An anode layer, a preparation method and application thereof

Abstract

The application relates to an anode layer and a preparation method and application thereof, and belongs to the technical field of solid oxide batteries. The preparation raw material of the anode layer provided by the application comprises the following components in percentage by mass: ceramic powder 20-38%, nickel oxide powder 10-20%, solvent 30-40%, resin compound 6-10%, dispersant 5-10%, and the balance is plasticizer; the resin compound comprises an additive and a polymer wrapped on the surface of the additive; the additive comprises a perovskite type oxide. By using the resin compound containing the specific additive, the size and distribution of the pores contained in the anode layer can be well controlled, so that the anode-supported battery has excellent electrical performance and a prolonged service life.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of solid oxide cells, and particularly relates to an anode layer and a preparation method and application thereof. BACKGROUND

[0002] Solid oxide cells include solid oxide fuel cells (SOFC) and solid oxide electrolysis cells (SOEC), which are high-efficiency and environmentally friendly full-solid-state chemical power generation devices, and anode-supported flat cells are widely studied, in which an anode layer in the cell structure is used as a support of a single cell overall structure, and an electrolyte layer is thinned to reduce the internal resistance of the cell and improve the output power of the cell.

[0003] In order to ensure that the solid oxide cell has high power output and good mechanical strength, the anode layer as the support should have appropriate porosity and support strength. In the preparation process, since the pores obtained by sintering the material of the anode layer are too few to meet the required porosity, an organic pore former such as carbon black or starch is selected to increase the porosity of the anode, but the shape of the pore former particles directly determines the morphology of the anode pores. The existing pore former particles have poor uniformity, and after sintering, irregularly sized and unevenly distributed pores are generated in the anode layer, which is not conducive to the transmission of gas in the reaction. In order to increase the porosity of the anode layer, a large amount of pore former is often used, and the excessive amount of pore former generates a large amount of heat during sintering, causing internal stress in the anode layer and causing the cell to crack. In addition, the increase in the porosity of the anode layer also leads to a decrease in the mechanical strength of the anode layer, which cannot guarantee the support strength, thereby affecting the overall electrical performance and service life of the cell. In addition, after the solid oxide cell burns fuel gas of a hydrocarbon type, carbon particles are easily generated inside the pores of the anode layer and deposited in the pore walls. When running for a long time in a high-temperature environment, the accumulated carbon covers the surface of the nickel metal or causes blockage of the gas passage, thereby reducing the reaction efficiency. At the same time, after a long time of running, the sulfur generated by combustion accumulates and reacts with nickel, causing poisoning, which may also lead to a decrease in electrochemical oxidation activity and stability, which has great limitations on improving the electrical performance and service life of the solid oxide cell. SUMMARY

[0004] The purpose of the present application is to overcome the problems existing in the prior art, and to provide an anode layer and a preparation method and application thereof.

[0005] The present application is realized by the following technical solutions:

[0006] In a first aspect, the present application provides an anode layer, the raw material for preparing the anode layer comprises the following components in mass percentage: ceramic powder 20-38%, nickel oxide powder 10-20%, solvent 30-40%, resin composite 6-10%, dispersant 5-10%, and the balance is plasticizer; the resin composite comprises an additive and a polymer wrapped on the surface of the additive; the additive comprises a perovskite oxide.

[0007] By using the resin composite containing the specific additive as the raw material for preparing the anode layer, the present application can achieve good regulation of the size and distribution of the pores contained in the anode layer, so that the electrical performance of the anode-supported battery is good and the service life is prolonged. The resin composite is prepared by wrapping the additive with a polymer, and then the anode layer is prepared. On the one hand, based on the uniform distribution of the polymer component in the resin composite inside the anode layer, after the glue removal is completely decomposed, uniform distributed pores are presented, the micro-pore structure presents single-shaped circular pores, the porosity and support strength are good in controllability, the interconnection between the pores is good, which is beneficial to the gas transmission in the reaction, speeds up the reaction speed to improve the electrical performance of the battery, and avoids the adverse effects caused by the excessive amount of traditional organic pore-forming agent or the uncontrollable shape. On the other hand, the perovskite oxide additive wrapped in the resin composite will be deposited on the inner wall to form a uniform protective layer while the pores are formed, which modifies the pores and improves the stability of the internal structure. On the basis of further improving the porosity, the requirement for support strength is met at the same time. The perovskite oxide deposited and covered in the pore wall makes the surface have rich oxygen vacancies, which can provide faster charge transfer rate for the oxidation-reduction reaction, improve the electronic conductivity and catalytic activity, improve the fuel gas combustion efficiency, reduce the generation of carbon particles, keep the gas passage of the pores good and not gradually deteriorate with the extension of the reaction time. In addition, the perovskite oxide additive contains lattice oxygen and adsorbed oxygen on the surface, which reacts with hydrogen sulfide gas to adsorb a small amount of H2S in the fuel to generate a sulfide layer, thereby inhibiting the reaction of hydrogen sulfide with nickel to cause nickel poisoning, and improving the anti-carbon deposition performance and anti-sulfur effect of the anode layer. Therefore, by adding the resin composite and reasonably compounding with other components to prepare the anode layer, the electrical performance and service life of the anode-supported battery are further optimized and improved.

[0008] When the resin composite content is too low, the porosity formed by sintering is small, which reduces the gas pore connectivity in the formed anode support layer structure, hinders the diffusion of fuel gas, and does not meet the gas diffusion requirements. In addition, the content of the wrapped additives is too low to achieve the anti-carbon deposition and anti-poisoning effects, making it difficult to achieve the purpose of extending the service life. When the resin composite content is too large, due to too many connected pores, the anode support structure collapses to a certain extent, the support strength decreases, and the excessive porosity increases the thermal expansion coefficient of the anode support layer, which does not match the electrolyte and causes the battery to crack. At the same time, too many additives are deposited on the inside of the pores, hindering the original redox reaction and reducing the service life of the battery.

[0009] Preferably, the perovskite oxide includes at least one of a single perovskite oxide and a double perovskite oxide; the single perovskite oxide includes at least one of LaTiO3 and LaMoO3, and the double perovskite oxide includes at least one of Sr2MgMoO6 (SMM), Sr2FeMoO6 (SFM), Sr2NiMoO6 (SNM), and Sr2CoMoO6 (SCM).

[0010] Preferably, the particle size D50 of the resin composite is 5-8 μm.

[0011] Preferably, the polymer includes at least one of polystyrene, polymethyl methacrylate, and polyvinyl chloride.

[0012] More preferably, the resin composite is obtained by suspending in-situ polymerization of resin monomers into the polymer to wrap the additive.

[0013] Preferably, the resin monomer includes at least one of styrene, methyl methacrylate, and chloroethylene.

[0014] Preferably, the mass ratio of the additive to the resin monomer is 1:(2-5); further preferably, the mass ratio of the additive to the resin monomer is 1:(2-4).

[0015] Preferably, the ceramic powder is yttria-stabilized zirconia ceramic powder; optionally, the ceramic powder includes at least one of 3YSZ, 5YSZ, 8YSZ, and 10YSZ.

[0016] Preferably, the particle size D50 of the ceramic powder is 1-10 μm; more preferably, the particle size D50 of the ceramic powder is 1-3 μm.

[0017] Preferably, the particle size D50 of the nickel oxide powder is 1-10 μm; more preferably, the particle size D50 of the nickel oxide powder is 1-3 μm.

[0018] Preferably, the solvent comprises at least one of methanol, ethanol, isopropanol, toluene, ethyl acetate, acetone.

[0019] Preferably, the dispersant comprises at least one of triethanolamine, cellulose derivatives, alkyl aryl sulfonate, polyethylene glycol (PEG).

[0020] Preferably, the plasticizer comprises at least one of n-butyl phthalate (DBP), n-octyl phthalate (DOP).

[0021] In a second aspect, the present application provides a preparation method of the anode layer, comprising the following steps:

[0022] (1) mixing ceramic powder, nickel oxide powder, resin compound, solvent, dispersant and plasticizer uniformly according to the mass ratio to obtain anode layer slurry;

[0023] (2) casting the anode layer slurry obtained in step (1) into a green body, drying and then sintering to obtain the anode layer.

[0024] Preferably, in step (1), the viscosity of the anode layer slurry is 2 Pa·s-4 Pa·s.

[0025] Preferably, in step (2), the thickness of the green body is 200 μm-350 μm.

[0026] Preferably, in step (2), the sintering conditions are as follows: heating at a rate of 30 ℃ / h-60 ℃ / h to 300 ℃-500 ℃, holding for 4 h-8 h, then heating to 1300 ℃-1500 ℃, holding for 8 h-12 h.

[0027] Preferably, the preparation method of the resin compound comprises the following steps: uniformly mixing solvent, additive and silane coupling agent at 80 ℃-85 ℃, then slowly adding a mixed solution of monomer, initiator and crosslinking agent, reacting for 24 h-36 h, and then grinding after washing and drying to obtain the resin compound.

[0028] In a third aspect, the present application provides an anode-supported battery comprising the anode layer.

[0029] Preferably, the preparation method of the anode-supported battery comprises the following steps:

[0030] S1. preparing an electrolyte layer on the anode layer, obtaining a half battery green body after laminating and hot pressing, and obtaining a half battery after degassing and sintering;

[0031] S2. printing an LSCF cathode on the half battery obtained in step S1 by silk screen printing, and sintering to obtain the anode-supported battery.

[0032] Preferably, in the step S1, the thickness of the electrolyte layer is 10-30 μm.

[0033] Preferably, in the step S1, the conditions of the glue removal sintering are as follows: heating at a rate of 30-60 ℃ / h to 300-500 ℃, holding for 4-8 h, and then heating to 1300-1500 ℃, holding for 8-12 h.

[0034] Preferably, in the step S2, the thickness of the cathode is 20-50 μm; and the sintering temperature is 1000-1100 ℃.

[0035] The present application has the following advantages:

[0036] The present application can realize good regulation of the size and distribution of the pores contained in the anode layer by using the resin composite containing the specific additive, so that the anode-supported battery has excellent electrical performance and prolonged service life. The resin composite is prepared by using the polymer to wrap the perovskite oxide, and then the anode layer is prepared, which can form pores with uniform distribution and uniform size on one hand, and improve the electrical performance of the battery, and on the other hand, the additive adheres to the surface of the pores to form a protective layer, which can further improve the stability of the structure, meet the synchronous improvement of the porosity and the supporting strength, and also improve the anti-carbon deposition performance and anti-poisoning performance of the anode layer in the long-time operation process, so that the service life of the battery is prolonged. DETAILED DESCRIPTION

[0037] For better illustrating the object, technical scheme and advantages of the present application, the present application will be further described in combination with specific examples. Those skilled in the art should understand that the specific examples described herein are only used to explain the present application, and are not used to limit the present application.

[0038] The test methods used in the examples are all conventional methods unless otherwise specified; and the materials, reagents, etc. used are all available from commercial channels unless otherwise specified.

[0039] Examples 1-12

[0040] The component contents of the anode layers of Examples 1-12 are shown in Table 1.

[0041] Comparative Examples 1-3

[0042] The component contents of the anode layers of Comparative Examples 1-3 are also shown in Table 1.

[0043] The preparation method of the anode layers of Examples 1-12 and Comparative Examples 1-3 comprises the following steps:

[0044] (1) The components were weighed according to the mass ratio in Table 1, and after being mixed for 24-48 h, the mixed slurry was degassed in vacuum, and the viscosity of the mixed slurry was controlled in the range of 2-4 Pa·s, to obtain an anode layer slurry;

[0045] (2) The anode layer slurry obtained in step (1) was cast into an anode layer green body with a thickness of 300 μm, and after drying, the anode layer was sintered to obtain an anode layer; the specific sintering conditions were as follows: degreasing temperature 400 ℃, heating rate 45 ℃ / h, holding time 6 h, sintering temperature 1400 ℃, and holding time 10 h.

[0046] In each of the examples and the comparative examples:

[0047] The ceramic powder is 3YSZ, and the D50 particle size is 2 μm;

[0048] The D50 particle size of the nickel oxide (NiO) powder is 2 μm;

[0049] The solvent is ethanol;

[0050] The dispersant is triethanolamine;

[0051] The plasticizer is DBP;

[0052] The component content of the resin composite 1-11 is shown in Table 2.

[0053] Unless otherwise specified, the component raw materials used in each of the examples and the comparative examples are commercially available raw materials, and the component raw materials used in each of the parallel experiments are the same.

[0054] Table 1 shows the component content of the anode layer in the examples and the comparative examples

[0055]

[0056] Table 2 shows the component content and particle size of the resin composite 1-11.

[0057] Resin monomer Additive Additive: monomer mass ratio D50 particle size / pm Composite 1 Styrene Sr2MgMoO6 1:3 5 Composite 2 Styrene Sr2MgMoO6 1:2 5 Composite 3 Styrene Sr2MgMoO6 1:4 5 Composite 4 Methyl methacrylate Sr2FeMoO6 1:3 5 Composite 5 Vinyl chloride Sr2NiMoO6 1:3 5 Composite 6 Styrene Sr2CoMoO6 1:3 5 Composite 7 Styrene LaTiO3 1:3 5 Composite 8 Styrene LaMoO3 1:3 5 Composite 9 Styrene Sr2MgMoO6 1:3 8 Composite 10 Styrene Sr2MgMoO6 1:5 5 Composite 11 Styrene Styrene 1:3 5

[0058] The preparation method of the resin composite 1-11 includes the following steps: adding 50 wt% of a mixed solvent of ethanol and water in a ratio of 50:50, 10 wt% of the additives shown in Table 2, and 5 wt% of silane coupling agent KH550 into a three-necked flask, heating in a water bath at a temperature of 80-85 ℃, and fully stirring to uniformly disperse the components; then adding 30 wt% of the resin monomer shown in Table 2, 4 wt% of initiator BPO, and 1 wt% of crosslinking agent 1,4-butanediol diacrylate; keeping the reaction for 24-36 h to allow the monomer to coat the additives by in-situ suspension polymerization; washing the obtained resin composite with ethanol, vacuum drying, and grinding to the particle size shown in Table 2, to obtain the resin composite 1-11.

[0059] The examples and comparative examples are made into anode-supported cells, including the following steps:

[0060] S1. An electrolyte layer is prepared on the anode layer obtained in the examples and comparative examples, the thickness of the electrolyte layer is 10 μm, and a half-cell green body is obtained after lamination and hot pressing; the prepared half-cell green body is placed in a high-temperature furnace for degassing sintering treatment, the degassing temperature is 400 ℃, the heating rate is 45 ℃ / h, the holding time is 6 h, the sintering temperature is 1400 ℃, and the holding time is 10 h, and a half-cell is obtained after sintering.

[0061] S2. The half-cell obtained in step S1 is sintered by screen printing an LSCF cathode, the thickness is 30 μm, and the sintering temperature is 1100 ℃, and an anode-supported cell is obtained after sintering.

[0062] The anode layers of the examples and comparative examples and the corresponding prepared cells are used for performance testing, the items and methods of performance testing are shown in Table 3, and the test results are shown in Table 4.

[0063] Table 3 Items and methods of performance testing

[0064]

[0065] Table 4 Performance test results of the anode layers of the examples and comparative examples and the prepared cells

[0066]

[0067]

[0068] It can be seen from the results in Table 4 that the anode layer of the present application can obtain good porosity and qualified gas through property, so that the cell has good support strength and low voltage decay rate, and the electrical performance is improved, and the service life of the cell is also greatly prolonged.

[0069] It can be seen from Comparative Examples 1-12 and Comparative Examples 1-3 that too much or too little addition amount of the resin composite will affect the performance of the cell. When the content of the resin composite is too low (Comparative Example 3), the porosity formed by sintering is small, so that the gas hole through property in the formed anode support layer structure is unqualified, and the content of the wrapped additive is less or there is no additive pure resin polymer (Comparative Example 1), which cannot achieve the effects of carbon deposition resistance and poisoning resistance, the voltage decay rate is high, and it is difficult to achieve the purpose of prolonging the service life; when the content of the resin composite is too large (Comparative Example 2), due to too many connected pores, the anode support structure collapses to a certain extent, the support strength is unqualified, and too much additive is deposited in the pores, which hinders the original redox reaction, the voltage decay rate is high, and the service life of the cell is reduced.

[0070] Finally, it should be noted that the above examples are merely intended to illustrate the technical solutions of the present application and not to limit the protection scope of the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present application.

Claims

1. An anode layer, characterized in that, The raw materials for preparing the anode layer include the following components by mass percentage: 20%-38% ceramic powder, 10%-20% nickel oxide powder, 30%-40% solvent, 6%-10% resin composite, 5%-10% dispersant, and the balance being plasticizer; the resin composite includes additives and polymers coated on the surface of the additives; the additives include perovskite oxides; the resin composite is obtained by polymerizing resin monomers in situ through suspension polymerization to encapsulate the additives; the mass ratio of the additives to the resin monomers is 1:(2-5).

2. The anode layer according to claim 1, characterized in that, The perovskite oxide includes at least one of single perovskite oxide and double perovskite oxide; the single perovskite oxide includes at least one of LaTiO3 and LaMoO3, and the double perovskite oxide includes at least one of Sr2MgMoO6, Sr2FeMoO6, Sr2NiMoO6, and Sr2CoMoO6.

3. The anode layer according to claim 1, characterized in that, The particle size D50 of the resin composite is 5μm-8μm.

4. The anode layer according to claim 1, characterized in that, The polymer includes at least one of polystyrene, polymethyl methacrylate, and polyvinyl chloride.

5. The anode layer according to claim 1, characterized in that, The particle size D50 of the ceramic powder is 1μm-10μm; and / or, the particle size D50 of the nickel oxide powder is 1μm-10μm.

6. The anode layer according to claim 1, characterized in that, The ceramic powder is yttrium oxide stabilized zirconia ceramic powder; and / or, the solvent includes at least one of methanol, ethanol, isopropanol, toluene, ethyl acetate, and acetone; and / or, the dispersant includes at least one of triethanolamine, cellulose derivatives, alkyl aryl sulfonates, and polyethylene glycol; and / or, the plasticizer includes at least one of n-butyl phthalate and n-octyl phthalate.

7. The method for preparing the anode layer according to any one of claims 1-6, characterized in that, Includes the following steps: (1) The ceramic powder, nickel oxide powder, resin composite, solvent, dispersant and plasticizer are mixed evenly according to the mass ratio to obtain the anode layer slurry; (2) The anode layer slurry obtained in step S1 is cast into a green blank, dried and sintered to obtain the anode layer.

8. An anode-supported battery, characterized in that, Includes the anode layer as described in any one of claims 1-6.

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