KR100350364B1 - Ceramic Fiber Reinforced Matrix for Molten Carbonate Fuel Cell and a Process for Production Thereof - Google Patents

Abstract

The present invention relates to a matrix used in a molten carbonate fuel cell (hereinafter referred to as MCFC) and a manufacturing method thereof. By adding ceramic fibers of short fibers when manufacturing the matrix for MCFC, it is possible to prevent cracking of the matrix and loss of carbonate due to phase change of carbonate which may occur during long-term operation of MCFC. High performance molten carbonate fuel cells with enhanced strength of the matrix itself can be constructed to facilitate redistribution at the electrodes and the matrix.

Description

Ceramic Fiber Reinforced Matrix for Molten Carbonate Fuel Cell and Manufacturing Method Thereof {Ceramic Fiber Reinforced Matrix for Molten Carbonate Fuel Cell and a Process for Production Thereof}

The present invention relates to a matrix used in a molten carbonate fuel cell (hereinafter referred to as MCFC) and a manufacturing method thereof. More particularly, the present invention relates to a method for producing a matrix for MCFC, which can be reinforced with ceramic fibers and exhibit a cell performance that is stronger in thermal cycle than a conventional matrix.

The matrix for MCFC serves to support molten carbonate, which is an electrolyte, and provides a passage when CO ₃ ^2- ions produced at the cathode are transferred to the anode. In addition, it electrically insulates the two electrodes, prevents the reaction gases such as fuel and air flowing into each electrode from mixing with each other in the cell and serves as a wet seal to prevent gas leakage to the outside of the cell.

Matrix of MCFC is solid at room temperature but carbonate melts at 650 ℃ and is impregnated into matrix pores, so it exists in paste state. Matrix performance is mainly due to internal resistance of battery, mixing of gas, wet Since it is determined by the sealing function, a proper pore size distribution and a stable structure must be maintained for good performance. In particular, since carbonate, which is an electrolyte, is melted at around 500 ° C., sufficient strength must be maintained so that the structure of the entire matrix does not change even when temperature changes such as heat shock due to heat cycle.

In general, the conditions that the matrix must have listed are as follows (see HC Maru, et al., "Review of Carbonate Fuel Cell Matrix and Electrolyte." Proceedings of the Second International Symposium on Molten Carbonate Fuel Cell Technology, Proceedings) Volume 90-16, The Electrochemical Society, Pennington, NJ, pp. 121-136 (1990)).

1) The material of the matrix must be chemically inert with other components of the cell or with the reactant gases.

2) Since the electrolyte is supported by the capillary of the matrix, the change in porosity or pore size should be small under the fuel cell operating conditions. That is, the sintering phenomenon due to surface diffusion, bulk diffusion, Oswald ripening at high temperature should be small.

3) Since the matrix must keep electrolytes in operation while preventing cross-over of gases, the pore size of the matrix must be smaller than the pore size of the two electrodes and the distribution must be narrow.

Considering the above conditions, LiAlO ₂ is currently known as a suitable matrix material, and a conventional MCFC matrix is a mixture of LiAlO ₂ powder having a diameter of 0.5 μm or less, an organic solvent, and an organic additive such as a dispersant, a plasticizer, and a binder. A slurry is prepared by molding into a sheet using tape casting or paper milling (see HC Maru, et al., "Review of Carbonate Fuel Cell Matrix and Electrolyte" Proceedings of the Second International Symposium on Molten Carbonate Fuel Cell Technology, Proceedings Volume 90-16, The Electrochemical Society, Pennington, NJ, pp. 121-136 (1990)).

On the other hand, in the long-term operation of the molten carbonate fuel cell, there is an interruption of operation due to a planned or accidental accident and a thermal cycle that follows. During the heat cycle, not only is the phase change of carbonate to liquid-solid-liquid, but also the battery components with different coefficients of thermal expansion undergo a temperature change of up to 600 ° C or more, so that the atmosphere of the battery can be controlled Careful attention should be paid to overcooling and temperature control. In particular, in order to construct a high-performance fuel cell capable of long life, it is possible to prevent cracking of the matrix and loss of carbonate caused by phase change of carbonate, and remelted carbonate can be redistributed smoothly in the electrode and the matrix. In order to improve the strength of the matrix itself, it is necessary to minimize the cracks generated during the heat cycle.

Therefore, many studies have been conducted to strengthen the MCFC matrix for this purpose. These studies can be divided into the following two types of ceramic materials used for matrix reinforcement:

1) A method of adding spherical or plate-like large particles to a matrix, wherein γ-LiAlO ₂ or α-Al ₂ O ₃ particles having a particle size of 10 μm or more are mainly used as large particles (see CY Yuh, et al., "Advances in Carbonate Fuel Cell Matrix and Electrolyte" Proceedings of the Fourth Internatioanl Symposium of Carbonate Fuel Cell Technology, The Electrochemical Society, Pennington, NJ, pp.66-78 (1997), or Farooque and CY Yuh, USA Patent 5,580,673 (1996)). According to this method, high-strength macroparticles act as crack arresters or crack deflectors to prevent cracking in the matrix and to increase the energy required to break the matrix by lengthening the propagation path of the cracks. As a result, the matrix can be strengthened.

2) A method of adding a powder having a high aspect ratio to a matrix, wherein a rod-like β-LiAlO ₂ powder having a diameter of about 1 μm and a length of about 5 μm is used, and γ- as the matrix material. The use of α-LiAlO ₂ rather than LiAlO ₂ has been reported to be superior in matrix strengthening effects (see K. Nakagawa, H. Ohzu, Y. Akasaka, and N. Tomimatsu, “Durable MCFC Electrolyte Plate Consisting of α). and β-LiAlO ₂ , "Denki Kagaku, 64 (6), 478-481 (1996)).

However, these conventional methods only provide a limited effect. That is, in the case of adding the macroparticles, there is a problem in dispersibility when preparing the slurry, and there is a disadvantage that the porosity is lowered when preparing the slurry together with the powder having a small particle size. In addition, large pores are formed due to the large particles, and the electrolyte impregnation in the matrix is incomplete, resulting in cross-over of fuel gas.

Accordingly, an object of the present invention is to produce a ceramic fiber reinforced matrix capable of suppressing the occurrence of cracking of the matrix due to thermal cycles and the deterioration of battery performance, which may occur during long-term operation of the molten carbonate fuel cell. One way is to provide it.

The object of the present invention is

a) mixing and ball milling LiAlO ₂ powder, a dispersant, an antifoaming agent and a solvent to prepare a slurry,

b) adding, mixing and ball milling a binder, a plasticizer and a ceramic fiber to the prepared slurry,

c) degassing the slurry of step b), and

d) forming the degassed slurry by tape casting followed by drying

It can be achieved by a method for producing a matrix for molten carbonate fuel cell comprising a.

1 is a process diagram of a method of manufacturing a ceramic fiber reinforced matrix of the present invention.

2 is a scanning electron micrograph of a cross section of a fiber reinforced matrix prepared by the conventional matrix and the method of the present invention.

Figure 3 is a graph showing the cooling and temperature increase rate for the unit cell heat shock cycle experiment.

Figure 4 is a graph showing the unit cell performance according to the heat cycle and operating time of the conventional matrix and the fiber reinforced matrix prepared by the method of the present invention.

5 is a process chart of a method of coating LiAlO ₂ on the α-Al ₂ O ₃ fiber surface.

6 is a graph showing zeta potential according to pH of α-Al ₂ O ₃ and boehmite.

The molten carbonate fuel cell matrix according to the present invention is prepared by adding ceramic fibers to a conventional matrix material based on LiAlO ₂ to prepare a slurry, and then molding the green sheet using a tape casting method.

LiAlO ₂ powder used in the present invention is generally used in the fuel cell matrix in the art, it may be in the α-, β-, γ- form.

As the ceramic fiber that can be used in the present invention, fibers of various materials having various lengths and diameters can be used. For example, α-Al ₂ O ₃ , γ-LiAlO ₂ , β-LiAlO ₂ , α-LiAlO ₂ , Li ₂ ZrO ₃ , yttria stabilized ZrO ₂ , LiTaO ₃ , LiNbO ₃ , CeO ₂ , and the like. However, the present invention is not limited thereto. In consideration of the large area and reproducibility of the matrix, short fibers of the α-Al ₂ O ₃ family are preferred.

In addition, as a preferred embodiment of the present invention, it may be desirable to coat with a specific component before adding the ceramic fiber in order to prevent the composition or shape deformation of the ceramic fiber. For example, when Al ₂ O ₃ fibers are used for matrix reinforcement of molten carbonate fuel cells, Li ₂ CO ₃ in carbonate reacts with Al ₂ O ₃ to produce LiAlO ₂ , which reduces electrolytes and changes in composition and fiber shape. The deformation can reduce the strengthening effect. Therefore, a matrix that is stable to molten carbonate and used as a matrix particle is coated on Al ₂ O ₃ fibers by a sol-gel method, and thus, a matrix having excellent reinforcing effect can be produced while maintaining a unique fiber shape for a long time. Such coating components include LiAlO ₂ , Li ₂ ZrO ₃ , yttria stabilized ZrO ₂ , LiTaO ₃ , LiNbO ₃ and CeO ₂ , which may be used as the matrix component.

Hereinafter, a method of manufacturing a matrix for a molten carbonate fuel cell according to the present invention will be described in detail with reference to FIG. 1 of the accompanying drawings.

First, a high surface area (HSA) LiAlO ₂ powder is mixed with a solvent, a dispersant and an antifoaming agent and the mixture is first ball milled. Thereafter, a binder, a plasticizer, a low surface area (LSA, LiAlO ₂ powder) and ceramic fibers are added to the secondary ball mill to prepare a slurry. The prepared slurry was removed by using a rotary evaporator to simultaneously control the viscosity of the slurry between 15,000 and 20,000 cP, and then formed into a sheet having a constant thickness and width in a tape molding machine, followed by drying to prepare a green sheet for the matrix. do.

The high surface area LiAlO ₂ powder used in the present invention corresponds to a powder having a small particle diameter, and the low surface area powder corresponds to a powder having a large particle diameter. In general, low surface area powders have been used in conventional matrix strengthening methods. The pore size and porosity of the matrix can be determined by controlling the composition ratio of these high surface area powders and low surface area powders, thereby determining the degree of electrolyte impregnation and the degree of gas mixing. In other words, when a large amount of the large powder (low surface area powder) is added, not only the strength is lowered but also the pore size becomes large so that the electrolyte cannot be sufficiently supported.

In the above process, it is preferable to use short fibers of generally 10 μm to 3 mm, preferably about 1 mm in length, for the ceramic fibers to have a uniform distribution in the matrix and to prevent macropore formation.

In addition, by adding LiAlO ₂ powder having a low surface area, it is possible to suppress the occurrence of microcracks in the matrix due to melting of the electrolyte and to obtain a suitable pore size and porosity of the matrix for MCFC.

As a solvent of the slurry, a mixture of toluene and alcohol is used, and after the addition of organic materials such as a dispersant, an antifoaming agent, a plasticizer, and a binder, a ball mill can be prepared to produce a stable slurry, and the components may be specially used in the art. There is no limit. Generally, fish oil, corn oil and the like are mainly used as the dispersant, and isopropyl alcohol and 2-propanol are the most widely used antifoaming agents such as DBP as the plasticizer and PVB as the binder.

In the present invention, polyvinyl butyral as a binder, bibutyl phthalate as a plasticizer, DAPPO-348 (San Nopco Korea) as an antifoam, and Solsperse-9000 (San Nopco Korea) as a dispersant were used. As a solvent, a mixture of toluene and ethanol may be used. The composition is based on LiAlO ₂ and 100 parts by weight of ceramic fibers, 10 to 40 parts by weight of binder, 10 to 40 parts by weight of plasticizer, 1 to 5 parts by weight of antifoaming agent, 1 to 2 parts by weight of dispersant and 150 to solvent. 250 parts by weight can be used.

In order to produce a constant and uniform thickness of the matrix green sheet during the tape casting in the process, it is preferable to remove the bubbles in the slurry and to adjust the viscosity at the same time. The viscosity of the slurry is preferably in the range of 15,000 to 20,000 cP.

The objects and advantages of the present invention will become more apparent through the embodiments of the present invention in conjunction with the accompanying drawings.

<Example 1>

With the composition shown in Table 1 below, γ-LiAlO ₂ HSA (high surface area) powder was placed in a ball mill and a solvent, a dispersant and an antifoaming agent were added. The mixture was ball milled at a speed of 100 rpm for 1 day and then ball milled again for 6 days by adding a binder, a plasticizer, γ-LiAlO ₂ LSA powder, and α-Al ₂ O ₃ fibers. The short fibers for preparing the ceramic fiber reinforced matrix were compared using α-Al ₂ O ₃ fibers having a fiber length of 1, 3 or 10 mm. The prepared slurry was bubbled for 30 to 40 minutes using a rotary evaporator, and the viscosity of the slurry was adjusted to between 15,000 and 20,000 cP. The prepared slurry was molded into a sheet having a constant thickness and width by a tape casting device having a width of 55 cm, and dried for 4 days in a constant temperature and humidity chamber maintained at a drying temperature of 25 ° C. and a relative humidity of 45% to prepare a matrix green sheet.

Composition of Slurry for Fabrication of Fiber Reinforced Matrix Green Sheets. Kinds ingredient Weight (g) Powder γ-LiAlO ₂ HSA (2 μm) HSA: 20LSA: 30 Fiber: 10 LSA (50 μm) Ceramic fiber ALMAX fiber (α-Al ₂ O ₃ 99.9%), 10 μm in diameter; 1, 3, 10 mm cutting Binder PVB-B76 (polyvinyl butyral) 35 Plasticizer DBP (dibutyl phthalate) 30 Antifoam DAPPO-348 25 Dispersant Solsperse-9000 2 menstruum toluene 123 ethanol 52

On the surface of the manufactured matrix green sheet, cracks that may occur during drying are not generally found, and no bubbles or coarse particles were seen. In addition, the surface was not only smooth but also very flexible.

In order to compare the performance of the ceramic fiber reinforced matrix, a conventional matrix was prepared in the same manner except that no α-Al ₂ O ₃ fibers were added as a control. That is, 70 g of γ-LiAlO ₂ HSA powder was placed in a ball mill and a solvent, a dispersant, and an antifoaming agent were added. The mixture was ball milled at a speed of 100 rpm for 1 day, and then ball milled again for 6 days with the addition of a binder, a plasticizer, and 30 g of γ-LiAlO ₂ LSA powder. The composition of the solvent and organic additives and the specific tape casting process were carried out under the same conditions as when the fibers were added.

After heat-treating the matrix green sheet at the actual battery operating temperature of 650 ° C, the pore size and porosity were measured by mercury porosimetry. It was present in the range of -0.30 ㎛ and porosity was in the range of 55 to 60% to confirm that a matrix having a pore property suitable for MCFC was prepared.

Figure 2 is a photograph taken of the fracture surface with a scanning electron microscope after removing all the organic additives by heat-treating the conventional matrix and the fiber-reinforced matrix green sheet of the present invention at 650 ℃. When 3 or 10 mm long fibers were added, the fibers in the matrix were not uniformly dispersed and there was at least 1 mm of fiber in the matrix that was too long to be measured by scanning electron microscopy. I could confirm it. On the other hand, in the 1 mm fiber addition matrix, the fiber length was also less than 300 μm with less dispersion problem.

After heat treatment of the matrix at 650 ℃, the strength was analyzed by the three-point bending strength measurement method, the results are shown in Table 2 below.

Bending strength of matrix matrix Bending strength [kg _f / cm ² ] No fiber 6.5 1 mm 10.2 3 mm 13.0 10 mm 16.5

As can be seen in Table 2, the conventional matrix is only about 6.5 kg _f / cm ² but the matrix reinforced with fibers exhibits a bending strength of about 10.2 ~ 16.5 kg _f / cm ² depending on the length of the added fiber After adding ceramic fiber, the strength can be improved by 57 ~ 250%.

Analysis of the unit cell performance (initial performance) of these fiber-added matrices showed that the 1 mm fiber-added matrix showed similar performance to that of the conventional matrix with 0.83 V or more at a current density of 150 mA / cm ² , but with 3 or 10 mm fibers. The addition matrix showed low values of 0.7 V or less at the same current density. This is because, as described in FIG. 2, the longer the added fibers, the more the fibers are not uniformly dispersed in the matrix and there are locally aggregated portions, so that large pores in the matrix are more likely to be formed. In other words, at the battery operating temperature, the matrix is present as a fluidic paste with the molten carbonate electrolyte, in which the rearrangement of matrix particles (γ-LiAlO ₂ and α-Al ₂ O ₃ fibers) and carbonate results in molten carbonate. Agglomeration between small γ-LiAlO ₂ particles occurs due to the surface tension of, and large pores are generated between the fibers and the matrix particles agglomerated, so that pores that are not filled with carbonate are present. This large pore generation phenomenon is more prominent as the length of the added fiber is longer and the amount added. The fiber length in the matrix is proportional to the length of the added fiber, and the longer the length is, the less fluidity is in the carbonate-matrix paste, so it is judged that the cell performance of 3 or 10 mm fiber addition of the fibers used in the present invention is not obtained.

Therefore, cell performance over heat cycle was analyzed using a conventional matrix and a 1 mm fiber addition matrix. The configuration and operating conditions of the unit cell are shown in Table 3 below, and the heat cycle (cooling and reheating) conditions were performed as shown in FIG. 3. That is, after cooling to 300 ° C at a rate of 0.5 ° C / min at an operating temperature of 650 ° C and maintained at that temperature for 1 hour. At the time of re-heating, the temperature of 0.5 ℃ / min up to 450 ℃ and 0.17 ℃ / min up to 550 ℃ was raised to 0.33 ℃ / min up to 650 ℃, which was the final battery operating temperature. Was repeated 20 times. The gas of the same composition as shown in Table 3 was supplied also at the time of cooling and reheating.

Unit Battery Configuration and Operation Conditions Anode Ni-10% Cr matrix Γ-LiAlO ₂ with fiber or γ-LiAlO ₂ without fiber Cathode NiO Electrolyte _{70 Li 2 CO 3/30 K} 2 CO 3 fuel 72% H ₂ /18% H ₂ /10% H ₂ O Oxidant 70% Air / 30% CO ₂ Temperature 650 ℃

Figure 4 shows the change in battery performance according to the heat cycle of the 1 mm fiber addition matrix and the conventional matrix prepared in the present invention. The cell performance difference between the conventional matrix and the matrix prepared by the present invention up to 20 heat cycles was not found, but the nitrogen concentration in the anode (anode) outlet gas, which is a measure of reaction gas mixing due to matrix cracking, was found to be the case of the fiber-added matrix. It can be seen that is lower. In addition, as a result of continuous operation at 650 ° C. after 20 heat cycles, the normal matrix showed a sharp decrease in performance after 600 hours, but the initial performance was maintained for 1500 hours or longer in the fiber-added matrix.

The reason for the long term operation of the cell equipped with the fiber-added matrix under the same operating conditions is that the reaction gas mixture is smaller than that of the conventional matrix, so that the performance deterioration due to oxidation of the electrode, especially the anode, can be suppressed. Rather, it is believed that the amount of electrolyte support is high due to the small cracks in the matrix. Therefore, it was possible to produce a high-strength matrix that meets the object of the present invention, i.e., a matrix having lower mechanical performance as well as a decrease in battery performance due to thermal cycles as compared with a conventional matrix.

<Example 2>

Γ-LiAlO ₂ , β-LiAlO ₂ , α-LiAlO ₂ , Li ₂ ZrO ₃ , yttria stabilized ZrO ₂ , LiTaO ₃ , LiNbO ₃ and CeO _{2 in} addition to the α-Al ₂ O ₃ ceramic fibers used in Example 1 The same method as in Example 1 was carried out except that ceramic fibers such as and the like were used. As a result, strength and performance similar to those in Example 1 in which α-Al ₂ O ₃ ceramic fibers were added were obtained.

<Example 3>

For the production of a fuel cell matrix was, and performs the same operation as in Example 1 except that the α-Al ₂ O ₃ coating on the surface of a LiAlO ₂ 1mm in length on the surface of the .α-Al ₂ O ₃ The process of coating LiAlO ₂ is shown in FIG. 5. Coating solos are 0.05M concentrations of boehmite (BE Yoldas, "Alumina Sol Preparation from Alkoxides" Am. Ceram, Soc. Bull, 54 (3), 289-290 (1975)). LiOO ₃ ) was dissolved in LiNO ₃ sol, and the Li / Al molar ratio was fixed at 1.2 in consideration of the evaporation of Li during heat treatment after coating. After the addition of the salt, the pH of the coating sol was adjusted to 4-5 by adding 1M aqueous HNO ₃ solution. As can be seen in FIG. 6, which shows zeta potential according to pH of α-Al ₂ O ₃ and boehmite, the isoelectric point of pure α-Al ₂ O ₃ is about 6, whereas the boehmite sol particles The isoelectric point of is about 9 and the pH of the sol should be in the range of 6-9 to achieve the coating by electrostatic attraction. However, it is impossible to prepare a stable boehmite sol in the range of pH 6-9, so that the surface charge of α-Al ₂ O ₃ is negative in the range of pH 4-5 where the boehmite sol is most stable. α-Al ₂ O ₃ surface was treated. That is, in the pH range of 4 to 5 of the coating sol, since the surface charge of pure α-Al ₂ O ₃ , like the sol particles and Li ⁺ ions, also has a positive value, the coating itself becomes difficult due to electrostatic repulsive force. However, in the process shown in FIG. 5, surface treatment of α-Al ₂ O ₃ with a polyelectrolyte aqueous solution changes the surface charge of α-Al ₂ O ₃ to a negative value, which causes sol particles and Li ⁺ Surface coating of ions is possible. Therefore, the fiber was immersed in an aqueous solution of ammonium polymethacrylate 1% for 10 minutes, taken out, dried at 100 ° C. for 30 minutes, and subjected to surface treatment. The surface treated fibers were coated in a mixed sol for 10 minutes and then dried at 100 ° C. for 1 hour, and this surface treatment-coating process was repeated twice. The coated fibers were heat-treated at 800 ° C. for 2 hours to prepare α-Al ₂ O ₃ fibers coated with final LiAlO ₂ .

The performance of the cell was analyzed after the matrix green sheet was prepared by the same tape casting process as in Example 1 using the prepared Al-Al ₂ O ₃ fibers coated with LiAlO ₂ . As a result, almost the same battery initial performance and heat cycle characteristics as those of 1 mm fiber addition of Example 1 were obtained. Therefore, as in Example 1, it was confirmed that the α-Al ₂ O ₃ fiber-added matrix coated with LiAlO ₂ of this example also had excellent mechanical strength and reduced battery performance due to heat cycle. Particularly, since LiAlO _{2, which} is chemically stable to molten carbonate, is coated on the surface, the reinforcing effect can be maintained for a longer time than when reinforced with pure α-Al ₂ O ₃ fibers of Example 1, and the reaction between the fiber and the electrolyte It is thought that stable long-term performance of MCFC can be expected since electrolyte consumption can be avoided.

In addition, since the sol-gel coating method used for the α-Al ₂ O ₃ fiber coating in the present embodiment is a liquid coating process, it is possible to continuously apply a large amount of coating at room temperature and atmospheric pressure, and the process is very simple, which requires no expensive equipment. The field is also large.

<Example 4>

As a coating material, Li ₂ ZrO ₃ , yttria stabilized ZrO ₂ , LiTaO ₃ , LiNbO ₃ , CeO ₂ , and the like, in addition to LiAlO ₂ used in Example 3, resulted in similar results as in Example 3.

In order to reinforce the matrix for a conventional molten carbonate fuel cell, the present invention is a slurry for producing a matrix green sheet of α-Al ₂ O ₃ monofilament coated with pure α-Al ₂ O ₃ monofilament or LiAlO ₂ . By adding to the manufacturing process, it is possible to produce a matrix for MCFC that has a higher strength than a normal matrix and has an excellent effect of suppressing the mixing of the reaction gas due to matrix crack generation after a heat cycle.

Claims (9)

a) preparing a slurry by mixing and ball milling LiAlO ₂ powder, a dispersant, an antifoaming agent and a solvent, which is a mixture of high surface area LiAlO ₂ having a diameter of 5 μm or less and low surface area LiAlO ₂ having a diameter of 10 μm or more, b) adding and mixing a binder, a plasticizer, and ceramic fibers having a diameter of 0.3 to 30 µm and a length of 10 µm to 3 mm or less to the slurry thus prepared, and ball milling, c) degassing the slurry of step b), and d) forming the degassed slurry by tape casting followed by drying Including; Here, the content of the low surface area LiAlO ₂ is 10 to 30 parts by weight based on a total of 100 parts by weight of the LiAlO ₂ mixed powder and the ceramic fiber, the ceramic fiber is a total of 100 weight of the LiAlO ₂ mixed powder and the ceramic fiber 5 to 20 parts by weight based on parts and used α-Al ₂ O ₃ , γ-LiAlO ₂ , β-LiAlO ₂ , α-LiAlO ₂ , Li ₂ ZrO ₃ , yttria stabilized ZrO ₂ , LiTaO ₃ , LiNbO ₃ and A method for producing a matrix for molten carbonate fuel cells, which is selected from the group consisting of CeO ₂ . The method of claim 1, wherein the LiAlO ₂ powder is selected from the group consisting of γ-LiAlO ₂ , β-LiAlO ₂ and α-Al ₂ O ₃ . delete delete delete According to claim 1, 10 to 40 parts by weight of the binder, 10 to 40 parts by weight of plasticizer, 1 to 5 parts by weight of antifoaming agent, 1 to 2 parts by weight of dispersant, and 150 to 250 parts by weight of solvent based on 100 parts by weight of powder and fiber The method used additionally. The method of claim 1, wherein the surface is coated with a component selected from LiAlO ₂ , Li ₂ ZrO ₃ , yttria stabilized ZrO ₂ , LiTaO ₃ , LiNbO _3, and CeO ₂ before adding the ceramic fiber. 8. The method of claim 7, wherein the ceramic fiber surface is coated after being treated with a composite electrolyte such as ammonium polymethacrylate. A matrix for a molten carbonate fuel cell prepared according to the method according to any one of claims 1, 2 and 6 to 8.