. The first film-shaped portion 22b is integrally formed with the composite portion 22a. The first film-shaped portion 22b may be formed in a uniform planar shape, or may be patterned into a desired planar shape such as a stripe shape. The thickness of the first film-shaped portion 22b is not particularly limited, but may be, for example, 10 μm or less, preferably 7 μm or less, and more preferably 5 μm or less. By providing such a first film-shaped portion 22b, it is possible to reduce the contact resistance between the cathode 12 and the electrolyte 16 as compared with the case where the cathode 12 and the porous base material 20 are in direct contact. .

  The second film-shaped portion 22c is continuous with the anode 14 side of the composite portion 22a. The second film-shaped portion 22c is formed in a film shape. The second film-shaped portion 22c is formed integrally with the composite portion 22a. The second film-shaped portion 22c may be formed in a uniform planar shape, or may be patterned into a desired planar shape such as a stripe shape. The thickness of the second film-shaped portion 22c is not particularly limited, but may be, for example, 10 μm or less, preferably 7 μm or less, and more preferably 5 μm or less. By providing such a second film-shaped portion 22c, the contact resistance between the anode 14 and the electrolyte 16 can be reduced as compared with the case where the anode 14 and the porous base material 20 are in direct contact with each other. .

  The method for producing the inorganic solid electrolyte body 22 is not particularly limited, but when the inorganic solid electrolyte body 22 is composed of LDH and the hydroxide basic layer of LDH contains Ni, Al, Ti and OH groups, It can be manufactured in steps (1) to (4).

  (1) Prepare the porous substrate 20.

  (2) An alumina / titania layer is formed by impregnating the entire porous substrate 20 with a mixed sol of alumina and titania and heat-treating the mixture. As described later, in order to grow LDH from the entire surface of the porous base material 20, it is important to form an alumina / titania layer on the entire surface of the porous base material 20, and therefore, a mixed sol of alumina and titania. Is impregnated and heat treated a plurality of times. Thereby, the alumina / titania layer can be formed on the entire surface of the porous substrate 20.

(3) The porous substrate 20 is immersed in a raw material aqueous solution containing nickel ions (Ni ²⁺ ) and urea.

  (4) By hydrothermally treating the porous substrate 20 in the raw material aqueous solution to form LDH on and in the porous substrate 20, the composite portion 22a, the first film-shaped portion 22b, And the inorganic solid electrolyte body 22 having the second film-shaped portion 22c is formed. At this time, the closed pores 24 can be formed in the composite part 22a by stopping the reaction before the pores are closed by appropriately adjusting the hydrothermal treatment time and the solution concentration. Since LDH grows with the alumina / titania layer formed on the surface of the porous substrate 20 as a nucleus, when the alumina / titania layer is formed on the entire surface of the porous substrate 20, the porous substrate 20 LDH will grow from the entire surface of the. As a result, the closed pores 24 can be separated from the porous substrate 20.

(Modification of the embodiment)
The embodiments of the present invention have been described above, but the present invention is not limited to these, and various modifications can be made without departing from the spirit of the present invention.

[Modification 1]
In the above embodiment, as an example of the electrochemical cell to which the electrolyte for an electrochemical cell according to the present invention is applied, an alkaline fuel cell using a hydroxide ion as a carrier has been described, but the electrolyte for an electrochemical cell according to the present invention is described. Is applicable to various electrochemical cells. The electrochemical cell can be applied to, for example, a fuel cell using protons as carriers, a secondary battery (nickel-zinc secondary battery, zinc-air secondary battery, etc.), an electrolytic cell that generates hydrogen and oxygen from water vapor, and the like. it can. When the electrochemical cell uses protons as carriers, the composite part 22a, the first film-shaped part 22b, and the second film-shaped part 22c contain a proton-conductive ceramics component instead of the hydroxide ion-conductive ceramics component. All you have to do is do it. The electrochemical cell is a device for converting chemical energy into electrical energy and a device for converting electrical energy into chemical energy. A pair of electrodes is used to generate electromotive force from the overall redox reaction. Is a general term for those placed.

[Modification 2]
In the above-described embodiment, the electrolyte 16 has the plurality of closed pores 24. However, if the electrolyte 16 has at least one closed pore 24, the composite portion will have no closed pores 24 at all. Since the 22a can be provided with flexibility, peeling of the electrolyte 16 can be suppressed.

[Modification 3]
In the above embodiment, the inorganic solid electrolyte body 22 has the composite portion 22a, the first film-shaped portion 22b, and the second film-shaped portion 22c, but it is sufficient that the inorganic solid electrolyte body 22 has at least the composite portion 22a. That is, the inorganic solid electrolyte body 22 may not include at least one of the first film-shaped portion 22b and the second film-shaped portion 22c.

  When the inorganic solid electrolyte body 22 does not include the first film-shaped portion 22b, the composite portion 22a may be impregnated into the entire continuous pores 20a of the porous base material 20, or the porous base material 20 may be continuous. Only the region of the hole 20a on the cathode 12 side may be impregnated. When the composite portion 22a is impregnated only in the region of the continuous hole 20a of the porous substrate 20 on the cathode 12 side, at least a part of the anode 14 may be arranged in the void region of the continuous hole 20a. The anode 14 arranged in the void region of the continuous hole 20a may be filled in the continuous hole 20a, or may be formed in a film shape so as to cover the inner surface of the continuous hole 20a.

  When the inorganic solid electrolyte body 22 does not include the second film-shaped portion 22c, the composite portion 22a may be impregnated into the entire continuous pores 20a of the porous base material 20 or the continuous porous base material 20. Only the region of the hole 20a on the anode 14 side may be impregnated. When the composite portion 22a is impregnated only in the region of the continuous hole 20a of the porous substrate 20 on the anode 14 side, at least a part of the cathode 12 may be arranged in the void region of the continuous hole 20a. The cathode 12 arranged in the void region of the continuous hole 20a may be filled in the continuous hole 20a, or may be formed in a film shape so as to cover the inner surface of the continuous hole 20a.

[Modification 4]
In the above embodiment, all of the plurality of closed pores are separated from the porous base material 20, but some of the plurality of closed pores may be in contact with the porous base material 20.

10 Solid Alkaline Fuel Cell 12 Cathode 14 Anode 16 Electrolyte 16S Cathode Side Surface 16T Anode Side Surface 20 Porous Base Material 20a Continuous Pore 22 Inorganic Solid Electrolyte Body 22a Composite Part 22b First Membrane Part 22c Second Membrane Part 24 Closed Pores

Claims (5)

An electrolyte for an electrochemical cell used in the presence of water or water vapor,
A porous substrate having a three-dimensional network structure and forming continuous pores,
Having ionic conductivity, an ionic conductor arranged in the continuous pores,
Closed pores formed in the ion conductor,
Equipped with
The porous substrate is composed of at least one selected from ceramic materials and polymer materials,
Electrolyte for electrochemical cells. The closed pores are separated from the porous substrate,
The electrolyte for an electrochemical cell according to claim 1. A plurality of closed pores formed in the ion conductor and including the closed pores;
The electrolyte for an electrochemical cell according to claim 1 or 2. The porous substrate has pores inside,
The pores are impregnated with the ionic conductor,
An electrolyte for an electrochemical cell according to any one of claims 1 to 3. A cathode supplied with an oxidant,
An anode supplied with fuel,
An electrolyte for an electrochemical cell according to any one of claims 1 to 4, which is arranged between the cathode and the anode,
An electrochemical cell comprising.

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