KR20130050402A - A method of producing a cell for a metal-supported solid oxide fuel cell - Google Patents

Abstract

PURPOSE: A manufacturing method of a metal-supported solid oxide fuel cell is provided to easily control thickness of various layers, to improve productivity, and to improve strength and flexibility of fuel cells. CONSTITUTION: A manufacturing method of a metal-supported solid oxide fuel cell, which includes a metal support, a diffusion-preventing layer, a fuel electrode layer, a solid electrolyte layer, and an air electrode layer, comprises a step of laminating and attaching a green sheet, which is manufactured by tape-casting raw material powder composing the diffusion-preventing layer, fuel electrode layer, and solid electrolyte layer, on one side of the metal support, using a warm isotactic press process.

Description

A method of producing a cell for a metal-supported solid oxide fuel cell}

The present invention relates to a solid oxide fuel cell, and more particularly, a sintered porous metal support or a metal plate on which gas channels are formed, which does not shrink in a subsequent heat treatment process, as a metal support, and on one side thereof, a diffusion barrier layer and an anode layer. In addition, the present invention relates to a method of manufacturing a metal support solid oxide fuel cell by sequentially stacking green sheets obtained by tape casting the solid electrolyte layers, respectively, and simultaneously firing the green sheets.

A solid oxide fuel cell (SOFC) has a structure in which a plurality of electricity generating units each comprising a unit cell and a separator plate are stacked. The unit cell includes a solid electrolyte layer, a fuel electrode (cathode) located on one surface of the solid electrolyte layer, and an air electrode (anode) located on the other surface of the solid electrolyte layer (film).

When oxygen is supplied to the cathode and hydrogen is supplied to the anode, oxygen ions generated by the reduction reaction of oxygen at the cathode move through the solid electrolyte layer to the anode and react with hydrogen supplied to the anode to generate water. At this time, electrons flow from the anode to the external circuit in the process of consumption and transfer to the cathode, the unit cell uses the electron flow to produce electrical energy. Therefore, the solid electrolyte layer is composed of a dense ion conductive layer through which gas cannot pass directly, and the air electrode and the fuel electrode should exhibit a porous structure and mixed conductivity (electron and ion conductivity) which are easily permeable to gas.

The solid oxide fuel cell includes an electrolyte-supported cell (ESC) type and an air electrode-supported cell type or an anode-supported cell type, among which an electrolyte-supported cell type (ESC) is a thick electrolyte that serves as a mechanical support. Layer, thin anode layer, and cathode layer In the case of the electrolyte support cell, when the solid electrolyte having a thickness of 100 to 500 um necessary for the mechanical support role is used, the ohmic resistance of the solid electrolyte is large. In order to achieve battery performance, fuel cells must be operated at high temperatures of 850 to 1000 ° C. In this case, expensive and heat resistant and oxidizing materials must be used for stacks and balance-of-plants (BOPs). There is a problem to rise.

The anode support cell forms a thin solid electrolyte layer of 5 to 20 um thick on the anode layer 300 to 1000 um thick to reduce ohmicity of the electrolyte, thereby lowering the SOFC operating temperature to a medium temperature of less than 800 ^o C. Although the economical efficiency is improved, the reliability of the SOFC stack can be secured only when the brittle fracture problem peculiar to ceramics is overcome.

On the other hand, since the metal support cell (MSC) uses a metal as a support, it is not only inexpensive to manufacture a cell, but also has excellent strength and flexibility.

Such a metal-supported solid oxide fuel cell has a cell structure in which a metal support / an anode / a solid electrolyte are stacked in this order.

In such a laminated structure, it is preferable that the metal support layer and the anode layer have a porous structure that facilitates gas permeation, and the solid electrolyte layer has a dense structure that does not transmit gas.

In addition, since the solid electrolyte layer has a higher resistance than the metal support and the anode layer, it is preferable that the thickness of the solid electrolyte layer is as thin as possible within the range where gas permeation is not possible.

As a method of manufacturing a metal support type solid oxide fuel cell, co-firing is performed in a reducing atmosphere after lamination of a green sheet manufactured by tape-casting powders forming a metal support, an anode layer, and a solid electrolyte layer, respectively. There is a way.

However, in the above method, the composition of the metal, the particle size, the surface roughness and the surface roughness are controlled so that the solid electrolyte layer, the thermal expansion coefficient of each of the anode layer and the metal support layer, and the sintering shrinkage ratio are precisely controlled and the metal support has a sufficient porosity even after high- And the firing atmosphere must be precisely controlled. In addition, such a manufacturing method has a disadvantage in that a large pin-hole or warpage is more likely to occur in the cell due to the fine sintering shrinkage rate and thermal expansion coefficient difference between the layers when the cell is large.

In addition, in the above method, sintering is carried out in a reducing atmosphere to prevent oxidation of the metal support during the co-firing process. At this time, NiO, the anode constituent material, is reduced to Ni, resulting in rapid grain growth, thereby reducing the electrochemical activity of the anode, thereby improving cell performance. There is a problem of this deterioration.

In manufacturing a cell for a metal support type solid oxide fuel cell, using a pre-sintered porous metal support or a metal sheet which does not occur shrinkage in the heat treatment process as a metal support, and in producing each component layer formed on the metal support Using a process of tape casting a constituent layer and laminating and co-firing, a method of manufacturing a metal support cell having excellent economy is provided.

In one embodiment of the present invention, a metal support type solid oxide fuel cell cell manufacturing method comprising a metal support, a diffusion barrier layer, an anode layer, a solid electrolyte layer and a cathode layer, wherein the diffusion barrier layer and the one side of the metal support Metal support-type solid oxide, characterized in that the green sheet manufactured by tape casting the raw material powder constituting the anode layer and the solid electrolyte layer by laminating by using a warm isostatic press (WIP) process. It provides a fuel cell manufacturing method.

In one embodiment of the present invention, it is preferable to use a sintered porous metal support or a metal plate on which gas channels are formed which do not shrink in a subsequent heat treatment process as a metal support to be used.

Method of manufacturing a cell for a solid oxide fuel cell according to an embodiment of the present invention

I) a first step of preparing the metal support;

Ii) a second step of sequentially stacking the green sheet of the diffusion barrier layer, the green sheet of the anode layer and the green electrolyte layer of a solid electrolyte layer on one surface of the metal support using the warm isotropic pressure press (WIP) process;

Iii) removing the binder and the plasticizer of the green sheet stacked on the metal support;

A fourth step of compressing the diffusion barrier layer, the anode layer, and the solid electrolyte layer by performing a cold isotropic press (CIP) process on the laminate from which the binder is removed;

Iii) a fifth step of simultaneously firing the laminate molded by the cold isotropic press; And

Iii) screen printing the cathode on the sintered solid electrolyte layer; The present invention also provides a method of manufacturing a cell for a metal-supported solid oxide fuel cell.

In the manufacturing method of the present invention, each green sheet of the second step is preferably formed by tape casting.

In the manufacturing method of the present invention, each warm isotropic pressure press (WIP) process of the second step is to vacuum-pack each formed green sheet and maintain the temperature of the water inside the cylinder in the vacuum-packed laminate at 60 to 80 ° C. It is preferable to carry out by putting into a hydrostatic pressure press apparatus and applying the pressure of 100-300 kgf / cm <^2> for 10-40 minutes.

In addition, the step of removing the binder and the plasticizer in the third step in the manufacturing method of the present invention is at least 2 ~ 5 hours at 200 ^o C, 350 ^o C, 500 ℃ while raising the temperature at an elevated temperature of 1 ~ 3 ^o C per minute in air It is desirable to maintain.

In addition, in the manufacturing method of the present invention, each cold isostatic pressure press (CIP) step of the fourth step is 1,000 ~ 5,000kgf / cm in a cold isotropic pressure press in the state in which the laminate is packaged in a vacuum and then put into a cold isostatic press It is preferable to carry out by applying isotropic pressure of ² to 5 to 30 minutes.

And the sintering of the fifth step in the production method of the present invention is preferably heat-treated for 1 to 5 hours in the range of 1,000 ~ 1070 ℃ in the sintering furnace of argon atmosphere.

In addition, the cathode layer of the fifth step in the manufacturing method of the present invention is not heat-treated in the cell manufacturing step, it is preferable that the heat treatment in the range of 750 ~ 850 ℃ in the process of bonding the sealing material during the stack or cell evaluation.

On the other hand, the diffusion barrier layer in the production method of the present invention, _{CeO 2, Ce 1 - x Ln} x O 2 -δ, (Ln = Gd, Sm, Y, x = 0.1 ~ 0.3, δ = 0 ~ 0.2) (La 1 - _x A _x ) Cr _{1 - y} B _y O _{3 ± δ} (A = Sr, Ca, or mixtures thereof x = 0.1-0.4; B = Mn, Co, Cu, Ni, V, Fe, Ti, Ce, Ru or The mixture, y = 0 to 0.5, δ = 0 to 0.3), (La _1-x A _x ) _s Ti _1-y B _y O _{3 ± δ} (A = Sr, Ca, or mixture thereof x = 0.1 to 0.6 B = Mn, Co, Cu, Ni, V, Fe, Ti, Ce, Ru or mixtures thereof, y = 0 to 0.5; s = 0.9 to 1.0, δ = 0 to 0.3), (Sr _{1 - x} A _x ) _s Ti _{1 - y} Nb _y O _{3 ± δ} (A = Y, La, Gd, Sm or mixtures thereof, x = 0.05 to 0.2; y = 0 to 0.5; s = 0.9 to 1.0, δ = 0 to 0.3) It is preferable that at least one of them is a selected complex.

The diffusion barrier layer is more preferably Ce _0.9 Gd _0.1 O _1.95 composition or a composition in which 0.2 ~ 0.8 wt% of Co ₃ O ₄ is added to the composition.

And the diffusion barrier layer is preferably an average thickness of 1 ~ 10um after sintering.

In addition, in the manufacturing method of the present invention, the anode layer is a composite of NiO and (ZrO ₂ ) _1-x (Y ₂ O ₃ ) _x (x = 0.08 ~ 0.1), NiO and (ZrO ₂ ) _0.90 (Sc ₂ O ₃ ) _{0.1 -x} (Yb ₂ O ₃ ) _x (x = 0 ~ 0.06) of Complex, and NiO Ce _{1 -} to _{x Ln x O 2 -δ, (} Ln = Gd, Sm, Y, x = 0.1 ~ 0.3, δ = 0 ~ 0.2) of any one of the complex or mixture of complexes is preferable.

The fuel electrode layer is NiO and _{(ZrO 2) 0.92 (Y 2} O 3) 0.08 The solid electrolyte powder or a composite NiO and _{Ce 0 .9 Gd 0 .1 O 2} -δ (δ = 0 ~ 0.2) of the composite solid electrolyte powder It is more preferable that the content of NiO in the composite is preferably in the range of 50 ~ 75 wt%.

In addition, the anode layer preferably has an average thickness of 10 μm to 50 μm after sintering.

On the other hand, in the manufacturing method of the present invention, the solid electrolyte layer is preferably Ce _{1 - x} Ln _x O _{2 -δ} (Ln = Gd, Sm, Y, x = 0.1 ~ 0.3, δ = 0 ~ 0.2) -based oxide Do.

The solid electrolyte layer is a mixture in which at least one or more of transition metal oxides of Co ₃ O ₄ , CoO, CuO, MnO, and MnO ₂ is added to the oxide powder in the range of 0.2 to 2 wt% based on the solid electrolyte powder. More preferred.

In addition, the solid electrolyte layer preferably has an average thickness of 5 um to 30 um after sintering.

The present invention is a fuel cell stack (Fuel Cell Stack) or fuel cell power generation system (Fuel Cell Power Generation System) manufactured using a fuel cell manufactured by any one of the manufacturing method of the present invention as described above To provide.

In the method of manufacturing a metal support-type solid oxide fuel cell according to an embodiment of the present invention, the diffusion barrier layer, the anode layer, and the solid electrolyte layer, which are manufactured by a tape casting method, are prepared on a pre-fabricated metal support having no sintering shrinkage in a subsequent heat treatment process. The sheets are laminated in sequence using a warm isostatic press (WIP), and then the laminated layers are manufactured using a method of sintering by cold isostatic press (CIP) again, thereby It is easy to adjust the thickness, excellent mass productivity, and lowers the cell manufacturing temperature, there is a technical effect that can solve the problem of excessive growth of nickel (Ni) particles of the anode layer that can occur when manufacturing at high temperatures.

Further, when the fuel cell is manufactured by the manufacturing method according to the embodiment of the present invention, the number of stacking and sintering processes can be reduced, thereby reducing the overall manufacturing cost.

In addition, when the fuel cell is manufactured by the manufacturing method according to an embodiment of the present invention, the metal support is used, and thus the manufacturing cost is lower than that of the ceramic-supported solid oxide fuel cell, and the technical effect is very excellent in strength and flexibility. There is.

Accordingly, the fuel cell stack and the fuel cell power generation system using the metal-supported solid oxide fuel cell fabricated according to an embodiment of the present invention can be applied to thermal and mechanical shock and vibration There is a technical effect that strong and rapid thermal cycling is possible.

In addition, the use of the manufactured fuel cell can improve the thermal and mechanical reliability, which is a weak point of the conventional ceramic support type SOFC stack in the field of power sources such as transportation equipment, mobile equipment, and portable equipment, and commercialization of the solid oxide fuel cell can be expected have.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used herein, the singular forms “a,” “an,” and “the” include plural forms as well, unless the phrases clearly indicate the opposite. As used herein, the term "comprising" embodies a particular characteristic, region, integer, step, operation, element, and / or component, and other specific characteristics, region, integer, step, operation, element, component, and / or group. It does not exclude the presence or addition of.

Unless defined otherwise, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. Commonly used predefined terms are further interpreted as having a meaning consistent with the relevant technical literature and the present disclosure, and are not to be construed as ideal or very formal meanings unless defined otherwise.

Hereinafter, embodiments of the present invention will be described in detail. These embodiments are only for illustrating the present invention, and the present invention is not limited thereto.

In the method for manufacturing a metal support solid oxide fuel cell according to an embodiment of the present invention, in the manufacture of a cell for a metal support solid oxide fuel cell, a sintered porous metal support or gas channel which does not shrink in a subsequent heat treatment process is The metal support-type solid oxide fuel cell capable of producing a compact solid electrolyte layer at a relatively low temperature by using the formed metal sheet as a metal support and using a wet powder process can be manufactured.

Method for manufacturing a metal support solid oxide fuel cell according to an embodiment of the present invention, in manufacturing a cell for a metal support solid oxide fuel cell on a metal support, produced by a tape casting process excellent in thickness uniformity and mass production The cell layer is co-fired through a warm isotropic press (WIP) process, a binder and plasticizer removal process, and a cold isotropic press (CIP) process, which is a solid electrolyte previously possible at around 1350-1400 ° C. Densification can be achieved in the vicinity of 1000 ~ 1070 ℃.

In the manufacturing method of the metal support solid oxide fuel cell according to an embodiment of the present invention, in the manufacture of the metal support solid oxide fuel cell, warming is achieved by laminating and co-firing the diffusion barrier layer, the anode layer, and the solid electrolyte layer at once. By reducing the number of isotropic presses (WIP), binders and plasticizers, cold isotropic presses (CIPs) and sintering processes, manufacturing time and costs can be reduced.

Method of manufacturing a metal support-type solid oxide fuel cell according to an embodiment of the present invention comprises the steps of: i) preparing a metal support (step 1); And ii) sequentially laminating a green sheet of a diffusion barrier layer (DBL), an anode layer, and a solid electrolyte layer on one side of the metal support using a warm isotropic press (WIP) process on one side of the metal support. Step (step 2); And iii) burning out the binder and plasticizer of the green sheet from the laminate (step 3); and iii) performing a cold isotropic press (CIP) process on the laminate from which the binder and the plasticizer are removed. Compressing the diffusion barrier layer and the anode layer to increase molding density and interlayer bonding force (step 4); And iii) co-firing the laminate formed by the cold isotropic press (step 5); And iii) screen printing the cathode on the solid electrolyte of the sintered laminate (step 6).

Hereinafter, each detailed process of a method of manufacturing a metal-supported solid oxide fuel cell according to an embodiment of the present invention will be described in sequence.

First, the step (step 1) of preparing a metal support will be described.

The metal support is preferably used as a substrate using a sintered body or a thin metal plate of the metal powder does not shrink in the subsequent heat treatment process. In addition, the metal support preferably has a three-dimensional continuous pore structure, or a plurality of through holes formed in order to pass the fuel gas.

The material for the metal support has a small electric conductivity decrease due to high temperature oxidation, has redox stability, and a material having a thermal expansion coefficient of about 10 to 13 x 10 ^-6 / ^o C is preferable. The reason why the thermal expansion coefficient of the metal support is limited is to reduce the difference in thermal expansion coefficient between the metal support and each of the ceramic functional layers stacked thereon to prevent the separation of the functional layer and the warping of the cell due to the difference in thermal expansion coefficient between the respective components to be.

Metal support materials having such characteristics include Ferritic Stainless Steel, the product names Crofer22APU and Crofer22H of Tyssenkrupp, Germany, and the product name ZMG232L of Hitachi Metal, Japan.

Also, Fe-Cr alloys having such characteristics include Fe-26Cr- (Mo, Ti, Y ₂ O ₃ ) and Fe-Cr-M _x alloys (M _x = Ni, Ti, Ce, Mn, Mo, Co). , La, Y, Al). In the case of such Fe-Cr alloys, 0 to 50 vol% of metal oxides (doped-Zirconia, doped-Ceria, MgO, CaO, SrO, CoO _x , ZnO, VO _x , Cr ₂ O ₃ , FeO, MoO _x , WO _x , Ga ₂ O ₃ , Al ₂ O ₃ , TiO ₂ and mixtures thereof) may be used.

Next, ii) a step (step 2) of sequentially stacking the diffusion barrier layer, the anode layer, and the green sheet of the solid electrolyte on one surface of the metal support will be described.

The diffusion barrier layer, the anode layer, and the solid electrolyte layer laminated in step 2 are formed by tape casting, and then laminated using a warm isotropic press (WIP) process. The average thickness of the green sheet of the diffusion barrier layer formed by the tape casting is 5 ~ 8um, the average thickness of the anode layer green sheet is 60 ~ 70um and the average thickness of the solid electrolyte layer sheet is 25 ~ 35um. The final thickness of each side can be adjusted by changing the thickness and lamination number of the green sheet.

Here, the warm isostatic press (WIP) process is to arrange the green sheet in order of the diffusion barrier layer, the anode layer and the solid electrolyte layer on one side of the prepared metal support, vacuum packing, and then the water temperature inside the cylinder is 60-80 ℃. into the warm, etc. bangap press apparatus is maintained at 100 ~ 300kgf / cm ² of a pressure of 10 ~ 40 min, more preferably 250 ~ 300kgf / cm ² of pressure 15 ~ 30 minutes, and more preferably 280kgf / cm ² The green sheet may be laminated by applying a pressure of 30 minutes. This warm isostatic press (WIP) method is a useful process for laminating and joining each component constituting a cell for fuel cells on a metal sheet on which a porous metal support or gas channel is formed, as well as homogeneous or heterogeneous green sheets.

In step 2, a laminate comprising a metal support (substrate) / diffusion barrier layer (green sheet) / anode layer (green sheet) / solid electrolyte (green sheet) is manufactured through the lamination process.

The binder constituting the green sheet of the diffusion barrier layer, the anode layer, and the solid electrolyte layer, and the plasticizer are dissolved in a solvent during the tape casting process, and after the solvent is dried, in the green sheet, the surface of the constituent powder of each layer and between Filling the space between the green sheet provides strength and flexibility, and serves to enable the lamination between the substrate and each layer by the warm isotropic press (WIP) process of step 2.

The diffusion barrier layer laminated in step 2 serves to prevent the interdiffusion reaction between the Fe and Cr components of the metal support and Ni of the Ni-based anode while allowing gas and electricity to pass therethrough. For this purpose, materials that can be used as the diffusion barrier layer are CeO ₂ , Ce _{1 - x} Ln _x O _{2 -δ} , (Ln = Gd, Sm, Y, x = 0.1 ~ 0.3, δ = 0 ~ 0.2) (La _{1 - x} A _x ) Cr _{1 - y} B _y O _{3 ± δ} (A = Sr, Ca, or mixtures thereof x = 0.1-0.4; B = Mn, Co, Cu, Ni, V, Fe, Ti, Ce, Ru or mixtures thereof , y = 0 to 0.5, δ = 0 to 0.3), (La _1-x A _x ) _s Ti _1-y B _y O _{3 ± δ} (A = Sr, Ca, or mixtures thereof x = 0.1 to 0.6; B = Mn, Co, Cu, Ni, V, Fe, Ti, Ce, Ru or mixtures thereof, y = 0 to 0.5; s = 0.9 to 1.0, δ = 0 to 0.3), (Sr _{1 - x} A _x ) _s Only in Ti _{1 - y} Nb _y O _{3 ± δ} (A = Y, La, Gd, Sm or mixtures thereof, x = 0.05 to 0.2; y = 0 to 0.5; s = 0.9 to 1.0, δ = 0 to 0.3) Or a complex in which at least one is selected.

More preferably, the material used as the diffusion barrier layer has a composition of Ce _0.9 Gd _0.1 O _1.95 or 0.2 to 0.8 wt%, more preferably 0.3 to 0.6 wt%, more preferably 0.5 wt% of Co ₃ O ₄ in such a composition. The composition added in the range is suitable. The addition of Co ₃ O ₄ may promote the sintering of Ce _0.9 Gd _0.1 O _1.95 to improve the adhesion between the substrate and the anode layer.However, as the addition amount increases, the density of the diffusion barrier layer increases, which hinders the passage of fuel gas. Reduce performance. The diffusion barrier layer has an average thickness after sintering of 1 to 10 um, more preferably 2 to 6 um, and more preferably 3 to 4 um. If the thickness of the diffusion barrier layer is too thin, a portion of the direct contact between the anode and the metal support is generated due to the surface roughness of the metal support, so that a diffusion reaction is likely to occur, and if too thick, the electrical resistance may increase.

The anode layer laminated in step 2 is a ceramic powder of NiO and (ZrO ₂ ) _1-x (Y ₂ O ₃ ) _x (x = 0.08 ~ 0.1), NiO and (ZrO ₂ ) _0.90 (Sc ₂ O ₃ ) _0.1-x (Yb ₂ O ₃ ) _x (x = 0 ~ 0.06) of Complex, and NiO _{Ce 1 - x Ln x O 2} -? Δ, (Ln = Gd, Sm, Y, x = 0.1 ~ 0.3, δ = 0 ~ 0.2) is any one of the complex or mixture of complexes is preferable.

More preferably, the fuel electrode layer of ceramic powders NiO and _{(ZrO 2) 0.92 (Y 2} O 3) 0.08 NiO complexes or of the solid electrolyte powder and _{Ce 0 .9 Gd 0 .1 O 2} -δ (δ = 0 ~ 0.2) It is a complex of solid electrolyte powder. The content of NiO in such composites here is in the range of 50-75 wt%, more preferably 60 wt%. The anode layer has an average thickness of 10 um to 50 um, more preferably 30 to 40 um after sintering.

On the other hand, the solid electrolyte layer laminated in step 2 is preferably Ce _{1 - x} Ln _x O _{2 -δ} (Ln = Gd, Sm, Y, x = 0.1 ~ 0.3, δ = 0 ~ 0.2) -based oxide. Wherein the solid electrolyte is 0.2 to 2 wt%, more preferably at least one of transition metal oxides such as Co ₃ O ₄ , CoO, CuO, MnO and MnO ₂ to the solid electrolyte powder in order to further improve its sinterability Preferably it is a mixture in which Co ₃ O ₄ is added in the range of 0.8 to 1.2 wt%, more preferably 1 wt%. The transition metal oxide added as a sintering aid forms a temporary liquid phase near the sintering temperature to help densification and grain boundary movement through material movement and helps densification. If the addition amount is too small, the sintering promotion effect is small. In case of, it is necessary to add the optimum amount because the open circuit voltage can be reduced due to the electron conductivity by the transition metal remaining after sintering.

The average thickness after sintering of the solid electrolyte layer thus formed is in the range of 5 um to 30 um, more preferably 10 to 15 um. The performance of an SOFC cell increases as the thickness of the solid electrolyte decreases as the ion conduction resistance decreases, but when too thin, the crossover of fuel gas and air directly meets through local defects in the solid electrolyte layer due to the roughness of the substrate. When the over phenomenon occurs, the electromotive force is not only reduced, but also a hot spot occurs around the portion, which causes deterioration of the cell performance. Therefore, an appropriate thickness that does not occur crossover phenomenon is required. do.

The following describes the step (step 3) of iii) burning out the binder and plasticizer of the green sheets from the laminate.

In step 3, 200 ^o C, 350 while raising the temperature at a temperature of 1 to 3 ^o C per minute in air to remove the PVB-based binder and the alkyl phthalate-based plasticizer contained in the diffusion barrier layer, the anode layer, and the solid electrolyte layer. ^o It is preferable to keep it at C and 500 degreeC for 2 to 5 hours or more, respectively.

As described above, the removal of the binder and the plasticizer is intended to improve the molding density by compressing the space between the powder produced after the removal of the binder and the plasticizer in a cold isotropic press (CIP) process.

Next, the step (step 4) of performing the cold isotropic pressure press (CIP) process on the laminate will be described.

In step 4, the laminate is vacuum packed and then placed in a cold isotropic press, and the isotropic pressure of 1,000 to 5,000 kgf / cm ² is 5 to 30 minutes, more preferably 1,500 to 3,000 kgf in a cold isostatic press. / isotropic pressure of ² cm and more preferably 5 ~ 30 minutes, is carried out by applying isotropic pressure for 5 minutes of 2,000 kgf / cm ^2. When such a process is performed, the forming density of the diffusion barrier layer, the anode layer, and the solid electrolyte layer stacked on the metal support is improved, and the adhesion is also increased.

Next, the steps (step 5) of simultaneously burning the laminate molded by the cold isotropic press will be described.

The sintering process of step 5 is a simultaneous firing process in which the diffusion barrier layer, the fuel electrode layer, and the solid electrolyte layer are sintered at once, and the process time and cost are greatly increased by reducing the number of lamination and sintering processes required in case of firing separately for each layer. There is an advantage to reduce. In addition, when the solid electrolyte and the anode layer are sintered at the same time, the bonding of the interface is better than that of the case of having a separate sintering process for each layer, and thus the electrochemical performance can be expected to be improved.

The sintering process by step 5 is to heat treatment in an argon atmosphere sintering furnace for 1 to 5 hours in the range of 1000 ~ 1070 ℃ to prevent oxidation of the metal support. This heat treatment temperature range is because the adhesion between the anode and the diffusion layer and the compactness of the solid electrolyte is insufficient at 1000 ^° C or less, and the oxidation of the metal support occurs badly at 1070 ^° C or more. By sintering in this way, the oxidation of the metal support can be prevented, and the adhesion between the layers and the densification of the solid electrolyte can be simultaneously achieved.

For example, Ceria-based solid electrolytes such as Ce _0.9 Gd _0.1 O _1.95 as ceramic materials for solid electrolyte layers usually have a relatively high sintering temperature of 1350 to 1400 ^o C for gas tight densification. To the solid electrolyte powder, a mixture in which Co ₃ O ₄ is added in a range of 0.2 to 2 wt%, more preferably 0.8 to 1.2 wt%, and more preferably 1 wt%, is prepared using the process proposed in the present invention. In the case of application, the pores of the solid electrolyte are sufficiently removed only by relatively low temperature sintering in the vicinity of 1000 to 1070 ° C., so that the fuel gas and air can directly meet through the residual pores and sinter enough enough to cause a combustion reaction.

In addition, in the conventional methods known to date, the ceramic layer formed on the substrate which cannot be accompanied by sintering shrinkage during the subsequent heat treatment process, such as metal sheet or sintering, prevents the shrinkage behavior of the ceramic layer on which the substrate is not contracted. While sufficient densification is not possible due to the constrained sintering phenomenon, when forming the solid electrolyte layer by the step 5 as described above, the shrinkage required for densification is greatly reduced by maximizing the adhesion and forming density with the metal support. Let's make 1000 ~ 1070 It is possible to obtain a solid electrolyte layer that is sufficiently dense so that the fuel gas of the anode layer and the air of the cathode layer meet directly in the range of 0 ° C. so as not to cause a combustion reaction. Finally, screen printing the cathode on the solid electrolyte (step 6). ) Will be described.

Step 6 is to form the cathode layer by the screen printing process, the cathode layer is a temperature for bonding the sealing material in the stack or cell evaluation process without a separate heat treatment in the cell manufacturing process 750 ~ 850 ℃, more preferably 800 ^o C By heat treatment at, the metal support-type solid oxide fuel cell is completed.

The composition of the cathode layer formed in step 6 is (A _{1- x} B _x ) _s Fe _{1 - y} Co _y O _{3 -δ} (A = La, Gd, Y, Sm, Ln or mixtures thereof, B = Ba, Sr , Ca and mixtures thereof, Ln = lanthanides) and (La _1-x Sr _x ) _s MnO _3-δ It is preferable that the conductive conductive oxide, or a composite of a solid electrolyte powder added to the electrically conductive oxide in the range of 10 to 50 vol%. In addition, the average thickness of the cathode layer is preferably in the range of 10 um to 50 um.

While the invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the scope of the following claims. Those who do it will easily understand.

Claims (20)

In the method of manufacturing a cell for a metal support type solid oxide fuel cell comprising a metal support, a diffusion barrier layer, an anode layer, a solid electrolyte layer and an cathode layer,
The green sheet manufactured by tape casting the raw material powder constituting the diffusion barrier layer, the anode layer, and the solid electrolyte layer on one surface of the metal support is laminated by using a warm isostatic press (WIP) process. A method of manufacturing a cell for a metal support-type solid oxide fuel cell, characterized in that the bonding. The method of claim 1,
The metal support is a method of manufacturing a cell for a solid oxide fuel cell using a sintered porous metal support or a metal plate formed with a gas channel does not shrink in a subsequent heat treatment process. The method of claim 2,
The method for manufacturing the solid oxide fuel cell
A first step of preparing the metal support;
A second step of sequentially stacking the green sheet of the diffusion barrier layer, the green sheet of the anode layer, and the green electrolyte layer of the solid electrolyte layer on one surface of the metal support using the warm isotropic press (WIP) process;
Removing a binder and a plasticizer of the green sheets stacked on the metal support;
Performing a cold isotropic press (CIP) process on the laminate from which the binder and the plasticizer have been removed to compress and mold the diffusion barrier layer, the anode layer, and the solid electrolyte layer;
A fifth step of simultaneously firing the laminate molded by the cold isotropic press; And
A sixth step of screen printing the cathode on the sintered solid electrolyte layer;
Wherein the solid oxide fuel cell comprises a metal-supported solid oxide fuel cell. The method of claim 3,
And in the second step, the green sheets are formed by tape casting. 5. The method of claim 4,
In the second step, the warm isotropic pressure press (WIP) process is to vacuum-pack each formed green sheet and the vacuum-packed laminate to a warm isotropic pressure press device in which the water temperature in the cylinder is maintained at 60 to 80 ° C. Method of producing a metal support-type solid oxide fuel cell cell is carried out by applying a pressure of 100 ~ 300kgf / cm ² for 10 to 40 minutes. 5. The method of claim 4,
The step of removing the binder and the plasticizer in the third step is a metal support type which is maintained at 200 ^o C, 350 ^o C, and 500 ° C. for 2 to 5 hours or more while raising the temperature at an elevated temperature of 1 to 3 ^o C per minute in air. Method for producing a cell for a solid oxide fuel cell. 5. The method of claim 4,
In the fourth step, each cold isostatic press (CIP) process is carried out in a cold isostatic pressure press in the cold isotropic pressure press while packing the laminate in a vacuum, and then isotropic pressure of 1,000 ~ 5,000kgf / cm ² A method for producing a cell for a metal support solid oxide fuel cell, which is applied for 5 to 30 minutes. 5. The method of claim 4,
In the fifth step, the simultaneous firing is heat-treated in an argon atmosphere sintering furnace in the range of 1,000 ~ 1070 ℃ 1 to 5 hours in the manufacturing method of a cell for a metal support solid oxide fuel cell. 5. The method of claim 4,
In the sixth step, the cathode layer is not subjected to a separate heat treatment in a cell manufacturing process, and a method of manufacturing a cell for a metal support-type solid oxide fuel cell which is heat treated at a bonding temperature of a sealant at 750 to 850 ° C. when a stack or a cell is evaluated. 10. The method according to any one of claims 1 to 9,
The diffusion barrier layer is _{CeO 2, Ce 1 - x Ln} x O 2 -δ, (Ln = Gd, Sm, Y, x = 0.1 ~ 0.3, δ = 0 ~ 0.2) (La 1 - x A x) Cr 1 - _{y B y O 3 ± δ (} A = Sr, Ca, or mixtures thereof x = 0.1 ~ 0.4; B = Mn, Co, Cu, Ni, V, Fe, Ti, Ce, Ru or mixtures thereof, y = 0 ~ 0.5, δ = 0 ~ 0.3) , (1-x A x La) s Ti 1-y B y O 3 ± δ (A = Sr, Ca, or mixtures thereof x = 0.1 ~ 0.6; B = Mn, Co, (Sr _{1 - x} A _x ) _s Ti _{1 - y} Nb (where n is an integer from 0 to 3) _y O _{3 ± δ} (A = Y, La, Gd, Sm or a mixture thereof, x = 0.05 to 0.2; y = 0 to 0.5; s = 0.9 to 1.0 and δ = 0 to 0.3) Wherein said solid support is a composite metal supported solid oxide fuel cell. The method of claim 10,
The diffusion barrier layer is a Ce _0.9 Gd _0.1 O _1.95 composition or a method for producing a metal support-type solid oxide fuel cell of the Co ₂ O ₄ 0.2 ~ 0.8 wt% composition. The method of claim 11,
Wherein the diffusion preventing layer has an average thickness after sintering of 1 to 10 μm. 10. The method according to any one of claims 1 to 9,
The fuel electrode layer is NiO and _{(ZrO 2) 1-x (} Y 2 O 3) x (x = 0.08 ~ 0.1) of the composite, NiO and _{(ZrO 2) 0.90 (Sc 2} O 3) 0.1-x (Yb 2 O ₃ ) _x (x = 0 to 0.06) of Complex, and NiO A composite of any one of Ce _{1 - x} Ln _x O _{2 - δ} , (Ln = Gd, Sm, Y, x = 0.1 to 0.3 and δ = 0 to 0.2) or a mixture thereof. &Lt; / RTI &gt; The method of claim 13,
Wherein the anode layer is a composite of NiO and Ce _{0 .9} Gd _{0 .1} O _{2 -δ} (δ = 0 to 0.2) solid electrolyte powder. 15. The method of claim 14,
NiO content of the composite is a method of manufacturing a cell for a metal support-type solid oxide fuel cell in the range of 50 ~ 75 wt%. 15. The method of claim 14, wherein the anode layer has an average thickness of 10 um to 50 um after sintering. 7. The method according to any one of claims 1 to 6,
_Wherein the solid electrolyte layer is a system oxide of Ce _{1 - x} Ln _x O _{2 -?} (Ln = Gd, Sm, Y, x = 0.1 to 0.3,? = 0 to 0.2) . 17. The method of claim 16,
The solid electrolyte layer may be formed of a metal support which is a mixture obtained by adding at least one of Co ₃ O ₄ , CoO, CuO, MnO, and MnO ₂ transition metal oxide to the solid oxide electrolyte in the range of 0.2 to 2 wt% A method of manufacturing a cell for a solid oxide fuel cell. 19. The method of claim 18,
The solid electrolyte layer is a method of manufacturing a metal support-type solid oxide fuel cell cell having an average thickness of 5 um ~ 30 um after sintering. A fuel cell stack or a fuel cell power generation system manufactured using a fuel cell manufactured by the manufacturing method of any one of claims 11, 15 and 18.