KR100958514B1 - Manufacturing method of solid oxide fuel cell - Google Patents

Abstract

Disclosed is a method of manufacturing a solid oxide fuel cell in a cathode support type capable of forming an electrolyte by tape casting using nano-sized Yttria Stabilized ZrO ₂ (YSZ) powder. In the solid oxide fuel cell, the process of manufacturing the solid oxide fuel cell can be simplified by two sintering processes by simultaneously firing the anode and the electrolyte using tape casting and forming the cathode using screen printing. Therefore, the surface area of the electrolyte is increased by forming an electrolyte using nano-sized YSZ powder, and when the electrolyte is formed by tape casting, an increase in interfacial resistance due to a decrease in contact area between the electrolyte, the fuel electrode and the air electrode is suppressed. can do. In addition, by reducing the output performance of the solid oxide fuel cell due to the electrolyte, it is possible to simultaneously fire the electrolyte and the anode using tape casting, thereby simplifying the manufacturing process of the solid oxide fuel cell and reducing manufacturing cost and time. do.

Solid Oxide Fuel Cell, SOFC, Nano Yttria Stabilized ZIRCONIA (YSZ) Powder, Tape Casting

Description

Manufacturing Method of Solid Oxide Fuel Cell {MANUFACTURING METHOD OF SOLID OXIDE FUEL CELL}

The present invention relates to a method for manufacturing a solid oxide fuel cell, and more particularly, to a method for manufacturing a solid oxide fuel cell using nano-sized Yttria Stabilized ZrO ₂ (hereinafter, referred to as YSZ) powder. .

Fuel cell types include molten carbonate fuel cells (MCFCs), solid oxide fuel cells (SOFCs) operating at high temperatures, phosphoric acid fuel cells (AFCs) operating at relatively low temperatures, polyelectrolyte fuel cells (PEMFCs), and direct methanol fuels. Batteries (DEMFC) and the like.

A solid oxide fuel cell (SOFC) is an energy conversion device that produces direct current electricity by electrochemically reacting an oxidant (eg oxygen) and a gaseous fuel (eg hydrogen) through an oxide electrolyte. . Key features of current solid oxide fuel cell techniques include solid-state structure, adaptability of multiple fuels, and high temperature operability. Due to the characteristics of such a solid oxide fuel cell, a solid oxide fuel cell has the potential to be a high performance, clean and efficient power source, has been developed for various power generation applications.

A solid oxide fuel cell is formed by stacking unit cells composed of an anode, an electrolyte, and a cathode in series. Here, the stack of each unit cell is an electrical connection between a fuel electrode of one unit cell and an air electrode of a unit cell arranged next, and a separator is formed between each unit cell.

The solid oxide fuel cell unit cell is a ceramic multilayer structure composed of an oxide electrolyte interposed between the anode and the cathode. A typical solid unit cells of oxide fuel cells, is used and the yttria-stabilized zirconia (Yttria Stabilized ZrO _2, YSZ) as the electrolyte, an air electrode as is, for strontium manganite doped lanthanum nitro (LSM) (for example, La _0.8 Sr _0.2 MnO ₃ ) is used, and as a fuel electrode, cermaet (NiO / YSZ) in which nickel oxide (NiO) and yttria stabilized zirconia are mixed is used.

The unit cell of the conventional anode-supported solid oxide fuel cell cannot simultaneously fire the cathode and the electrolyte due to the difference in thermal expansion of the materials forming the cathode and the electrolyte. Therefore, in general, a unit cell of a solid oxide fuel cell sinters a fuel electrode, an electrolyte, and an air electrode, or first sinters a fuel electrode serving as a support, then sinters by coating an electrolyte on the fuel electrode, and finally, sinters by applying an air electrode. Is prepared.

Since the anode, the electrolyte, and the cathode must be sintered separately, the manufacturing process of the unit cell is not only complicated, and it is difficult to continuously perform the manufacturing process, which requires a lot of time and manpower when manufacturing the unit cell. This increases the manufacturing cost of the unit cell, which becomes a more serious problem as the size and output of the unit cell increases.

Recently, various studies have been conducted to shorten the multi-step sintering process. In particular, when manufacturing the anode using tape casting, the anode and the electrolyte may be fired at the same time, but due to the bending, two or more baking processes are required. In addition, when the fuel electrode, the electrolyte and the air electrode are laminated at the same time and fired simultaneously, there is a problem in that the output is reduced by 25% or more compared with the conventional one and thus cannot be used.

On the other hand, a method of producing a cathode support-type solid oxide fuel cell is disclosed relatively simply by manufacturing an anode and an electrolyte using a tape casting method and firing at the same time. However, this method has a problem in that the solid oxide fuel cell can be manufactured relatively simply, but the output performance of the unit cell is lowered.

Specifically, the electrolyte sheet formed by the tape casting is stressed in the longitudinal direction to reduce the contact area between the electrolyte and the fuel electrode and the air electrode, thereby reducing the contact between the electrolyte, the fuel electrode and the air electrode The interlayer interface resistance is increased. Therefore, due to such an increase in interfacial resistance, the movement of ions at the interface between the electrolyte, the anode and the cathode is not smooth, which degrades the performance of the solid oxide fuel cell.

For this reason, development of a solid oxide fuel cell such as a tape casting process requires development of a raw material that does not increase interfacial resistance, in particular, YSZ powder constituting the electrolyte.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and to provide a method for producing a powder of yttria stabilized zirconia (YSZ) for reducing the interfacial interface resistance between the anode, the cathode and the electrolyte in a solid oxide fuel cell. will be.

In addition, the present invention is to provide a method for forming an electrolyte for a solid oxide fuel cell using the yttria stabilized zirconia powder prepared by the above method.

In addition, the present invention is to provide a method for producing a solid oxide fuel cell that can be simplified by using the electrolyte prepared by the above method, there is no performance degradation, and can simplify the manufacturing process.

According to embodiments of the present invention for achieving the above object of the present invention, the yttria stabilized zirconia powder forming method for producing an electrolyte for a solid oxide fuel cell is formed in nano size using the coprecipitation method. That is, the yttria stabilized zirconia powder formation method mixes zirconium oxychloride (ZrOCl ₂ ) and yttrium chloride anhydride (YCl ₃ ) in distilled water. Then, the first mixed solution precipitant mixed as described above is added to and mixed to generate a precipitation reaction. The precipitate is filtered to recover the precipitate from the second mixture formed with the precipitate. The filtration step recovers the precipitate from the second mixed liquid using a filter paper. Then, the recovered precipitate is heated to a predetermined temperature and dried. Finally, the dried precipitate may be heat treated to obtain yttria stabilized zirconia (Yttria Stabilized ZrO ₂ , YSZ) powder.

In an embodiment, the YSZ powder finally obtained has a diameter of 10 to 30 nm and a surface area of 10 to 30 cm 2 / g.

In an embodiment, the precipitant uses ammonium hydroxide (NH ₄ OH) or sodium hydroxide (NaOH).

In an embodiment, the precipitate is heated to a temperature of 100 to 120 ° C. and dried, and the dried precipitate is heat treated at a temperature of 550 to 950 ° C.

On the other hand, according to other embodiments of the present invention for achieving the above object of the present invention, the method for producing an electrolyte for a solid oxide fuel cell, nano-sized Yttria Stabilized ZrO ₂ (YSZ) powder It is formed by using the tape casting method. Here, the YSZ powder is formed by a coprecipitation method, the electrolyte is a slurry formed by the YSZ powder, and the slurry is formed by using a tape casting equipment, and then the sheets are laminated to form an electrolyte.

In an embodiment, the YSZ powder has a diameter of 10 to 30 nm and a surface area of 10 to 30 cm 2 / g to increase the surface area of the electrolyte.

In an embodiment, in order to form the electrolyte, the sheet is formed to a thickness of 5 to 15 µm, and a plurality of sheets are stacked to form an electrolyte having a thickness of 5 to 30 µm.

On the other hand, according to another embodiment of the present invention for achieving the above object of the present invention, the method for manufacturing a solid oxide fuel cell, by firing the anode and the electrolyte at the same time using a tape casting, using screen printing By forming the cathode, the manufacturing process of the solid oxide fuel cell is simplified by two sintering.

Specifically, the electrolyte is formed of nano-sized YSZ powder formed by coprecipitation. The electrolyte is laminated on the fuel electrode by tape casting using the YSZ powder to form a first laminate. The lamination process and the calcination process are sequentially performed on the first laminate, and the first laminate is sintered at a predetermined temperature to form a first preliminary fuel cell. Next, the cathode is screen printed on the electrolyte in the first preliminary fuel cell. As described above, the second laminate formed by stacking the fuel electrode, the electrolyte, and the air electrode is subjected to a lamination process and a calcining process, and is then sintered at a predetermined temperature to form a solid oxide fuel cell.

In an embodiment, the electrolyte forms nano-sized YSZ powder by coprecipitation. Next, a slurry is formed of the YSZ powder, and a sheet is formed by using a tape casting equipment. Next, the sheet is laminated on the fuel electrode to form the electrolyte.

In an embodiment, the first preliminary fuel cell is formed by calcining the first laminate at a first temperature and then sintering at a second temperature. For example, the first laminate is calcined at a temperature of 950-1050 ° C. The first laminate is sintered at a temperature of 1250 to 1450 ° C. Here, the first preliminary fuel cell is pressurized to 30 to 45 kgf / cm 2 and sintered.

In an embodiment, the solid oxide fuel cell is formed by calcining the second laminate at a third temperature and then sintering at a fourth temperature. For example, the second laminate is calcined at a temperature of 950-1050 ° C. And, the second laminate is sintered at a temperature of 1050 to 1200 ℃. Here, the solid oxide fuel cell is pressurized to 30 to 45 kgf / ㎠ sintered.

In an embodiment, the first stack and the second stack are laminated under the same conditions. For example, the first laminate and the second laminate are heated to a temperature of 70 to 90 ° C. and pressurized with a force of 150 to 250 kgf / cm 2.

In an embodiment, the anode is formed as a NiO / YSZ cermet in which nickel oxide (NiO) and YSZ are mixed, and NiO and YSZ are mixed in a weight ratio of 50:50 to 60:40. The cathode is formed as an LSM / YSZ cermet in which manganese-based brobrosite (LSM) and YSZ are mixed, and the LSM and YSZ are mixed in a weight ratio of 50:50 to 60:40.

According to the present invention, first, nano-sized yttria stabilized zirconia (YSZ) powder can be prepared by coprecipitation.

Second, by forming an electrolyte using nano-sized YSZ powder, the surface area of the electrolyte is increased. In addition, such an increase in the surface area of the electrolyte increases the contact area between the electrolyte, the anode, and the cathode, thereby reducing the interface resistance between the electrolyte, the anode, and the cathode. Therefore, the output performance of the solid oxide fuel cell can be improved.

Third, since the increase in the interfacial resistance between the electrolyte, the fuel electrode, and the air electrode is suppressed, the electrolyte can be manufactured in particular by using a tape casting method. In addition, the anode and the electrolyte may be manufactured and baked at the same time by using a tape casting method, and the number of manufacturing processes may be reduced.

Fourth, since the anode and the electrolyte are sintered at the same time, and the cathode can be manufactured by the screen printing method on the electrolyte, the solid oxide fuel cell can be manufactured in two steps. Therefore, the manufacturing process of the solid oxide fuel cell can be simplified and the number of processes can be reduced, and the time and cost required for the manufacturing process can be reduced.

As described above, although described with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

Although the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, the present invention is not limited or restricted by the embodiments.

1 is a cross-sectional view for explaining the structure of a solid oxide fuel cell according to one embodiment of the present invention.

Hereinafter, a method of manufacturing a solid oxide fuel cell according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 5E.

For reference, the solid oxide fuel cell is formed by stacking (stacking, stacking) a unit cell composed of an anode, an electrolyte, and a cathode, and in the present embodiment, a solid oxide fuel cell. Battery means the unit cell as described above.

Referring to FIG. 1, the solid oxide fuel cell 10 has a flat plate shape in which a fuel electrode 11, an electrolyte 12, and an air electrode 13 are sequentially stacked.

Here, the anode 11 serves as a mechanical support structure of the solid oxide fuel cell 10 and includes the anode support layer 11a and the anode reaction layer 11b.

For example, the anode 11 is formed of a cermet (NiO / YSZ) in which yttria stabilized zirconia (Yttria Stabilized ZrO ₂ , YSZ) and nickel oxide (NiO) are mixed.

The electrolyte 12 is formed of the YSZ.

The air electrode 13 is formed from a strontium-doped lanthanum manganite (the one hereinafter referred to as LSM) (for _{example, La 0 .8 Sr 0 .2 MnO} 3) and YSZ are mixed cermets (LSM / YSZ) do.

Meanwhile, the anode 11 and the electrolyte 12 are formed by a tape casting method. In addition, the cathode 13 is formed on the electrolyte 12 by a screen printing method.

2 is a diagram illustrating a main part of a tape casting device 100 for manufacturing the solid oxide fuel cell 10.

Referring to FIG. 2, the tape casting apparatus 100 includes a hopper 103 in which the slurry 210 is accommodated, and a carrier film 105 and a roller 107 for flowing the slurry 210. And a blade 101 for adjusting the thickness of the slurry 210.

In order to form the fuel electrode 11 and the electrolyte 12, powders 211 and 212, a binder, a plasticizer, and a dispersant of the composition materials constituting the fuel electrode 11 and the electrolyte 12 are formed. And an additive 213 such as solvent to form a slurry 210 for the electrodes 11, 12, 13. In addition, the slurry 210 is introduced into the tape casting apparatus 100 to form a sheet 220 having a predetermined thickness.

In the tape casting apparatus 100, as the carrier film 105 moves in one direction by the roller 107, the slurry 210 is attached to a predetermined thickness on the carrier film 105, and the sheet 220 is formed. ) Is formed. In particular, the thickness of the sheet 220 is determined by the distance between the blade 101 and the carrier film 105 and the moving speed of the carrier film 105.

The fuel electrode 11 and the electrolyte 12 are formed by stacking a plurality of green sheets 210 formed as described above, and the fuel electrode 11 and the electrolyte 12 as described above. This sequentially laminated laminate is sintered at a predetermined temperature.

In addition, the cathode 13 having a predetermined thickness is formed by screen printing the composition material of the cathode 13 on the electrolyte 12.

Finally, the laminate stacked as above is sintered at a predetermined temperature to form a solid oxide fuel cell.

On the other hand, when manufacturing the electrolyte 12 by the tape casting method as described above, by reducing the particle size of the YSZ powder, the resistance at the interface between the electrolyte 12, the fuel electrode 11 and the air electrode 13 This increase can be effectively prevented.

In particular, the YSZ powder has a diameter of 10 to 30nm, the surface area of 10 to 30 cm 2 / g is prepared.

Figure 3 is a flow chart illustrating a method for producing yttria stabilized zirconia (YSZ) powder according to an embodiment of the present invention.

Hereinafter, a method of manufacturing YSZ powder according to an embodiment of the present invention will be described. In the present invention, the YSZ powder is prepared using a co-precipitation method.

First, zirconium oxychloride (ZrOCl ₂ ) and yttrium anhydride (YCl ₃ ), which are raw materials for the YSZ powder, are mixed with distilled water (hereinafter referred to as a first mixed solution) (S11).

Here, the first mixed solution is a mixture of 92% zirconium oxychloride (ZrOCl ₂ ) and 2% yttrium anhydride (YCl ₃ ) in distilled water of the quantitative, the zirconium oxychloride (ZrOCl ₂ ) and the yttrium chloride anhydride (YCl ₃ A) to mix well.

Next, a precipitant is added to form a precipitate in the first mixed solution (S12).

When a precipitant is added to the first mixed solution, YSZ is co-precipitated in the first mixed solution due to the interaction between the zirconium oxychloride (ZrOCl ₂ ), the yttrium anhydride (YCl ₃ ) and the precipitant.

For example, the precipitant may be ammonium hydroxide (NH ₄ OH) or sodium hydroxide (NaOH). Here, ammonium hydroxide (NH ₄ OH) is prepared by diluting five times in distilled water, and sodium hydroxide (NaOH) is prepared in a 1 mol% solution. Then, ammonium hydroxide (NH ₄ OH) and sodium hydroxide (NaOH) prepared as described above are added to the first mixture, and a precipitate is formed in the first mixture while stirring.

Next, the precipitate is recovered from the second mixed liquid in which the precipitate is formed as described above (S13). In this example, a filtration method was used to recover the precipitate.

Specifically, the precipitate is filtered by passing the second mixed liquid through the filter paper. Then, distilled water is added to the container containing the precipitate about 5 to 6 times to clean the container.

Here, the cleaning level of the vessel is a cleaning solution is put into the silver chloride (AgCl) precipitation reaction by adding a small amount of silver nitrate solution (AgNO ₃ ) solution to the sample collected through the filter paper Shall be completed.

Next, the precipitate recovered as above is dried (S14).

For example, the precipitate is dried at 100 to 120 ° C. for about 6 hours.

Next, the dried precipitate is heated to a predetermined temperature (S15).

Here, the heat treatment step (S15) of the precipitate as a step for checking the physical properties of the precipitated YSZ, by performing a heat treatment for about 2 hours at a temperature of 550 to 950 ℃, to obtain the YSZ powder (S16).

The YSZ powder obtained by performing the co-precipitation method as described above can obtain a powder of fine particles having a particle diameter of 10 to 30 nm and a surface area of 10 to 30 cm 2 / g.

On the other hand, using the nano-sized YSZ powder obtained as described above to form an electrolyte. Here, since the particles of the YSZ powder is fine, the electrolyte 12 formed using the YSZ powder has an effect that the surface area thereof is increased. In addition, an increase in the surface area of the electrolyte 12 increases the contact area between the electrolyte 12, the anode 11, and the cathode 13, which is the electrolyte 12, the anode 11, and the cavity. By reducing the resistance at the interface of the cathode 13, the output performance of the solid oxide fuel cell is improved.

4 is a flowchart illustrating a method of manufacturing the solid oxide fuel cell of FIG. 1, and FIGS. 5A to 5E are cross-sectional views illustrating each step of the method of manufacturing the solid oxide fuel cell of FIG. 4.

Hereinafter, a method of manufacturing the electrolyte 12 and the solid oxide fuel cell 10 using the YSZ powder formed as described above with reference to FIGS. 4 to 5E will be described in detail.

First, the fuel electrode 11 serving as the support of the solid oxide fuel cell 10 is formed.

Here, the anode 11 is formed of the anode support layer 11a and the anode reaction layer 11b, and after forming the anode support layer 11a having a predetermined thickness (S21), the anode support layer 11a is formed on the anode support layer 11a. A thickness of the anode reaction layer 11b is formed (S22).

The anode support layer 11a and the anode reaction layer 11b are both made of NiO and YSZ, have the same composition, and are formed by tape casting.

Specifically, in order to form the anode support layer 11a, NiO and YSZ, a solvent, a binder, a plasticizer, a dispersant, and the like are mixed to form a first slurry.

Here, the first slurry is mixed NiO and YSZ in a weight ratio of 50:50 to 60:40.

Then, the first slurry is formed using a tape casting apparatus to form a plurality of first sheets 111.

Here, the first sheet 111 is formed to a thickness of 30 to 40 ㎛. The anode support layer 11a has a thickness of 1 to 2 mm. That is, the anode support layer 11a is formed by stacking 40 to 60 first sheets 111.

Next, the anode reaction layer 11b is formed using a tape casting method (S22). Here, the anode reaction layer 11b is formed using the same slurry as the anode support layer 11a.

That is, the anode reaction layer 11b is formed using the first slurry, and unlike the first sheet 111, the second sheet 112 having a thickness of 10 μm to 20 μm is formed.

The anode reaction layer 11b is formed to a thickness of 10 to 50 μm, and one to five sheets of the second sheet 112 are stacked on the anode support layer 11a to form the anode reaction layer 11b. ).

Next, an electrolyte 12 is formed on the anode reaction layer 11b (S23).

Here, the electrolyte 12 is formed using the nano-size YSZ formed as described above.

Specifically, a solvent, a binder, a plasticizer, a dispersant, and the like are mixed with the YSZ powder to form a second slurry. In addition, the second slurry is formed using a tape casting apparatus to form a third sheet 121 having a thickness of 5 to 15 μm.

The first laminate 21 is formed by stacking one to six sheets of the third sheet 121 on the anode reaction layer 11b to form the electrolyte 12 having a thickness of 5 to 30 μm. To form.

Next, the first laminate 21 is laminated (S24).

Here, the lamination step (S24) is a step of pressing the first laminate 21 at a temperature of approximately 70 to 90 ℃ with a force of 150 to 250 kgf / ㎠ for a predetermined time. Preferably, the lamination process S24 presses the first laminate 21 for 30 minutes at a force of 200 kgf / cm 2 at 80 ° C.

When the lamination process S24 is completed, the first laminate 21 is calcined (S25).

In the calcination step (S25), in the tape casting process of the fuel electrode 11 and the electrolyte 12, the components such as solvent, binder, plasticizer and dispersant mixed in the step of forming each slurry are volatilized at a predetermined temperature. Process to remove it.

In detail, in the calcination step, the volatile component contained in the first laminate 21 is volatilized and removed by heating the first laminate 21 to a predetermined temperature. For example, the calcination step S25 heats the first laminate 21 to a temperature of 950 to 1050 ° C. Preferably, the calcination step (S25) is to heat the first laminate 21 to 1000 ℃ to maintain about 3 hours and to maintain at room temperature.

On the other hand, in the calcination step (S25) when the calcination temperature is lower than 1000 ℃ sintering efficiency is lowered, the breakage after sintering of the solid oxide fuel cell easily occurs. When the calcining temperature is higher than 1000 ° C., warpage occurs in the first laminate 21 in the calcining process, and appearance defects of the final sintered solid oxide fuel cell are generated.

Next, the first preliminary fuel cell is formed by heating the sintered first laminate 21 to a predetermined temperature and sintering it (S26).

For example, the first preliminary fuel cell is sintered by heating the first laminate 21 to 1200 to 1500 ° C. Preferably, the first preliminary fuel cell is sintered at 1350 ° C.

On the other hand, when performing the sintering step (S26) it is heated and sintered while applying a predetermined force to the first laminate (21). For example, by arranging a predetermined pressing body 120 having a predetermined size and weight on the first laminated body 21, the first laminated body 21 is pressurized and heated to the sintering temperature described above. . Here, the first laminate 21 is pressed with a force of 35 to 40 kgf / cm 2.

Here, the press body 120 for sintering the first preliminary fuel cell chemically reacts with or sinters the first stack 21, that is, the electrolyte 12 and the fuel electrode 11 in the sintering process. It is preferable that the pressure body 120 is formed of a material that does not physically chemically deform at a temperature. For example, the press body 120 corresponds to the first laminate 21 and has a flat plate shape or a block shape, and is formed of zirconia ceramic.

In addition, in the sintering step S26, the first preliminary fuel cell may be satisfactorily formed after sintering by pressing and sintering the first laminate 21 by using the press body 120.

Next, the cathode 13 is formed on the electrolyte 12 in the first preliminary fuel cell formed as described above (S31).

Here, the cathode 13 is formed on the electrolyte 12 by a screen printing method.

In detail, the air electrode 13 is a cermet in which LSM and YSZ are mixed, and are mixed in a weight ratio of LSM and YSZ 50:50 to 60:40. In addition, the cathode 13 forms the cathode 13 having a thickness of 50 to 70 μm on the electrolyte 12 using a screen printing apparatus.

Here, in the present embodiment, the air electrode 13 is formed by screen printing, but in addition, the spray coating method, the dip coating method, the slurry coating method, the electric vapor deposition method (EVD), or the chemical vapor deposition method ( It is possible to form the cathode 13 using a method such as chemical vapor deposition or CVD.

That is, according to the present embodiment, the fuel electrode 11 and the electrolyte 12 are sintered at the same time by using a tape casting method, and then the air electrode 13 is laminated and sintered on the electrolyte 12. It goes through two sintering processes.

In detail, as described above, the anode support layer 11a, the anode reaction layer 11b, the electrolyte 12, and the cathode 13 are sequentially stacked to form a second laminate 22.

Next, the second laminate 22 is laminated (S32).

The lamination process S32 is performed under the same conditions as the lamination process S24 of the first laminate 21. That is, in the lamination process S32 of the second laminate 22, the second laminate 22 is pressed at 80 ° C. with a force of 200 kgf / cm 2 for 30 minutes.

Next, when the lamination process S32 is completed, a calcination process is performed on the second laminate 22 under the same conditions as the calcination process S25 of the first laminate 21 (S33).

In the calcination step (S33), the second laminate 22 is heated to a temperature of 950 to 1050 ° C., preferably 1000 ° C. to maintain about 3 hours and to be maintained at room temperature.

Here, when the calcination temperature is lower than 1000 ° C during the calcination step (S33), the sintering efficiency is lowered, the breakage easily occurs after sintering. When the calcination temperature is higher than 1000 ° C., warpage occurs in the second laminate 22 in the calcination process.

Next, a solid oxide fuel cell is formed by sintering the second laminate 22 in which calcining is completed as described above (S34).

For example, in the sintering process of the second laminate 22, unlike the sintering process S26 of the first laminate 21, the sintering process is performed at 1050 to 1200 ° C. Preferably, the second laminate 22 is sintered at 1150 ° C.

On the other hand, the sintering process (S34) of the second laminate 22 is heated and sintered while applying a predetermined force to the second laminate (22) similarly to the sintering process of the first laminate (21). For example, by arranging a predetermined pressing body 120 having a predetermined size and weight on the second stack 22, the second stack 22 is loaded with a force of 35 to 40 kgf / cm 2. Is pressed.

Here, the press body 120 for pressurizing the second laminate 22 also chemically reacts with the second laminate 22 and the cathode 13 in a sintering process, or the press body (at a sintering temperature) 120) It is preferably formed of a material that does not occur physically and chemically modified. For example, the press body 120 is a zirconia ceramic block.

Here, by pressing and sintering the second laminate 22 with the press body 120, a good appearance of the solid oxide fuel cell 10 after sintering may be obtained.

6 and 7 are graphs showing the performance of a solid oxide fuel cell according to an embodiment of the present invention. FIG. 6 is a graph measuring output performance, and FIG. 7 is a graph measuring resistance of an electrolyte.

6 and 7, 'Comparative Example' is a result of measuring the performance of the solid oxide fuel cell according to the prior art, 'Example' is a measurement of the performance of the solid oxide fuel cell according to an embodiment of the present invention Show results.

Here, to evaluate the effect of the size of the YSZ powder constituting the electrolyte on the output performance of the solid oxide fuel cell, Comparative Example and Example are the same except for the size of the YSZ powder of the electrolyte solid oxide fuel The battery was manufactured and the output performance of the solid oxide fuel cell thus prepared was measured.

That is, in Examples and Comparative Examples, the anode, the electrolyte, and the cathode were formed to have the same composition and the same thickness. In the embodiment, an electrolyte was formed using YSZ powder having a diameter of 10 to 30 nm and a surface area of 10 to 30 cm 2 / g. In contrast, in Comparative Example, an electrolyte was formed using YSZ powder having a diameter of 1 μm or more and a surface area of 4 to 8 cm 2 / g.

In order to measure the output performance of the solid oxide fuel cell according to the Examples and Comparative Examples, the Examples and Comparative Examples respectively flow H 2 containing 3% H 2 O as the anode at a rate of 200 ml / min at 800 ° C. In the air cathode, air flows at 300 ml / min. After operating for 8 hours, an electric load is applied to each solid oxide fuel cell, and a current-voltage curve is formed by measuring a voltage output from each solid oxide fuel cell. , And the results are shown in FIG.

Referring to FIG. 6, the output of the unit cell of the solid oxide fuel cell is 0.31 W / cm 2, and it can be seen that the performance is improved by approximately two times or more than the 0.17 W / cm 2 of the comparative example.

And, the results of measuring the polarization resistance of the unit cell in the solid oxide fuel cell according to the comparative example and the embodiment are shown in FIG.

Referring to FIG. 7, it can be seen that the polarization resistance of the unit cell of the example is 0.55 Ωcm 2 and the unit cell polarization resistance of 0.80 Ωcm 2 of the comparative example, and the resistance of the electrolyte itself in the example and the comparative example is almost identical.

Accordingly, it can be seen from the results of FIGS. 6 and 7 that the embodiment has improved the output performance of the solid oxide fuel cell due to the interface resistance between the electrolyte, the anode and the cathode by changing the particle size of the YSZ powder of the electrolyte.

According to the present embodiment, the anode 11 and the electrolyte 12 are simultaneously sintered at once using a tape casting method, and the cathode 13 is formed on the electrolyte 12 using a screen printing method to sinter. In this way, the manufacturing process of the solid oxide fuel cell is reduced by two sintering furnace processes, and the process is simplified. In addition, by simplifying the process and reducing the number of processes, it is possible to effectively reduce the time and cost required for the manufacturing process of the solid oxide fuel cell.

In addition, by increasing the surface area of the electrolyte 12 by using nano-sized YSZ powder, the interface resistance between the electrolyte 12 and the anode 11 and the cathode 13 is reduced, Improve output performance.

1 is a cross-sectional view for explaining a solid oxide fuel cell according to an embodiment of the present invention;

2 is a flow chart illustrating a method for preparing yttria stabilized zirconia (YSZ) powder according to an embodiment of the present invention;

3 is a side view showing an example of a tape casting device for explaining a method for manufacturing a solid oxide fuel cell according to an embodiment of the present invention;

4 is a flowchart illustrating a method of manufacturing a solid oxide fuel cell according to an embodiment of the present invention;

5A to 5E are cross-sectional views for explaining main steps in the method of manufacturing the solid oxide fuel cell of FIG. 4;

6 is a graph measuring output performance of a solid oxide fuel cell according to an embodiment of the present invention;

7 is a graph measuring polarization resistance of a solid oxide fuel cell according to an exemplary embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

10: solid oxide fuel cell 11: anode

11a: anode support layer 11b: anode reaction layer

12: electrolyte 13: air electrode

21: first laminate 22: second laminate

111, 112, 121, 131: sheet

120: pressurized body

Claims (26)

delete delete delete delete delete delete delete delete delete Forming an anode sheet using a tape casting method; Forming an electrolyte sheet by nanocasting Yttria Stabilized ZrO ₂ (YSZ) powder formed by coprecipitation using a tape casting method; Stacking the electrolyte sheet on the anode sheet to form a first laminate; Laminating the first laminate; Sintering the first laminate in which the lamination is completed to form a first preliminary fuel cell; Forming a cathode on the first preliminary fuel cell to form a second laminate; Laminating the second laminate; And Sintering the second laminate in which the lamination is completed to form a solid oxide fuel cell; Including, The electrolyte forming step, Forming a slurry using nano-sized YSZ powder formed by coprecipitation; And Forming an electrolyte sheet by tape casting the slurry; Solid oxide fuel cell manufacturing method comprising a. delete The method of claim 10, The first preliminary fuel cell forming step, Calcination of the laminated first laminate at a first temperature; And Sintering the first laminate having been calcined at a second temperature; Solid oxide fuel cell manufacturing method comprising a. The method of claim 12, The first temperature is a method for producing a solid oxide fuel cell, characterized in that 950 to 1050 ℃. The method of claim 12, The second temperature is a manufacturing method of a solid oxide fuel cell, characterized in that 1250 to 1450 ℃. The method of claim 12, The sintering step of the first preliminary fuel cell is a method of manufacturing a solid oxide fuel cell, characterized in that the pressure to 30 to 45 kgf / ㎠. The method of claim 10, The solid oxide fuel cell forming step, Calcining the laminated second laminate at a third temperature; And Sintering the second laminate having been calcined at a fourth temperature; Solid oxide fuel cell manufacturing method comprising a. The method of claim 16, The third temperature is a manufacturing method of a solid oxide fuel cell, characterized in that 950 to 1050 ℃. The method of claim 16, The fourth temperature is a method of manufacturing a solid oxide fuel cell, characterized in that 1050 to 1200 ℃. The method of claim 16, The sintering step of the solid oxide fuel cell is a method of manufacturing a solid oxide fuel cell, characterized in that the pressure to 30 to 45 kgf / ㎠. The method of claim 10, The lamination step of the first laminate and the second laminate is a method of manufacturing a solid oxide fuel cell, characterized in that heated to a temperature of 70 to 90 ℃ respectively. The method of claim 10, The lamination step of the first laminate and the second laminate is a manufacturing method of a solid oxide fuel cell, characterized in that the pressure of 150 to 250 kgf / ㎠ respectively. delete The method of claim 10, The cathode is a method of manufacturing a solid oxide fuel cell, characterized in that formed by the screen printing method. The method of claim 10, The anode sheet is a NiO / YSZ cermet in which nickel oxide (NiO) and YSZ are mixed. A method of manufacturing a solid oxide fuel cell, wherein NiO and YSZ are mixed in a weight ratio of 50:50 to 60:40. The method of claim 10, The air electrode is LSM / YSZ cermet mixed with manganese-based brobrosite (LSM) and YSZ, Method for producing a solid oxide fuel cell, characterized in that the LSM and YSZ is mixed in a weight ratio of 50:50 to 60:40. The method of claim 10, The YSZ powder has a particle diameter of 10 to 30 nm, the surface area of the manufacturing method of a solid oxide fuel cell, characterized in that 10 to 30 cm 2 / g.

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