阅读说明：本技术 固体氧化物型燃料电池及其制备方法 (Solid oxide fuel cell and method for producing the same ) 是由 陈沁锴 于 2021-08-03 设计创作，主要内容包括：本发明公开了一种固体氧化物型燃料电池及其制备方法；包括固体电解质层,固体电解质层的一侧设置有燃料极层；固体电解质层的另一侧设置有氧极层；固体电解质层材料为La-(0.9-x-)-(y)Rh-(x)Ba-(y)Sr-(0.1)Ca-(1-z)Mg-(z)O-(3-a)；其中,0.01≤x≤0.03,0.01≤y≤0.02,0.1≤z≤0.3。制备方法为：采用丝网印刷技术在固体电解质层的一侧涂抹燃料极层材料,烧结；在固体电解质层的另一侧涂抹氧极层材料,煅烧,封装,得到固态氧化物型燃料电池。制得的固体电解质层具有优良热膨胀系数以及较高的导电率与断裂韧性,将其与隔离缓冲层、氧极层、燃料极层复合制得了具有优良电化学性能的固体氧化物型燃料电池。(The invention discloses a solid oxide fuel cell and a preparation method thereof; the fuel cell comprises a solid electrolyte layer, wherein a fuel electrode layer is arranged on one side of the solid electrolyte layer; an oxygen electrode layer is arranged on the other side of the solid electrolyte layer; the solid electrolyte layer material is La 0.9‑x‑ y Rh x Ba y Sr 0.1 Ca 1‑z Mg z O 3‑a (ii) a Wherein x is more than or equal to 0.01 and less than or equal to 0.03, y is more than or equal to 0.01 and less than or equal to 0.02, and z is more than or equal to 0.1 and less than or equal to 0.3. The preparation method comprises the following steps: coating a fuel electrode layer material on one side of the solid electrolyte layer by adopting a screen printing technology, and sintering; and coating an oxygen electrode layer material on the other side of the solid electrolyte layer, calcining, and packaging to obtain the solid oxide fuel cell. The prepared solid electrolyte layer has excellent thermal expansion coefficient and higher conductivity and fracture toughness, and is isolated and bufferedThe punching layer, the oxygen electrode layer and the fuel electrode layer are compounded to prepare the solid oxide fuel cell with excellent electrochemical performance.)

1. A solid oxide fuel cell includes a solid electrolyte layer having a fuel electrode layer provided on one side thereof; an oxygen electrode layer is arranged on the other side of the solid electrolyte layer;

the solid electrolyte layer material is La_0.9-x-yRh_xBa_ySr_0.1Ca_1-zMg_zO_3-a(ii) a Wherein the content of the first and second substances,

0.01≤x≤0.03，0.01≤y≤0.02，0.1≤z≤0.3。

2. a solid oxide fuel cell according to claim 1, wherein: the conductivity of the solid electrolyte layer is higher than 0.04S/cm.

3. A solid oxide fuel cell according to claim 1, wherein: the fuel electrode layer is made of NiO/SDC material.

4. A solid oxide fuel cell according to claim 1, wherein: the oxygen electrode layer is made of BaCo_1-m-nFe_mZr_nO_3-bWherein m is more than 0.05 and less than or equal to 0.2, and n is more than 0.03 and less than or equal to 0.1.

5. A solid oxide fuel cell according to claim 1, wherein: the thickness of the solid electrolyte layer is 8-15 mu m.

6. A method of manufacturing a solid oxide fuel cell as claimed in claim 1, comprising the steps of:

coating a fuel electrode layer material on one side of the solid electrolyte layer by adopting a screen printing technology, and sintering at a high temperature; and coating an oxygen electrode layer material on the other side of the solid electrolyte layer, and carrying out high-temperature calcination and packaging to obtain the solid oxide fuel cell.

7. The method for producing a solid oxide fuel cell according to claim 6, wherein: the high-temperature sintering temperature of the fuel electrode layer is 1000-1100 ℃, and the time is 2-3 h; the high-temperature sintering temperature of the oxygen electrode layer is 1000-1100 ℃, and the time is 3-5 h.

8. The method for producing a solid oxide fuel cell according to claim 6, wherein: and an isolation buffer layer composed of Sm-containing oxide between the solid electrolyte layer and the fuel electrode layer.

9. The method for producing a solid oxide fuel cell according to claim 6, wherein: the solid electrolyte layer material is La_0.9-x-yRh_xBa_ySr_0.1Ca_1-zMg_zO_3-aThe preparation method comprises the following steps: and grinding and uniformly mixing lanthanum oxide, rhodium oxide, barium carbonate, strontium carbonate, gallium oxide and magnesium oxide, baking, pressing into a wafer, sintering at a high temperature, crushing, baking, pressing under the pressure of 200-300 MPa to prepare an electrolyte sheet, and sintering at a high temperature to obtain the solid electrolyte layer material.

10. The method for producing a solid oxide fuel cell according to claim 6, wherein: the oxygen electrode layer is made of BaCo_1-m-nFe_mZr_nO_3-bThe preparation method comprises the following steps: dissolving barium salt, cobalt salt, ferric salt, zirconium salt and yttrium salt in deionized water, adding a complexing agent, heating, stirring and sintering to obtain BaCo_1-m-nFe_mZr_nO_3-bA material.

Technical Field

The invention belongs to the field of solid oxide fuel cells, and particularly relates to a solid oxide fuel cell and a preparation method thereof.

Background

With the rapid development of the industry worldwide, the worldwide demand for energy is increasing. In addition, the energy is mainly fossil fuel, and a large amount of CO is discharged₂、N₂O and sulfide and other pollutants cause environmental pollution and seriously harm the health of people. Therefore, a clean and efficient energy utilization mode is adopted, new energy is actively developed, and the sustainable development of the nation and the social economy is facilitated. The fuel cell is an electrochemical power generation device, and is isothermally operatedThe electrochemical mode directly converts chemical energy into electric energy without a heat engine process and is not limited by Carnot cycle, so that the energy conversion efficiency is high, and the method has no noise and pollution and is becoming an ideal energy utilization mode. Meanwhile, as the fuel cell technology is continuously mature and sufficient natural gas sources are provided by the west-east gas transmission engineering, the commercial application of the fuel cell has wide development prospect.

The prior art discloses a solid oxide fuel cell as disclosed in publication No. CN 101558520A; a solid oxide fuel cell having a solid electrolyte layer between a fuel electrode and an air electrode, wherein one of the fuel electrode and the air electrode is a support, and the fuel cell has at least a first layer and a second layer from the support side. Further, the solid oxide fuel cell is provided, wherein the first layer is formed of a cerium-containing oxide, the second layer is formed of a lanthanum gallate oxide containing at least lanthanum and gallium, the first layer contains a sintering aid capable of improving the sinterability of the cerium-containing oxide, and 2< T <70 when the thickness of the second layer is T [ mu ] m.

Disclosure of Invention

The invention aims to provide a solid electrolyte layer material with excellent thermal expansion coefficient and higher conductivity and fracture toughness, and the solid electrolyte layer material is compounded with an isolation buffer layer, an oxygen electrode layer and a fuel electrode layer to prepare a solid oxide fuel cell, which has excellent electrochemical performance, namely higher maximum output power and current density.

The technical scheme adopted by the invention for realizing the purpose is as follows:

a solid oxide fuel cell includes a solid electrolyte layer having a fuel electrode layer provided on one side thereof; an oxygen electrode layer is arranged on the other side of the solid electrolyte layer;

the solid electrolyte layer material is La_0.9-x-yRh_xBa_ySr_0.1Ca_1-zMg_zO_3-a(ii) a Wherein the content of the first and second substances,

0.01≤x≤0.03，0.01≤y≤0.02，0.1≤z≤0.3。

the invention adopts LSCM as a substrate material of a solid electrolyte layer, belonging to the field of solid electrolyteDoping and modifying perovskite type composite oxide by adopting metal Ba and metal rhodium to prepare La_0.9-x-yRh_xBa_ySr_0.1Ca_1-zMg_zO_3-aThe obtained solid electrolyte layer material has excellent thermal expansion coefficient and can be well matched with a traditional perovskite structure oxygen electrode and a common medium-low temperature oxygen electrode layer; meanwhile, the doping of the rhodium component can improve the grain boundary and electron movement characteristics of the internal structure of the solid electrolyte layer, so that the solid electrolyte layer has excellent fracture toughness and higher conductivity; the composite material is compounded with the isolating buffer layer, the oxygen pole layer and the fuel pole layer to prepare the solid oxide fuel cell with excellent electrochemical performance, so that the solid oxide fuel cell has higher maximum output power and current density.

Further, it should be noted that the value of a in the oxygen anion and the metal cation satisfy the conservation of positive and negative charges.

Further, in some embodiments of the present invention, the solid electrolyte layer has an electrical conductivity greater than 0.04S/cm.

Further, in some embodiments of the present invention, the material of the fuel electrode layer is a NiO/SDC material.

Further, in some embodiments of the present invention, the oxygen electrode layer material is BaCo_1-m-nFe_mZr_nO_3-bWherein m is more than 0.05 and less than or equal to 0.2, and n is more than 0.03 and less than or equal to 0.1.

Further, it should be noted that the b value in the oxygen anion and the metal cation satisfy the charge conservation of positive and negative.

Further, in some embodiments of the present invention, the thickness of the solid electrolyte layer is 8 to 15 μm.

The invention also discloses a preparation method of the solid oxide fuel cell, which comprises the following steps:

coating a fuel electrode layer material on one side of the solid electrolyte layer by adopting a screen printing technology, and sintering at a high temperature; and coating an oxygen electrode layer material on the other side of the solid electrolyte layer, and performing high-temperature calcination and packaging to obtain the solid oxide fuel cell.

Further, in some embodiments of the present invention, the high temperature sintering temperature of the fuel electrode layer is 1000 to 1100 ℃ for 2 to 3 hours; the high-temperature sintering temperature of the oxygen electrode layer is 1000-1150 ℃, and the time is 3-5 h.

Further, in some embodiments of the present invention, the isolation buffer layer between the solid electrolyte layer and the fuel electrode layer is made of an oxide containing Sm, and has a thickness of 3 to 7 μm, preferably an SDC material, and is prepared from samarium oxide and cerium salt according to a conventional technical scheme, and the sintering temperature is 1000 to 1100 ℃ and the time is 2 to 4 hours.

Further, in some embodiments of the invention, the solid electrolyte layer material is La_{0.9-x- y}Rh_xBa_ySr_0.1Ca_1-zMg_zO_3-aThe preparation method comprises the following steps: and grinding and uniformly mixing lanthanum oxide, rhodium oxide, barium carbonate, strontium carbonate, gallium oxide and magnesium oxide, baking, pressing into a wafer, sintering at a high temperature, crushing, baking, pressing under the pressure of 200-300 MPa to prepare an electrolyte sheet, and sintering at a high temperature to obtain the solid electrolyte layer material.

Further, in some embodiments of the present invention, the grinding time of the raw material is 5 to 10 hours.

Furthermore, in some embodiments of the invention, the high-temperature sintering temperature of the wafer is 950-1050 ℃ and the time is 10-14 h; the high-temperature sintering temperature of the electrolyte sheet is 1350-1450 ℃, and the time is 18-24 hours, so that the electrolyte layer material with a compact structure is obtained.

Further, in some embodiments of the present invention, the oxygen electrode layer material is BaCo_1-m-nFe_mZr_nO_3-bThe preparation method comprises the following steps: dissolving barium salt, cobalt salt, ferric salt, zirconium salt and yttrium salt in deionized water, adding a complexing agent, heating, stirring and sintering to obtain BaCo_1-m-nFe_mZr_nO_3-bA material.

Further, in some embodiments of the present invention, the oxygen electrode layer material is BaCo_1-m-n-kFe_mZr_nGd_kO_3-bWherein k is more than 0.05 and less than or equal to 0.1, and doping with metal Gd, whichThe substitution of part of Zr further improves the conductivity of the oxygen electrode layer and makes it have a good thermal expansion coefficient, probably because the doping with a specific content of Gd makes up for the BaCo_1-m-nFe_mZr_nO_3-bThe defect structure has better matching property with the thermal expansion performance of the solid electrolyte, and the solid oxide fuel cell is prepared by compounding the defect structure with the isolation buffer layer, the solid electrolyte layer and the fuel electrode layer, so that the electrochemical performance of the solid fuel cell is improved.

Still further, in some embodiments of the invention, the complexing agent is ethylenediaminetetraacetic acid, EDTA.

Further, in some embodiments of the present invention, the molar ratio of metal cations in barium, cobalt, iron, zirconium and yttrium salts to ethylenediaminetetraacetic acid to EDTA is 1:1 to 3:1 to 2.

Further, in some embodiments of the present invention, the heating and stirring temperature is 45-55 ℃ for 30-60 min.

Furthermore, in some embodiments of the present invention, the sintering curve of the oxygen electrode layer material is pre-sintered at 500-600 ℃ for 2-4 h, and then calcined at 1000-1150 ℃ for 4-6 h.

According to the invention, the LSCM is adopted as a substrate material of the solid electrolyte layer, belongs to the perovskite type composite oxide, and is doped and modified by the metal Ba and the metal rhodium to obtain the solid electrolyte layer material, so that the solid oxide type fuel cell is prepared, and the LSCM has the following beneficial effects: the solid electrolyte layer material has excellent thermal expansion coefficient, and can be well matched with the traditional perovskite structure oxygen electrode and the common medium-low temperature oxygen electrode layer; meanwhile, the doping of the rhodium component can improve the grain boundary and electron movement characteristics of the internal structure of the solid electrolyte layer, so that the solid electrolyte layer has excellent fracture toughness and higher conductivity; the composite material is compounded with isolating buffer layer, oxygen pole layer and fuel pole layer to produce the solid oxide fuel cell with excellent electrochemical performance. Therefore, the invention is a solid electrolyte layer material with excellent thermal expansion coefficient and higher conductivity and fracture toughness, and the solid electrolyte layer material is compounded with the isolation buffer layer, the oxygen electrode layer and the fuel electrode layer to prepare the solid oxide type fuel cell, which has excellent electrochemical performance, namely higher maximum output power and current density.

Drawings

Fig. 1 is a schematic sectional structure view of a solid oxide fuel cell;

fig. 2 is an XRD pattern of the solid electrolyte layer materials in example 3 and comparative example 1;

FIG. 3 is an SEM photograph of a solid electrolyte layer in example 3;

fig. 4 is an SEM image of the oxygen electrode layer in example 6.

Reference numerals: 1. an oxygen electrode layer; 2. a solid electrolyte layer; 3. an isolation buffer layer; 4. a fuel electrode layer.

Detailed Description

To further illustrate the present invention, a solid oxide fuel cell according to the present invention will be described in detail with reference to the following examples, but it should be understood that the examples are carried out on the premise of the technical solution of the present invention, and the detailed embodiments and the specific operation procedures are given only for further illustrating the features and advantages of the present invention, not for limiting the claims of the present invention, and the scope of the present invention is not limited to the following examples.

In some embodiments of the invention, the starting materials are not specifically described, and are prepared according to conventional techniques or are commercially available. The cross-sectional structure of the solid oxide fuel cell of the present invention is schematically shown in FIG. 1, wherein the oxygen electrode layer 1 is BaCo_{1-m- n}Fe_mZr_nO_3-bMaterial, solid electrolyte layer 2 is La_0.9-x-yRh_xBa_ySr_0.1Ca_1-zMg_zO_3-aThe isolation buffer layer 3 is made of SDC material; the fuel electrode layer 4 is NiO/SDC material.

Example 1:

a method of manufacturing a solid oxide fuel cell, comprising the steps of:

in La_0.86Rh_0.02Ba_0.02Sr_0.1Ca_0.75Mg_0.25O_2.43Of solid electrolyte layersOne side is coated with a layer of SDC as an isolation buffer layer by adopting a screen printing technology, and then is sintered for 3 hours in a high-temperature furnace at 1000 ℃, and the thickness of the isolation buffer layer is measured to be 3.5 mu m; then, coating NiO/SDC fuel electrode layer material on the SDC layer by adopting a screen printing technology, and sintering the SDC layer in a high-temperature furnace at 1050 ℃ for 2.5 h; then coating BaCo on the other side of the solid electrolyte layer_0.85Fe_0.1Zr_0.05O_2.525And (3) placing the oxygen electrode layer material in a high-temperature furnace at 1050 ℃ for sintering for 4h, finally packaging the cell in an alumina tube by adopting DAD-87 conductive glue, and leading out two silver wires to be used as current collectors to obtain the solid oxide fuel cell.

Specifically, in the present embodiment, the solid electrolyte layer La_0.86Rh_0.02Ba_0.02Sr_0.1Ca_0.75Mg_0.25O_2.44The preparation method comprises the following steps: lanthanum oxide, rhodium oxide, barium carbonate, strontium carbonate, gallium oxide and magnesium oxide are put in a mortar according to the molar ratio of metal ions of 0.86:0.02:0.02:0.1:0.75:0.25 and ground for 8 hours to be uniformly mixed, then the mixture is put under a baking lamp to be baked, pressed into a wafer with the diameter of 15mm, then the wafer is sintered for 10 hours in a high-temperature furnace at 950 ℃, then the wafer is crushed and baked under the baking lamp, pressed into an electrolyte sheet under the pressure of 230MPa, and then the electrolyte sheet is sintered for 18 hours in a high-temperature furnace at 1350 ℃ to obtain a solid electrolyte layer, wherein the thickness of the solid electrolyte layer is 10 mu m.

Specifically, in this embodiment, the oxygen electrode layer material is BaCo_0.85Fe_0.1Zr_0.05O_2.525The preparation method comprises the following steps: barium nitrate, cobalt nitrate hexahydrate, ferric nitrate nonahydrate and zirconium nitrate anhydrous are placed in deionized water to be dissolved according to the molar ratio of metal cations of 1:0.85:0.1:0.05, then ethylene diamine tetraacetic acid and EDTA are added, wherein the molar ratio of the metal cations to the ethylene diamine tetraacetic acid to the EDTA is 1:1:2, the heating and stirring temperature is 45 ℃, the time is 30min, then the mixture is placed in a heating furnace to be presintered for 2h at 500 ℃, and then sintered for 4h at 1000 ℃ to obtain BaCo_0.85Fe_0.1Zr_0.05O_2.1A material.

Example 2:

a method for producing a solid oxide fuel cell, the other steps being the same as in example 1, except that:

specifically, in the present embodiment, the solid electrolyte layer La_0.86Rh_0.03Ba_0.01Sr_0.1Ca_0.75Mg_0.25O_2.445The preparation method comprises the following steps: lanthanum oxide, rhodium oxide, barium carbonate, strontium carbonate, gallium oxide and magnesium oxide are put in a mortar according to the molar ratio of metal ions of 0.86:0.03:0.01:0.1:0.75:0.25 and ground for 8 hours to be uniformly mixed, then the mixture is put under a baking lamp to be baked, pressed into a wafer with the diameter of 15mm, then the wafer is sintered for 10 hours in a high-temperature furnace at 950 ℃, then the wafer is crushed and baked under the baking lamp, an electrolyte sheet is pressed under the pressure of 230MPa, and the wafer is sintered for 18 hours in a high-temperature furnace at 1400 ℃, so that a solid electrolyte layer is obtained, wherein the thickness of the solid electrolyte layer is 10.5 mu m.

Example 3:

a method for producing a solid oxide fuel cell, the other steps being the same as those of example 2, except that:

specifically, in this embodiment, the oxygen electrode layer material is BaCo_0.7Fe_0.2Zr_0.1O_2.2The preparation method comprises the following steps: dissolving barium nitrate, cobalt nitrate hexahydrate, ferric nitrate nonahydrate and zirconium nitrate anhydrous in deionized water according to the molar ratio of metal cations of 1:0.7:0.2:0.1, adding ethylenediamine tetraacetic acid and EDTA (ethylene diamine tetraacetic acid), heating and stirring at 50 ℃ for 50min, pre-sintering at 550 ℃ for 2h, and sintering at 1100 ℃ for 5h to obtain BaCo_0.7Fe_0.2Zr_0.1O_2.2A material.

Example 4:

a method for producing a solid oxide fuel cell, the other steps being the same as in example 3, except that in example 3:

in La_0.86Rh_0.03Ba_0.01Sr_0.1Ca_0.75Mg_0.25O_2.445One side of the solid electrolyte layer is coated with a SDC layer as an isolation buffer by adopting a screen printing technologySintering the layer in a high temperature furnace at 1050 ℃ for 3h, and measuring the thickness of the layer to be 5.5 mu m; coating NiO/SDC fuel electrode layer material on the SDC layer by adopting a screen printing technology, and sintering the SDC layer in a high-temperature furnace at 1100 ℃ for 5 hours; then coating BaCo on the other side of the solid electrolyte layer_0.7Fe_0.2Zr_0.1O_2.2And (3) placing the oxygen electrode layer material in a high-temperature furnace at 1150 ℃ for sintering for 5h, finally packaging the cell in an alumina tube by adopting DAD-87 conductive glue, and leading out two silver wires to be used as current collectors to obtain the solid oxide fuel cell.

Example 5:

a method for producing a solid oxide fuel cell, the other steps being the same as in example 3, except that in example 3:

specifically, in this embodiment, the oxygen electrode layer material is BaCo_0.62Fe_0.2Zr_0.1Gd_0.08O_2.24The preparation method comprises the following steps: dissolving barium nitrate, cobalt nitrate hexahydrate, ferric nitrate nonahydrate, zirconium nitrate anhydrous and gadolinium nitrate hexahydrate in deionized water according to the molar ratio of metal cations of 1:0.62:0.2:0.1:0.08, adding ethylenediamine tetraacetic acid and EDTA (ethylene diamine tetraacetic acid) according to the molar ratio of the metal cations to the EDTA of 1:1:2, heating and stirring at 50 ℃ for 50min, pre-sintering the mixture in a heating furnace at 550 ℃ for 2h, and sintering the mixture at 1100 ℃ for 5h to obtain BaCo_0.62Fe_0.2Zr_0.1Gd_0.08O_2.24A material.

Example 6:

a method for producing a solid oxide fuel cell, the other steps being the same as in example 3, except that in example 3:

specifically, in this embodiment, the oxygen electrode layer material is BaCo_0.61Fe_0.2Zr_0.1Gd_0.09O_2.245The preparation method comprises the following steps: dissolving barium nitrate, cobalt nitrate hexahydrate, ferric nitrate nonahydrate, zirconium nitrate anhydrous hydrate and gadolinium nitrate hexahydrate in deionized water according to the molar ratio of metal cations of 1:0.61:0.2:0.1:0.09, and adding ethylenediamine tetraacetic acid and EDTA, wherein the metal cations and the ethylenediamine tetraacetic acid areThe molar ratio of acetic acid to EDTA is 1:1:2, the heating and stirring temperature is 50 ℃, the time is 50min, then the mixture is placed in a heating furnace and presintered at 550 ℃ for 2h, and then sintered at 1100 ℃ for 5h to obtain BaCo_0.61Fe_0.2Zr_0.1Gd_0.09O_2.245A material.

Example 7:

a method for producing a solid oxide fuel cell, the other steps being the same as in example 3, except that in example 3:

specifically, in this embodiment, the oxygen electrode layer material is BaCo_0.6Fe_0.2Zr_0.1Gd_0.1O_2.25The preparation method comprises the following steps: dissolving barium nitrate, cobalt nitrate hexahydrate, ferric nitrate nonahydrate, zirconium nitrate anhydrous and gadolinium nitrate hexahydrate in deionized water according to the molar ratio of metal cations of 1:0.6:0.2:0.1:0.1, adding ethylenediamine tetraacetic acid and EDTA (ethylene diamine tetraacetic acid) according to the molar ratio of the metal cations to the EDTA of 1:1:2, heating and stirring at 50 ℃ for 50min, pre-sintering the mixture in a heating furnace at 550 ℃ for 2h, and sintering the mixture at 1100 ℃ for 5h to obtain BaCo_0.6Fe_0.2Zr_0.1Gd_0.1O_2.25A material.

Example 8:

a method for producing a solid oxide fuel cell, the other steps being the same as in example 7, except that in example 7: specifically, in the present example, specifically, La was obtained without adding rhodium trioxide to the solid electrolyte layer in the present example_0.89Ba_0.01Sr_0.1Ca_0.75Mg_0.25O_2.445。

Comparative example 1:

a method for producing a solid oxide fuel cell, the other steps being the same as in example 3, except that in example 3: specifically, in this example, La was obtained without adding rhodium trioxide to the solid electrolyte layer_0.89Ba_0.01Sr_0.1Ca_0.75Mg_0.25O_2.445。

Test example 1:

1. determination of X-ray powder diffraction infrared spectrum of solid electrolyte layer material

Rigaku D/max rB X-ray diffractometer is adopted, CuK alpha is used as a ray source, the scanning range is 10-90 degrees, and the scanning speed is 8 degrees/min.

Fig. 2 is an XRD pattern of the solid electrolyte layer materials in example 3 and comparative example 1. Curves a and b are XRD patterns of the solid electrolyte layer materials in example 3 and comparative example 1, respectively; as can be seen from fig. 2, the solid electrolyte layer La in example 3_0.86Rh_{0.0 3}Ba_0.01Sr_0.1Ca_0.75Mg_0.25O_2.445La as a solid electrolyte layer material with respect to comparative example 1_0.89Ba_0.01Sr_0.1Ca_0.75Mg_{0.2 5}O_2.445The diffraction peak position of the optical element is shifted to the right probably because the solid electrolyte layer material is doped with Rh, the content of the Rh is more than or equal to 0.01 and less than or equal to 0.03, the unit cell volume is reduced, and the diffraction peak position is shifted to a high angle.

2. Determination of surface morphology of solid electrolyte layer material

And (3) observing the appearance of the surface of the sample by using a Quanta200 scanning electron microscope, wherein the accelerating voltage is 10 kV.

Fig. 3 is an SEM image of the solid electrolyte layer in example 3, and fig. 4 is an SEM image of the oxygen electrode layer in example 6. As can be seen from fig. 3, the solid electrolyte layer material is sintered compactly, the grains are tightly combined with each other, no obvious holes are formed, the grain size is uniform, and the grains can be clearly distinguished from the grain boundary; as can be seen from fig. 4, the oxygen electrode layer material in example 6 has a dense microstructure and no significant voids.

Test example 2:

1. measurement of thermal expansion coefficient of solid electrolyte layer and oxygen electrode layer

And placing the solid electrolyte layer and the oxygen electrode layer sample in a quartz groove, feeding the quartz groove into a constant temperature area of a horizontal resistance wire for heating, transferring thermal expansion displacement to a displacement sensor outside the furnace by a quartz rod, and recording data by an X-Y recorder connected with the sensor, wherein the test temperature range is from room temperature to 900 ℃.

TABLE 1 solid electrolyte layer and oxygenCoefficient of thermal expansion of the electrode layer (× 10)^-6/K)

Experimental group	Solid electrolyte layer	Oxygen electrode layer
			Example 1	15.3	18.6
Example 2	16.1	18.4
			Example 3	15.9	17.8
Example 4	16.0	17.8
			Example 5	16.1	16.9
Example 6	16.0	16.3
			Example 7	15.9	16.6
Example 8	13.5	16.7
			Comparative example 1	13.6	17.8

As can be seen from Table 1, the thermal expansion coefficients of the solid electrolyte layers in examples 1 to 4 were higher than 15X 10^-6A thermal expansion coefficient (average value between 500 ℃ and 900 ℃) of the conventional perovskite structure oxygen electrode and the common medium-low temperature oxygen electrode layer is 19.9 multiplied by 10^-6The difference of/K) is not large, namely the solid electrolyte layer prepared by the invention can be matched with the traditional perovskite structure oxygen electrode and the common medium-low temperature oxygen electrode layer; in addition, the thermal expansion coefficient of the oxygen electrode layer in the present invention is lower than 18.7X 10^-6The thermal expansion coefficient difference between the solid electrolyte layer and the solid electrolyte layer is small, so that the solid electrolyte layer and the solid electrolyte layer have good compatibility, and the physical and chemical properties of the solid oxide fuel cell are improved; the thermal expansion coefficients of the solid electrolyte layers in examples 2 to 7 were within the error range; comparing example 3 with comparative example 1, the thermal expansion coefficient of the solid electrolyte layer in example 3 is higher than that in comparative example 1, which shows that doping Rh in the solid electrolyte layer material, the content of which is 0.01. ltoreq. x.ltoreq.0.03, improves the thermal expansion coefficient of the solid electrolyte layer; comparing example 3 with examples 5-7, the thermal expansion coefficient of the oxygen electrode layer in examples 5-7 is lower than that in example 3, which shows that Gd is doped in the oxygen electrode layer material, the content of Gd is more than 0.05 and less than or equal to k and less than or equal to 0.1, the thermal expansion coefficient of the oxygen electrode layer is reduced, the thermal expansion coefficient of the oxygen electrode layer is enabled to be closer to that of the solid electrolyte layer, the compatibility of the oxygen electrode layer and the solid electrolyte layer is further improved, the matching degree is higher, and then the solid oxide type fuel cell with excellent performance is obtained.

2. Solid electrolyte layer conductivity performance testing

The conductivity of the sample at 750 ℃ in a hydrogen environment is tested by a current impedance method by adopting an electrochemical interface SI 1280.

TABLE 2 conductivity (S/cm) of solid electrolyte layer and oxygen electrode layer

Experimental group	Solid electrolyte layer	Oxygen electrode layer
			Example 1	0.041	0.030
Example 2	0.046	0.031
			Example 3	0.046	0.034
Example 4	0.045	0.033
			Example 5	0.046	0.042
Example 6	0.046	0.045
			Example 7	0.046	0.040
Example 8	0.027	0.041
			Comparative example 1	0.027	0.034

As can be seen from table 2, the conductivity of the solid electrolyte layer was higher than 0.04S/cm and the conductivity of the oxygen electrode layer was not lower than 0.03S/cm in examples 1 to 4, and the conductivity of the solid electrolyte layer was higher than that of comparative example 1 in comparative example 3 and comparative example 1, which shows that doping Rh, whose content is 0.01. ltoreq. x.ltoreq.0.03, in the solid electrolyte layer material improves the conductivity of the solid electrolyte layer to have excellent conductivity properties at 750 ℃; comparing example 3 with examples 5-7, the conductivity of the oxygen electrode layer in examples 5-7 is higher than that in example 3, which shows that Gd is doped in the oxygen electrode layer material, the content of Gd is more than 0.05 and less than or equal to k and less than or equal to 0.1, and the conductivity of the oxygen electrode layer is improved, so that the oxygen electrode layer has better matching property with the solid electrolyte, and the performance of the solid oxide fuel cell is further improved.

3. Fracture toughness Performance test of solid electrolyte layer

Measuring the fracture toughness by adopting an indentation method; indentation is carried out on an FM-700 type microhardness instrument, the load is 1Kg, and the loading time is 25 s. A2.5 Kg load was applied to a Vickers hardness tester type HVA-10A, and cracks were generated for 25 seconds. Calculating K according to the indentation load P and the indentation crack propagation length 2C_ICThe calculation formula is as follows:

Hv＝1.854×9.8×P/(d×10^-3)²

K_IC＝0.319P/(al^1/2)

in the formula: hv isVickers hardness, MPa; p is load, Kg; d is the average value of the length of the diagonal line, mm; k_ICFor fracture toughness, MPa.m^1/2(ii) a a is half the length of the diagonal, mm; l is half the crack length, mm; crack length and strike were observed with SEM.

TABLE 3 fracture toughness (MPa. m) of solid electrolyte layer^1/2)

Experimental group	Fracture toughness
		Example 1	6.95
Example 2	7.28
		Comparative example 1	4.63

As can be seen from Table 3, the fracture toughness of the solid electrolyte layer in examples 1-2 was higher than 6.9MPa · m^1/2Comparing example 2 with comparative example 1, the fracture toughness of the solid electrolyte layer in example 2 is higher than that of comparative example 1, which shows that doping Rh in the solid electrolyte layer material, wherein x is more than or equal to 0.01 and less than or equal to 0.03, improves the fracture toughness of the solid electrolyte layer and enables the solid electrolyte layer to have more excellent mechanical properties.

4. Electrochemical performance testing of solid oxide fuel cells

The test was performed with an electronic load 2400(IT8511+) of edx. The test temperature is 700 ℃ and 600 ℃, hydrogen is used as fuel and air is used as oxidant, the flow of the hydrogen is controlled at 80-110ml/min, and the air pressure is standard atmospheric pressure.

TABLE 4 electrochemical Performance of solid oxide Fuel cells

Experimental group	Maximum output power (mW/cm)2)	Current Density (mA/cm)2)
			Example 1	552	1237
Example 2	555	1242
			Example 3	563	1251
Example 4	560	1248
			Example 5	571	1272
Example 6	577	1280
			Example 7	576	1275
Example 8	512	1039
			Comparative example 1	498	1016

As can be seen from Table 5, the maximum output power of the fuel cells in examples 1-4 in the range of 700 ℃ and 600 ℃ was higher than 550mW/cm²The current density is higher than 1235mA/cm²Comparing example 3 with comparative example 1, the maximum output power and current density of the fuel cell in example 3 are higher than those in comparative example 1, which shows that Rh is doped in the solid electrolyte layer material, the content of the Rh is 0.01-0.03, and the Rh is compounded with the isolation buffer layer, the oxygen electrode layer and the fuel electrode layer to prepare the solid oxide type fuel cell, so that the electrochemical performance of the fuel cell is improved; the maximum output power in the range of 700-600 ℃ in examples 5-7 is higher than 570mW/cm²The current density is higher than 1270mA/cm²Comparing example 3 with examples 5 to 7, and example 8 with comparative example 1, the maximum output power and current density of the fuel cell in examples 5 to 7 are higher than those in example 3, and the maximum output power and current density of the fuel cell in example 8 are higher than those in comparative example 1, which shows that Gd is doped in the oxygen electrode layer material, the content of Gd is more than 0.05 and less than or equal to k and less than or equal to 0.1, and the Gd is compounded with the isolation buffer layer, the solid electrolyte layer and the fuel electrode layer to prepare the solid oxide fuel cell, so that the electrochemical performance of the solid oxide fuel cell is further improved.

Conventional operations in the operation steps of the present invention are well known to those skilled in the art and will not be described herein.

The above embodiments are merely illustrative, and not restrictive, and those skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, all equivalent technical solutions also belong to the scope of the present invention, and the protection scope of the present invention should be defined by the claims.