Nacreous metal-ceramic composite sofc fracture-resistant electrode and method of making

Abstract

The application provides a pearl layer type metal-ceramic composite SOFC fracture-resistant electrode and a preparation method, and belongs to the technical field of solid oxide fuel cells, and comprises the following steps: mixing NiO powder and yttria-stabilized zirconia YSZ powder to prepare slurry, and obtaining a NiO-YSZ film through flow casting; stacking after silk printing a NiO layer on the surface of each film, and obtaining a green anode support layer ASL through lamination and isostatic pressing, and obtaining the anode support layer ASL after sintering reduction; preparing functional layers on the ASL in sequence through silk screen printing and sintering, and finally obtaining a target cell. The application constructs a pearl layer type metal-ceramic composite structure with the Ni-YSZ layer and the NiO layer alternately stacked, ensures the stability of the electrochemical performance of the SOFC, significantly improves the mechanical strength and the fracture resistance of the anode support layer, effectively inhibits crack propagation, prolongs the service life of the cell, is simple in process, controllable in cost, and has a wide application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solid oxide fuel cell, in particular to a pearl layer-like metal-ceramic composite SOFC anti-fracture electrode and a preparation method thereof. BACKGROUND

[0002] As a high-efficiency electrochemical energy conversion device, solid oxide fuel cell (SOFC) has a wide application prospect in distributed power generation and high-temperature energy conversion due to its high energy conversion efficiency and strong fuel adaptability. Nickel-yttria stabilized zirconia (Ni-YSZ) metal-ceramic composite material has become the mainstream material system of the current SOFC anode because of its good electrocatalytic activity, excellent thermal / chemical stability and easy industrialization manufacturing. In terms of preparation, tape casting is the traditional process for the multi-layer ceramic structure of SOFC. The existing technology also optimizes the electrochemical performance through isostatic pressing, electrolyte surface modification, screen printing functional layer and other ways, and achieves certain results in improving the interface activity and reducing the internal resistance.

[0003] With the expansion of the application scenarios of SOFC, the requirements for its long-term stability and structural reliability are continuously improved. The biological hierarchical structure of natural pearl layer and snail shell has excellent stress dispersion and anti-fracture properties, and its "hard-soft alternating" layered design provides inspiration for solving the problem of material mechanical properties. Therefore, introducing the bionic structure design into the anode support layer (ASL) of SOFC to realize the synergistic optimization of electrochemical performance and mechanical reliability has become an important research direction to improve the long-term service ability of the device.

[0004] However, the existing SOFC related technologies mainly focus on the improvement of electrochemical performance, and pay insufficient attention to the anti-fracture property, crack inhibition ability and mechanical toughness of the anode support layer. During the operation of SOFC, complex thermal mechanical stress is generated due to the mismatch of external load, temperature gradient and material thermal expansion coefficient, which easily leads to the cracking of the anode support layer and the degradation of the electrode / electrolyte interface, significantly reducing the battery life and system efficiency. In addition, the existing technology has not fully solved the core problem of considering both electrochemical performance and mechanical reliability, and lacks a low-cost structure design and preparation process that can simultaneously improve the anti-fracture ability. SUMMARY

[0005] In order to overcome the deficiencies of the prior art, the purpose of the present application is to provide a pearl layer-like metal-ceramic composite SOFC anti-fracture electrode and a preparation method thereof. By constructing a pearl layer-like metal-ceramic composite structure with alternating stacking of Ni-YSZ layers and NiO layers, the mechanical strength and anti-fracture ability of the anode support layer are significantly improved while ensuring the stability of the electrochemical performance of SOFC, the crack propagation is effectively inhibited, the battery service life is prolonged, the process is simple and the cost is controllable, and it has a wide application prospect.

[0006] To achieve the above object, the present application provides the following scheme:

[0007] In one aspect, the present application provides a preparation method of a pearl layer-shaped metal-ceramic composite SOFC anti-fracture electrode, comprising the following steps:

[0008] S1, mixing NiO powder and YSZ powder, adding dispersant, plasticizer, binder and solvent, adjusting viscosity to prepare NiO-YSZ slurry;

[0009] S2, the NiO-YSZ slurry is obtained by flow casting, drying and cutting;

[0010] S3, a NiO layer is arranged on the surface of each layer of the NiO-YSZ film to obtain a NiO-YSZ / NiO composite film, and a plurality of layers of the NiO-YSZ / NiO composite film are stacked and subjected to laminating treatment and isostatic pressing treatment in a constant temperature water bath to obtain a closely combined integrated blank;

[0011] S4, the integrated blank is sequentially subjected to pre-sintering, sintering and reduction treatment to obtain an anode support layer ASL with a simulated pearl layer-shaped composite structure, i.e. a pearl layer-shaped metal-ceramic composite SOFC anti-fracture electrode is prepared.

[0012] Preferably, in S1, the mass ratio of the NiO powder to the YSZ powder is 6:4, and the YSZ is 3mol% yttria-stabilized zirconia.

[0013] Preferably, in S1, the dispersant is triethanolamine, the plasticizer is a combination of polyethylene glycol and butyl phthalate, the binder is polyvinyl butyral, and the solvent is ethanol.

[0014] Preferably, in S3, the NiO layer is arranged on the surface of the NiO-YSZ film by a screen printing process.

[0015] Preferably, in S3, the anode support layer ASL blank after laminating is first cut into a strip with a size of 20x5mm 2 , and then subjected to isostatic pressing treatment in a constant temperature water bath.

[0016] Preferably, in S4, the pre-sintering temperature is 1100℃, the holding time is 2 hours; the sintering temperature is 1450℃, the holding time is 4 hours; the reduction treatment atmosphere is pure hydrogen, the treatment temperature is 800℃, and the holding time is 2 hours.

[0017] In another aspect, the present application also provides a pearl-layer metal-ceramic composite SOFC anti-fracture electrode prepared by the above preparation method, wherein the electrode is an anode support layer ASL, and the structure of the electrode is a pseudo-pearl-layer composite structure formed by alternately stacking a Ni-YSZ layer and a porous metal Ni layer.

[0018] Further, the present application also provides a method for preparing a solid oxide fuel cell based on the above pearl-layer metal-ceramic composite SOFC anti-fracture electrode, and the method further comprises the following steps:

[0019] The anode functional layer, the electrolyte layer, the barrier layer and the cathode layer are printed on the green anode support layer ASL in sequence by using a screen printing process;

[0020] The layers are subjected to corresponding sintering treatment, and then after the sintering of the cathode layer is completed, silver paste and silver wire are coated on the surfaces of the cell on both sides as current collectors, so that a solid oxide fuel cell with a pearl-layer metal-ceramic composite structure anti-fracture electrode is finally obtained.

[0021] Preferably, the sintering process of each layer is as follows:

[0022] The green anode support layer ASL and the electrolyte layer are first subjected to pre-sintering at 1100℃ for 2 hours, and then subjected to sintering at 1450℃ for 4 hours to obtain;

[0023] The barrier layer is subjected to sintering at 1250℃ for 3 hours to obtain;

[0024] The cathode layer is subjected to sintering at 1000℃ for 2 hours to obtain.

[0025] Further, the solid oxide fuel cell prepared by the above method comprises an anode support layer ASL, an anode functional layer, an electrolyte layer, a barrier layer and a cathode layer, wherein the anode functional layer, the electrolyte layer, the barrier layer and the cathode layer are stacked on the surface of the anode support layer ASL in sequence; the material of the barrier layer is Gd 0.1 Ce 0.9 O 2-δ The material of the cathode layer is La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ The active area of the cathode layer is 0.5cm 2 .

[0026] According to the specific embodiments of the present application, the following technical effects are provided:

[0027] (1) The present application realizes the synergistic effect of stress dispersion, crack deflection and energy dissipation by constructing the imitation pearl layer-like composite structure of the alternating stacking of the Ni-YSZ layer and the porous Ni layer, fully learning from the mechanical advantages of the hard-soft alternation of the natural pearl layer. The structure can effectively inhibit the crack initiation and rapid expansion caused by the thermal mechanical stress in the operation process of the SOFC, significantly improve the fracture toughness, anti-fracture ability and overall mechanical strength of the anode support layer, and solve the problems of easy cracking and mechanical failure of the traditional anode support layer from the root.

[0028] (2) While optimizing the mechanical structure, the present application does not damage the ion conduction channel and gas diffusion network inside the electrode, specifically: the composite system of Ni-YSZ and NiO retains the excellent electrocatalytic activity and thermal / chemical stability of the Ni-YSZ material, and the ordered preparation and sintering process of each functional layer guarantees the good combination of the electrode / electrolyte interface. Test results show that the electrode exhibits stable I-V output characteristics and low polarization impedance at different temperatures such as 800 DEG C, 750 DEG C and 700 DEG C, and the electrochemical performance of the complete battery prepared by the ASL without the porous metal Ni layer is similar, realizing the synchronous optimization of mechanical reliability and electrochemical performance.

[0029] (3) The preparation method provided by the present application integrates mature industrialized technologies such as flow casting, screen printing and lamination, and has simple and controllable process, relatively low cost, does not need complex special equipment, and is convenient for large-scale production. The anti-fracture ability and long-term stability of the electrode are significantly improved, the service life of the SOFC is effectively prolonged, the operation and maintenance cost is reduced, the distributed power generation and high-temperature energy conversion practical application scenarios can be better adapted, key technical support is provided for the engineering application of high-reliability SOFC, and has wide popularization prospect. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0031] Figure 1 The flow chart of the preparation method of the pearl layer-like metal-ceramic composite SOFC anti-fracture electrode of the present application;

[0032] Figure 2 The three different electrode structure design schematic diagrams provided by embodiment 1 of the present application;

[0033] Figure 3 The load-displacement curve diagram of different samples in the three-point bending test provided by embodiment 1 of the present application;

[0034] Figure 4 Fracture morphology images of different samples at macroscopic and microscopic scales provided in Embodiment 1 of the present invention;

[0035] Figure 5 This is a comparison chart of the electrochemical performance of SOFCs prepared with different anode structures according to Example 1 of the present invention; wherein, Figure 5 (a) shows the IV curves of SOFCs prepared with different anode structures. Figure 5 (b) in the figure shows the EIS curves of SOFCs prepared with different anode structures. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0038] like Figure 1 As shown, this invention provides a method for preparing a pearl-layered metal-ceramic composite SOFC fracture-resistant electrode, comprising the following steps:

[0039] S1. Mix NiO powder and YSZ powder, add dispersant, plasticizer, binder and solvent, and adjust the viscosity to prepare NiO-YSZ slurry.

[0040] Specifically, the mass ratio of NiO powder to YSZ powder is controlled at 6:4. This ratio balances the electrocatalytic activity and structural stability of the material, laying the foundation for the subsequent formation of a high-performance composite structure. The YSZ used is 3 mol% yttrium-stabilized zirconium oxide (3YSZ), which exhibits excellent ionic conductivity and thermal stability at high temperatures, making it a classic and preferred material for SOFC anode systems. Triethanolamine is used as the dispersant, effectively reducing the agglomeration force between particles in the slurry and ensuring uniform dispersion of the components. The plasticizer is a combination of polyethylene glycol and butyl phthalate; their synergistic effect enhances the flexibility of the film and prevents cracking during subsequent molding. Polyvinyl butyral is used as the binder, enhancing the bonding strength of the slurry and ensuring that the film is not easily damaged after molding. Ethanol is used as the solvent, as its moderate volatility allows for slow removal during drying, preventing porosity caused by rapid solvent evaporation. Through the rational combination of the above components and viscosity adjustment, a uniformly dispersed NiO-YSZ slurry with good molding performance is obtained.

[0041] S2, the NiO-YSZ slurry is formed by tape casting, dried, and cut to obtain a NiO-YSZ film.

[0042] Specifically, the tape casting process has the advantages of low equipment requirements and flexible process, and can efficiently prepare a multilayer ceramic film with uniform thickness, which is suitable for the large-scale production of SOFC electrodes. The drying process is naturally completed in air, which can avoid film warping or cracking caused by high-temperature drying; the NiO-YSZ film obtained after cutting has a thickness of 0.06 mm and a regular and uniform size, which can ensure the consistency of the subsequent stacking structure and provide a prerequisite for forming a regular pearl-like layered composite structure.

[0043] S3, a NiO layer is arranged on the surface of each NiO-YSZ film to obtain a NiO-YSZ / NiO composite film, and a plurality of the NiO-YSZ / NiO composite films are stacked and subjected to isostatic pressing treatment in a constant-temperature water bath to obtain a tightly combined integrated body.

[0044] Specifically, the NiO layer is arranged by a screen printing process, which is simple to operate and controllable in precision, and can ensure that the NiO layer has a uniform thickness and is tightly combined with the NiO-YSZ film, laying a foundation for the subsequent reduction to form a porous metal Ni layer. The body after lamination is cut into a strip with a size of 20x5mm 2 , and then subjected to isostatic pressing treatment in a constant-temperature water bath. The size design is suitable for the subsequent mechanical property test requirements, and the isostatic pressing treatment in a constant-temperature water bath can make the stress of the body uniform, effectively eliminate the interlayer gap, realize the tight combination of the composite films, and improve the structural density of the integrated body.

[0045] S4, the integrated body is sequentially subjected to pre-sintering, sintering, and reduction treatment to obtain a pearl-like layered anode support layer ASL, i.e., a pearl-like layered metal-ceramic composite SOFC anti-fracture electrode is prepared.

[0046] Specifically, the pre-sintering temperature is set to 1100℃ and the holding time is 2 hours, which can remove the organic components in the body and improve the initial mechanical strength of the body, avoiding damage in the subsequent treatment process; the sintering temperature is 1450℃ and the holding time is 4 hours, which can fully densify the body and enhance the bonding strength between the layers, ensuring the structural stability; the reduction treatment is carried out in a pure hydrogen atmosphere at 800℃ for 2 hours, which can reduce the NiO layer to a porous metal Ni phase, and finally form a pearl-like layered composite structure in which the Ni-YSZ layers and the porous metal Ni layers are alternately stacked, which can fully exert the mechanical advantage of "hard-soft alternation" and improve the electrode anti-fracture ability.

[0047] Based on the above preparation method, the application also provides a pearl layer-shaped metal-ceramic composite SOFC anti-fracture electrode, which specifically comprises: the electrode is an anode support layer (ASL), which has a pseudo-pearl layer-shaped composite structure formed by alternately stacking Ni-YSZ layers and porous metal Ni layers. The porous metal Ni layer as a "soft phase" can realize stress dispersion and energy dissipation, and the Ni-YSZ layer as a "hard phase" can guarantee structural strength and electrocatalytic performance, and the synergistic effect of the two can effectively inhibit crack propagation, thereby solving the technical pain point of easy cracking of the traditional anode support layer. The electrode structure is regular and tightly combined, which not only retains the excellent electrochemical performance of the Ni-YSZ material, but also significantly improves the mechanical reliability through the design of the bionic structure.

[0048] Based on the prepared pearl layer-shaped metal-ceramic composite SOFC anti-fracture electrode, the application further provides a method for preparing a solid oxide fuel cell (SOFC) based on the above anti-fracture electrode, which comprises the following steps:

[0049] An anode functional layer, an electrolyte layer, a barrier layer and a cathode layer are sequentially printed on the green anode support layer (ASL) by using a screen printing process, and then corresponding sintering treatment is performed on each layer. After the sintering of the cathode layer is completed, silver paste and silver wire are coated on the surfaces of the cell on both sides as current collectors, and finally a solid oxide fuel cell with a pearl layer-shaped metal-ceramic composite structure anti-fracture electrode is obtained.

[0050] Specifically, the screen printing process can accurately control the thickness and coverage range of each functional layer, ensuring that each layer structure is uniform and tightly combined with the substrate. The anode functional layer can enhance the electrocatalytic activity, the electrolyte layer can guarantee ion conduction, the barrier layer can avoid element interdiffusion, and the cathode layer is responsible for the oxygen reduction reaction, and the orderly arrangement of each layer constitutes a complete SOFC reaction system. After the sintering of the cathode layer is completed, silver paste and silver wire are coated as current collectors, and silver has excellent electrical conductivity and chemical stability, which can effectively reduce the contact resistance and improve the current collection efficiency.

[0051] The sintering process of each layer is as follows:

[0052] The green anode support layer and the electrolyte layer are first pre-sintered at 1100℃ for 2 hours, and then sintered at 1450℃ for 4 hours; the pre-sintering can remove the organic components in the electrolyte layer, and the subsequent high-temperature sintering can realize the full densification of the electrolyte layer, avoid gas leakage, and guarantee the sealing performance and ion conduction efficiency of the cell.

[0053] The barrier layer is sintered at 1250℃ for 3 hours; this temperature can guarantee the densification of the barrier layer material (Gd 0.1 Ce 0.9 O 2-δ , GDC), and avoid excessive reaction with the adjacent layers, thereby effectively playing a role in preventing element interdiffusion.

[0054] Cathode layer: sintered at 1000℃ for 2 hours; this temperature allows the cathode material (La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ , LSCF) to form a stable structure and tightly bond with the barrier layer, while retaining the high catalytic activity of the cathode material, ensuring efficient oxygen reduction reactions.

[0055] Further, the solid oxide fuel cell prepared based on the above method specifically comprises:

[0056] The solid oxide fuel cell comprises an anode support layer (ASL), an anode functional layer, an electrolyte layer, a barrier layer, and a cathode layer, and the anode functional layer, the electrolyte layer, the barrier layer, and the cathode layer are sequentially stacked on the surface of the anode support layer (ASL). The barrier layer material is selected from Gd 0.1 Ce 0.9 O 2-δ (GDC), which has good ionic conductivity and chemical stability, and can effectively block the interdiffusion of elements between the cathode and the electrolyte; the cathode layer material is selected from La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ (LSCF), which has excellent catalytic activity for oxygen reduction reactions at medium and high temperatures, and has good matching of the thermal expansion coefficient with the adjacent layers; the active area of the cathode layer is set to 0.5 cm 2 , which is suitable for the conventional testing requirements of the laboratory and can ensure the stability and repeatability of the cell output performance. The entire cell structure is reasonably designed, and the layers work together to not only improve the fracture resistance through the imitation of the pearl layer anode support layer, but also ensure excellent electrochemical performance, achieving simultaneous optimization of mechanical reliability and energy conversion efficiency.

[0057] The above content will be further described through specific embodiments, and the provided embodiments are only part of the embodiments of the present application.

[0058] Embodiment 1

[0059] This embodiment aims to verify the synergistic optimization effect of the pearl layer metal-ceramic composite structure on the fracture resistance electrode mechanical properties and electrochemical properties of the solid oxide fuel cell (SOFC), by preparing three different structures of the anode support layer (ASL) and carrying out systematic tests, the technical advantages of the biomimetic structure are determined.

[0060] The materials used in the experiment include commercial NiO powder, 3 mol% yttria-stabilized zirconia (3YSZ) powder, triethanolamine (dispersant), polyethylene glycol and butyl phthalate (plasticizer), polyvinyl butyral (binder), ethanol (solvent), and Gd 0.1 Ce 0.9 O 2-δ (GDC, barrier layer material), La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ (LSCF, cathode material), silver paste, silver wire (current collector), and ceramic sealant. The experimental equipment includes a tape casting machine, a screen printing machine, a laminator, a constant temperature water bath isostatic press, a muffle furnace, a high-temperature three-point bending in-situ testing device, a fuel cell test bench, an electrochemical impedance spectroscopy (EIS) tester, and a scanning electron microscope (SEM).

[0061] The preparation process starts with NiO-YSZ slurry and film. NiO powder and 3YSZ powder are mixed in a mass ratio of 6:4, and dispersant, plasticizer, binder, and solvent are added to adjust the viscosity. After ball milling and dispersion, a uniform NiO-YSZ slurry is obtained. The slurry is tape cast, naturally air dried, and then cut into NiO-YSZ films with a thickness of 0.06 mm for standby use.

[0062] Based on the film, three different structures of ASL are further prepared, as shown in Figure 2 .

[0063] ASL-1 is a traditional comparative structure. Ten layers of NiO-YSZ film are directly stacked, laminated, cut into 20×5 mm 2 strips, and then treated by constant temperature water bath isostatic pressing to obtain an integrated billet. Subsequently, it is pre-sintered at 1100°C for 2 hours, sintered at 1450°C for 4 hours (the size after sintering is about 15×4 mm 2 ), and finally reduced at 800°C in a pure hydrogen atmosphere for 2 hours to obtain ASL-1 with a traditional laminated structure.

[0064] ASL-2 is the imitation pearl layer-like alternating structure of the present embodiment. A thin NiO layer is coated on the surface of each layer of NiO-YSZ film by screen printing process to obtain a NiO-YSZ / NiO composite film. Seven layers of the composite film are alternately stacked, laminated, cut, and treated by constant temperature water bath isostatic pressing. Then, it is pre-sintered, sintered, and reduced. The NiO layer is reduced to a porous Ni layer (PNL), and finally an imitation pearl layer-like composite structure with Ni-YSZ layers and PNL layers alternately stacked is formed.

[0065] ASL-3 is a brick-type hierarchical layered structure. First, each layer of NiO-YSZ thin film is cut to two-thirds of its thickness by a patterning cutting process, so that a grid structure of 1 mm x 1 mm is formed on the surface of the thin film. Then, a NiO layer is screen printed on the grid surface to obtain a NiO-YSZ / NiO composite thin film with a grid. After stacking, laminating, cutting, isostatic pressing in a constant temperature water bath and subsequent heat treatment, a brick-type hierarchical layered structure with a grid of Ni-YSZ layers and PNL layers stacked alternately is formed.

[0066] Subsequently, mechanical property tests were carried out on the three different structures of ASL. A high-temperature three-point bending in-situ test was used. During the test, a mixture gas of 5 vol% H2 and 95 vol% N2 was continuously introduced at a flow rate of 600 mL / min to maintain a reducing environment. The loading mode was displacement control, and the loading rate was 0.05 mm / min. Each structure of sample was tested repeatedly for 3 times to ensure the reliability of the results. As shown in Figure 3 Figure 3 is a load-displacement curve diagram of different samples. It can be seen from the diagram that compared with ASL-1, the maximum fracture displacement of ASL-3 is reduced, and the maximum fracture displacement of ASL-2 is significantly improved, indicating that the bionic structure can effectively disperse stress and inhibit crack propagation, and the pre-cutting of ASL-3 sample introduces a pre-crack, which leads to early fracture; Figure 4 is a fracture morphology diagram of different samples at macro and micro scales. Macroscopically, the fracture surface of ASL-1 is flat, showing typical brittle fracture characteristics, and the fracture surfaces of ASL-2 and ASL-3 are rough, with obvious crack deflection traces. Microscopically, the separation occurs at the interlayer bonding site of ASL-1 Ni-YSZ layer, and the crack propagates along the interlayer straight line. The grid structure of ASL-3 guides stress transfer, causing the crack to deflect multiple times and not form a through fracture, fully verifying the stress dispersion and crack inhibition effect of the bionic structure.

[0067] Further, based on two kinds of ASL (ASL-1 and ASL-2), SOFC button cells were further prepared. Anode functional layer, electrolyte layer, GDC barrier layer and LSCF cathode layer were printed on the surface of ASL in sequence by screen printing process, and the active area of the cathode layer was set to 0.5 cm 2 . The sintering process of each layer is as follows: the electrolyte layer is first pre-sintered at 1100°C for 2 hours, and then sintered at 1450°C for 4 hours; the GDC barrier layer is sintered at 1250°C for 3 hours; the LSCF cathode layer is sintered at 1000°C for 2 hours. Finally, silver paste is coated on the surface of the cathode layer and silver wire is laid as a current collector, and ceramic sealant is used to seal the edges of the cell to complete the assembly of the SOFC button cell.

[0068] ​Subsequently, the two ASL-prepared SOFC button cells were subjected to electrochemical performance tests, specifically: at 800℃, 750℃ and 700℃ respectively, the anode was fed with hydrogen gas with a humidity of 3% (flow rate 100 mL / min), and the cathode was exposed to air, and I-V tests and EIS tests (EIS test frequency range: 0.01-100000 Hz, single amplitude: 10 mV) were carried out respectively.

[0069] The obtained performance test results are shown in Figure 5 , wherein Figure 5 (a) in (a) is the I-V curve of the SOFC corresponding to ASL-1 and ASL-2 at different temperatures, as can be seen from the figure, the SOFCs of the two structures both exhibit stable output characteristics, and the open-circuit voltage and maximum output power density of the battery corresponding to ASL-2 at each temperature are similar to those of ASL-1; Figure 5 (b) in (b) is the corresponding EIS curve, and the polarization impedance of the battery corresponding to ASL-2 is comparable to that of ASL-1, proving that the imitation pearl layer alternating structure improves the mechanical properties without damaging the ion conduction channel and gas diffusion network of the battery, and maintains excellent electrochemical stability.

[0070] Based on the above, through the preparation and test verification of the system, it is shown that the pearl layer metal-ceramic composite structure design can significantly improve the fracture toughness and mechanical failure resistance of ASL, while maintaining or even optimizing the electrochemical performance of SOFC, realizing the simultaneous optimization of mechanical reliability and energy conversion efficiency, and the preparation process integrates mature technologies such as tape casting, screen printing and lamination, without the need for complex special equipment, with controllable cost and potential for large-scale production, providing a feasible technical solution for the development of high-reliability SOFC.

[0071] Therefore, by using the above pearl layer metal-ceramic composite SOFC anti-fracture electrode and preparation method, by constructing an imitation pearl layer metal-ceramic composite structure of alternating stacking of Ni-YSZ layers and NiO layers, the mechanical strength and anti-fracture ability of the anode support layer are significantly improved while ensuring the stability of the electrochemical performance of the SOFC, the crack propagation is effectively inhibited, the service life of the battery is prolonged, the process is simple and the cost is controllable, and it has a wide application prospect.

[0072] The principles and implementation modes of the present application are described by applying specific examples in this paper, and the above examples are only used to help understand the method and its core idea of the present application; at the same time, for those skilled in the art, according to the idea of the present application, the specific implementation mode and application range will be changed. In view of the above, the content of the specification should not be understood as a limitation of the present application.

Claims

1. A method for the production of a nacreous metal-ceramic composite SOFC break-resistant electrode, characterized in that, The method comprises the following steps: S1, mixing NiO powder and YSZ powder, adding dispersant, plasticizer, binder and solvent, adjusting viscosity to prepare NiO-YSZ slurry; S2, the NiO-YSZ slurry is formed by flow casting, dried, and cut to obtain NiO-YSZ film; S3, a NiO layer is arranged on the surface of each layer of the NiO-YSZ film to obtain a NiO-YSZ / NiO composite film, and a plurality of layers of the NiO-YSZ / NiO composite film are stacked and subjected to isostatic pressing treatment in a constant temperature water bath to obtain a tightly combined integrated blank; S4, the integrated blank is sequentially subjected to pre-sintering, sintering and reduction treatment to obtain an anode support layer ASL with a simulated pearl layer-like composite structure, that is, a pearl layer-like metal-ceramic composite SOFC fracture-resistant electrode is prepared.

2. The production method according to claim 1, characterized by, In S1, the mass ratio of the NiO powder to the YSZ powder is 6:4, and the YSZ is 3mol% yttria stabilized zirconia.

3. The preparation method according to claim 1, characterized in that, In S1, the dispersant is triethanolamine, the plasticizer is a combination of polyethylene glycol and butyl phthalate, the binder is polyvinyl butyral, and the solvent is ethanol.

4. The method of claim 1, wherein, In S3, the NiO layer is arranged on the surface of the NiO-YSZ film by a screen printing process.

5. The preparation method according to claim 1, characterized in that, In S3, the laminated anode support layer ASL green body is first cut into 20 x 5 mm strips, and then is subjected to isothermal water bath isostatic pressing treatment. 2 In S3, the laminated anode support layer ASL green body is first cut into 20 x 5 mm strips, and then is subjected to isothermal water bath isostatic pressing treatment.

6. The method of claim 1, wherein, In S4, the pre-sintering temperature is 1100°C, and the holding time is 2 hours; the sintering temperature is 1450°C, and the holding time is 4 hours; the reduction treatment is carried out in a pure hydrogen atmosphere at a temperature of 800°C for 2 hours.

7. A nacreous metal-ceramic composite SOFC fracture-resistant electrode prepared by the method according to any one of claims 1 to 6, characterized in that, The electrode is an anode support layer ASL with a simulated pearl layer-like composite structure formed by alternately stacking Ni-YSZ layers and porous metal Ni layers.

8. A method of manufacturing a solid oxide fuel cell based on the fracture resistant electrode of the pearl layer type metal-ceramic composite SOFC according to claim 7, characterized in that, The method further comprises the following steps: An anode functional layer, an electrolyte layer, a barrier layer and a cathode layer are printed on the green anode support layer ASL in sequence by a screen printing process; Each layer is subjected to corresponding sintering treatment, and then silver paste and silver wire are coated on the surfaces of both sides of the cell as current collectors after the sintering of the cathode layer is completed, so that a solid oxide fuel cell with a pearl layer-like metal-ceramic composite structure fracture-resistant electrode is finally obtained.

9. The method of claim 8, wherein, The sintering process of each layer is as follows: The green anode support layer ASL and the electrolyte layer are first pre-sintered at 1100°C for 2 hours and then sintered at 1450°C for 4 hours; The barrier layer is sintered at 1250°C for 3 hours; The cathode layer is sintered at 1000°C for 2 hours.

10. A solid oxide fuel cell produced by the method of claim 8, characterized by The application relates to a multilayered anode, which comprises an anode support layer (ASL), an anode functional layer, an electrolyte layer, a barrier layer and a cathode layer, wherein the anode functional layer, the electrolyte layer, the barrier layer and the cathode layer are sequentially stacked on the surface of the anode support layer (ASL); the material of the barrier layer is Gd 0.1 Ce 0.9 O 2-δ The material of the cathode layer is La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ The active area of the cathode layer is 0.5 cm 2 .

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