Solid Oxide Fuel Cell Anode and Its Preparation Method, Single Cell and Stack

Abstract

The present invention belongs to the field of SOFC, and specifically relates to a SOFC anode prepared based on nickel foam, a preparation method, a single cell, and a stack. The present invention provides a solid oxide fuel cell anode, and the solid oxide fuel cell anode includes nickel foam and a YSZ / NiO porous ceramic supported on the nickel foam. The present invention uses nickel foam as a carrier, and utilizes its characteristics of having a large number of natural pores, good ductility, and being easy to cut into various shapes. A Ni-YSZ composite slurry is loaded on the nickel foam to prepare a SOFC anode, so that the anode naturally has a large number of pores, good ductility, and a formed Ni network; the SOFC anode has good mechanical properties and good electronic conductivity, and can meet different usage requirements.

Description

Technical Field

[0001] The present invention belongs to the field of solid oxide fuel cells, and particularly relates to a solid oxide fuel cell anode, a preparation method thereof, a single cell and a stack. Background Art

[0002] A solid oxide fuel cell (SOFC) is a power generation device that can directly convert the chemical energy in fuel into electrical energy. It is considered a promising fuel cell due to its high energy conversion efficiency, wide range of fuel options, no need for noble metal catalysts, and all-solid-state structure. An SOFC generally consists of an anode, an electrolyte layer, and a cathode. To reduce the ohmic internal resistance of the battery, the electrolyte layer, which is an oxygen ion conductor, is usually made into a thin film. At this time, the anode or cathode is required to be used as the support structure of the SOFC.

[0003] Among a series of similar structures, using a Ni-YSZ composite cermet as the anode support is currently the most commonly used SOFC battery structure. Among them, Ni provides electron conductivity and catalytic active reaction sites for direct electrochemical oxidation or methane steam reforming; YSZ makes the thermal expansion coefficient of the anode material match that of the most common current electrolyte material (8YSZ), and extends ion conduction to the reaction zone of the anode; in addition, YSZ plays the role of a structural support in the anode, endowing the anode with sufficient mechanical strength and preventing further aggregation and growth of Ni in a long-term high-temperature working environment.

[0004] Currently, there are mainly two traditional preparation methods for Ni-YSZ composite anodes: (1) Dry pressing method: pressing a Ni-YSZ or NiO-YSZ mixed powder into a certain shape in a steel mold with a fixed specification, and then sintering and reducing to obtain a Ni-YSZ anode with a certain shape; (2) Tape casting method: preparing a Ni-YSZ or NiO-YSZ and other mixed powders into a tape casting slurry, obtaining a Ni-YSZ anode film with a certain thickness through tape casting, and then cutting, sintering, and reducing to obtain a Ni-YSZ anode with a regular shape. The main disadvantages of these two methods for preparing Ni-YSZ anodes are as follows: 1. Usually, a pore-forming agent needs to be added to meet the porosity requirements of the anode, and the existence state of pores (size, morphology, open pores or closed pores) cannot be controlled; 2. The electron conductivity of the anode depends on the formation of the Ni network, but this process cannot be controlled; 3. The support strength of the anode depends on the YSZ skeleton, but the formation of the YSZ skeleton cannot be controlled either; 4. The prepared Ni-YSZ cermet composite anode has extremely poor ductility, and it is difficult to fit tightly with the mold due to inevitable slight unevenness during the subsequent battery sealing process, resulting in the crushing of single cell pieces or air leakage of the battery. Summary of the Invention

[0005] The object of the present invention is to overcome the problems of uncontrollable anode pore state, Ni network and YSZ framework state existing in the prior art, and to provide a solid oxide fuel cell anode prepared based on nickel foam. The solid oxide fuel cell anode provided by this method has the advantages of good ductility, high open porosity and high electronic conductivity, etc.

[0006] To achieve the above object, one of the objects of the present invention is to provide a solid oxide fuel cell anode, which includes nickel foam and a YSZ / NiO porous ceramic loaded on the nickel foam.

[0007] Another object of the present invention is to provide a method for preparing a solid oxide fuel cell anode, which includes the following steps:

[0008] S1. Obtain pretreated nickel foam;

[0009] S2. Obtain YSZ / NiO slurry;

[0010] S3. Immerse the YSZ / NiO slurry in the pretreated nickel foam to obtain an NF / YSZ / NiO composite;

[0011] S4. Under the atmosphere of a protective gas, perform hot pressing sintering on the NF / YSZ / NiO composite to obtain the solid oxide fuel cell anode.

[0012] Another object of the present invention is to provide a solid oxide fuel cell anode obtained by the above method.

[0013] Another object of the present invention is to provide a solid oxide fuel cell, which sequentially includes an anode, an electrolyte layer and a cathode layer from bottom to top. The anode is the aforementioned solid oxide fuel cell anode. The solid oxide fuel cell anode has an upper surface and a lower surface, and a YSZ / NiO porous ceramic is loaded on the upper surface; wherein, the upper surface is in contact with the electrolyte layer, and the lower surface is away from the electrolyte layer.

[0014] Another object of the present invention is to provide a stack, which includes the above-mentioned solid oxide fuel cell single cell.

[0015] Compared with the prior art, the present invention has the following technical effects:

[0016] The present invention uses nickel foam as a carrier. Taking advantage of its natural characteristics of having a large number of pores, good ductility, and being easy to cut into various shapes, a Ni-YSZ composite slurry is loaded on the nickel foam. The prepared anode of the solid oxide fuel cell has a large number of pores, good ductility, and a formed Ni network. The anode of the solid oxide fuel cell prepared by this method has good mechanical properties and good electronic conductivity, and can meet different usage requirements.

[0017] Meanwhile, the technology provided by the present invention is simple and easy for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a flowchart for preparing the anode of a solid oxide fuel cell according to an embodiment of the present invention;

[0019] Figure 2 is a schematic structural diagram of a solid oxide fuel cell according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below in conjunction with embodiments. The following description is only used to illustrate the technical solutions of the present invention and not to limit them.

[0021] In the ranges disclosed herein, the endpoints and any values are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0022] In the present invention, unless otherwise stated, the orientation terms such as "upper" and "lower" are based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0023] In the present invention, YSZ refers to ZrO2 doped with Y2O3; wherein, the doping concentration of Y2O3 is 3-8 mol%. When the doping concentration of Y2O3 is 3 mol%, the molecular formula of YSZ is (Y2O3) 0.03 (ZrO2) 0.97 , which is simply referred to as 3YSZ; when the doping concentration of Y2O3 is 8 mol%, the molecular formula of YSZ is (Y2O3) 0.08 (ZrO2) 0.92 , which is simply referred to as 8YSZ.

[0024] Nickel Foam: NF for short.

[0025] The present invention provides a solid oxide fuel cell anode, which includes nickel foam and a YSZ / NiO porous ceramic loaded on the nickel foam.

[0026] Preferably, the solid oxide fuel cell anode has an upper surface and a lower surface, and the loading amount of the YSZ / NiO porous ceramic gradually decreases from the upper surface to the lower surface.

[0027] Preferably, the apparent porosity of the solid oxide fuel cell anode is 10 - 30%.

[0028] Preferably, the pore size of the pores in the solid oxide fuel cell anode is 0.5 - 4 μm, preferably 0.5 - 2 μm.

[0029] Preferably, the polarization resistance of the solid oxide fuel cell anode is less than 3 Ω·cm 2 , preferably less than 1.5 Ω·cm 2 .

[0030] Figure 1 is a flowchart of the preparation of a solid oxide fuel cell anode according to an embodiment of the present invention; as Figure 1 shown, the present invention also provides a method for preparing a solid oxide fuel cell anode, including the following steps:

[0031] S1. Obtain pretreated nickel foam;

[0032] S2. Obtain YSZ / NiO slurry;

[0033] S3. Immerse the pretreated nickel foam in the YSZ / NiO slurry to obtain an NF / YSZ / NiO composite;

[0034] S4. Under the atmosphere of a protective gas, hot press and sinter the NF / YSZ / NiO composite to obtain the solid oxide fuel cell anode.

[0035] In the present invention, the oil stain on the surface of the nickel foam can be removed through pretreatment, and the pretreatment method can be known to those skilled in the art. Exemplarily, the pretreatment includes: ultrasonically treating the nickel foam in a sodium hydroxide solution first, then ultrasonically treating it in an acetone solution, and finally ultrasonically washing it in deionized water and absolute ethanol in sequence, and finally drying it under vacuum conditions.

[0036] In the present invention, the method for preparing the YSZ / NiO slurry may be well-known to those skilled in the art. Exemplarily, the preparation method may include: adding water, a dispersant, and a binder to a mixture of YSZ powder and NiO powder, and then performing ball milling and mixing to obtain the YSZ / NiO slurry.

[0037] In the present invention, preferably, in step S2, in the YSZ / NiO slurry, the mass ratio of YSZ to NiO is 1:1 - 1.8.

[0038] The inventors of the present invention have found that if the solid content of the YSZ / NiO slurry is too low, NiO / YSZ cannot be effectively adsorbed in the pores of the nickel foam; if the solid content of the YSZ / NiO slurry is too high, the viscosity of the slurry will increase accordingly, and then NiO / YSZ cannot effectively enter the pores of the nickel foam, resulting in a decrease in the loading amount. Preferably, the solid content of the YSZ / NiO slurry is 20 - 40 wt%.

[0039] In the present invention, the particle size and specific surface area of the YSZ powder and NiO powder will affect the viscosity of the slurry, and thus affect the amount of the YSZ / NiO slurry entering the pores of the nickel foam. Preferably, the D 50 of YSZ is 50 - 80 nm, and the specific surface area is 60 - 80 m 2 / g. Further preferably, the D 50 of NiO is 50 - 80 nm, and the specific surface area is 60 - 80 m 2 / g.

[0040] In some preferred embodiments of the present invention, in step S3, the impregnation method includes: repeatedly impregnating one side of the nickel foam in the YSZ / NiO slurry 2 - 10 times. After each impregnation, the nickel foam absorbing the slurry is dried.

[0041] Preferably, the impregnation method includes:

[0042] 1) Weigh the mass of the pretreated nickel foam NF and record it as M0;

[0043] 2) Immerse one side of the nickel foam in the slurry for 10 - 20 min;

[0044] 3) Dry the nickel foam NF absorbing the slurry and weigh it again and record it as M1;

[0045] 4) Repeat steps 2) and 3);

[0046] 5) Repeat the above process until the mass difference between Mx (x is 1, 2, 3... x) and M0 reaches a predetermined value, and end the above impregnation process.

[0047] Preferably, in the NF / YSZ / NiO composite, the unit loading of the slurry is 0.03 - 0.3 g / cm 2 ; preferably 0.05 - 0.1 g / cm 2 , and the loading refers to the average loading of the slurry in the nickel foam.

[0048] The anode prepared by the present invention uses nickel foam as the supporting framework and is loaded with NiO-YSZ porous ceramics. One side of the nickel foam is NiO-YSZ porous ceramics based on the nickel foam network structure. The nickel foam provides an excellent Ni conductive network and voids, endowing the anode support with sufficient electronic conductivity and porosity; the NiO-YSZ slurry after slip casting first fills some of the voids in the nickel foam network, forming a relatively flat and dense surface, which is beneficial to the screen printing process of the subsequent electrolyte layer. Secondly, YSZ is added, so that ion conduction can be extended to the reaction zone of the anode, increasing the length of the triple-phase interface.

[0049] The other side of the nickel foam is not slip cast, so it still retains the characteristics of high ductility, high porosity and good conductivity of the nickel foam itself. It can not only play the role of transmitting electrons, but also effectively solve the problem of the battery sheet being crushed under pressure during the battery sealing process. At the same time, it can also closely fit the battery mold, which is beneficial to the aggregation and conduction of current between the anode and the battery mold.

[0050] In the present invention, preferably, in step S4, the conditions of the hot pressing sintering include: the temperature is 900 - 1000 °C, the time is 1 - 5 h, and the pressure is 10 - 50 MPa.

[0051] Performing hot pressing sintering in a protective gas atmosphere can reduce the oxidation of the nickel foam. The purpose of the pressing sintering is to obtain a relatively flat surface as much as possible, so as to prepare for the subsequent screen printing process.

[0052] The protective gas atmosphere is well-known to those skilled in the art. For example, it can be a nitrogen atmosphere and / or an inert gas atmosphere.

[0053] Preferably, the YSZ is yttria-stabilized zirconia with 3 - 8 mol%.

[0054] The present invention also provides a solid oxide fuel cell anode prepared by the above method.

[0055] Preferably, the solid oxide fuel cell anode includes nickel foam and YSZ / NiO porous ceramics loaded on the nickel foam.

[0056] Further preferably, the solid oxide fuel cell anode has an upper surface and a lower surface, and the loading of the YSZ / NiO porous ceramics gradually decreases from the upper surface to the lower surface.

[0057] The pore size of the anode of the solid oxide fuel cell is 0.5 - 1.5 μm.

[0058] Preferably, the surface porosity of the anode of the solid oxide fuel cell is 10 - 25%.

[0059] Preferably, the polarization resistance of the anode of the solid oxide fuel cell is less than 3 Ω·cm 2 。

[0060] The anode of the solid oxide fuel cell provided by the present invention serves both as an anode support layer and an anode functional layer. That is, the side without the loaded porous ceramic has the function of an anode support layer, and the side with the loaded porous ceramic has the function of an anode functional layer. It can not only provide a triple-phase interface to provide electron conductivity and catalytically active reaction sites for direct electrochemical oxidation or methane steam reforming, but also serve as a support structure for the solid oxide fuel cell

[0061] Figure 2 is a schematic structural diagram of a solid oxide fuel cell according to an embodiment of the present invention. As Figure 2 shown, the present invention also provides a solid oxide fuel cell 10, which sequentially includes an anode 11, an electrolyte layer 12, and a cathode layer 13 from bottom to top. The anode is the aforementioned anode of the solid oxide fuel cell. The anode of the solid oxide fuel cell has an upper surface 11a and a lower surface 11b, and a YSZ / NiO porous ceramic is loaded on the upper surface 11a. Among them, the upper surface 11a is in contact with the electrolyte layer 12, and the lower surface 11b is away from the electrolyte layer.

[0062] Preferably, the thickness of the anode is 500 - 2000 μm, for example, it can be 1000 μm.

[0063] Preferably, the thickness of the electrolyte layer is 5 - 50 μm, preferably 10 - 30 μm, and more preferably 10 μm.

[0064] Preferably, the thickness of the cathode layer is 5 - 50 μm, preferably 10 - 30 μm, and more preferably 20 μm.

[0065] The present invention also provides a stack, which includes the above-mentioned solid oxide fuel cell single cell.

[0066] The following specifically describes the present invention with specific embodiments.

[0067] In the following examples, the thickness of the nickel foam (NF) is 1 mm, and the porosity > 95%.

[0068] In the following examples, the three-point flexural strength of the anode is obtained by testing with a universal material testing machine;

[0069] The conductivity of the anode was measured by a digital multimeter (Keithley - DMM6500) using the four - probe method at a measurement temperature of 750 °C. It needed to be reduced by hydrogen before testing.

[0070] The polarization impedance of the anode was measured by an electrochemical workstation (DH7001A) using the two - probe method at a measurement temperature of 750 °C. It needed to be reduced by hydrogen before testing.

[0071] The viscosity of the NiO - YSZ composite slurry was measured by a rotational viscometer (NDJ - 1).

[0072] After hot - pressing sintering of the nickel foam, the surface porosity and pore size of the side loaded with porous ceramics were measured by a metallurgical microscope (IMAS - 2000) and obtained through Image - J software. The formula for calculating the surface porosity is: surface porosity = surface pore size / area.

[0073] Example 1

[0074] S1. Pretreatment of nickel foam:

[0075] The nickel foam was cut into a square (side length 10 cm). Then the nickel foam was ultrasonically treated in 1 mol / L sodium hydroxide solution for 30 min, then ultrasonically treated in acetone solution for 10 min, and finally ultrasonically washed in deionized water and absolute ethanol for 10 min each. It was dried at 60 °C under vacuum conditions, and the weight of the nickel foam was measured as 2.50 g, denoted as M0, and reserved for use.

[0076] S2. Preparation of NiO - YSZ composite slurry:

[0077] In NiO powder (D 50 is 50 nm, specific surface area 60 m 2 / g), 8YSZ powder (D 50 is 50 nm, specific surface area 60 m 2 / g), polyvinyl alcohol (PVA), carboxymethyl cellulose (CMC) and deionized water were added. The solid content was 30%. Among them, the mass ratio of 8YSZ to NiO was 1:1.5, the dosage of PVA was 1 wt% of the total weight of the powder (the total weight of NiO powder and 8YSZ powder), and the dosage of CMC was 0.4 wt% of the total weight of the powder.

[0078] S3. Preparation of NF / YSZ / NiO composite

[0079] Immerse one side of the processed nickel foam (at a position not less than 1 / 3) in the NiO-YSZ composite slurry. After 10 minutes, take it out and place it on a tray, then dry it in an oven. Weigh the mass of the nickel foam at this time and record it as M1. Then repeat this process 7 times. The mass and performance of the nickel foam after each coating are shown in Table 1;

[0080] S4. Preparation of the anode of the solid oxide fuel cell by hot pressing and sintering:

[0081] The nickel foam after coating needs to be hot pressed and sintered in a nitrogen atmosphere. The sintering temperature is 1000 °C, the holding time is 1 h, and the pressure is 30 MPa to obtain the anode of the solid oxide fuel cell.

[0082] Table 1:

[0083]

[0084]

[0085] It can be seen from Table 1 that as the number of coating times increases, the loading amount of YSZ / NiO in the nickel foam also increases slowly, and the increasing rate of the loading amount gradually decreases; when X = 5 (i.e., at the 5th coating), the loading amount of YSZ / NiO hardly increases significantly. This is because as the number of coating times increases, the pores of the nickel foam are filled, the pore diameter gradually decreases, and the adsorption capacity for the slurry gradually weakens. When the pore diameter on the surface of the nickel foam decreases to a certain extent, it can no longer adsorb the slurry, so the loading amount tends to be stable.

[0086] As the number of coating times increases, after hot pressing and sintering and hydrogen reduction, the pore porosity and pore size of the anode of the solid oxide fuel cell are continuously decreasing. This shows that the pore porosity and pore size of the anode can be adjusted by controlling the number of coating times.

[0087] When the number of coating times is less than 5, as the number of coating times increases, the electronic conductivity of the anode hardly changes. This shows that using nickel foam as the substrate material endows the anode with extremely high electronic conductivity. While for the anode prepared by the conventional method (casting YSZ-NiO slurry or dry pressing YSZ-NiO powder and then sintering the cast film or green body) (about 1×10 5 S / m).

[0088] When the number of slurry coating reaches 5 times, with the increase of the number of slurry coating, the polarization impedance of the anode continuously decreases until it tends to be stable. This is because when the number of slurry coating is small, the number of triple-phase interfaces on the anode at this time is insufficient, lacking sufficient catalytic ability for hydrogen, and insufficient transport ability for electrons and oxygen ions, resulting in a large polarization impedance, and even the polarization impedance value cannot be measured at all. When X ≥ 5, due to the shrinkage of pores at this time, nickel foam can no longer adsorb more slurry, and the porosity and pore size of the anode no longer change significantly, and the magnitude of the polarization impedance begins to tend to be stable.

[0089] Examples 2 - 3 and Comparative Examples 1 - 2

[0090] The anodes of solid oxide fuel cells were prepared by referring to the method used in Example 1. The difference is that the solid contents of the slurries in Examples 2 and 3 are 20 wt% and 40 wt% respectively, and the solid contents of the slurries in Comparative Examples 1 and 2 are 10 wt% and 50 wt% respectively, as shown in Table 2 specifically.

[0091] Table 2 shows the loading, viscosity, and polarization impedance of slurries with different solid contents after 5 times of slurry coating.

[0092] Table 2:

[0093]

[0094] As can be seen from Table 5, with the increase of the solid content of the slurry, the overall viscosity of the slurry continuously increases, while the loading shows a trend of first increasing and then decreasing. This is because when the viscosity of the slurry is low, NiO / YSZ cannot be effectively adsorbed in the pore diameter of nickel foam, and when the viscosity of the slurry is too high, due to the action of surface tension, it cannot enter the pores of nickel foam well, resulting in a decrease in the loading. This also explains why the polarization impedance of the anode first decreases and then increases, because with the change of the loading, the length of the triple-phase interface of the anode changes.

[0095] Examples 4 and Comparative Examples 3 - 5

[0096] The anodes of solid oxide fuel cells were prepared by referring to the method used in Example 1. The difference is that the hot-pressing sintering temperature in Example 4 is 900 °C, and the hot-pressing sintering temperatures in Comparative Examples 3, 4, and 5 are 800 °C, 1100 °C, and 1200 °C respectively.

[0097] Table 3 shows the surface porosity and pore size of the anodes prepared at different hot-pressing sintering temperatures.

[0098] Table 3:

[0099]

[0100] As can be seen from Table 3, with the increase of the hot-pressing sintering temperature, both the surface porosity and pore size of the anode are continuously decreasing. When the hot-pressing sintering temperature reaches 1100 - 1200 °C, due to the excessively high hot-pressing sintering temperature, the anode is almost completely densified, which obviously does not meet the requirement of SOFC for the anode to have sufficient porosity. When the temperature is reduced to 800 °C, the surface porosity of the anode is too high at this time, affecting the length of the triple-phase interface, resulting in extremely high polarization resistance of the anode.

[0101] Examples 5 - 6 and Comparative Examples 6 - 7

[0102] The anode of the solid oxide fuel cell was prepared by referring to the method used in Example 1, except that the mass ratio of 8YSZ and nickel oxide is shown in Table 4.

[0103] Table 4 shows the viscosities of the slurries with different NiO:8YSZ mass ratios, the loadings after slurry coating; as well as the surface porosity, pore size, and polarization resistance of the anodes prepared under different mass ratio conditions.

[0104] Table 4

[0105]

[0106] As can be seen from Table 4, when the solid content is fixed, changing the mass ratio of nickel oxide and 8YSZ in the slurry does not have an obvious impact on the viscosity of the slurry, and thus does not affect the process of slurry coating.

[0107] It can also be seen from Table 4 that with the increase of the proportion of nickel oxide, both the surface porosity and pore size of the anode are continuously increasing. This is because a part of the anode porosity comes from the process of NiO being reduced by hydrogen to form Ni. Therefore, with the increase of the mass of 8YSZ, the surface porosity and pore size of the sintered anode are continuously increasing. This leads to a trend of first decreasing in the polarization resistance of the anode because more and larger pores are beneficial for gas entry and exchange. However, when the mass ratio of nickel oxide:8YSZ reaches 1:2, the pores of the anode are too large at this time, and the content of Ni also decreases with the increase of the content of 8YSZ. The dual factors lead to a decrease in the length of the triple-phase interface, resulting in an increase in the polarization resistance of the anode.

[0108] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and all should be covered within the protection scope of the present invention.

Claims

1. A method for preparing an anode of a solid oxide fuel cell, characterized in that, It includes the following steps: S1. Obtain pretreated nickel foam; S2. Obtain YSZ / NiO slurry; S3. Immerse the pretreated nickel foam in the YSZ / NiO slurry to obtain an NF / YSZ / NiO composite; the immersion method includes: repeatedly immersing one side of the nickel foam in the YSZ / NiO slurry for 5 - 10 times, and after each immersion, drying the nickel foam that has absorbed the slurry; S4. Under the atmosphere of protective gas, perform hot - press sintering on the NF / YSZ / NiO composite to obtain the anode of the solid oxide fuel cell; In step S2, the solid content of the YSZ / NiO slurry is 20 - 40%, and in the YSZ / NiO slurry, the mass ratio of YSZ to NiO is 1:1 - 1.8; The conditions for the hot - press sintering include: the temperature is 900 - 1000 °C, and the pressure is 10 - 50 MPa; The anode of the solid oxide fuel cell includes nickel foam and YSZ / NiO porous ceramic loaded on the nickel foam; The anode of the solid oxide fuel cell has an upper surface and a lower surface, and the loading amount of the YSZ / NiO porous ceramic gradually decreases from the upper surface to the lower surface.

2. The method according to claim 1, characterized in that, In step S2, the D of the YSZ 50 is 50 - 80 nm, and the specific surface area is 60 - 80 m 2 / g.

3. The method according to claim 2, wherein In step S2, the D of the NiO 50 is 50 - 80 nm, and the specific surface area is 60 - 80 m 2 / g.

4. The method according to any one of claims 1 to 3, characterized in that In the NF / YSZ / NiO composite, the unit loading of the slurry is 0.03 - 0.3 g / cm 2 .

5. The method according to claim 4, wherein In the NF / YSZ / NiO composite, the unit loading of the slurry is 0.05 - 0.1 g / cm 2 .

6. The method according to any one of claims 1-3, characterized in that In step S4, the conditions for the hot - press sintering further include: the time is 1 - 5 h.

7. A solid oxide fuel cell anode, characterized in that, Prepared by the method according to any one of claims 1 - 6.

8. The anode of the solid oxide fuel cell according to claim 7, characterized in that, The anode of the solid oxide fuel cell includes nickel foam and YSZ / NiO porous ceramic loaded on the nickel foam.

9. The anode of the solid oxide fuel cell according to claim 8, characterized in that, The anode of the solid oxide fuel cell has an upper surface and a lower surface, and the loading amount of the YSZ / NiO porous ceramic gradually decreases from the upper surface to the lower surface.

10. The anode of the solid oxide fuel cell according to any one of claims 7 to 9, characterized in that The open porosity of the anode of the solid oxide fuel cell is 10 - 30%.

11. The anode of the solid oxide fuel cell according to any one of claims 7 to 9, characterized in that, The pore diameter of the pores in the anode of the solid oxide fuel cell is 0.5 - 4 μm.

12. The anode of the solid oxide fuel cell according to any one of claims 7 to 9, characterized in that The polarization impedance of the anode of the solid oxide fuel cell is less than 3 Ω·cm 2 .

13. The anode of the solid oxide fuel cell according to claim 12, characterized in that, The polarization impedance of the anode of the solid oxide fuel cell is less than 1.5 Ω·cm 2 .

14. A solid oxide fuel cell, which sequentially includes an anode (11), an electrolyte layer (12), and a cathode layer (13) from bottom to top, is characterized in that, The anode is the anode of the solid oxide fuel cell according to any one of claims 7 - 13. The anode of the solid oxide fuel cell has an upper surface (11a) and a lower surface (11b), and the YSZ / NiO porous ceramic is loaded on the upper surface (11a); wherein, the upper surface (11a) is in contact with the electrolyte layer (12), and the lower surface (11b) is away from the electrolyte layer.

15. A stack, comprising the solid oxide fuel cell according to claim 14.

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