JP2012059476A - Anode support type half cell and method for manufacturing the same, and anode support type cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing an anode support type half cell which can reduce occurrence of a thorough hole in a solid electrolyte membrane.SOLUTION: A method for manufacturing an anode support type half cell having an anode support substrate, an anode layer formed on the anode support substrate, and an electrolyte layer formed on the anode layer, comprises a paste preparation step, a pulverization step, and a layer forming step. In the pulverization step, aggregate is pulverized until the maximum particle diameter of the aggregate, which is measured by a grind meter, becomes 10 μm or less.

Description

  The present invention relates to an anode-supported half cell and a method for manufacturing the same. In particular, the present invention relates to a technique for suppressing through-holes in an electrolyte layer when an anode layer is formed by screen printing and then formed on the anode green layer by screen printing.

  Fuel cells are attracting attention as a source of clean energy, and their use has been rapidly researched for improvement and practical application mainly from household power generation to commercial power generation, and further to power generation for automobiles.

  A typical structure of a solid oxide fuel cell is basically a stack in which a large number of cells each provided with an anode electrode on one side and a cathode electrode on the other side are stacked in the vertical direction. As described above, a fuel cell has a structure in which a cell having an anode electrode / solid electrolyte membrane / cathode electrode and separators for separating and circulating fuel gas and air are alternately stacked. In addition to applying a large laminating load, since the operating temperature is about 700 to 1000 ° C. and undergoes considerable thermal stress, high strength and heat resistance are required. Because of these required characteristics, a zirconia-based ceramic sheet is mainly used as a material for the solid electrolyte membrane, and a self-supporting membrane cell in which an anode electrode and a cathode electrode are formed by screen printing on both sides of the ceramic sheet is used. Has been.

  In order to improve the power generation performance of the fuel cell, it is effective to make the solid electrolyte membrane dense and thin. This is because the solid electrolyte membrane is required to have high density that reliably prevents mixing of fuel gas and air that is a power generation source and excellent ionic conductivity that can suppress conduction loss as much as possible. This is because it is required to be dense.

  However, in a self-supporting membrane cell, the thinner the solid electrolyte membrane, the more likely it is that cracks are likely to occur due to the stacking load when many cells are stacked. Therefore, in order to make the solid electrolyte membrane thinner, an anode support type cell in which an anode support substrate for supporting the anode and the solid electrolyte is provided on the anode electrode side of the solid electrolyte membrane has been proposed. As a method for manufacturing such an anode-supported cell, an anode electrode is formed on an anode support substrate by screen printing, a solid electrolyte membrane is formed thereon by screen printing, and a cathode electrode is further screen-printed thereon. By adopting the method of forming by this, a method of further reducing the conductive loss by thinning the solid electrolyte membrane has been proposed.

  Here, as a technique for forming a ceramic layer constituting a solid electrolyte, an anode electrode, a cathode electrode, etc., for example, a technique for adjusting an average particle diameter of ceramic powder in a paste and a mass ratio of the ceramic powder and a binder (Patent Literature) 1 (see claims 1 and 2)); a technique for adjusting the viscosity of a paste (see patent document 2 (claim 1, paragraph 0011)).

JP 2001-332273 A JP 2001-325993 A

  As described above, by employing the anode-supported cell, the solid electrolyte membrane can be made thinner, and the conductive loss can be further reduced. However, in order to reduce the thickness of the solid electrolyte membrane, it is also necessary to form a thinner electrolyte paste for screen printing on the anode electrode. Thus, the electrolyte paste formed into a thin film has a problem that through-holes are likely to occur during sintering.

  This invention is made | formed in view of the said situation, and it aims at providing the manufacturing method which can reduce the through-hole of a solid electrolyte membrane in the manufacturing method of an anode support type | mold half cell.

  The present inventors have further studied the through-hole generated in the solid electrolyte membrane when manufacturing the anode-supported cell. As a result, if aggregates derived from the raw material are present in the anode paste used for screen printing, the aggregates also remain in the paste layer after film formation, and these aggregates are formed during sintering of the anode layer and the electrolyte layer. The present invention was completed by finding that a through hole was generated due to strain.

  The manufacturing method of the present invention that has solved the above-described problems includes an anode support substrate, an anode layer laminated on the anode support substrate, and an anode layer (opposite to the surface on which the anode support substrate is in contact). A paste preparation step of preparing an anode paste by mixing at least ceramic powder, a solvent and a binder; and agglomerates in the anode paste; A crushing step of crushing; and a stratification step of forming an anode green layer on the anode support substrate by screen printing using the anode paste; a stratification step of forming an electrolyte green layer on the anode green layer by screen printing And measured by a grindometer in the crushing step Maximum particle size of agglomerates which are characterized by crushing until 10μm or less.

  In the production method of the present invention, particles in the anode paste printed on the anode support substrate or the anode support substrate green sheet are used to pulverize the aggregates in the anode paste used for forming the anode green layer to 10 μm or less. Aggregates with a diameter exceeding 10 μm do not exist. Therefore, when the anode green layer and the electrolyte green layer are co-fired, it is possible to suppress the through-holes in the electrolyte layer caused by the aggregates.

  In the crushing step, it is preferable to crush the aggregate using a three-roll mill. By using a three-roll mill, the aggregate can be efficiently crushed in a short time. The gap between the rolls of the three-roll mill is preferably set to 1 μm or more and 10 μm or less.

  The present invention also includes an anode-supported half cell obtained by the above production method and an anode-supported cell in which a cathode layer is formed on the anode-supported half cell.

  According to the present invention, an anode-supported half cell with reduced through-holes in the solid electrolyte membrane can be obtained.

It is a figure which shows the relationship between the largest particle diameter of an aggregate, and the acceptance rate of an anode support type half cell.

The production method of the present invention includes an anode support substrate, an anode layer stacked on the anode support substrate, and an electrolyte layer stacked on the anode layer (the surface opposite to the surface in contact with the anode support substrate). A paste preparation step of preparing an anode paste by mixing at least ceramic powder, a solvent and a binder; a crushing step of crushing agglomerates in the anode paste; and A process for forming an anode-supporting half-cell, comprising: forming an anode green layer on the anode support substrate by screen printing using an anode paste; and further forming an electrolyte green layer on the anode green layer by screen printing. A grinding process in the crushing step. Maximum particle size of aggregates as measured by chromatography, characterized in that the disintegrated until 10μm or less.
Hereinafter, this invention is demonstrated for every process.

  1. Anode paste preparation step In the anode paste preparation step, at least ceramic powder, a solvent and a binder are mixed to prepare an anode paste.

  The ceramic powder may be produced by a conventional method, or a commercially available product may be used. The ceramic powder is a mixture of a conductive component that exhibits conductivity in a reducing atmosphere, and a skeletal component that is an important component for ensuring the lamination load resistance strength and redox resistance of the anode layer. If it is used as a conductive component and a skeleton component, it is not particularly limited.

  For example, the conductive component contains two or more kinds of oxides of metals that change into conductive metals in a reducing atmosphere during fuel cell operation, such as iron oxide, nickel oxide, and cobalt oxide. Examples thereof include composite metal oxides such as nickel ferrite and cobalt ferrite. On the other hand, skeletal components include zirconia stabilized with yttrium oxide, cerium oxide, scandium oxide, ytterbium oxide, etc .; ceria doped with yttrium oxide, samarium oxide, gadolinium oxide, etc .; lanthanum gallate and lanthanum gallium lanthanum or A lanthanum gallate perovskite structure oxide in which a part of gallium is substituted with strontium, calcium, barium, magnesium, aluminum, indium, cobalt, iron, nickel, copper, or the like can be used.

  In particular, as skeletal component powder, zirconia stabilized with 3 to 10 mol% yttrium oxide, 4 to 12 mol% zirconia stabilized with scandium oxide, 8 to 12 mol% With the following scandium oxide and zirconia stabilized with 4 mol% to 15 mol% ytterbium oxide, or 8 mol% to 12 mol% scandium oxide and 0.5 mol% to 5 mol% cerium oxide. It is preferable to use stabilized zirconia as the skeleton component. A material obtained by adding alumina, silica, titania or the like as a sintering aid or a dispersion strengthening agent to these stabilized zirconia can also be suitably used.

  The conductive component powder preferably has an average particle size of 0.5 μm or more and 3 μm or less. In addition, the average particle diameter in this invention shall mean the median diameter calculated | required from a particle size distribution, ie, a 50 volume% diameter (D50). Specifically, those having an average particle diameter of 0.5 μm or more and 3 μm or less and a 90 volume% diameter (D90) of 5 μm or less are preferable, and more preferably, the average particle diameter is 0.7 μm or more, 2 0.5 μm or less, and 90% by volume diameter is 4 μm or less. These average particle diameters and 90 volume% diameters are based on the particle size distribution measured using a 0.2 mass% sodium metaphosphate aqueous solution as a dispersion medium using a laser diffraction / scattering particle size distribution measuring apparatus such as LA-920 manufactured by HORIBA, Ltd. Can be sought.

  As the skeleton component powder, it is preferable to use a fine powder having an average particle size of 0.3 μm or more and 0.7 μm or less. In addition, the average particle diameter in this invention shall mean the median diameter calculated | required from a particle size distribution, ie, a 50 volume% diameter (D50). As the skeleton component powder, those having a small particle size distribution are suitable. Specifically, those having an average particle diameter of 0.3 μm or more and 0.7 μm or less and a 90 volume% diameter (D90) of 1.2 μm or less are preferable, and more preferably the average particle diameter is 0.00. 4 μm or more and 0.6 μm or less, and 90% by volume diameter is 1.0 μm or less.

  The solvent is not particularly limited, and various organic solvents such as alcohols, glycol ethers, aliphatic hydrocarbons, ketones, and esters can be used. Specific examples of the organic solvent include α-terpineol, dihydroterpineol, terpineol acetate, dihydroterpineol acetate, kerosene, 1-butanol, 1-hexanol, 2-butanone, isopropyl alcohol, polyethylene glycol, glycerin, and butyl carbitol. Examples include acetate, butyl carbitol, toluene, cyclohexane, and methyl ethyl ketone. These may be used alone or in combination of two or more. The amount of the solvent used is not particularly limited, and may be appropriately adjusted in consideration of the viscosity of the anode paste when screen printing is performed.

  In addition to the ceramic particles and the solvent, a binder, a dispersant, a plasticizer, a surfactant, an antifoaming agent, and the like may be added to the anode paste. Moreover, you may add a pore formation agent as needed.

  The binder is not particularly limited, and a conventionally known organic binder can be appropriately selected and used. Examples of organic binders include ethylene copolymers, styrene copolymers, acrylate and methacrylate copolymers, vinyl acetate copolymers, maleic acid copolymers, vinyl butyral resins, and vinyl acetals. Examples thereof include resins, vinyl formal resins, vinyl alcohol resins, waxes, and celluloses such as ethyl cellulose.

  The dispersant promotes peptization and dispersion of the ceramic powder. Examples of the dispersant include polyelectrolytes such as polyacrylic acid and ammonium polyacrylate; organic acids such as citric acid and tartaric acid; copolymers of isobutylene or styrene and maleic anhydride and ammonium salts or amine salts thereof. A copolymer of butadiene and maleic anhydride, and an ammonium salt thereof;

  The plasticizer imparts flexibility to the anode green layer. Examples of the plasticizer include phthalic acid esters such as dibutyl phthalate, dioctyl phthalate and ditridecyl phthalate; glycols and glycol ethers such as propylene glycol; phthalic acid polyester, adipic acid polyester, sebacic acid polyester, and the like. Polyesters.

  The amount of the plasticizer is preferably 0.5 parts or more and 30 parts or less based on 100 parts by weight of the ceramic powder in the anode paste. More preferably, the amount is 2 parts or more and 15 parts or less.

  The pore forming agent provides pores necessary for the fuel gas to diffuse into the fired anode layer. The pore-forming agent is not particularly limited as long as it is burned off when the anode green layer is fired; an aggregate of crosslinked fine particles made of an acrylic resin; wheat flour, corn starch (corn starch), sweet potato starch, potato starch, Natural organic powders such as tapioca starch; thermal decomposable or sublimable resin powders such as melamine cyanurate; carbonaceous powders such as carbon black and activated carbon.

  The pore forming agent preferably has an average particle diameter of 1 μm or more and 10 μm or less. More preferably, the average particle size is 2 μm or more and 5 μm or less. In addition, the average particle diameter in this invention shall mean the median diameter calculated | required from a particle size distribution, ie, a 50 volume% diameter (D50). Moreover, it is preferable that the amount of the pore forming agent is 1 part or more and 10 parts or less based on 100 parts by weight of the ceramic powder in the anode paste. More preferably, the amount is 2 parts or more and 5 parts or less.

  The anode paste is prepared by mixing appropriate amounts of the above components. At that time, in order to make each particle fine or to make the particle diameter uniform, the particles may be mixed while being pulverized using a ball mill or the like. Moreover, the order of addition of each component is not particularly limited, and may be according to a conventional method.

  2. Crushing step In the crushing step, aggregates in the anode paste are crushed. In particular, in the production method of the present invention, in the crushing step, it is important to crush until the maximum particle size of the aggregate in the anode paste measured by a grindometer is 10 μm or less. By setting the maximum particle size of the aggregates in the anode paste to 10 μm or less, an electrolyte green layer is further formed on the anode green layer formed on the anode support substrate, and the anode green layer and the electrolyte green layer are fired simultaneously. At the time of co-firing, it is possible to suppress the formation of through holes caused by aggregates.

  The method for crushing the anode paste is not particularly limited, and a three-roll mill, a planetary ball mill, a ball mill, a bead mill, or the like can be used. Among these, a three-roll mill is preferable because the time required for crushing is short and the amount of paste that can be processed per batch is large.

  A three-roll mill is an apparatus in which three rolls are arranged so that their respective rotation axes are horizontal or inclined. The three-roll mill rotates adjacent rolls at different rotational directions and rotational speeds, and performs dispersion by a compressing action using pressure between rolls and a shearing action between rolls having different speeds. In the present invention, when a three-roll mill is used, the material of the roll constituting the three-roll mill is a ceramic material such as alumina, silicon nitride, or silicon carbide; a metal material such as steel; In order to prevent this, it is preferable to use a ceramic roll.

  When the anode paste is crushed using a three-roll mill, the number of crushing operations (the number of passes through the three-roll mill) may be one, but preferably two or more, and more preferably three. By performing the crushing operation twice or more, the maximum particle diameter of the aggregate in the anode paste can be more reliably reduced to 10 μm or less. Even if the crushing operation is performed four times or more, the crushing action becomes saturated and is not economical.

  3. Layering Step In the layering step, an anode green layer is formed on the anode supporting substrate green sheet by screen printing using the anode paste, and an electrolyte green layer is further formed on the anode green layer by screen printing.

  As an aspect of forming the anode layer and the electrolyte layer on the anode support substrate green sheet, an anode layer paste is formed on the anode support substrate green sheet by screen printing and dried, and the anode green layer and the anode support substrate green sheet are formed. A laminate is produced. Thereafter, an electrolyte paste is formed on the anode green layer of the laminate by screen printing, dried, and then the electrolyte green layer, the anode green layer, and the anode support substrate green sheet are fired simultaneously (embodiment 1); anode support substrate A mode in which a green sheet is fired, an anode green layer is formed on the obtained anode support substrate by screen printing, and then an electrolyte paste is formed on the anode green layer by screen printing and dried to fire the electrolyte green layer ( Aspect 2) and the like can be mentioned. Among these, the aspect 1 is most preferable because the electrolyte green layer, the anode green layer, and the anode supporting substrate green sheet can be fired simultaneously, and the operation can be simplified.

  Hereinafter, the said aspect 1 is demonstrated as an example of a stratification process. First, a method for producing a laminate of the anode green layer and the anode support substrate green sheet will be described. The anode support substrate green sheet is prepared by uniformly mixing a conductive component, a skeletal component, and a pore forming agent together with a binder, a solvent, and, if necessary, a dispersant, a plasticizer, etc. It can be obtained by spreading on a smooth sheet (for example, a polyester sheet) at an appropriate thickness by an arbitrary method such as a method, a calender roll method or an extrusion method, followed by drying to volatilize and remove the solvent.

  The conductive component is an essential component for imparting conductivity to the anode layer and the anode support substrate, and the conductive component powder as a raw material thereof is such as iron oxide, nickel oxide, and cobalt oxide when the fuel cell is operated. Examples thereof include metal oxides that change to conductive metals in a reducing atmosphere, or composite metal oxides such as nickel ferrite and cobalt ferrite containing two or more of these oxides. These may be used alone or in combination of two or more as necessary.

  The skeletal component is an important component for ensuring the lamination load strength and redox resistance of the anode layer and the anode support substrate. As the skeletal component, zirconia, alumina, titania, ceria, aluminum magnesium spinel, aluminum nickel spinel, or the like is used in order to make the thermal expansion of the anode layer and the anode supporting substrate and the electrolyte layer as much as possible. These may be used alone or in admixture of two or more.

  The pore-forming agent is not particularly limited as long as it burns down when the green sheet is fired, and is a cross-linked fine particle aggregate made of an acrylic resin; wheat flour, corn starch (corn starch), sweet potato starch, potato starch, tapioca starch Natural organic powders such as: heat decomposable or sublimable resin powders such as melamine cyanurate; carbonaceous powders such as carbon black and activated carbon.

  The binder, solvent, dispersant, and plasticizer can be selected from those listed as materials for the anode paste in accordance with the material for the green sheet to be coated. Further, in particular, the solvent may be the same as the anode paste, but in order to speed up drying after coating, ethyl acetate, methyl acetate, butyl acetate, methanol, ethanol, acetone, xylene, pentane, Hexane, heptane or the like may be used.

  In addition, what is necessary is just to prepare the compounding quantity of each raw material of the slurry for anode support substrates suitably according to a desired physical property. Moreover, the drying conditions of the sheet | seat obtained from the slurry should just be a grade which can evaporate a solvent, for example, what is necessary is just to heat about 70 to 120 degreeC for 1 hour or more and about 10 hours or less. Here, the thickness of the anode supporting substrate green sheet is preferably 100 μm or more and 500 μm or less.

  When it is necessary to increase the thickness of the anode support substrate in order to secure a desired strength, a plurality of anode support substrate green sheets may be laminated to form an anode support substrate green sheet laminate. The anode support substrate green sheet laminate is obtained by hot pressing a plurality of anode support substrate green sheets. At this time, the conditions of the heat press are not particularly limited, and may be, for example, about 30 ° C. or higher and 100 ° C. or lower and 0.2 MPa or higher and 2 MPa or lower for 10 seconds or longer and 5 minutes or shorter.

  The anode paste is screen-printed on the obtained anode support substrate green sheet. Screen printing may be performed in the same manner as a conventional method.

  The anode paste viscosity at the time of screen printing is preferably 20 Pa · s or more, more preferably 40 Pa · s, measured using a Brookfield viscometer under the conditions of spindle No. 14, rotation speed 10 rpm, measurement temperature 24 ° C. s or more, more preferably 60 Pa · s or more, preferably 180 Pa · s or less, more preferably 160 Pa · s or less, and still more preferably 100 Pa · s or less. When the viscosity of the anode paste is within the above range, the moldability of the paste is good and the anode green layer can be easily formed.

  The thickness of the anode paste formed on the anode support substrate green sheet is preferably 5 μm or more, more preferably 7 μm or more, further preferably 10 μm or more, preferably 30 μm or less, more preferably 25 μm or less, and still more preferably. 22 μm or less.

  The anode paste printed on the anode support substrate green sheet is dried to volatilize and remove the solvent. The drying condition of the anode paste may be such that the solvent can be evaporated, and for example, it may be heated at 70 ° C. or higher and 120 ° C. or lower for 15 minutes or longer and 10 hours or shorter. The thickness of the anode green layer after drying is preferably about 5 μm to 25 μm.

Next, the electrolyte paste is screen-printed on the obtained anode layer. Screen printing may be performed in the same manner as a conventional method.
The electrolyte paste is prepared by mixing at least ceramic powder, a solvent, and a binder.

  The ceramic powder may be produced by a conventional method, or a commercially available product may be used. The ceramic powder is not particularly limited as long as it is normally used as a material for the electrolyte layer. For example, zirconia stabilized with yttrium oxide, cerium oxide, scandium oxide, ytterbium oxide, etc .; yttrium oxide, samarium oxide, oxide Ceria doped with gadolinium and the like; lanthanum gallate and lanthanum gallate perovskite in which lanthanum or part of lanthanum gallate is substituted with strontium, calcium, barium, magnesium, aluminum, indium, cobalt, iron, nickel, copper, etc. Structural oxides and the like can be used.

  In particular, as a ceramic powder, zirconia stabilized with 3 to 10 mol% yttrium oxide, 4 to 12 mol% zirconia stabilized with scandium oxide, 8 to 12 mol% Of zirconia stabilized with 4 to 15 mol% of ytterbium oxide, or 8 to 12 mol% of scandium oxide and 0.5 to 5 mol% of cerium oxide. It is preferable to use converted zirconia as a skeleton component. A material obtained by adding alumina, silica, titania or the like as a sintering aid or a dispersion strengthening agent to these stabilized zirconia can also be suitably used.

  The ceramic powder preferably has a fine average particle diameter of 0.3 μm or more and 0.7 μm or less. In addition, the average particle diameter in this invention shall mean the median diameter calculated | required from a particle size distribution, ie, a 50 volume% diameter (D50). Further, as the ceramic powder, those having a small particle size distribution are suitable. Specifically, those having an average particle diameter of 0.3 μm or more and 0.7 μm or less and a 90 volume% diameter (D90) of 1.2 μm or less are preferable, and more preferably the average particle diameter is 0.00. 4 μm or more and 0.6 μm or less, and 90% by volume diameter is 1.0 μm or less. These average particle diameters and 90 volume% diameters are based on the particle size distribution measured using a 0.2 mass% sodium metaphosphate aqueous solution as a dispersion medium using a laser diffraction / scattering particle size distribution measuring apparatus such as LA-920 manufactured by HORIBA, Ltd. Can be sought.

  The solvent is not particularly limited, and various organic solvents such as alcohols, glycol ethers, aliphatic hydrocarbons, ketones, and esters can be used. Specific examples of the organic solvent include α-terpineol, dihydroterpineol, terpineol acetate, dihydroterpineol acetate, kerosene, 1-butanol, 1-hexanol, 2-butanone, isopropyl alcohol, polyethylene glycol, glycerin, and butyl carbitol. Examples include acetate, butyl carbitol, toluene, cyclohexane, and methyl ethyl ketone. These may be used alone or in combination of two or more. The amount of the solvent used is not particularly limited, and may be appropriately adjusted in consideration of the viscosity of the electrolyte paste during screen printing.

  In addition to the ceramic particles and the solvent, a binder, a dispersant, a plasticizer, a surfactant, an antifoaming agent, and the like may be added to the electrolyte paste.

  The binder is not particularly limited, and a conventionally known organic binder can be appropriately selected and used. Examples of organic binders include ethylene copolymers, styrene copolymers, acrylate and methacrylate copolymers, vinyl acetate copolymers, maleic acid copolymers, vinyl butyral resins, and vinyl acetals. Examples thereof include resins, vinyl formal resins, vinyl alcohol resins, waxes, and celluloses such as ethyl cellulose.

  The dispersant promotes peptization and dispersion of the ceramic powder. Examples of the dispersant include polyelectrolytes such as polyacrylic acid and ammonium polyacrylate; organic acids such as citric acid and tartaric acid; copolymers of isobutylene or styrene and maleic anhydride and ammonium salts or amine salts thereof. A copolymer of butadiene and maleic anhydride, and an ammonium salt thereof;

  The plasticizer imparts flexibility to the electrolyte layer. Examples of the plasticizer include phthalic acid esters such as dibutyl phthalate, dioctyl phthalate and ditridecyl phthalate; glycols and glycol ethers such as propylene glycol; phthalic acid polyester, adipic acid polyester, sebacic acid polyester, and the like. Polyesters.

  The electrolyte paste is prepared by mixing an appropriate amount of the above components. At that time, in order to make each particle fine or to make the particle diameter uniform, the particles may be mixed while being pulverized using a ball mill or the like. Moreover, the order of addition of each component is not particularly limited, and may be according to a conventional method.

  Next, the aggregate in the electrolyte paste is crushed. In particular, in the production method of the present invention, in order to prevent the formation of through-holes during firing due to aggregates in the electrolyte layer, the largest particles of aggregates in the electrolyte paste measured by a grindometer in the crushing step It is important to crush until the diameter becomes 10 μm or less. By controlling the maximum particle size of the aggregates in the electrolyte paste to 10 μm or less, the formation of through-holes caused by the aggregates in the electrolyte layer can be suppressed during co-firing of the anode green layer and the electrolyte green layer. Can do.

  The method for crushing the electrolyte paste is not particularly limited, and a three-roll mill, a planetary ball mill, a ball mill, a bead mill, or the like can be used. Among these, a three-roll mill is preferable because the time required for crushing is short and the amount of paste that can be processed per batch is large.

  When a three-roll mill is used, the material of the roll constituting the three-roll mill is a ceramic material such as alumina, silicon nitride, or silicon carbide; a metal material such as steel; In addition, it is preferable to use a ceramic roll.

  When crushing the electrolyte paste using a three-roll mill, the gap between adjacent rolls of the three-roll mill is preferably 10 μm or less, more preferably 8 μm or less, and even more preferably 6 μm or less. When the gap between the rolls of the three-roll mill is 10 μm or less, the maximum particle diameter of the aggregate in the electrolyte paste can be easily reduced to 10 μm or less. In addition, since work efficiency will fall when the clearance gap between the adjacent rolls of a 3 roll mill is made too narrow, the clearance gap between rolls has preferable 1 micrometer or more.

  When crushing the electrolyte paste using a three-roll mill, the number of crushing operations (the number of passes through the three-roll mill) may be one, but is preferably two or more, and more preferably three. By performing the crushing operation twice or more, the maximum particle size of the aggregates in the electrolyte paste can be more reliably reduced to 10 μm or less. Even if the crushing operation is performed four times or more, the crushing action becomes saturated and is not economical.

  The electrolyte paste viscosity at the time of screen printing is preferably 20 Pa · s or more, more preferably 40 Pa · s, measured using a Brookfield viscometer under the conditions of spindle No. 14, rotation speed 10 rpm, measurement temperature 24 ° C. s or more, more preferably 60 Pa · s or more, preferably 180 Pa · s or less, more preferably 160 Pa · s or less, and still more preferably 100 Pa · s or less. If the viscosity of the electrolyte paste is within the above range, the paste has good moldability and the electrolyte green layer can be easily formed. The thickness of the electrolyte paste printed on the anode green layer is preferably 5 μm or more, more preferably 7 μm or more, further preferably 10 μm or more, preferably 30 μm or less, more preferably 25 μm or less, and further preferably 20 μm or less. is there. The electrolyte paste printed on the anode green layer is dried to volatilize and remove the solvent. The drying condition of the electrolyte paste may be such that the solvent can be evaporated, and for example, it may be heated at 70 ° C. or higher and 120 ° C. or lower for 15 minutes or longer and 10 hours or shorter. The thickness of the electrolyte layer after drying is preferably about 5 μm to 25 μm.

  Then, the electrolyte green layer, the anode green layer, and the anode support substrate green sheet are fired simultaneously. The firing conditions for firing these may be appropriately adjusted according to the raw materials and thickness thereof, and may be, for example, about 900 ° C. to 1500 ° C. for about 2 hours to 10 hours. In addition, when performing a stratification process by the said aspect 2, what is necessary is just to perform baking of an anode support substrate green sheet and an anode green layer similarly to the said baking conditions.

  4). Anode-supporting half-cell The anode-supporting half-cell of the present invention comprises an anode-supporting substrate, an anode layer laminated on the anode-supporting substrate, and the anode layer (the surface opposite to the surface in contact with the anode-supporting substrate). The electrolyte layer is formed by the above-described manufacturing method. The anode-supported half cell obtained by the production method of the present invention has a through-hole formation suppressed despite the fact that the electrolyte layer is made thinner. A full cell with excellent power generation performance such as output and durability can be obtained.

  The thickness of the electrolyte layer is preferably 3 μm or more, more preferably 5 μm or more, preferably 20 μm or less, more preferably 10 μm or less. The thickness of the anode layer is preferably 5 μm or more, more preferably 7 μm or more, preferably 25 μm or less, more preferably 20 μm or less. The thickness of the anode support substrate is preferably 100 μm or more, more preferably 150 μm or more, preferably 1500 μm or less, more preferably 1000 μm or less.

  5. Anode-supported cell In the anode-supported cell of the present invention, in the anode-supported half cell, a cathode layer is formed on the electrolyte (a surface opposite to the surface in contact with the anode layer). The cathode layer is prepared by uniformly mixing a cathode layer material with a binder, a solvent, and, if necessary, a dispersing agent or a plasticizer to prepare a paste, and depositing the prepared paste on the electrolyte layer by screen printing or the like, It can be formed by drying and baking.

  As the cathode layer material, a material made of a perovskite oxide which is excellent in electronic conductivity and stable even in an oxidizing atmosphere is generally used. Specifically, La0.8Sr0.2MnO3, La0.6Sr0.4CoO3, La0.6Sr0.4FeO3, La0.6Sr0.4Co0.2Fe0.8O3, etc., lanthanum manganite, lanthanum ferrite, etc., in which part of lanthanum is replaced with strontium Lanthanum cobaltite and the like are preferable as the cathode layer material. Further, in order to impart oxygen ion conductivity to the cathode layer, ceria or zirconia doped with a rare earth element or the like may be appropriately mixed.

  The binder, solvent, dispersant, plasticizer and the like used for the cathode layer paste may be the same as those used for the electrolyte paste. In addition, what is necessary is just to prepare the compounding quantity of each raw material suitably according to a desired physical property. A method for forming the obtained paste on the electrolyte layer is not particularly limited, but screen printing is preferable. Screen printing may be performed in the same manner as a conventional method.

  The cathode layer paste formed on the electrolyte layer is dried and fired to form the cathode layer. The drying condition of the cathode paste may be such that the solvent can be evaporated, and for example, it may be heated at about 70 ° C. to 120 ° C. for about 15 minutes to about 10 hours. The firing conditions of the cathode green layer may be appropriately adjusted according to the raw material and thickness thereof, and may be, for example, fired at about 700 ° C. to 1300 ° C. for about 2 hours to 10 hours. The thickness of the cathode layer formed on the electrolyte is preferably 10 μm or more and 80 μm or less.

  The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to the following examples, and may be appropriately modified and implemented within a range that can meet the purpose described above and below. All of which are within the scope of the present invention.

Evaluation method 1.
Maximum particle diameter of aggregates Measured using a grindometer according to JIS K5400 (1900) 4.7.2 filament method. That is, the anode paste is dropped in a groove of a grindometer (by BYK), and an anode paste layer having a continuously varying thickness is formed in the iron groove using a scraper. At this time, the thickness of the layer where three or more filaments in the anode paste began to appear was read and used as the maximum particle size of the aggregate. In addition, the measurement was performed 3 times and the average value of 3 times was calculated | required.

2. Through-hole detection test 50 ml of 12% aqueous ammonia (manufactured by Wako Pure Chemical Industries, Ltd.) was placed in a glass bottle having an opening with a diameter of about 10 cm. The half cell produced in the production example was placed so that the electrolyte surface was up so as to close the opening of the glass bottle, and the periphery was sealed and fixed with an O-ring. Subsequently, a 1.0 w / v% phenolphthalein ethanol solution (manufactured by Wako Pure Chemical Industries, Ltd.) was dropped on the electrolyte surface and thinned over the entire surface, and then the electrolyte surface side was reduced in pressure using an aspirator. When the ammonia in the glass bottle passed through the electrolyte layer and the phenolphthalein on the electrolyte surface caused a color reaction and turned red, it was evaluated that a through hole was present in the electrolyte layer.

Production Example 1-1 1-1.
Preparation of Anode Support Substrate Green Sheet 60 parts by mass of nickel oxide (made by Shodo Chemical Co., Ltd.) as a conductive component, 8 mol% yttrium-stabilized zirconia powder (made by Daiichi Rare Element Co., Ltd., trade name “HSY-8” 0.0 ") 40 parts by mass, carbon black as a pore-forming agent (SEC Carbon Co., SGP-3) 10 parts by mass, mixed solvent of 60 parts by mass of toluene and 40 parts by mass of ethanol, butyral as a binder 10 parts by mass of resin (manufactured by Sekisui Chemical Co., Ltd., product name “BM-S”), 3 parts by mass of dibutyl phthalate (manufactured by Wako Pure Chemical Industries, Ltd.) as a plasticizer, 2 parts by mass of a sorbitan fatty acid ester surfactant as a dispersant Were mixed by a ball mill to prepare a slurry. Using the obtained slurry, a sheet was formed by a doctor blade method and dried at 70 ° C. for 5 hours to prepare a 300 μm thick anode supporting substrate green sheet.

1-2.
Production of anode paste 36 parts by mass of nickel oxide (made by Kishida Chemical Co., Ltd.) as a conductive component, 8 mol% yttrium-stabilized zirconia powder (made by Daiichi Rare Element Co., Ltd., trade name “HSY-8.0”) as a skeleton component 24 parts by mass, 2 parts by mass of carbon black as a pore-forming agent (SEC Carbon Co., SGP-3), 36 parts by mass of α-terpineol (manufactured by Wako Pure Chemical Industries, Ltd.) as a solvent, and ethyl cellulose (Japanese After mixing 4 parts by mass of Kojun Pharmaceutical Co., Ltd.), 4 parts by mass of dibutyl phthalate (made by Wako Pure Chemical Industries) as a plasticizer, and 4 parts by mass of a sorbitan fatty acid ester surfactant as a dispersant using a mortar. Crushing was performed using a three-roll mill (manufactured by EXAKT technologies, model “M-80S”, roll material: alumina). Here, the gap between adjacent rolls of the three-roll mill was adjusted to 20 μm, and crushing by the three-roll mill was performed three times. With respect to the pulverized anode paste, the maximum particle size of the aggregate was measured and shown in Table 1.

1-3.
Formation of Anode Green Layer The pulverized anode paste was printed on the anode supporting substrate green sheet obtained above by screen printing so as to have a thickness of 20 μm and dried at 100 ° C. for 30 minutes to form an anode layer. .

1-4.
Formation of electrolyte membrane 8 mol% yttrium-stabilized zirconia powder (made by Daiichi Rare Element Co., Ltd., trade name “HSY-8.0”, average particle diameter (D50) 0.5 μm, 90 volume% diameter (D90) 0.9 μm) 60 parts by mass, 5 parts by mass of ethyl cellulose (manufactured by Wako Pure Chemical Industries, Ltd.) as a binder, 40 parts by mass of α-terpineol (manufactured by Wako Pure Chemical Industries, Ltd.) as a solvent, and dibutyl phthalate (Wako Pure) After mixing 6 parts by mass of Yaku Kogyo Co., Ltd. and 5 parts by mass of a sorbitan acid ester surfactant (trade name “IONET S-80”, manufactured by Sanyo Kasei Co., Ltd.) as a dispersant using a mortar, a 3-roll mill (Made by EXAKT technologies, model “M-80S”, roll material: alumina). Here, the gap between adjacent rolls of the three-roll mill was adjusted to 2 μm, and crushing by the three-roll mill was performed three times.

  The pulverized electrolyte paste was printed on the anode green layer obtained above by screen printing so as to have a thickness of 15 μm, and dried at 100 ° C. for 30 minutes. After drying, it was punched into a circular shape with a diameter of 100 mm and fired at 1300 ° C. for 2 hours to produce 20 anode-supporting half cells. The obtained anode-supported half cell was checked for the presence or absence of electrolyte through-holes. The results are shown in Table 1.

Production Examples 2-7
Anode-supported half-cell as in Production Example 1, except that the gap between adjacent rolls of the three-roll mill was changed to 15 μm, 12 μm, 10 μm, 7 μm, 5 μm, or 2 μm when crushing the anode paste. 20 pieces of each were produced. The maximum particle size of the aggregates in the anode paste after pulverization and the through holes of the electrolyte were confirmed, and the results are shown in Table 1.

  As shown in Table 1 and FIG. 1, when the maximum aggregate particle size in the anode paste is 13 μm or more, the produced anode-supporting half cell has a through hole in the electrolyte layer with a probability of more than half. For this reason, the acceptance rate of the produced anode-supported half-cell is also a very low value of 30% or less, and the productivity is very poor.

  On the other hand, when the maximum particle size of the aggregate in the anode paste is 10 μm or less, the produced anode-supported half cell has a rate of through-holes in the electrolyte layer of 15% or less, and an acceptance rate of 85 It can be seen that it is dramatically improved by more than%. In particular, when the maximum aggregate particle size in the anode paste is 5 μm or less, the pass rate is further improved to 95%.

Claims (5)

A method of manufacturing an anode-supporting half-cell having an anode support substrate, an anode layer formed on the anode support substrate, and an electrolyte layer formed on the anode layer;
An anode paste preparation step of preparing an anode paste by mixing at least ceramic powder, a solvent and a binder; a crushing step of crushing agglomerates in the anode paste; and the anode support substrate by screen printing using the anode paste A method for producing an anode-supporting half-cell comprising: a stratification step of forming an anode green layer thereon; and a firing step of sintering the formed anode green layer into an anode layer,
In the said crushing process, it crushes until the maximum particle diameter of the aggregate measured with a grindometer becomes 10 micrometers or less, The manufacturing method characterized by the above-mentioned.   The production method according to claim 1, wherein in the crushing step, the aggregate is crushed using a three-roll mill.   The manufacturing method of Claim 2 which sets the clearance gap between each roll of the said 3 roll mill to 1 micrometer or more and 10 micrometers or less.   An anode-supported half cell obtained by the manufacturing method according to claim 1.   An anode-supported cell, wherein a cathode layer is formed on the anode-supported half cell according to claim 4.

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