Oxide ion conductive solid electrolyte, mixed powder, paste for fuel electrode, paste for solid electrolyte layer, fuel electrode component, and solid electrolyte layer component

Abstract

To provide a more lightweight oxide ion conductive solid electrolyte.SOLUTION: An oxide ion conductive solid electrolyte comprises a compound with a perovskite-type structure containing calcium (Ca), titanium (Ti), and aluminum (Al), and calcium aluminate. The perovskite-type structured compound is represented by CaTi1-xAlxO3-δ, with 0<x<1. Relative to the total of the oxide ion conductive solid electrolyte, the Al content is 21 mol% or more and 33 mol% or less in terms of oxide.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an oxide ion conductive solid electrolyte, a mixed powder, a paste for a fuel electrode, a paste for a solid electrolyte layer, a fuel electrode component, and a solid electrolyte layer component. [Background technology]

[0002] Solid electrolytes with oxide ion conductivity can be used in various electrical devices, such as solid oxide fuel cells (SOFCs), solid oxide electrolytic cells (SOECs), oxygen sensors, and oxygen pumps.

[0003] In recent years, a highly efficient energy system combining SOFCs and SOECs has attracted attention as one way to realize the Power to Gas / Chemical technology concept, which has been gaining attention for the widespread adoption of renewable energy.

[0004] SOFCs and SOECs are both electrochemical cells that operate at high temperatures. The former can handle various fuels such as hydrogen, carbon monoxide, and methane, while the latter can electrolyze the water and carbon dioxide produced by the operation of SOFCs and convert them back into hydrogen and carbon monoxide.

[0005] SOFCs and SOECs have a solid electrolyte layer between two electrodes, and operate through the conduction of oxide ions within this solid electrolyte layer.

[0006] In SOFCs and SOECs, solid electrolytes such as yttria-stabilized zirconia (YSZ) are used for the oxide ion-conducting solid electrolyte layer. [Prior art documents] [Non-patent literature]

[0007] [Non-Patent Document 1] Journal of the American Ceramic Society,73,563-88(1993)

Summary of the Invention

Problems to be Solved by the Invention

[0008] YSZ, which is assumed to be used as an oxide ion conductive solid electrolyte layer, is characterized by a relatively high density. Therefore, in the future, when weight reduction of SOFCs and SOECs becomes necessary, the oxide ion conductive solid electrolyte layer composed of YSZ may be difficult to apply. Also, along with this, it is expected that the development of a lighter oxide ion conductive solid electrolyte layer will be required.

[0009] The present invention has been made in view of such a background, and an object of the present invention is to provide a lighter oxide ion conductive solid electrolyte.

Means for Solving the Problems

[0010] In the present invention, an oxide ion conductive solid electrolyte comprising a perovskite-type structure compound containing calcium (Ca), titanium (Ti), and aluminum (Al), calcium aluminate, is provided, where the perovskite-type structure compound is represented by CaTi 1-x Al x O 3-δ where 0 < x < 1, and in the entire oxide ion conductive solid electrolyte, Al is contained in an amount of 21 mol% or more and 33 mol% or less in terms of oxide conversion.

[0011] Also, in the present invention, a mixed powder for a fuel electrode member of a solid oxide fuel cell, comprising a powder of a transition metal or a transition metal compound, a solid electrolyte powder, is provided, The provided solid electrolyte powder is a mixed powder for a fuel electrode component, wherein the solid electrolyte powder is a powder of an oxide ion conductive solid electrolyte having the characteristics described above.

[0012] Furthermore, in this invention, A paste for the fuel electrode of a solid oxide electrolytic cell, Dispersion medium and A mixed powder for a fuel electrode component having the aforementioned characteristics, A paste for the fuel electrode of a solid oxide type electrolytic cell is provided, having the following properties.

[0013] Furthermore, in this invention, A paste for the solid electrolyte layer of a solid oxide type electrolytic cell, Dispersion medium and Solid electrolyte powder and It has, The provided paste for a solid electrolyte layer is a powder of an oxide ion conductive solid electrolyte having the aforementioned characteristics.

[0014] Furthermore, in this invention, A fuel electrode component for a solid oxide type electrolytic cell, The fuel electrode component comprises a transition metal and a solid electrolyte. The provided fuel electrode component includes an oxide ion conductive solid electrolyte having the aforementioned characteristics.

[0015] Furthermore, in this invention, A component for the solid electrolyte layer of a solid oxide type electrolytic cell, The solid electrolyte layer member has a solid electrolyte, The provided solid electrolyte layer member includes an oxide ion conductive solid electrolyte having the aforementioned characteristics. [Effects of the Invention]

[0016] The present invention can provide a lighter oxide ion conductive solid electrolyte. [Brief explanation of the drawing]

[0017] [Figure 1] It is a flow chart schematically showing an example of a method for manufacturing an oxide ion conductive solid electrolyte according to an embodiment of the present invention. [Figure 2] It is a diagram schematically showing the configuration of a SOFC to which an oxide ion conductive solid electrolyte according to an embodiment of the present invention is applied. [Figure 3] It is a diagram showing the X-ray diffraction pattern of an oxide ion conductive solid electrolyte (Sample 1) according to an embodiment of the present invention. [Figure 4] It is a diagram showing the X-ray diffraction pattern of an oxide ion conductive solid electrolyte (Sample 2) according to another embodiment of the present invention. [Figure 5] It is a diagram showing the X-ray diffraction pattern of an oxide ion conductive solid electrolyte (Sample 3) according to another embodiment of the present invention.

Mode for Carrying Out the Invention

[0018] Hereinafter, an embodiment of the present invention will be described.

[0019] In one embodiment of the present invention, an oxide ion conductive solid electrolyte, a perovskite-type structure compound containing calcium (Ca), titanium (Ti), and aluminum (Al), calcium aluminate, and the perovskite-type structure compound is CaTi 1-x Al x O 3-δ represented by, provided that 0 < x < 1, an oxide ion conductive solid electrolyte is provided in which Al is contained in an amount of 21 mol% or more and 33 mol% or less in terms of oxide based on the entire oxide ion conductive solid electrolyte.

[0020] In the present application, the "perovskite-type structure compound" has a general formula of CaTi 1-x X x O 3―δThis refers to the general term for compounds represented by [the formula]. Note that 0 ≤ x < 1, and X is a trivalent metallic element.

[0021] Perovskite-type compounds contain oxygen vacancies and have the general formula CaTi 1-x X x O 3-δ In this case, δ corresponds to the oxygen deficiency. Here, 0 ≤ δ ≤ 0.5.

[0022] One embodiment of the present invention has the characteristic that X = Al in the above general formula. In this embodiment of the present invention, Al may be located at the site of Ti.

[0023] Furthermore, in one embodiment of the present invention, the oxide ion-conducting solid electrolyte includes calcium aluminate. The total amount of aluminum contained in the perovskite-type compound and calcium aluminate is 21 mol% or more and 33 mol% or less of the total oxide ion-conducting solid electrolyte.

[0024] In oxide ion-conducting solid electrolytes containing compounds with such perovskite-type structures, density can be significantly suppressed.

[0025] For example, the density of YSZ containing 8 wt% Y2O3, which is used in the solid electrolyte layer of a typical SOFC, is approximately 6 g / cm³. 3 It is approximately as follows. In contrast, the density of an oxide ion conductive solid electrolyte according to one embodiment of the present invention is, for example, 2.7 g / cm³. 3 ~3.5g / cm 3 It can be set to the range of

[0026] Furthermore, in one embodiment of the present invention, the total amount of Al is 33 mol% or less, which significantly suppresses the decrease in the ionic conductivity of the oxide ion-conducting solid electrolyte. For example, in one embodiment of the present invention, the ionic conductivity of the oxide ion-conducting solid electrolyte at 900°C is 1.0 × 10⁻⁶. -3 S / cm~2.6×10 -3 It may also be within the range of S / cm.

[0027] (Method for producing an oxide ion conductive solid electrolyte according to one embodiment of the present invention) Next, with reference to Figure 1, an example of a method for producing an oxide ion-conducting solid electrolyte according to one embodiment of the present invention will be described.

[0028] Figure 1 schematically shows an example of a flow chart for a method of producing an oxide ion conductive solid electrolyte according to one embodiment of the present invention (hereinafter referred to as the "first manufacturing method").

[0029] As shown in Figure 1, the first manufacturing method is (1) A step of mixing Ca source, Ti source, and Al source in predetermined proportions to obtain a mixed powder (step S110), (2) A step of calcining the mixed powder to obtain calcined powder (step S120), (3) A step of sintering the calcined powder to obtain a sintered body (step S130), It has.

[0030] The following explains each step.

[0031] (Step S110) First, a mixed powder is prepared. For this purpose, a Ca source, a Ti source, and an Al source are prepared.

[0032] The Ca source may be selected from, for example, metallic calcium, calcium carbonate, calcium oxide, calcium hydroxide, calcium nitrate, calcium sulfate, calcium fluoride, calcium chloride, calcium bromide, calcium iodide, and calcium carboxylate salts such as calcium acetate.

[0033] The Ti source may be selected from, for example, metallic Ti and / or oxides such as titanium(IV) oxide, titanium(III) oxide, and titanium(II) oxide, or titanium alkoxides such as titanium hydroxide, titanium fluoride, titanium chloride, titanium bromide, titanium iodide, titanium isopropoxide, and titanium butoxide. Titanium(IV) oxide may be either rutile or anatase form.

[0034] The Al source may be selected from, for example, metallic aluminum, α-alumina, γ-alumina, aluminum hydroxide, aluminum nitrate, aluminum sulfate, aluminum fluoride, aluminum chloride, aluminum bromide, aluminum iodide, and aluminum carboxylate salts such as aluminum acetate.

[0035] Each raw material is weighed and mixed to obtain a solid electrolyte having the desired composition.

[0036] For mixing, it is preferable to use a ball mill such as a planetary ball mill. For example, each raw material is wet-mixed with zirconia balls in the presence of an alcohol solvent such as isopropanol.

[0037] By using a ball mill, each raw material can be properly mixed without overmixing. Furthermore, using an alcohol solvent can suppress the decomposition of the raw materials in the solvent.

[0038] Subsequently, the slurry containing the raw materials is dried to remove the alcohol solvent. The drying temperature is not particularly limited, but is, for example, in the range of 80°C to 250°C.

[0039] This yields a dry mixed powder.

[0040] (Process S120) Next, the mixed powder is calcined.

[0041] This process allows for the detachment of carbonate and nitrate rhizomes from the mixed powder, generating compounds with a perovskite-type structure. Simultaneously, calcium aluminate can be formed.

[0042] In the first manufacturing method, the resulting perovskite-type compound has some of its Ti sites replaced by Al, so its general formula is CaTi 1-x Al x O 3-δ It is represented as follows: Here, 0 <x<1である。

[0043] While there are no particular limitations on the calcination conditions, a calcination temperature of 1300°C or higher is preferable to obtain the desired mixture. However, if the calcination temperature is too high, excessive sintering will occur in the mixed powder, making pulverization difficult. Therefore, a calcination temperature of 1400°C or lower is preferable.

[0044] The calcination time is, for example, around 5 to 24 hours. However, the calcination time also varies depending on the calcination temperature; the higher the calcination temperature, the shorter the calcination time can be.

[0045] (Step S130) Next, the calcined powder is subjected to a sintering process to form a solid electrolyte.

[0046] The sintering temperature is, for example, 1300°C or higher. However, if the sintering temperature is too high, the sintered body may melt. Therefore, a sintering temperature of 1400°C or lower is preferable. The sintering time is not particularly limited, but for example, it is about 5 to 48 hours.

[0047] Furthermore, for the sintering process, a pressure sintering method that performs molding and sintering simultaneously, such as hot press sintering or discharge plasma sintering, may be used.

[0048] By following the above steps, an oxide ion-conducting solid electrolyte according to one embodiment of the present invention can be manufactured.

[0049] If necessary, the resulting sintered body may be crushed and powdered.

[0050] The above describes a method for producing an oxide ion-conducting solid electrolyte according to one embodiment of the present invention, using the first manufacturing method as an example. However, the first manufacturing method is merely an example, and the oxide ion-conducting solid electrolyte according to one embodiment of the present invention may be produced by other methods.

[0051] (Example of application of an oxide ion conductive solid electrolyte according to one embodiment of the present invention) An oxide ion-conducting solid electrolyte according to one embodiment of the present invention can be applied to SOFCs and SOECs.

[0052] Figure 2 schematically shows the configuration of an SOFC to which an oxide ion conductive solid electrolyte according to one embodiment of the present invention is applied.

[0053] As shown in Figure 2, the SOFC 100 has an oxygen electrode 110, a fuel electrode 120, and a solid electrolyte layer 130 between the two electrodes. A SOFC stack may be constructed by stacking multiple SOFCs 100.

[0054] When SOFC100 with this configuration is in operation, the following reactions occur at the oxygen electrode 110, for example: O2+4e - →2O 2- (1) Formula Oxide ions generated at the oxygen electrode 110 pass through the solid electrolyte layer 130 and reach the fuel electrode 120 on the opposite side. At the fuel electrode 120, for example, the following reactions occur: 2H2 + 2O 2- →2H2O+4e - Equation (2) Therefore, when SOFC100 is connected to the external load 150, the reactions in equations (1) and (2) continue, and power can be supplied to the external load 150.

[0055] Here, if an oxide ion conductive solid electrolyte according to one embodiment of the present invention is used as the solid electrolyte layer 130, the density of the solid electrolyte layer 130 can be significantly suppressed.

[0056] Therefore, compared to the case where YSZ is used as the solid electrolyte layer 130, it is possible to significantly reduce the overall weight of SOFC100.

[0057] On the other hand, SOEC typically has a configuration similar to that of SOFC100 shown in Figure 2.

[0058] However, in SOEC, as shown in Figure 2 above, the following reaction occurs at the oxygen electrode 110: 20 2- →O2+4e - Equation (3) Furthermore, at the fuel electrode 120, for example, the following reaction occurs: 2H2O + 4e - →2H2+2O 2- (4) Formula Oxide ions generated at the fuel electrode 120 pass through the solid electrolyte layer 130 and reach the oxygen electrode 110 on the opposite side. Therefore, when the SOEC is connected to an external power source, reactions (3) and (4) continue.

[0059] In SOEC as well, when an oxide ion conductive solid electrolyte according to one embodiment of the present invention is used as the solid electrolyte layer 130, the density of the solid electrolyte layer 130 can be significantly suppressed.

[0060] Therefore, compared to the case where YSZ is used as the solid electrolyte layer 130, it is possible to significantly reduce the overall weight of SOEC.

[0061] (Provision of a solid electrolyte according to one embodiment of the present invention) Next, an example of a solid electrolyte provision method according to one embodiment of the present invention will be described.

[0062] A solid electrolyte according to one embodiment of the present invention may be provided as a solid electrolyte powder (hereinafter referred to as "the first powder").

[0063] Furthermore, such a first powder may be provided in the following various embodiments.

[0064] (Paste for solid electrolyte layer) The first powder may be provided as a paste for the solid electrolyte layer of an SOFC or SOEC.

[0065] Such a paste (hereinafter referred to as the "first paste") may be prepared by mixing a dispersion medium with the first powder mentioned above.

[0066] The dispersion medium is not particularly limited, but may be at least one of the following: water, alcohol, ketone, ester, ether, and hydrocarbon. Among these, one or more solvents such as terpene alcohols (e.g., terpineol and dihydroterpineol), polyhydric alcohols (e.g., ethylene glycol and propylene glycol), hydrocarbons (e.g., decane, toluene and xylene), and ethers (e.g., ethyl carbitol and butyl carbitol) can be used individually or in combination.

[0067] The paste may contain a binder resin to adjust its viscosity and binding properties. Examples of binder resins include at least one of acrylic resins, epoxy resins, phenolic resins, alkyd resins, polyester resins, rosin resins, polycarbonate resins, and cellulose resins. Of these, it is particularly preferable that the paste contains a cellulosic polymer such as ethylcellulose.

[0068] (solid electrolyte layer) The first powder may be applied to the solid electrolyte layer of an SOFC or SOEC.

[0069] In that case, the first paste described above may be prepared from the first powder, and a solid electrolyte layer may be formed using this first paste.

[0070] When forming a solid electrolyte layer from the first paste, for example, the following steps may be performed.

[0071] First, the first paste is applied onto the fuel electrode support to form a coating film. The application method is not particularly limited, and general methods such as screen printing, doctor blade method, or spin coating method may be used.

[0072] Next, after drying the coating film, the coating film may be heat-treated to form a solid electrolyte layer. The heat treatment temperature is, for example, in the range of 1000°C to 1450°C.

[0073] (Mixed powder for fuel electrodes) The first powder may be applied to a mixed powder for the fuel electrode of an SOFC or SOEC.

[0074] In this case, the transition metal or transition metal compound powder may be mixed with the first powder. The transition metal or transition metal compound powder is, for example, a metal or oxide powder such as a 3d transition element such as nickel, copper, iron, or cobalt. The content of the first powder in the mixed powder is, for example, in the range of 20 wt% to 90 wt%. More preferably, it is in the range of 30 wt% to 80 wt%, and even more preferably, in the range of 30 wt% to 70 wt%.

[0075] (Paste for fuel electrodes) The first powder may be provided as a paste for the fuel electrode of an SOFC or SOEC.

[0076] Such a paste (hereinafter referred to as the "second paste") may be prepared by adding the aforementioned mixed powder for the fuel electrode to a dispersion medium.

[0077] The dispersion medium is not particularly limited, but the same dispersion medium or binder resin as used in the first paste can be used.

[0078] (Fuel electrode) The first powder may be applied to the fuel electrode of an SOFC or SOEC.

[0079] In that case, the second paste described above may be prepared from the first powder, and the fuel electrode may be formed using this second paste.

[0080] When forming a fuel electrode from a second paste, for example, the following steps may be performed.

[0081] First, the second paste is applied onto the solid electrolyte support. The application method is not particularly limited, and common methods such as screen printing, doctor blade method, and spin coating method may be used.

[0082] Next, after the second paste has been dried, the second paste may be heat-treated to form a fuel electrode. The heat treatment temperature is, for example, in the range of 1000°C to 1450°C. [Examples]

[0083] The following describes examples of the present invention. In the following description, Examples 1 to 3 are examples, and Example 11 is a comparative example.

[0084] (Example 1) A solid electrolyte was produced using the first manufacturing method described above.

[0085] First, 1.851 g of CaCO3 powder (manufactured by Kojunkagaku Co., Ltd.) as a Ca source, 1.264 g of TiO2 powder (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as a Ti source, and 1.885 g of Al2O powder (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as an Al source were mixed to prepare a mixed powder.

[0086] In the mixed powder, the Al source was added in an amount of 21 mol% in terms of oxides.

[0087] Next, the mixed powders were thoroughly mixed in the presence of a solvent using a planetary ball mill and zirconia balls. 10 g of 2-propanol was used as the solvent. The planetary ball mill was set to a rotation speed of 300 rpm, and the processing time was 60 minutes.

[0088] Next, the resulting mixed powder was dried in the air at a high temperature for 2 hours. The processing temperature was 140°C. This resulted in a dried mixed powder from which the solvent had been removed.

[0089] Next, the dry mixed powder was calcined in the air.

[0090] The processing temperature was set to 1400°C, and the processing time was set to 10 hours.

[0091] Next, the obtained treated material was sintered in an atmospheric environment. The sintering temperature was 1400°C, and the sintering time was 10 hours.

[0092] The resulting sintered body is referred to as "Sample 1".

[0093] (Example 2) A solid electrolyte was prepared using the same method as in Example 1.

[0094] However, in this Example 2, the proportions of CaCO3 powder, TiO2 powder, and Al2O powder in the mixed powder were changed from those in Example 1.

[0095] In the mixed powder, the Al source was added in an amount of 25 mol% in terms of oxides.

[0096] The resulting sintered body is referred to as "Sample 2".

[0097] (Example 3) A solid electrolyte was prepared using the same method as in Example 1.

[0098] However, in this Example 3, the proportions of CaCO3 powder, TiO2 powder, and Al2O powder in the mixed powder were changed from those in Example 1.

[0099] In the mixed powder, the Al source was added to a concentration of 33 mol% in terms of oxides.

[0100] The resulting sintered body is referred to as "Sample 3".

[0101] (Example 11) A solid electrolyte was prepared using the same method as in Example 1.

[0102] However, in this example 11, Al2O powder was not added to the mixed powder. That is, the mixed powder was prepared using only CaCO3 powder and TiO2 powder.

[0103] The resulting sintered body is referred to as "Sample 11".

[0104] (evaluation) The following evaluations were performed using each sample.

[0105] (X-ray diffraction analysis) X-ray diffraction analysis was performed on each sample using an X-ray diffractometer (Bruker D2PHASER).

[0106] (density) The density of each sample was measured at room temperature using the Archimedes method.

[0107] (Evaluation of ionic conductivity) The oxide ion conductivity of each sample was measured using the AC impedance method as described below.

[0108] (Preparation of sample for measurement) Each sample was processed into a disc shape with a diameter of 15 mm. Platinum paste (Tanaka Kikinzoku: U-3401) was applied to the top and bottom surfaces of the discs, and they were heat-treated at 1000°C for 15 minutes in an air atmosphere. This prepared measurement samples with platinum electrodes on the top and bottom surfaces.

[0109] (Measurement of AC impedance) Each sample was placed in an electric furnace (Nolex Probostat) under an atmospheric environment. Both sides of the sample were sandwiched between platinum electrodes connected to platinum wires and connected to a potentiometer galvanostat (Solartron Analytical 1260A). Impedance measurements were performed, and Cole-Cole plots were obtained. The measurement frequency was 10 MHz to 100 mHz, and the modulation potential amplitude was 100 mV. Conductivity was calculated by dividing the impedance value obtained from the measurement by the thickness of the sample.

[0110] Table 1 below summarizes the evaluation results obtained for each sample. [Table 1] X-ray diffraction analysis revealed that in samples 1 to 3, the main phase was a perovskite-type compound (CaTi 1-x Al x O 3-δ In addition to ), calcium aluminate (CaAl2O4, and Ca 12 Al 14 O 33 A diffraction peak corresponding to was observed.

[0111] Figure 3 shows the X-ray diffraction pattern of sample 1. Figure 4 shows the X-ray diffraction pattern of sample 2. Furthermore, Figure 5 shows the X-ray diffraction pattern of sample 3.

[0112] Figure 3 shows that in Sample 1, in addition to the perovskite-type compound, a diffraction peak of calcium aluminate was observed.

[0113] Similarly, as shown in Figure 4, in Sample 2, in addition to the perovskite-type compound, diffraction peaks of calcium aluminate were also observed.

[0114] Furthermore, as shown in Figure 5, in Sample 3, in addition to the perovskite-type compound, diffraction peaks of calcium aluminate were also observed.

[0115] Table 1 shows that the density in samples 1 to 3 was significantly lower compared to sample 11.

[0116] Thus, it was confirmed that in oxide ion-conducting solid electrolytes containing calcium (Ca), titanium (Ti), and aluminum (Al), the density is significantly suppressed by setting the Al content to between 21 mol% and 33 mol% in terms of oxide.

[0117] (Aspects of the present invention) The present invention includes the following embodiments. (Aspect 1) A solid electrolyte that conducts oxide ions, Compounds with a perovskite structure containing calcium (Ca), titanium (Ti), and aluminum (Al), Calcium aluminumate and It has, The compound having the perovskite-type structure is CaTi 1-x Al x O 3-δ It is represented as, however, 0 <x<1であり、 An oxide ion conductive solid electrolyte in which Al is contained in an oxide equivalent amount of 21 mol% or more and 33 mol% or less relative to the entire oxide ion conductive solid electrolyte. (Aspect 2) The density at 20℃ is 3.5 g / cm³. 3 The oxide ion conductive solid electrolyte described in Embodiment 1 is as follows: (Aspect 3) The oxide ion conductive solid electrolyte according to embodiment 1 or 2, wherein the Al contained in the compound having the perovskite structure is located at the site of the Ti in the perovskite structure. (Aspect 4) A mixed powder for fuel electrode material of a solid oxide type electrolytic cell, A powder of a transition metal or a transition metal compound, Solid electrolyte powder and It has, The solid electrolyte powder is a mixed powder for a fuel electrode member, wherein the solid electrolyte powder is a powder of an oxide ion conductive solid electrolyte according to any one of embodiments 1 to 3. (Aspect 5) A paste for the fuel electrode of a solid oxide electrolytic cell, Dispersion medium and The mixed powder for the fuel electrode member described in Embodiment 4, A paste for the fuel electrode of a solid oxide electrolytic cell, having the following properties. (Aspect 6) A paste for the solid electrolyte layer of a solid oxide type electrolytic cell, Dispersion medium and Solid electrolyte powder and It has, The solid electrolyte powder is a powder of an oxide ion conductive solid electrolyte according to any one of embodiments 1 to 3, and is a paste for a solid electrolyte layer. (Aspect 7) A fuel electrode component for a solid oxide type electrolytic cell, The fuel electrode component comprises a transition metal and a solid electrolyte. The solid electrolyte comprises an oxide ion conductive solid electrolyte according to any one of embodiments 1 to 3, for use as a fuel electrode component. (Pattern 8) A component for the solid electrolyte layer of a solid oxide type electrolytic cell, The solid electrolyte layer member has a solid electrolyte, The solid electrolyte is a member for a solid electrolyte layer, comprising an oxide ion conductive solid electrolyte according to any one of embodiments 1 to 3. [Explanation of Symbols]

[0118] 100 SOFC 110 Oxygen electrode 120 Fuel electrode 130 Solid electrolyte layer 150 External load

Claims

1. A solid electrolyte that conducts oxide ions, Compounds with a perovskite structure containing calcium (Ca), titanium (Ti), and aluminum (Al), Calcium aluminumate and It has, The compound having the perovskite-type structure is CaTi １－ｘ Al ｘ O ３－δ It is expressed as such, where 0 < x < 1, The amount of Al in the entire oxide ion-conducting solid electrolyte is between 21 mol% and 33 mol% in terms of oxide. An oxide ion-conducting solid electrolyte having a density of 3.5 g / cm³ or less at 20°C.

2. The oxide ion conductive solid electrolyte according to claim 1, wherein the Al contained in the perovskite-type compound is located at the site of Ti in the perovskite-type structure.

3. The oxide ion conductive solid electrolyte according to claim 1 or 2, wherein the density at 20°C is 2.99 g / cm³ or less.

4. A mixed powder for fuel electrode material of a solid oxide type electrolytic cell, A powder of a transition metal or a transition metal compound, Solid electrolyte powder and It has, The solid electrolyte powder is a mixed powder for a fuel electrode member, wherein the solid electrolyte powder is the oxide ion conductive solid electrolyte powder described in claim 1 or 2.

5. A paste for the fuel electrode of a solid oxide electrolytic cell, Dispersion medium and A mixed powder for a fuel electrode member according to claim 4, A paste for the fuel electrode of a solid oxide electrolytic cell, having the following properties.

6. A paste for the solid electrolyte layer of a solid oxide type electrolytic cell, Dispersion medium and Solid electrolyte powder and It has, The solid electrolyte powder is the oxide ion conductive solid electrolyte powder described in claim 1 or 2, in a paste for a solid electrolyte layer.

7. A fuel electrode component for a solid oxide type electrolytic cell, The fuel electrode component comprises a transition metal and a solid electrolyte. The solid electrolyte comprises the oxide ion conductive solid electrolyte described in claim 1 or 2, for use as a fuel electrode component.

8. A component for the solid electrolyte layer of a solid oxide type electrolytic cell, The solid electrolyte layer member has a solid electrolyte, The solid electrolyte is a member for a solid electrolyte layer, comprising the oxide ion conductive solid electrolyte described in claim 1 or 2.

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