阅读说明：本技术 一种新型结构的固体氧化物燃料电池及其制备方法 (Solid oxide fuel cell with novel structure and preparation method thereof ) 是由 杨晓幸 袁金良 苗鹤 于 2020-05-09 设计创作，主要内容包括：本发明公开了一种新型结构的固体氧化物燃料电池,所述固体氧化物燃料电池由中间层及对称设置在所述中间层两侧的阴极层和阳极层组成；所述中间层为结构致密的YbSZ电解质基板,所述阴极层和阳极层均为浸渍有电极材料的YbSZ电解质薄片,所述YbSZ电解质薄片为疏松多孔结构。本发明的新型结构的固体氧化物燃料电池,结构设计新颖独特,具有稳定性强、运行寿命长和制造成本低的优点,可满足固体氧化物燃料电池长期稳定运行的要求。本发明还公开了一种该新型结构的固体氧化物燃料电池的制备方法。(The invention discloses a solid oxide fuel cell with a novel structure, which consists of an intermediate layer, and a cathode layer and an anode layer which are symmetrically arranged at the two sides of the intermediate layer; the middle layer is a dense-structure YbSZ electrolyte substrate, the cathode layer and the anode layer are YbSZ electrolyte sheets soaked with electrode materials, and the YbSZ electrolyte sheets are loose and porous structures. The solid oxide fuel cell with the novel structure has the advantages of novel and unique structural design, strong stability, long service life and low manufacturing cost, and can meet the requirement of long-term stable operation of the solid oxide fuel cell. The invention also discloses a preparation method of the solid oxide fuel cell with the novel structure.)

1. The solid oxide fuel cell with the novel structure is characterized by comprising an intermediate layer, and a cathode layer and an anode layer which are symmetrically arranged on two sides of the intermediate layer; the middle layer is a dense-structure YbSZ electrolyte substrate, the cathode layer and the anode layer are YbSZ electrolyte sheets soaked with electrode materials, and the YbSZ electrolyte sheets are loose and porous structures.

2. The solid oxide fuel cell with the novel structure as claimed in claim 1, wherein the intermediate layer is a raw material of zirconium hydroxide, ytterbium acetate tetrahydrate, 2-butanone, ethanol, polyvinyl butyral and dibutyl phthalate, and is prepared into a dense-structure YbSZ electrolyte substrate green body by a casting method.

3. The solid oxide fuel cell with the novel structure according to claim 2, wherein the molar ratio of the zirconium hydroxide to the ytterbium acetate tetrahydrate is 1:8.5 to 10.5, the volume ratio of the 2-butanone to the ethanol is 1 to 3:1, and the mass ratio of the 5YbSZ powder composed of the zirconium hydroxide and the ytterbium acetate tetrahydrate to the mixed solvent composed of the 2-butanone and the ethanol to the polyvinyl butyral and the dibutyl phthalate is 100:50 to 70:2 to 4:1 to 3.

4. The solid oxide fuel cell of the novel structure according to claim 1, wherein the intermediate layer is prepared by a method comprising: calcining zirconium hydroxide at 450-550 ℃ for 2h to obtain zirconium oxide, performing ball milling on the zirconium oxide and ytterbium acetate tetrahydrate for 12h at a molar ratio of 1: 8.5-10.5, drying at 400 ℃ for 4h, crushing, calcining at 1050-1250 ℃ for 2h, and cooling to obtain 5YbSZ powder; mixing 2-butanone and ethanol according to a volume ratio of 1-3: 1 to obtain a uniform mixed solvent; finally, mixing the prepared 5YbSZ powder and mixed solvent with polyvinyl butyral and dibutyl phthalate according to the mass ratio of 100: 50-70: 2-4: 1-3, and performing ball milling for 12-20 hours to prepare electrolyte slurry; and preparing the electrolyte slurry into the intermediate layer by a tape casting method.

5. The solid oxide fuel cell of the novel structure of claim 1, wherein the porosity of the YbSZ electrolyte sheet of the porous structure is 30% to 60% in both the cathode layer and the anode layer.

6. The solid oxide fuel cell of the novel structure of claim 1, wherein the YbSZ electrolyte sheet of the porous structure is prepared by a casting method using zirconium hydroxide, ytterbium acetate tetrahydrate, 2-butanone, ethanol, polyvinyl butyral, dibutyl phthalate, and starch as raw materials.

7. The solid oxide fuel cell with the novel structure according to claim 6, wherein the molar ratio of the zirconium hydroxide to the ytterbium acetate tetrahydrate is 1: 8.5-10.5, the volume ratio of the 2-butanone to the ethanol is 1-3: 1, the mass ratio of the 5YbSZ powder composed of the zirconium hydroxide and the ytterbium acetate tetrahydrate to the mixed solvent composed of the 2-butanone and the ethanol to the polyvinyl butyral and the dibutyl phthalate is 100: 50-70: 2-4: 1-3, and the addition amount of the starch accounts for 10% -50% of the total mass of the 5YbSZ powder, the mixed solvent, the polyvinyl butyral and the dibutyl phthalate.

8. The solid oxide fuel cell with a novel structure as claimed in claim 1, wherein the preparation method of the YbSZ electrolyte sheet with a loose porous structure comprises the following steps: calcining zirconium hydroxide at 450-550 ℃ for 2h to obtain zirconium oxide, performing ball milling on the zirconium oxide and ytterbium acetate tetrahydrate for 12h at a molar ratio of 1: 8.5-10.5, drying at 400 ℃ for 4h, crushing, calcining at 1050-1250 ℃ for 2h, and cooling to obtain 5YbSZ powder; mixing 2-butanone and ethanol according to a volume ratio of 1-3: 1 to obtain a uniform mixed solvent; finally, mixing the prepared 5YbSZ powder and mixed solvent with polyvinyl butyral and dibutyl phthalate according to the mass ratio of 100: 50-70: 2-4: 1-3, and performing ball milling for 12-20 hours to prepare electrolyte slurry; adding starch into the electrolyte slurry according to the mass ratio of 10% -50%, continuing ball milling for 6-10 h, and preparing the YbSZ electrolyte sheet green compact with the loose porous structure by a tape casting method.

9. The solid oxide fuel cell of the novel structure of claim 1, wherein the electrode material is PrBaCo₂O₅₊、(SmPr)FeO₃And one or more of SrCoFeOx.

10. A method for manufacturing a solid oxide fuel cell of a novel structure according to claim 1, comprising the steps of:

preparing a S1 dense YbSZ electrolyte substrate: calcining zirconium hydroxide at 450-550 ℃ for 2h to obtain zirconium oxide, performing ball milling on the zirconium oxide and ytterbium acetate tetrahydrate for 12h at a molar ratio of 1: 8.5-10.5, drying at 400 ℃ for 4h, crushing, calcining at 1050-1250 ℃ for 2h, and cooling to obtain 5YbSZ powder; mixing 2-butanone and ethanol according to a volume ratio of 1-3: 1 to obtain a uniform mixed solvent; finally, mixing the prepared 5YbSZ powder and mixed solvent with polyvinyl butyral and dibutyl phthalate according to the mass ratio of 100: 50-70: 2-4: 1-3, and performing ball milling for 12-20 hours to prepare electrolyte slurry; preparing a part of the electrolyte slurry by a tape casting method to obtain a YbSZ electrolyte substrate green compact with a compact structure;

preparing a YbSZ electrolyte sheet with an S2 loose porous structure: taking the residual electrolyte slurry obtained in the step S1, adding starch into the electrolyte slurry according to the mass ratio of 10% -50%, continuing ball milling for 6-10 h, and preparing the YbSZ electrolyte sheet green compact with the loose porous structure by a tape casting method;

preparation of S3 SSOFC structural framework: pressing the YbSZ electrolyte substrate green compact with the compact structure prepared in the step S1 and the YbSZ electrolyte sheet green compact with the loose porous structure prepared in the step S2 according to the structure of the loose porous YbSZ/compact YbSZ/loose porous YbSZ to obtain the SSOFC structural frame;

preparation of a solid oxide fuel cell SSOFC with a novel structure of S4: and impregnating the SSOFC structural frame with an electrode material, taking out the SSOFC structural frame after the impregnation is finished, putting the SSOFC structural frame into an oven at the constant temperature of 200 ℃ for 12 hours to obtain the primarily impregnated SSOFC structural frame, and co-roasting the primarily impregnated SSOFC structural frame in an air atmosphere at the temperature of 1000-1200 ℃ for 5-7 hours to obtain the complete SSOFC of the solid oxide fuel cell with the novel structure.

Technical Field

The invention relates to the technical field of solid oxide fuel cells, in particular to a solid oxide fuel cell with a novel structure and a preparation method thereof.

Background

A Solid Oxide Fuel Cell (SOFC) is an existing energy conversion device that directly converts chemical energy into electrical energy, and has an advantage of a wide range of applications. Although the current commercial SOFC (i.e., the conventional SOFC) can exhibit excellent power output density and good stability even under high-temperature operating conditions, the cost and profitability are fundamental to the commercial application as a commercial battery, whereas the conventional SOFC has a multilayer structure, and not only is the manufacturing process complicated, but also the cost is relatively high. In addition, conventional SOFCs operate under prior art conditions, and the cell is prone to stress imbalance during thermal cycling and redox cycling, which can deform or even crack the cell, resulting in rapid degradation of the cell performance or even failure to function properly. The conventional SOFC has a problem that the requirement on fuel gas is relatively high, and H with relatively high purity is generally selected₂If fuel gas such as natural gas or hydrocarbon is used, sulfur poisoning and carbon deposition of the battery are likely to occur.

In view of the above, it is desirable to provide a solid oxide fuel cell with high stability, long operation life and low manufacturing cost, so as to improve the stability and operation life of the solid oxide fuel cell during operation.

Disclosure of Invention

In view of the defects of the prior art, the invention provides a solid oxide fuel cell with a novel structure and a preparation method thereof, and aims to solve the problems of weak stability, short service life and high manufacturing cost of the conventional solid oxide fuel cell.

In order to achieve the above purposes, the technical scheme adopted by the invention is as follows:

a solid oxide fuel cell with a novel structure is composed of an intermediate layer, and a cathode layer and an anode layer which are symmetrically arranged at two sides of the intermediate layer; the middle layer is a dense YbSZ electrolyte substrate with porosity of 8-10%, the cathode layer and the anode layer are YbSZ electrolyte sheets impregnated with electrode materials, and the YbSZ electrolyte sheets are loose porous structures.

The preparation method of the intermediate layer comprises the following steps: calcining zirconium hydroxide at 450-550 ℃ for 2h to obtain zirconium oxide, wherein the zirconium oxide and ytterbium acetate tetrahydrate (Yb (Ac)₃·4H₂O) performing ball milling for 12 hours according to the molar ratio of 1: 8.5-10.5, then drying for 4 hours at 400 ℃, crushing, then calcining for 2 hours at 1050-1250 ℃, and cooling to obtain 5YbSZ powder; mixing 2-ketobutyric acid and ethanol according to the volume ratio of 1-3: 1 to obtain a uniform mixed solvent; finally, mixing the prepared 5YbSZ powder and mixed solvent with polyvinyl butyral and dibutyl phthalate according to the mass ratio of 100: 50-70: 2-4: 1-3, and performing ball milling for 12-20 hours to prepare electrolyte slurry; and preparing the electrolyte slurry into the intermediate layer by a tape casting method.

The thickness of the middle layer is 60-150 mu m.

The preparation method of the YbSZ electrolyte sheet with the loose porous structure comprises the following steps: calcining zirconium hydroxide at 450-550 ℃ for 2h to obtain zirconium oxide, wherein the zirconium oxide and ytterbium acetate tetrahydrate (Yb (Ac)₃·4H₂O) performing ball milling for 12 hours according to the molar ratio of 1: 8.5-10.5, then drying for 4 hours at 400 ℃, crushing, then calcining for 2 hours at 1050-1250 ℃, and cooling to obtain 5YbSZ powder; mixing 2-ketobutyric acid and ethanol according to the volume ratio of 1-3: 1 to obtain a uniform mixed solvent; finally, mixing the prepared 5YbSZ powder and mixed solvent with polyvinyl butyral and dibutyl phthalate according to the mass ratio of 100: 50-70: 2-4: 1-3, and performing ball milling for 12-20 hours to prepare electrolyte slurry; adding starch into the electrolyte slurry according to the mass ratio of 10% -50%, continuing ball milling for 6-10 h, and preparing the YbSZ electrolyte sheet with the loose porous structure by a tape casting method.

In the cathode layer and the anode layer, the thickness of the YbSZ electrolyte sheet with a loose porous structure is 60-90 mu m.

In the cathode layer and the anode layer, the porosity of the YbSZ electrolyte sheet with a loose porous structure is 30-60%.

The electrode material is PrBaCo2O₅₊、(SmPr)FeO₃And one or more of SrCoFeOx.

The PrBaCo₂O₅₊The preparation method of the electrode material comprises the following steps: first, according to PrBaCo₂O₅₊The stoichiometric ratio in the chemical formula respectively weighs a certain amount of Pr₆O₁₁、Ba(NO₃)₂And Co (NO)₃)₂·6H₂Weighing the amount of EDTA and citric acid according to the molar mass ratio of the metal ions to the EDTA and the citric acid of 1:1: 1.5; adding EDTA into a beaker of about 300mL of deionized water, heating the EDTA to 85 ℃ in a water bath, continuously stirring, and adding a proper amount of ammonia water to fully dissolve the EDTA; then, Pr is added₆O₁₁Dissolving in diluted nitric acid to form Pr (NO)₃)₃Solution of Pr (NO)₃)₃Solution, Ba (NO)₃)₂Solution and Co (NO)₃)₂·6H₂Pouring O into the beakers respectively to form mixed liquid; and finally, adding citric acid, adjusting the pH value to 6-7 by using ammonia water, and stirring the prepared mixed solution by using a magnetic stirrer to continuously evaporate water until a purple red gel mixed solution is formed. Putting the gel into an oven at the constant temperature of 200 ℃ for 12h to obtain a black spongy precursor, and roasting the precursor in the air at the temperature of 1100 ℃ for 6h to obtain black PBCO powder, namely the PrBaCo powder₂O₅₊An electrode material.

The (SmPr) FeO₃The preparation method of the electrode material comprises the following steps: mixing Sm₂O₃、Pr(NO₃)₃And Fe (NO)₃)₂Dissolving the mixture in distilled water according to a theoretical stoichiometric ratio, adding ethylene glycol and citric acid (the mass ratio of total metal ions to the ethylene glycol to the citric acid is 1: 1.7-1.9: 1.4-1.6), completely dissolving the mixture under magnetic stirring, and adjusting the pH value of the mixed solution to 7 by using ammonia water and nitric acid to avoid precipitation; then putting the solution into a water bath kettle with the constant temperature of 80 ℃ and stirring for 5 hours to change the transparent solution into sol; exposing the sol in a beaker to air, heating the sol on a heating plate to 400 ℃ and spontaneous combustion to obtain fluffy (SmPr) FeO₃A precursor; putting the grinded precursor into a high-temperature box type resistorRoasting at 900-1000 ℃ for 5h in a furnace at the heating rate of 2 ℃/min to obtain the required powder; dissolving the calcined powder in ethanol, ball-milling for 48h, and calcining to obtain (SmPr) FeO₃An electrode material.

The preparation method of the SrCoFeOx electrode material comprises the following steps: sr (NO)₃)₂，Co(NO₃)₂·6H₂0 and Fe (NO)₃)₂·9H₂0 is dissolved in distilled water according to the theoretical stoichiometric ratio, and ethylene glycol and citric acid (the ratio of the total metal ions to the substances of ethylene glycol and citric acid is 1: 1.6-1.9: 1.3-1.7) are added to be completely dissolved under magnetic stirring. Adjusting the pH value of the mixed solution to 7 by ammonia water and nitric acid to avoid precipitation; then putting the solution into a water bath kettle with the constant temperature of 80 ℃ and stirring for 5 hours to change the transparent solution into sol; the sol is put in a beaker and exposed in the air, and is put on a heating plate to be heated to 400 ℃ for spontaneous combustion, so as to obtain a fluffy SrCoFeOx precursor; placing the grinded precursor into a high-temperature box-type resistance furnace, roasting for 5h at the temperature of 900-; and dissolving the calcined powder in ethanol, performing ball milling for 48 hours, and calcining to obtain the SrCoFeOx electrode material.

A method for preparing a solid oxide fuel cell having a novel structure as described above, comprising the steps of:

preparing a S1 dense YbSZ electrolyte substrate: calcining zirconium hydroxide at 450-550 ℃ for 2h to obtain zirconium oxide, wherein the zirconium oxide and ytterbium acetate tetrahydrate (Yb (Ac)₃·4H₂O) performing ball milling for 12 hours according to the molar ratio of 1: 8.5-10.5, then drying for 4 hours at 400 ℃, crushing, then calcining for 2 hours at 1050-1250 ℃, and cooling to obtain 5YbSZ powder; mixing 2-butanone and ethanol according to a volume ratio of 1-3: 1 to obtain a uniform mixed solvent; finally, mixing the prepared 5YbSZ powder and mixed solvent with polyvinyl butyral and dibutyl phthalate according to the mass ratio of 100: 50-70: 2-4: 1-3, and performing ball milling for 12-20 hours to prepare electrolyte slurry; preparing part of the electrolyte slurry by a tape casting method to obtainA compact-structure YbSZ electrolyte substrate green body;

preparing a YbSZ electrolyte sheet with an S2 loose porous structure: taking the residual electrolyte slurry obtained in the step S1, adding starch into the electrolyte slurry according to the mass ratio of 10% -50%, continuing ball milling for 6-10 h, and preparing the YbSZ electrolyte sheet green compact with the loose porous structure by a tape casting method;

preparation of S3 SSOFC structural framework: pressing the YbSZ electrolyte substrate green compact with the compact structure prepared in the step S1 and the YbSZ electrolyte sheet green compact with the loose porous structure prepared in the step S2 according to the structure of the loose porous YbSZ/compact YbSZ/loose porous YbSZ to obtain the SSOFC structural frame;

preparation of a solid oxide fuel cell SSOFC with a novel structure of S4: and impregnating the SSOFC structural frame with an electrode material, taking out the SSOFC structural frame after the impregnation is finished, putting the SSOFC structural frame into an oven at the constant temperature of 200 ℃ for 12 hours to obtain the primarily impregnated SSOFC structural frame, and co-roasting the primarily impregnated SSOFC structural frame in an air atmosphere at the temperature of 1000-1200 ℃ for 5-7 hours to obtain the complete SSOFC of the solid oxide fuel cell with the novel structure.

The invention relates to a solid oxide fuel cell (SSOFC) with a novel structure, wherein the SSOFC is divided into 3 layers in total, a dense YbSZ electrolyte is adopted as a support in the middle layer, loose and porous YbSZ electrolytes are adopted in the cathode layer and the anode layer on both sides, and an electrode material PrBaCo is impregnated in the YbSZ electrolyte₂O₅₊(PBCO)、(SmPr)FeO₃(SPFO), SrCoFeOx (SCFO). Compared with the traditional SOFC, the symmetric cell (SSOFC) adopts a structure with compact and loose and porous two electrodes in the middle, and adopts an impregnation method to impregnate two electrode materials, so that a single cell can be prepared by one-step co-firing, and the cost problem caused by multiple times of roasting is avoided; because almost no interface exists between the electrolyte and the electrode, the SSOFC has better adaptability in the process of thermal cycle and oxidation reduction, and can ensure more stable operation of the SSOFC; in addition, the Symmetrical Solid Oxide Fuel Cell (SSOFC) with the novel structure adopts perovskite as a bipolar impregnation material, and carbon deposition and sulfur generated by carbon-based fuel in the long-term operation of the cell are slowed downPoisoning, increasing its operating life.

The solid oxide fuel cell with the novel structure has good stability when working at the temperature of 600-900 ℃, and has good adaptability to carbon-based fuel, so that the type of fuel gas applicable to the SSOFC is more diversified.

The invention has the beneficial effects that:

the solid oxide fuel cell with the novel structure uses a symmetrical structure, and two electrodes adopt the same electrode material, so that the preparation process of the cell is simplified, and the manufacturing cost is reduced.

The solid oxide fuel cell with the novel structure has almost no interface between the electrolyte and the electrode material, improves the problems of chemical compatibility and thermal matching of the cell component, and improves the stability of the cell.

According to the solid oxide fuel cell with the novel structure, the anode/cathode is made of perovskite materials, so that the problems of carbon deposition and sulfur poisoning of carbon-based fuel in the long-term operation of the cell can be relieved, and the service life of the cell is prolonged.

Drawings

FIG. 1 shows the I-P-V curves of the cell discharge test of the battery of example 1 of the present invention at different temperatures;

FIG. 2 shows the I-P-V curves of the cell discharge test of the battery of example 2 of the present invention at different temperatures;

FIG. 3 shows the I-P-V curves of the cell discharge test of the battery of example 3 of the present invention at different temperatures;

FIG. 4 shows the I-P-V curves of the cell discharge test of comparative example 1 of the present invention at various temperatures;

FIG. 5 shows that the cell of example 1 of the present invention was operated at a constant current density of 0.1A/cm at 800 deg.C²) A discharge cycling stability test curve;

FIG. 6 shows that the cell of example 2 of the present invention has a constant current density (0.1A/cm) at 800 deg.C²) A discharge cycling stability test curve;

FIG. 7 shows that the cell of example 3 of the present invention was operated at a constant current density of 800 ℃ (0.1A/cm)²) PutElectrical cycling stability test curves;

FIG. 8 is a graph showing that the cell of comparative example 1 of the present invention was operated at a constant current density of 0.1A/cm at 800 deg.C²) Cycling stability test curve for discharge.

Detailed Description

The following description is presented to disclose the invention so as to enable any person skilled in the art to practice the invention. The preferred embodiments in the following description are given by way of example only, and other obvious variations will occur to those skilled in the art.