WO2022193524A1

WO2022193524A1 - Method for preparing metal support plate for fuel cell

Info

Publication number: WO2022193524A1
Application number: PCT/CN2021/108851
Authority: WO
Inventors: 包崇玺; 陈志东; 颜巍巍; 童璐佳; 朱志荣
Original assignee: 东睦新材料集团股份有限公司
Priority date: 2021-03-19
Filing date: 2021-07-28
Publication date: 2022-09-22
Also published as: CN113067005A

Abstract

The present invention relates to a method for preparing a metal support plate for a fuel cell. The method sequentially comprises the following steps: 1) using one of sintered stainless steel, heat-resistant steel, a nickel-based alloy, a cobalt-based alloy, a titanium alloy and a chromium-based alloy; 2) sieving the powder in step 1); 3) mixing the powder in step 2) with a forming agent, to obtain a powder as a semi-solid metal fluid; 4) placing the powder in step 3) into a rolling mill, and rolling same to form a metal substrate; 5) coating the upper surface of the metal substrate with an anode slurry to form an anode layer on the upper surface of the metal substrate; 6) coating the upper surface of the anode layer with an electrolyte slurry to form an electrolyte coating on a surface of the anode layer; and 7) coating the upper surface of the electrolyte coating with a cathode slurry to form a cathode layer on the upper surface of the electrolyte coating, so as to prepare a metal support plate. Sintering deformation is eliminated, and the bonding tightness between the anode layer and the metal substrate is improved.

Description

A kind of preparation method of metal support plate for fuel cell

technical field

The invention belongs to the technical field of fuel cells, and in particular relates to a preparation method of a metal support plate for fuel cells.

Background technique

Solid oxide fuel cell is an ideal fuel cell, which not only has the advantages of high efficiency and environmental friendliness of fuel cells, but also has the following outstanding advantages:

(1) The solid oxide fuel cell is an all-solid structure, and there is no corrosion problem and electrolyte loss caused by the use of a liquid electrolyte, and it is expected to achieve long-life operation. (2) The working temperature of solid oxide fuel cells is 800-1000 °C. Not only does the electrocatalyst not need to use precious metals, but also natural gas, coal gas and hydrocarbons can be directly used as fuels, which simplifies the fuel cell system. (3) The high-temperature waste heat discharged from the solid oxide fuel cell can form a combined cycle with a gas turbine or a steam turbine, which greatly improves the overall power generation efficiency.

At present, traditional solid oxide fuel cells mostly use ceramic materials or metal-ceramic composite materials as supports. Ceramic materials are not easy to be machined, and have poor thermal shock resistance and welding performance, which are not conducive to the assembly of fuel cell (SOFC) stacks. Metal-supported solid oxide fuel cells (MS-SOFC) use metals or alloys as the fuel cell supporter SOFC (as shown in Figure 1), MS-SOFC has its unique advantages: (1) low cost: The cost of metal materials is much lower than that of metal-ceramic composite materials; (2) Fast start-up: The good thermal conductivity of metal can reduce the temperature gradient inside the battery and achieve fast start-up, so that it can be used in the mobile field; (3) Processability: Compared with ceramics, metal materials have better processability, which will greatly reduce the difficulty of SOFC processing; (4) Ease of sealing: The welding and sealing technology of metal materials can avoid the problem of difficult sealing of SOFC. The main function of the metal support is to transport gas, conduct current, and provide stable structural support for the battery. When MS-SOFC uses hydrocarbon fuel, the metal support can be used as an in-situ reforming layer. The hydrocarbon fuel takes the lead in chemical reformation in the metal support, and the generated synthesis gas undergoes electrochemical oxidation in the anode layer. This structure The design can enhance the anode's resistance to carbon deposition and improve the long-term stability of the battery in hydrocarbon fuels. MS-SOFC is not only suitable for traditional solid oxide fuel cell (SOFC) applications, such as stationary power stations, backup power supplies and charging piles, etc., but also as a range extender for mobile devices such as heavy-duty vehicles or electric vehicles.

The current metal-supported solid oxide fuel cells, such as the Chinese invention patent application "Method for the Preparation of Porous Metal-supported Low-Temperature Solid Oxide Fuel Cells", whose patent application number is CN200610118649.9 (application publication number CN1960047A) discloses a For the preparation method of the porous metal-supported low-temperature solid oxide fuel cell, NiO-ScSZ (or CGO) is selected as the raw material of the support body to prepare the support body, and the process is complicated and the manufacturing is difficult.

In addition, at present, the Fe-Cr alloy support, anode and electrolyte blank prepared by casting are laminated and then sintered at high temperature in a reducing atmosphere. The anode catalyst is injected into the metal support side of the half-cell, and the surface of the electrolyte is screened. The cathode layer was printed, and the anode and cathode were sintered in situ during battery testing. This process effectively avoids the diffusion of metal elements at high temperature. However, the in-situ sintering temperature is too low, the bonding strength of the interface between the cathode and the electrolyte is low, and the battery performance is attenuated. The porous metal body with anode and electrolyte is prepared by co-casting method. Due to the different sintering temperature of metal and electrolyte, this material is prone to sintering deformation and peeling of anode or electrolyte layer. The metal support body and the micro-tubular metal support body are prepared by the dry pressing method. Due to the thin metal support layer, the metal support plate is prone to uneven thickness after dry pressing, resulting in inconsistent sintering deformation and affecting the bonding between the anode, electrolyte, etc. and the substrate; and the metal thickness of the micro-tubular metal support body is not easy to achieve uniform control. , affecting the combination with the anode, etc.

Fe-based alloys and Ni-based alloys are used as metal supports for MS-SOFC. Due to the large difference between the thermal expansion coefficient of Ni-based alloys and electrolyte materials, during battery operation, the internal thermal stress is too large, and cracks are likely to occur, and even the electrolyte layer is peeled off. ; The pure Ni support has poor anti-oxidation performance and is easy to agglomerate and coarsen, which makes the SOFC performance attenuate sharply. These shortcomings of Ni-based alloys seriously hinder their application in SOFC supports; while Fe-based alloys are used as supports, especially ferritic stainless steel, although ferritic stainless steel has a high temperature thermal expansion coefficient CTE (11×10 ^-6 ~ 13×10 ^-6 K ^-1 ) is very close to YSZ (yttria-stabilized zirconia) and GDC (Gd ₂ O ₃ doped CeO ₂ ) (13×10 ^-6 ～14×10 ^-6 K ^-1 ) electrolytes , but long-term work in a medium-high temperature and humid atmosphere can easily lead to oxidation of metal materials and mutual diffusion of elements between Fe and Cr elements in the stainless steel support and the Ni-based anode. During the preparation or operation of MS-SOFC, the Fe and Cr elements in the support diffuse into the anode, and oxides are formed during the operation of the battery, which leads to the rapid degradation of the battery performance; at the same time, the Ni element in the anode diffuses into the stainless steel support. In the process, the thermal expansion coefficient of the support body changes, the internal stress of the battery increases, and the structural stability decreases.

Therefore, there is a need to further improve the existing methods for preparing metal support plates for fuel cells.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a method for preparing a metal support plate for a fuel cell that eliminates sintering deformation and improves the bonding tightness between the anode layer and the substrate in view of the current state of the prior art.

The technical solution adopted by the present invention to solve the above-mentioned technical problems is: a method for preparing a metal support plate for a fuel cell, which is characterized in that the following steps are included in sequence:

1) Use one of sintered stainless steel, heat-resistant steel, nickel-based alloy, cobalt-based alloy, titanium alloy, and chromium-based alloy;

2) sieve the powder in step 1), and select the particle size of the powder to be 13-250 μm;

3) mixing the powder in step 2) with the forming agent, in terms of mass percentage, the powder accounts for 92-95%, and the forming agent accounts for 5-8%, and after mixing uniformly, a solid metal fluid powder is obtained;

4) putting the powder in step 3) into a rolling mill for rolling, thereby forming a metal substrate;

5) coating the anode slurry on the upper surface of the metal substrate, then placing the uncoated lower surface of the metal substrate on the setter plate, and drying, thereby forming an anode layer on the upper surface of the metal substrate;

6) coating the electrolyte slurry on the upper surface of the anode layer, then placing the uncoated lower surface of the metal substrate on the setter plate and drying, thereby forming an electrolyte coating on the upper surface of the anode layer;

7) coating the cathode slurry on the upper surface of the electrolyte coating, then placing the uncoated lower surface of the metal substrate on a setter plate and drying, thereby forming a cathode layer on the upper surface of the electrolyte coating, Thereby a metal support plate is made;

A sintering treatment is performed between steps 4) and 5) or after step 7).

Preferably, the sintering treatment is to place a metal substrate or a metal support plate of a required size on a setter plate for sintering, the sintering temperature is 1000°C to 1350°C, the sintering time is 5 to 240 minutes, and the vacuum degree is 10 ^-3 Pa ~10 ² Pa. After sintering, the metal support body has high strength, and the anode and the metal support body are tightly bonded. Co-sintering of anode, electrolyte and cathode can improve production efficiency, reduce production cost, and improve the bonding state of the three interfaces of metal support plate-anode-electrolyte-cathode.

Preferably, when the sintering treatment is between step 4) and step 5), the sintered metal substrate is flattened, and then the flattened metal substrate is subjected to a wax dip treatment, that is, a metal substrate of a desired size is placed in the The wax melt is placed in the wax melt for 1 to 30 minutes. After the wax melt penetrates into the pores in the metal substrate, the metal substrate is taken out and cooled. In this way, a relatively flat metal support plate is obtained, and the pores of the metal support plate are reduced by dipping the wax.

Preferably, sintered stainless steel is selected in step 1), and the components of the sintered stainless steel, in terms of mass percentage, include the following components: carbon: <0.03%, nickel: 0-25%, molybdenum: 0-4%, chromium: 10～30%, Niobium: 0～3%, Aluminum: 0～10%, Titanium: 0～3%, Silicon: 0～1%, Manganese: 0～2%, unavoidable impurities not exceeding 2%, Iron: surplus. The sintered stainless steel of this composition has a thermal expansion coefficient that matches the anode and electrolyte.

The components of the forming agent have various forms, but preferably, the components of the forming agent in step 2), in terms of mass percentage, include the following components: paraffin wax: 40-60%; microcrystalline wax: 20-30% ; Castor oil: 0.5-20%; polyethylene wax: 5-15%; EVA wax: 5-15%; stearic acid: 1-2%. This combined forming agent is easy to remove during sintered dewaxing and the green strength of the support plate is high.

Specifically, in step 5), step 6) and step 7), sintering is performed after drying, and the sintering temperature used in the sintering in step 5) and the sintering in step 6) is both 1050 ℃ ~ 1400 ℃, sintering The time is 10～300min, the sintering temperature used in the sintering in step 7) is 800°C～1200°C, the sintering time is 5～300min, and the vacuum degree is 10 ^-3 Pa～10 ² Pa.

Preferably, in step 4), the metal fiber felt with a porosity greater than 50% is also added to the rolling mill, and the metal fiber felt and the powder are rolled into a metal substrate. The porosity of the metal fiber mat is large, and some metal powder particles will enter the pores of the fiber when rolling, which can change the structure of the fiber. At the same time, the strength of the sintered fiber mat is high, which can improve the strength of the metal support plate.

The component content of the metal fiber felt has various forms, preferably, the metal fiber felt, in terms of mass percentage, includes the following components: carbon: ≤0.06%, nickel: 0-25%, molybdenum: 0-4%, Chromium: 10 to 30%, Niobium: 0 to 3%, Aluminum: 0 to 10%, Titanium: 0 to 3%, Silicon: 0 to 1%, Manganese: 0 to 2%, unavoidable not exceeding 2% Impurities, Iron: Balance. The metal fiber felt of this material is similar to the stainless steel powder material, which is beneficial to improve the strength of the metal support, especially the high temperature strength.

Preferably, the anode slurry contains NiO, methyl ethyl ketone, ethanol, triethanolamine, starch, polyvinyl butyral PVB, polyethylene glycol PEG and glutamic acid PHT, and also includes yttria-stabilized zirconia and One of Sr _2-x Ca _x Fe _1.5 Mo _0.5 O ₆ _-δ , wherein x=0, 0.1, 0.3, 0.5. Conducive to the production of battery pan-Asia.

Preferably, the electrolyte slurry includes butanone, ethanol, triethanolamine, polyvinyl butyral PVB, polyethylene glycol PEG, glutamic acid PHT, and also includes yttria-stabilized zirconia and LaGaO ₃ -based electrolytes , one of Ba(Sr)Ce(Ln)O ₃ and CeO ₂ -based solid electrolytes. The thermal expansion coefficient of this electrolyte slurry is close to that of the anode and cathode, and the combination is better after sintering.

Preferably, the cathode slurry is Sr _2-x Ca _x Fe _1.5 Mo _0.5 O _6-δ , LSM(La _1-x Sr _x Mn0 ₃ ), LSCF((La, Sr)(Co, Fe)O ₃ ), one of A ₂ Ru ₂ O _7-x (A=Pb, Bi) ceramics with pyrochlore structure, Ag-YDB composite ceramics and L-type ceramics with perovskite structure, the aforementioned x=0, 0.1, 0.3, 0.5. This cathode material is tightly bound to the electrolyte layer.

Compared with the prior art, the present invention has the advantages that the preparation method of the metal support plate for the fuel cell is simple in process, can realize mass production of the metal support plate without a mold, reduces the production cost and improves the production efficiency; During sintering, the sintering deformation is eliminated due to the support of the setter and the sintering shrinkage of the metal support plate is basically close to the anode material, and the bonding tightness between the anode layer and the metal substrate is improved. The powder rolling of the forming agent has higher green strength, controllable sintering shrinkage, and controllable sintering deformation. Compared with the support plate using sheet metal, the density is lower and the weight is lighter, which is conducive to achieving light weight. In addition, the support plate prepared from the metal sheet requires multiple coating treatments, which is expensive. In addition, through the wax dipping process, the pores of the metal substrate can be controlled to ensure that the gas can easily pass through the metal substrate.

Description of drawings

1 is a sectional view of the structure of a metal support plate fuel cell;

Fig. 2 is the pore morphology after sintering in Example 1;

Fig. 3 is the pore morphology after sintering in Example 2;

Figure 4 is the pore morphology after sintering in Example 7;

Figure 5 is the pore morphology after sintering in Example 8;

Figure 6 is the pore morphology after sintering in Example 13;

FIG. 7 is the pore morphology after sintering in Example 14. FIG.

Detailed ways

The present invention will be further described in detail below with reference to the embodiments of the accompanying drawings.

Example 1:

The method for preparing a metal support plate for a fuel cell in this embodiment sequentially includes the following steps:

1) 434L stainless steel powder is selected, and 434L stainless steel powder is calculated by mass percentage, including the following components: C: 0.025%, Cr: 17.5%, Mn: 0.8%, Si: 0.6%, Mo: 1.05%, iron: balance;

2) sieve the above-mentioned powder, select a particle size of 325-500 mesh, and powder bulk density of 2.25g/cm ³ ; wherein, the particle size range of 60-mesh-1000-mesh is 13-250 μm;

3) Mixing: mix the powder in step 2) with a forming agent, and the forming agent, in terms of mass percentage, includes the following components: paraffin wax: 50%; microcrystalline wax: 25%; castor oil: 10%; polyethylene wax: 5%; EVA wax: 8%; stearic acid: 2%, mixing ratio: metal powder accounts for 92%, forming agent accounts for 8%, mixing temperature is above 82 ℃, after mixing evenly, semi-solid metal fluid, semi-solid metal fluid The temperature should be kept at 60℃～80℃;

4) Rolling the green body: place the material in step 3) in the powder rolling hopper, and roll the green body strip, the green body is a metal substrate, the thickness of the strip is 0.55mm, and the width is 130mm. The material is cut into a metal substrate 4 of 110mm×110mm×0.55mm, and placed on the setter plate;

5) Sintering: place the setter plate with the rolled green body in a vacuum furnace for sintering, the sintering temperature is 1250°C, the sintering time is 50 minutes, and the vacuum degree in the vacuum sintering furnace is 10 ^-3 Pa, in order To prevent the evaporation of elements such as chromium, it can backflush argon gas of 4×10 ⁴ Pa;

6) Flattening: place the sintered blank of the metal support plate between two flat templates, apply pressure, and press the height of the sintered blank to 0.55mm to form a metal support plate.

7) Wax immersion: Melt polyethylene wax at 110°C, melting temperature is 119°C, put the metal support plate into the wax melt for 10 minutes, and take out the metal plate to cool after the pores have penetrated into the wax.

It can be seen from Figure 2 that the metal support plate has many pores, which can ensure good air permeability.

Example 2:

1) Prepare the raw materials, the material is 434L stainless steel powder: C: 0.025%, Cr: 17.5%, Mn: 0.8%, Si: 0.6%, Mo: 1.05%, iron: balance;

2) The above powder is sieved, and the particle size is 325 meshes, and the bulk density of the powder is 2.25 g/cm ³ .

3) Mixing: mix the powder in step 2) with a forming agent, and the forming agent, in terms of mass percentage, includes the following components: paraffin wax: 45%; microcrystalline wax: 30%; castor oil: 8%; polyethylene wax: 7%; EVA wax: 8%; stearic acid: 2%, mixing ratio: metal powder accounts for 94%, forming agent accounts for 6%, mixing temperature is above 85 ℃, after mixing evenly, semi-solid metal fluid, semi-solid metal fluid The temperature should be kept at 60℃～80℃.

4) Rolling green body: The material of step 3) is placed in the powder rolling hopper, and the green strip is rolled, with a thickness of 0.9 mm and a width of 130 mm. The green strip was cut to a metal substrate 4 of 110 x 110 x 0.9 mm and placed on a setter plate.

5) Sintering: The setter on which the powder rolled green body is placed is placed in a pusher furnace for sintering. The sintering temperature was 1200°C, and the sintering time was 30 minutes. The sintering atmosphere is a mixed gas of high-purity hydrogen and argon, wherein the volume ratio of argon is 30%.

7) Wax immersion: Melt polyethylene wax at a melting temperature of 120°C, put the metal support plate into the wax melt for 5 minutes, and take out the metal plate to cool after the pores have penetrated into the wax.

It can be seen from Figure 3 that the metal support plate has many pores, which can ensure good air permeability.

Example 3:

1) Prepare the raw material, the material is 430L stainless steel powder: C: 0.025%, Cr: 17.1%, Mn: 0.8%, Si: 0.6%, iron: the balance;

2) Sieve the above powder, the particle size range is 200-325 mesh, and the powder bulk density is 2.30 g/cm ³ .

4) Rolling the green body: place the material in step 3) in the powder rolling hopper, roll the green strip, the strip thickness is 0.9mm, the width is 130mm, and the green strip is cut to 110×110×0.9 mm of metal substrate 4 and placed on the setter plate.

5) Sintering: The setter on which the powder rolled green body is placed is placed in a push rod furnace for sintering. The sintering temperature is 1250°C, and the sintering time is 30 minutes. The sintering atmosphere used in the sintering process is a mixture of high-purity hydrogen and argon. Mixed gas, in which the volume ratio of argon is 30%.

Example 4:

1) Prepare the raw material. The material is 316L stainless steel powder: C: 0.03%, Cr: 17.8%, Ni: 12.5%, Mn: 1.2%, Si: 0.8%, Mo: 2.48%, iron: balance;

3) Mixing: mix the powder in step 2) with a forming agent, and the forming agent, in terms of mass percentage, includes the following components: paraffin wax: 45%; microcrystalline wax: 30%; castor oil: 8%; polyethylene wax: 7%; EVA wax: 9%; stearic acid: 1%, mixing ratio: metal powder accounts for 94%, forming agent accounts for 6%, mixing temperature is above 85 ℃, after mixing evenly, semi-solid metal fluid, semi-solid metal fluid The temperature should be kept at 60℃～80℃.

5) Sintering: The setter on which the powder rolled green body is placed is placed in a pusher furnace for sintering, the sintering temperature is 1300°C, the sintering time is 30 minutes, and the sintering atmosphere is a mixture of high-purity hydrogen and argon, in which argon The volume ratio is 30%.

Example 5:

1) Prepare the raw materials. The materials are iron-chromium-aluminum powder: C: 0.06%, Cr: 21.1%, Mn: 0.9%, Si: 0.3%, Al: 4.79%, iron: balance;

5) Sintering: The setter on which the powder rolled green body is placed is placed in a pusher furnace for sintering. The sintering temperature was 1300°C, and the sintering time was 30 minutes. The sintering atmosphere is a mixed gas of high-purity hydrogen and argon, wherein the volume ratio of argon is 30%.

7) Dip wax: melt polyethylene wax at a melting temperature of 120°C. Put the metal support plate into the wax melt for 5 minutes, and take out the metal plate to cool after the pores have penetrated into the wax.

Example 6:

1) Prepare the raw materials, the material is 310 stainless steel, C: ≤ 0.25%, Si: ≤ 1.50%, Mn: ≤ 2.00%, P: ≤ 0.045%, S: ≤ 0.0.03%, Cr: 24.0-26.0%, Ni: 19.0-22.0%, Iron: balance.

7) Dip wax: melt polyethylene wax at a melting temperature of 120°C. Put the metal support plate into the wax melt for 5 minutes, and take out the metal plate to cool after the pores have penetrated into the wax. One of paraffin wax, EVA wax or PP wax can also be used.

Example 7:

1) Prepare the raw materials. The material is 434L stainless steel powder. The stainless steel powder is calculated by mass percentage, including the following components: C: 0.025%, Cr: 17.5%, Mn: 0.8%, Si: 0.6%, Mo: 1.05%, iron :margin;

2) The above powder is sieved, and the particle size is selected to be 100-200 mesh, and the powder bulk density is 2.35 g/cm ³ .

3) Mixing: mix the powder in step 2) with a forming agent, and the forming agent, in terms of mass percentage, includes the following components: paraffin wax: 50%; microcrystalline wax: 25%; castor oil: 10%; polyethylene wax: 5%; EVA wax: 8%; stearic acid: 2%, mixing ratio: metal powder accounts for 92%, forming agent accounts for 8%, the mixing temperature is above 82 ℃, and the semi-solid metal fluid is obtained after mixing evenly, and the temperature needs to be kept at 60℃～80℃.

5) Anode layer preparation: the anode slurry is uniformly coated on the upper surface of the cut metal substrate 4 by screen printing or dip coating, and the uncoated lower surface of the metal substrate 4 is placed on the setter plate. The anode layer 2 is formed on the upper surface of the metal substrate 4 by drying. The aforementioned anode slurry includes yttria-stabilized zirconia YSZ, NiO, methyl ethyl ketone, ethanol, triethanolamine, starch, polyvinyl butyral PVB, polyethylene glycol PEG and glutamic acid PHT.

6) Electrolyte coating preparation: the prepared electrolyte slurry is evenly coated on the anode layer 2 by screen printing or dip coating method, and the uncoated lower surface is placed on a setter plate for drying and sintering, Thus, the electrolyte coating layer 3 is formed on the upper surface of the anode layer 2 . The aforementioned electrolyte slurry includes yttria-stabilized zirconia electrolyte, methyl ethyl ketone, ethanol, triethanolamine, polyvinyl butyral PVB, polyethylene glycol PEG and glutamic acid PHT.

7) Preparation of cathode layer: the cathode slurry made of Sr _2-x Ca _x Fe _1.5 Mo _0.5 O _6-δ (x=0) cathode material is uniformly coated on the electrolyte coating by screen printing or dip coating method. On the upper surface of the layer, the uncoated lower surface is placed on a setter plate for drying, so that a cathode layer 1 is formed on the upper surface of the electrolyte coating layer 3, as shown in FIG. 1 for details.

8) Sintering: The metal support plate with the anode layer, the cathode layer and the electrolyte coating is placed on the setter plate and then placed in a vacuum furnace for sintering to prepare the metal support plate. The sintering temperature is 1300 ° C and the sintering time is 50 The vacuum degree in the vacuum sintering furnace is 10 ^-3 Pa. In order to prevent the evaporation of elements such as chromium, argon gas of 4×10 ⁴ Pa can be backfilled.

Figure 4 shows the pores of the metal support plate. It can be seen that there are many connected pores in the support plate, the density is low, and the porosity is greater than 50%. The support plate of this embodiment is about 50% of the weight of the existing metal support plate with the same thickness, so as to achieve the purpose of light weight.

Example 8:

2) sieve the above powder, the particle size is less than 325 mesh, and the powder bulk density is 2.25g/cm ³ .

3) Mixing: mix the powder in step 2) with a forming agent, and the components of the forming agent are paraffin wax: 45%; microcrystalline wax: 30%; castor oil: 8%; polyethylene wax: 7%; EVA wax: 8% ; Stearic acid: 2%, mixing ratio: metal powder accounts for 94%, forming agent accounts for 6%, the mixing temperature is above 85 ° C, and the semi-solid metal fluid is obtained after mixing evenly, and the temperature needs to be maintained at 60 ° C ~ 80 ° C.

5) Anode layer preparation: the anode slurry is uniformly coated on the upper surface of the cut metal substrate 4 by screen printing or dip coating, and the uncoated lower surface of the metal substrate 4 is placed on the setter plate. The anode layer 2 is formed on the upper surface of the metal substrate 4 by drying. The aforementioned anode slurry includes Sr _2-x Ca _x Fe _1.5 Mo _0.5 O _6- _δ (x=0), NiO, methyl ethyl ketone, ethanol, triethanolamine, starch, polyvinyl butyral PVB, polyethylene glycol Alcohol PEG and Glutamate PHT.

6) Electrolyte coating preparation: the prepared electrolyte slurry is evenly coated on the anode layer 2 by screen printing or dip coating method, and the uncoated lower surface is placed on a setter plate for drying and sintering, Thus, the electrolyte coating layer 3 is formed on the upper surface of the anode layer 2 . The aforementioned electrolyte slurry includes LaGaO3 _- based electrolyte, butanone, ethanol, triethanolamine, polyvinyl butyral PVB, polyethylene glycol PEG and glutamic acid PHT.

7) Preparation of cathode layer: the cathode slurry made of Sr _2-x Ca _x Fe _1.5 Mo _0.5 O _6-δ (x=0.1) cathode material is uniformly coated on the electrolyte coating by screen printing or dip coating method. On the upper surface of the layer, the cathode layer 1 is formed on the upper surface of the electrolyte coating layer 3 after drying the uncoated lower surface on a setter plate.

8) Sintering: The setter on which the powder rolled green body is placed is placed in a pusher furnace for sintering. The sintering temperature was 1200°C, and the sintering time was 30 minutes. The sintering atmosphere is a mixed gas of high-purity hydrogen and argon, wherein the volume ratio of argon is 30%.

Figure 5 shows the pores of the metal support plate. It can be seen that there are many connected pores in the support plate, the density is low, and the porosity is greater than 50%. The support plate of the present invention is about 50% of the weight of the conventional metal support plate of the same thickness, and thus the weight is reduced.

Example 9:

5) Anode layer preparation: the anode slurry is uniformly coated on the upper surface of the cut metal substrate 4 by screen printing or dip coating, and the uncoated lower surface of the metal substrate 4 is placed on the setter plate. The anode layer 2 is formed on the upper surface of the metal substrate 4 by drying. The aforementioned anode slurry includes Sr _2-x Ca _x Fe _1.5 Mo _0.5 O _6- _δ (x=0.1), NiO, methyl ethyl ketone, ethanol, triethanolamine, starch, polyvinyl butyral PVB, polyethylene glycol Alcohol PEG and Glutamate PHT.

6) Electrolyte coating preparation: the prepared electrolyte slurry is evenly coated on the anode layer 2 by screen printing or dip coating method, and the uncoated lower surface is placed on a setter plate for drying and sintering, Thus, the electrolyte coating layer 3 is formed on the upper surface of the anode layer 2 . The aforementioned electrolyte slurry includes Ba(Sr)Ce(Ln)O ₃ electrolyte, butanone, ethanol, triethanolamine, polyvinyl butyral PVB, polyethylene glycol PEG and glutamic acid PHT.

7) Preparation of cathode layer: the cathode slurry made of Sr _2-x Ca _x Fe _1.5 Mo _0.5 O _6-δ (x=0.3) cathode material is uniformly coated on the electrolyte coating by screen printing or dip coating method. On the upper surface of the layer, the cathode layer 1 is formed on the upper surface of the electrolyte coating layer 3 after drying the uncoated lower surface on a setter plate.

8) Sintering: The setter on which the powder rolled green body is placed is placed in a pusher furnace for sintering. The sintering temperature was 1250°C, and the sintering time was 30 minutes. The sintering atmosphere is a mixed gas of high-purity hydrogen and argon, wherein the volume ratio of argon is 30%.

Example 10:

3) Mixing: mix the powder in step 2) with a forming agent, and the components of the forming agent are paraffin wax: 45%; microcrystalline wax: 30%; castor oil: 8%; polyethylene wax: 7%; EVA wax: 9% ; Stearic acid: 1%, mixing ratio: metal powder accounts for 94%, forming agent accounts for 6%, the mixing temperature is above 85 ° C, and the semi-solid metal fluid is obtained after mixing evenly, and the temperature needs to be maintained at 60 ° C ~ 80 ° C.

5) Anode layer preparation: the anode slurry is uniformly coated on the upper surface of the cut metal substrate 4 by screen printing or dip coating, and the uncoated lower surface of the metal substrate 4 is placed on the setter plate. The anode layer 2 is formed on the upper surface of the metal substrate 4 by drying. The aforementioned anode slurry includes Sr _2-x Ca _x Fe _1.5 Mo _0.5 O _6- _δ (x=0.5), NiO, methyl ethyl ketone, ethanol, triethanolamine, starch, polyvinyl butyral PVB, polyethylene glycol Alcohol PEG and Glutamate PHT.

6) Electrolyte coating preparation: the prepared electrolyte slurry is evenly coated on the anode layer 2 by screen printing or dip coating method, and the uncoated lower surface is placed on a setter plate for drying and sintering, Thus, the electrolyte coating layer 3 is formed on the upper surface of the anode layer 2 . The aforementioned electrolyte slurry includes CeO2 _- based solid electrolyte, methyl ethyl ketone, ethanol, triethanolamine, polyvinyl butyral PVB, polyethylene glycol PEG and glutamic acid PHT.

7) Preparation of cathode layer: the cathode slurry made of Sr _2-x Ca _x Fe _1.5 Mo _0.5 O _6-δ (x=0.5) cathode material is uniformly coated on the electrolyte coating by screen printing or dip coating method. On the upper surface of the layer, the cathode layer 1 is formed on the upper surface of the electrolyte coating layer 3 after drying the uncoated lower surface on a setter plate.

Example 11:

2) Sieve the above powder, the particle size range is -200+325 mesh, and the powder bulk density is 2.30 g/cm ³ .

5) Preparation of anode layer: yttria-stabilized zirconia (YSZ) is made into slurry. The electrolyte slurry ingredients include YSZ, NiO, butanone, ethanol, triethanolamine, starch, polyvinyl butyral PVB, polyethylene glycol PEG, glutamic acid PHT, etc. The prepared slurry is evenly coated on one side of the cut metal substrate 4 by methods such as screen printing or dip coating, and the uncoated side is placed on a setter plate for drying.

6) Electrolyte coating preparation: The anode slurry is uniformly coated on the upper surface of the cut metal substrate 4 by screen printing or dip coating, and the uncoated lower surface of the metal substrate 4 is placed on the sintering The plate is dried, whereby the anode layer 2 is formed on the upper surface of the metal substrate 4 . The aforementioned anode slurry includes yttria-stabilized zirconia YSZ, NiO, methyl ethyl ketone, ethanol, triethanolamine, starch, polyvinyl butyral PVB, polyethylene glycol PEG and glutamic acid PHT.

8) Sintering: The setter on which the powder rolled green body is placed is placed in a pusher furnace for sintering. The sintering temperature was 1330°C, and the sintering time was 30 minutes. The sintering atmosphere is a mixed gas of high-purity hydrogen and argon, wherein the volume ratio of argon is 20%.

Example 12:

1) Prepare the raw materials, the material is 310 stainless steel, C: ≤ 0.25%; Si: ≤ 1.50%; Mn: ≤ 2.00%; P: ≤ 0.045%; S: ≤ 0.0.03%; Cr: 24.0-26.0%; Ni: 19.0-22.0%, Iron: balance.

8) Sintering: The setter on which the powder rolled green body is placed is placed in a pusher furnace for sintering. The sintering temperature was 1300°C, and the sintering time was 30 minutes. The sintering atmosphere is a mixed gas of high-purity hydrogen and argon, wherein the volume ratio of argon is 40%.

Example 13:

1) Prepare the raw materials: 434L stainless steel powder is selected as the material. In terms of mass percentage, 434L stainless steel includes the following components: C: 0.025%, Cr: 17.5%, Mn: 0.8%, Si: 0.6%, Mo: 1.05%, iron :margin;

2) The above powder is sieved, and the particle size is 100-200 mesh, and the bulk density of the powder is 2.35 g/cm ³ .

3) Mixing: mix the powder in step 2) with a forming agent, and the components of the forming agent are paraffin wax: 50%; microcrystalline wax: 25%; castor oil: 10%; polyethylene wax: 5%; EVA wax: 8% ; Stearic acid: 2%, mixing ratio: metal powder accounts for 92%, forming agent accounts for 8%, mixing temperature is above 82 ℃, after mixing evenly, a semi-solid metal fluid is obtained, and the temperature needs to be maintained at 60 ℃ ~ 80 ℃.

4) Rolling green body: another part of the material is metal fiber felt. According to the mass percentage, the metal fiber felt includes the following components: C: 0.015%, Cr: 18.5%, Mn: 0.6%, Si: 0.3%, Ni: 10.1%, iron: balance; the porosity of the metal fiber felt is 80%, and the thickness is 0.1 mm; the material in step 3) and the metal fiber felt are placed in the hopper for powder rolling, and the green strip is rolled together. The thickness of the material is 0.7 mm and the width is 120 mm. The green strip is cut into a metal substrate 4 of 110×110×0.9 mm and placed on the setter.

7) Preparation of cathode layer: the cathode slurry made of Sr _2-x Ca _x Fe _1.5 Mo _0.5 O _6-δ (x=0) cathode material is uniformly coated on the electrolyte coating by screen printing or dip coating method. On the upper surface of the layer, the cathode layer 1 is formed on the upper surface of the electrolyte coating layer 3 after drying the uncoated lower surface on a setter plate.

8) Sintering: The setter plate on which the powder rolled green body is placed is placed in a vacuum furnace for sintering. The sintering temperature was 1300°C, and the sintering time was 50 minutes. The vacuum degree in the vacuum sintering furnace is 10-3Pa. In order to prevent the evaporation of elements such as chromium, argon gas of 4×10 ⁴ Pa can be back flushed.

Figure 6 shows the pores of the metal support plate. It can be seen that there are many connected pores in the support plate, the density is low, and the porosity is greater than 50%. The support plate of the present invention is about 50% of the weight of the conventional metal support plate of the same thickness, and thus the weight is reduced.

Example 14:

1) Prepare the raw material. The material is 430L stainless steel powder. 430L stainless steel includes the following components according to the mass percentage: C: 0.025%, Cr: 17.2%, Mn: 0.9%, Si: 0.5%, iron: balance;

2) The above powder is sieved, and the particle size is selected to be less than 325 meshes, and the bulk density of the powder is 2.25 g/cm ³ .

4) Rolling green body: another part of the material is metal fiber felt. According to the mass percentage, the metal fiber felt includes the following components: C: 0.015%, Cr: 17.5%, Mn: 0.6%, Si: 0.3%, Ni: 13.4%, Mo: 2.46%, Iron: balance. The metal fiber felt has a porosity of 60% and a thickness of 1.1 mm; the material in step 3) and the metal fiber felt are placed in a powder rolling hopper, and a green strip is rolled together, with a thickness of 1.6 mm and a width of 130 mm. The green strip was cut to a metal substrate 4 of 110 x 110 x 0.9 mm and placed on a setter plate.

5) Preparation of anode layer: yttria-stabilized zirconia (YSZ) is made into slurry. The electrolyte slurry ingredients include YSZ, NiO, methyl ethyl ketone, ethanol, triethanolamine, starch, polyvinyl butyral PVB, polyethylene glycol PEG and glutamic acid PHT. The prepared slurry is evenly coated on one side of the cut metal substrate 4 by methods such as screen printing or dip coating, and the uncoated side is placed on a setter plate for drying.

6) Electrolyte coating preparation: yttria-stabilized zirconia (YSZ) is made into slurry. The prepared slurry is uniformly coated on the anode layer by methods such as screen printing or dip coating, and the uncoated side is placed on the setter for drying.

Figure 7 shows the pores of the metal support plate. It can be seen that there are many connected pores in the support plate, the density is low, and the porosity is greater than 50%. The support plate of the present invention is about 50% of the weight of the conventional metal support plate of the same thickness, and thus the weight is reduced.

Example 15:

The preparation method of the metal support plate for a fuel cell in this embodiment includes the following steps:

1) Prepare the raw materials. The material is 434L stainless steel powder. 434L stainless steel includes the following components according to the mass percentage: C: 0.025%, Cr: 17.5%, Mn: 0.8%, Si: 0.6%, Mo: 1.05%, iron: margin;

4) Rolled green body: another part of the material is metal fiber felt. According to the mass percentage, the metal fiber felt includes the following components: C: 0.015%, Cr: 17.2%, Mn: 0.9%, Si: 0.5%, iron: margin. The porosity of the metal fiber felt is 60%, and the thickness is 0.4 mm; the material in step 3) and the metal fiber felt are placed in the hopper for powder rolling, and rolled together to form a green strip with a thickness of 0.8 mm and a width of 130 mm. The green strip is cut into a metal substrate 4 of 110×110×0.9 mm and placed on a setter.

Example 16:

1) Prepare the raw materials. The material is 434L stainless steel powder. 434L stainless steel includes the following components in terms of mass percentage: C: 0.025%, Cr: 17.5%, Mn: 0.8%, Si: 0.6%, Mo: 1.05%, iron: margin;

2) Sieve the above-mentioned powder, and select a particle size of 200-325 mesh and a powder bulk density of 2.30 g/cm ³ .

4) Rolling green body: another part of the material is metal fiber felt. According to the mass percentage, the metal fiber felt includes the following components: C: 0.006%, Cr: 21.1%, Mn: 0.9%, Si: 0.3%, Al: 4.79 %, iron: balance; porosity 65%, thickness 0.2mm; place the material and metal fiber felt in step 3) in the hopper for powder rolling, and roll it into a green strip with a thickness of 0.6mm, A width of 130 mm, the green strip was then cut to a metal substrate 4 of 110 x 110 x 0.9 mm and placed on a setter plate.

Example 17:

The only difference between this embodiment and the above-mentioned Embodiment 16 is: 1. The metal fiber mat is different. Specifically, the metal fiber mat includes the following components in terms of mass percentage: C: 0.006%, Cr: 10%, Mn: 2 %, Si: 1%, Al: 10%, Nb: 2%, Ti: 2%, Ni: 25%, Iron: balance.

Different from stainless steel, specifically, heat-resistant steel is used. In terms of mass percentage, the heat-resistant steel includes the following components: C: 0.025%, Cr: 30%, Mn: 2%, Mo: 4%, iron: balance.

The sintering parameters in step 8) are different, specifically, the sintering temperature is 1050° C., and the sintering time is 300 min.

Example 18:

The only difference between this embodiment and the above-mentioned Embodiment 16 is: 1. The metal fiber mat is different. Specifically, the metal fiber mat includes the following components in terms of mass percentage: C: 0.006%, Ni: 25%, Cr: 30% %, Mo: 4%, Nb: 3%, Al: 5%, Ti: 3%, Iron: balance.

2. Sintered stainless steel is different. Specifically, sintered stainless steel includes the following components in terms of mass percentage: C: 0.025%, Cr: 10%, Si: 1%, Ni: 25%, Nb: 3%, Al: 10 %, Ti: 3%, Iron: balance.

The sintering parameters in step 8) are different, specifically, the sintering temperature is 1400° C., and the sintering time is 10 min.

In addition, it is also possible to replace the sintered stainless steel with one of nickel-based alloys, cobalt-based alloys, titanium alloys, and chromium-based alloys. The setter plates of the above embodiments are not easily deformed and cracked during sintering, heating and cooling.

Claims

A method for preparing a metal support plate for a fuel cell, characterized in that it comprises the following steps in sequence:

1) Use one of sintered stainless steel, heat-resistant steel, nickel-based alloy, cobalt-based alloy, titanium alloy, and chromium-based alloy;

2) sieve the powder in step 1), and select the particle size of the powder to be 13-250 μm;

3) Mixing the powder in step 2) with the forming agent, according to the mass percentage, the powder accounts for 92-95%, and the forming agent accounts for 5-8%, and the powder of the semi-solid metal fluid is obtained after mixing uniformly;

4) putting the powder in step 3) into a rolling mill for rolling, thereby forming a metal substrate;

5) coating the anode slurry on the upper surface of the metal substrate, then placing the uncoated lower surface of the metal substrate on the setter plate, and drying, thereby forming an anode layer on the upper surface of the metal substrate;

6) coating the electrolyte slurry on the upper surface of the anode layer, then placing the uncoated lower surface of the metal substrate on the setter plate and drying, thereby forming an electrolyte coating on the upper surface of the anode layer;

7) coating the cathode slurry on the upper surface of the electrolyte coating, then placing the uncoated lower surface of the metal substrate on a setter plate and drying, thereby forming a cathode layer on the upper surface of the electrolyte coating, Thereby a metal support plate is made;

A sintering treatment is performed between steps 4) and 5) or after step 7).
The preparation method according to claim 1, wherein the sintering treatment is to place a metal substrate or a metal support plate of a required size on a setter plate for sintering, the sintering temperature is 1000°C to 1350°C, and the sintering time is 5～240min, the vacuum degree is 10 -3 Pa～10 2 Pa.
The preparation method according to claim 2, wherein: when the sintering process is between steps 4) and 5), the sintered metal substrate is flattened, and then the flattened metal substrate is dipped in wax In the treatment, the metal substrate of the required size is placed in the wax melt for 1-30 minutes, and after the wax melt penetrates into the pores in the metal substrate, the metal substrate is taken out and cooled.
The preparation method according to claim 1, characterized in that: in step 1), sintered stainless steel is selected, and the components of the sintered stainless steel, in terms of mass percentage, include the following components: carbon: ≤ 0.06%, nickel: 0-25 %, Molybdenum: 0～4%, Chromium: 10～30%, Niobium: 0～3%, Aluminum: 0～10%, Titanium: 0～3%, Silicon: 0～1%, Manganese: 0～2% , not more than 2% unavoidable impurities, iron: balance.
The preparation method according to claim 1, characterized in that: the components of the forming agent in step 2), in terms of mass percentage, include the following components: paraffin wax: 40-60%; microcrystalline wax: 20-30% ; Castor oil: 0.5-20%; polyethylene wax: 5-15%; EVA wax: 5-15%; stearic acid: 1-2%.
The preparation method according to claim 1, characterized in that: in step 5), step 6) and step 7), sintering is performed after drying, and the sintering in step 5) and the sintering in step 6) adopt The sintering temperature is 1050℃～1400℃, the sintering time is 10～300min, the sintering temperature used in the sintering in step 7) is 800℃～1200℃, the sintering time is 5～300min, and the vacuum degree is 10 -3 Pa ~10 2 Pa.
The preparation method according to claim 1, characterized in that: in step 4), the metal fiber felt with a porosity greater than 50% is also added to the rolling mill, and the metal fiber felt and the powder are rolled into a metal substrate.
The preparation method according to claim 7, wherein the metal fiber felt comprises the following components in terms of mass percentage: carbon: <0.03%, nickel: 0-25%, molybdenum: 0-4%, chromium : 10～30%, Niobium: 0～3%, Aluminum: 0～10%, Titanium: 0～3%, Silicon: 0～1%, Manganese: 0～2%, unavoidable impurities not exceeding 2% , iron: margin.
The preparation method according to any one of claims 1 to 8, wherein the anode slurry comprises NiO, methyl ethyl ketone, ethanol, triethanolamine, starch, polyvinyl butyral PVB, polyvinyl butyral Ethylene glycol PEG and glutamic acid PHT, and one of yttria-stabilized zirconia and Sr 2-x Ca x Fe 1.5 Mo 0.5 O 6-δ , wherein x=0, 0.1, 0.3, 0.5.
The preparation method according to claim 9, wherein the electrolyte slurry comprises butanone, ethanol, triethanolamine, polyvinyl butyral PVB, polyethylene glycol PEG, and glutamic acid PHT, and further comprises There is one of yttria-stabilized zirconia, LaGaO 3 based electrolyte, Ba(Sr)Ce(Ln)O 3 and CeO 2 based solid electrolyte.
The preparation method according to claim 10, wherein the cathode slurry is Sr 2-x Ca x Fe 1.5 Mo 0.5 O 6-δ , LSM (La 1-x Sr x MnO 3 ), LSCF ((( One of La,Sr)(Co,Fe) O3 ), A2Ru2O7-x(A=Pb,Bi) ceramics with pyrochlore structure, Ag-YDB composite ceramics and L-type ceramics with perovskite structure, the aforementioned x= 0, 0.1, 0.3, 0.5.