Microcrystalline glass material for fuel cell connecting component

Abstract

The present application relates to the field of fuel cells, and discloses a microcrystalline glass material for a fuel cell connecting component. The microcrystalline glass material is composed of crystallization phases and a glass phase, and the mass percentage content of the crystallization phases is greater than or equal to 30%; a main crystallization phase among the crystallization phases comprises at least one of akermanite, feldspar, olivine, clinokurchatovite, silicon dioxide, cerium dioxide, lanthanum aluminum borate, and lanthanum calcium borate. According to the present application, the composition and mass percentage of the main crystallization phase of the microcrystalline glass material are adjusted, and the mass percentage content of the crystallization phases of the microcrystalline glass material is adjusted, so that a connecting component having high-temperature, sealing and insulation characteristics is prepared; the connecting component does not have poor performance or point leakage and the like even if the connecting component operates for a long time under a high-temperature working condition. Therefore, the connecting component prepared from the microcrystalline glass material of the present application provides technical support for commercial application of a fuel cell system.

Description

A glass-ceramic material for fuel cell connection components Technical Field

[0001] The present application belongs to the field of fuel cells, and specifically relates to a microcrystalline glass material for fuel cell connecting components. Background Art

[0002] A fuel cell is a chemical device that converts the chemical energy of a fuel directly into electrical energy. Fuel cells use fuel and oxygen as raw materials and have no mechanical transmission parts, resulting in zero noise pollution. They also emit minimal harmful gases, minimizing environmental pollution.

[0003] A fuel cell power generation system usually contains two or more fuel cells, and each fuel cell stack needs to be connected and gas transported through pipes. Therefore, the connecting pipes between each fuel cell stack must have good sealing and insulation properties to prevent short circuits between the positive and negative electrodes of the fuel cell stack during operation. At the same time, in order to meet the characteristics of some models of fuel cells working at high temperatures, the connecting pipes must also have the characteristics of not generating microcracks or air leakage in the joint area under long-term high-temperature (600-800℃) operating conditions.

[0004] In view of the performance requirements of the connecting pipes between the above-mentioned fuel cell stacks, finding a sealing and insulating connecting component with good mechanical properties at high temperatures is the current research focus in the fuel cell field.

[0005] Summary of the Invention

[0006] The purpose of this application is to overcome the shortcomings of the above-mentioned prior art and provide a microcrystalline glass material for fuel cell connecting components. The connecting components made of the microcrystalline glass material are sealed and insulated, and have good high-temperature mechanical properties. There will be no performance problems or point leakage problems when operating under long-term high-temperature conditions.

[0007] To achieve the above objectives, the technical solutions adopted in this application are:

[0008] A microcrystalline glass material for fuel cell connecting components, the microcrystalline glass material consisting of a crystalline phase and a glass phase, the mass percentage of the crystalline phase in the microcrystalline glass material being ≥30%; the main crystalline phase in the crystalline phase comprising at least one of magnesia chalcedony, feldspar, olivine, calcite, silica, cerium dioxide, lanthanum aluminum borate, and calcium lanthanum borate.

[0009] Microcrystalline glass material is a well-known material used as metal-metal, metal-ceramic and ceramic-ceramic sealing materials, as well as high-performance coatings for metals and ceramics; compared with glass, microcrystalline glass can provide higher operating temperatures, better mechanical properties and corrosion resistance, and also has a very wide range of thermal expansion coefficients (CTE); the connecting parts made of the microcrystalline glass material described in this application are sealed and insulated, and have good high-temperature mechanical properties. When operating under long-term high-temperature conditions, there will be no problems of poor performance and point leakage.

[0010] The inventors found that in the present application, the main crystal phase system is mainly a magnesium-containing glass system, and the main precipitate phase in this system is a magnesium-containing phase. The magnesium-containing phase has better stability and is not easy to react with volatile substances in stainless steel, which can make the performance of the connecting components finally produced by the present application better during use.

[0011] Through a large number of experiments, the inventors found that only when the mass percentage of the crystalline phase in the microcrystalline glass material is ≥30% can the final connecting components be connected without leakage, microcracks, etc.; if the mass percentage of the crystalline phase in the microcrystalline glass material is <30%, the microcrystalline glass material contains more glass phase, which makes the densification of the microcrystalline glass material lower. When the fuel cell is running, the easily diffusible cations in the metal components will penetrate into the microcrystalline glass material, which can easily cause deterioration of the joining area between the alloy and the glass phase, resulting in microcracks and leakage in the joining area of ​​the final connecting components; and if the content of the crystalline phase is too little, the stability of the system will deteriorate, and the connecting components will change when running for a long time at high temperature, resulting in their structural failure.

[0012] As a preferred embodiment of the microcrystalline glass material used for fuel cell connecting components in the present application, the mass percentage of the crystalline phase is ≥60%; the inventors have found through a large number of experiments that when the mass percentage of the crystalline phase is ≥60%, the performance of the final connecting component can be better, and the tensile and shear strength that can be withstood at a temperature of 800°C is greater.

[0013] As a preferred embodiment of the microcrystalline glass material used for fuel cell connecting components in the present application, the mass percentage of the crystalline phase is ≥85%; the inventors have found through a large number of experiments that when the mass percentage of the crystalline phase is ≥85%, the residual glass phase in the microcrystalline glass material is relatively small, and the few residual glass phases are confined to the structure of the crystalline phase. The entire microcrystalline glass structure has a relatively small porosity and does not form a continuous channel through the main body of the material, which can minimize the migration of ions through the glass phase at high temperatures, thereby inhibiting any continuous reaction between the alloy part and the microcrystalline glass part in the prepared connecting component; at the same time, the crystalline phase is a thermodynamically stable phase, which is stable even when operated for a long time at high temperatures, and is less likely to soften, change in size, or change in phase, which can make the sealing structure of the final connecting component the most stable, prevent ion penetration in the alloy and glass bonding area, and prevent any adverse conditions in the bonding area performance under long-term operation.

[0014] As a preferred embodiment of the glass-ceramic material for fuel cell connection components of the present application, the main crystalline phase in the crystalline phase includes magnesia feldspar and silicon dioxide.

[0015] It should be noted that the main component of the magnesia feldspar in the present invention is 2CaO·MgO·2SiO2.

[0016] As a more preferred embodiment of the microcrystalline glass material for fuel cell connecting components of the present application, the microcrystalline glass material includes the following components in mass percentage: 5%-60% of magnesia feldspar and 3%-10% of silica; wherein the mass ratio of magnesia feldspar and silica is magnesia feldspar: silica = 0.3-8:1; the inventors have found through a large number of experiments that when the mass percentage and mass ratio of magnesia feldspar and silica are within the above-mentioned range, the final fuel cell connecting component can withstand at least 40N of tension and 15N of shear force under high temperature conditions of 800°C, and there is no leakage during operation.

[0017] As a preferred embodiment of the glass-ceramic material for fuel cell connection components of the present application, the main crystalline phase in the crystalline phase includes feldspar and silicon dioxide.

[0018] As a more preferred embodiment of the glass-ceramic material for fuel cell connection components of the present application, the feldspar is at least one of anorthite, barium feldspar, and strontium feldspar.

[0019] As a more preferred embodiment of the microcrystalline glass material for fuel cell connecting components of the present application, the microcrystalline glass material includes the following components in mass percentage: feldspar 20%-65%, silica 10%-30%; wherein, the mass ratio of feldspar and silica is feldspar: silica = 0.3-5:1; in the present application, feldspar is a key factor in determining the CTE of the microcrystalline glass material, while the CTE of silica is relatively low and the content cannot be too high, so the mass ratio of the two needs to be strictly controlled. The inventors have found through a large number of experiments that when the mass percentage and mass ratio of feldspar and silica are within the above range, the final fuel cell connecting component can withstand at least 40N of tension and 15N of shear force under high temperature conditions of 800°C, and there is no leakage during operation.

[0020] As a preferred embodiment of the glass-ceramic material for fuel cell connection components of the present application, the main crystalline phase in the crystalline phase includes magnesia feldspar and olivine.

[0021] As a preferred embodiment of the glass-ceramic material for fuel cell connection components of the present application, the olivine is at least one of forsterite and calcite.

[0022] As a more preferred embodiment of the microcrystalline glass material for fuel cell connecting components of the present application, the microcrystalline glass material includes the following components in mass percentage: 0%-50% of magnesia feldspar and 5%-50% of olivine; wherein the mass ratio of magnesia feldspar and olivine is magnesia feldspar: olivine = 0-15:1; the inventors have found through a large number of experiments that when the mass percentage and mass ratio of magnesia feldspar and olivine are within the above-mentioned range, the final fuel cell connecting component can withstand at least 40N of tension and 15N of shear force under high temperature conditions of 800°C, and there is no leakage during operation.

[0023] In a second aspect, the present application provides a connecting component for a fuel cell, wherein the connecting component includes a microcrystalline glass portion made of the microcrystalline glass material as described in the first aspect.

[0024] As a preferred embodiment of the connecting component for a fuel cell of the present application, the connecting component further includes an alloy portion.

[0025] As a preferred embodiment of the connecting component for a fuel cell of the present application, the glass-ceramic portion and the alloy portion in the connecting component are sealed end to end.

[0026] As a more preferred embodiment of the connecting component for a fuel cell of the present application, the alloy portion is made of an alloy material.

[0027] As a more preferred embodiment of the connection component for a fuel cell of the present application, the glass-ceramic portion and the alloy portion are tubular in shape.

[0028] As a more preferred embodiment of the connection component for a fuel cell of the present application, both ends of the microcrystalline glass portion have grooves or bosses.

[0029] As the most preferred embodiment of the connection component for a fuel cell of the present application, the alloy portion is a flanged tubular alloy portion or a corrugated tubular alloy portion that is flanged inward or outward.

[0030] As the most preferred embodiment of the connection component for a fuel cell of the present application, the flanged tubular alloy portion has a flange length of 1-50 mm;

[0031] Preferably, the flanging length of the flanging tubular alloy portion is 2-10 mm;

[0032] More preferably, the flanging length of the flanging tubular alloy portion is 4-5 mm.

[0033] As a preferred embodiment of the connection component for a fuel cell of the present application, the flanged tubular alloy portion has a flange thickness of 1-5 mm;

[0034] Preferably, the flange thickness of the flanged tubular alloy portion is 0.1-2 mm;

[0035] More preferably, the flanging thickness of the flanging tubular alloy portion is 0.2-0.4 mm.

[0036] The present application also provides a method for preparing the connecting component for a fuel cell, comprising the following steps: contacting the alloy part with the microcrystalline glass part and heating them until crystallization occurs in the microcrystalline glass part, thereby bonding the microcrystalline glass part and the alloy part to obtain the connecting component.

[0037] In a third aspect, the present application provides a fuel cell system, which includes a gas delivery pipe made of the connecting component as described in the second aspect.

[0038] As a preferred embodiment of the fuel cell system of the present application, the fuel cell system further includes a manifold and a fuel cell stack.

[0039] As a more preferred embodiment of the fuel cell system of the present application, the gas delivery pipe, manifold and fuel cell stack are connected in the following manner: the gas delivery pipe is connected to one end of the manifold, and the fuel cell stack is connected to the other end of the manifold.

[0040] Compared with the existing technology, the beneficial effect of the present application is that: the present application prepares a connecting component with high-temperature sealing and insulating properties by adjusting the composition and mass ratio of the main crystal phase in the microcrystalline glass material and adjusting the mass percentage of the crystalline phase in the microcrystalline glass material. The high-temperature mechanical properties of the connecting component are good, and even if it is operated under long-term high-temperature conditions, there is no poor performance and no point leakage problems during long-term operation. The connecting component prepared from the microcrystalline glass material described in the present application provides technical support for the commercial application of fuel cell systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] FIG1 is a schematic diagram of a fuel cell stack module of the fuel cell system described in this application;

[0042] (1): Microcrystalline glass part, (2): Alloy part, (3): Fuel cell stack. DETAILED DESCRIPTION

[0043] In order to better illustrate the purpose, technical solutions and advantages of this application, this application will be further described below in conjunction with specific embodiments.

[0044] Unless otherwise specified, the reagents, methods and equipment used in this application are conventional reagents, methods and equipment in this technical field.

[0045] Examples 1-9

[0046] The formula of the microcrystalline glass material for fuel cell connecting components described in Examples 1-9 of the present application is shown in Table 1.

[0047] In Examples 1-9, the connecting component includes an alloy part and a microcrystalline glass part. The alloy part is prepared by placing the alloy material iron-based alloy SUS 444 in a mold and heating and sintering it. The shape of the alloy part is a flanging tube with an inner diameter of 24 mm, an outer diameter of 32 mm, a flanging length of 4 mm, and a flanging thickness of 0.4 mm; the microcrystalline glass part is prepared by placing the microcrystalline glass material in Table 1 in a mold and heating and sintering it. The microcrystalline glass part is a glass tube with an inner diameter of 16 mm, an outer diameter of 32 mm, a boss at one end, an inner diameter of the boss of 16 mm, an outer diameter of the boss of 22 mm, and a height of 2 mm.

[0048] The preparation method of the connecting component is: contacting the above-mentioned alloy part with the microcrystalline glass part, heating to the crystallization temperature of the microcrystalline glass part in an air atmosphere, so that the microcrystalline glass part and the alloy part are sealed together end to end, thereby obtaining the connecting component.

[0049] Table 1

[0050] Comparative Examples 1-7

[0051] The only difference between Comparative Example 1-7 of the present application and Example 1-9 is that the formula of the microcrystalline glass material used for the fuel cell connecting components is different, as shown in Table 2; the remaining parameters of Comparative Example 1-7 are consistent with those of Example 1-9.

[0052] Table 2

[0053] Examples 10-15

[0054] The only difference between Examples 10-15 of the present application and Examples 1-9 is that the formula of the microcrystalline glass material used for the fuel cell connecting components is different, as shown in Table 3; the remaining parameters of Examples 10-15 are consistent with those of Examples 1-9.

[0055] Table 3

[0056] Comparative Examples 8-14

[0057] The only difference between comparative examples 8-14 of the present application and embodiments 1-9 is that the formula of the microcrystalline glass material used for fuel cell connecting components is different, as shown in Table 4; the remaining parameters of comparative examples 8-14 are consistent with those of embodiments 1-9.

[0058] Table 4

[0059] Examples 16-21

[0060] The only difference between Examples 16-21 of the present application and Examples 1-9 is that the formula of the microcrystalline glass material used for fuel cell connecting components is different, as shown in Table 5; the remaining parameters of Examples 16-21 are consistent with those of Examples 1-9.

[0061] Table 5

[0062] Comparative Examples 15-19

[0063] The only difference between comparative examples 15-19 of the present application and examples 1-9 is that the formula of the microcrystalline glass material used for fuel cell connecting components is different, as shown in Table 6; the remaining parameters of comparative examples 15-19 are consistent with those of examples 1-9.

[0064] Table 6

[0065] Examples 22-23

[0066] The only difference between Examples 22-23 of the present application and Examples 1-9 is that the formula of the microcrystalline glass material used for the fuel cell connecting components is different, as shown in Table 7; the remaining parameters of Examples 22-23 are consistent with those of Examples 1-9.

[0067] Table 7

[0068] Effect Examples

[0069] A gas delivery pipe made from the connecting components prepared in the above embodiments and comparative examples was connected to one end of a fuel cell manifold, and the other end of the manifold was connected to a fuel cell point to prepare a fuel cell system. The following performance tests were performed, and the test results are shown in Table 8. A schematic diagram of the stack module of the fuel cell system is shown in Figure 1.

[0070] 1. Thermal shock performance test: Ramp up and down at 5℃ / min, keep at 800℃ for 2h, cycle 20 times, and observe the appearance of the product; perform air leak detection at room temperature, maintain pressure at 6000Pa, and leakage rate <10Pa / min is considered qualified;

[0071] 2. Aging performance test: Ramp up and down at 1°C / min, keep at 800°C for 2000h, and observe the appearance of the product; perform air leak detection at room temperature, maintain pressure at 6000Pa, and leakage rate <10Pa / min is considered qualified;

[0072] 3. Insulation test: Apply 1000V voltage continuously for at least 15s. When the voltage value is stable, the measured resistivity is greater than 1×10 4 Ω·cm is qualified;

[0073] 4. Mechanical properties test: According to the national standard GB-T 4338-2006 high temperature tensile test method for metal materials, the test is carried out at a high temperature of 800℃. The maximum tensile force that the test piece can withstand without leakage is tested. Qualified products can withstand at least 40N of tensile force and 15N of shear force without leakage.

[0074] Table 8

[0075] According to the data in Table 8, the connecting components made of the microcrystalline glass materials described in Examples 1-23 of the present application can withstand at least 40N of tension and 15N of shear force at a high temperature of 800°C, and have good high-temperature mechanical properties. There is no leakage in the impact resistance test and aging performance test, and it has good thermal shock resistance and high-temperature reliability. It can withstand a continuous application of 1000V voltage for at least 15s, and the voltage value remains stable, and the resistivity is greater than 1×10 4 Ω·cm, with good high-temperature voltage resistance and insulation. However, since the mass percentage of silica in the main crystalline phase of Comparative Example 1 is not within the range provided by the present invention, the final high-temperature mechanical properties are not as good as those of Examples 1-6. Comparative Examples 2-7 also have poor high-temperature mechanical properties due to the mass percentage or mass ratio of magnesia feldspar and silica in the main crystalline phase not being within the range provided by the present invention, or the mass percentage of the crystalline phase in the microcrystalline glass material is too low. Moreover, the heat shock resistance and high-temperature reliability of Comparative Examples 4-7 are also poor. Comparative Examples 8-14 also have poor high-temperature mechanical properties due to the mass percentage of feldspar and silica in the main crystalline phase. Or the mass ratio is not within the range provided by the present invention, or the mass percentage of the crystalline phase in the microcrystalline glass material is too low, resulting in poor final high-temperature mechanical properties, and the heat shock resistance and high-temperature reliability of Examples 11-14 are also poor; Comparative Examples 15-19 are also because the mass percentage or mass ratio of forsterite and forsterite in the main crystalline phase is not within the range provided by the present invention, or the mass percentage of the crystalline phase in the microcrystalline glass material is too low, resulting in poor final high-temperature mechanical properties, and the heat shock resistance and high-temperature reliability of Comparative Examples 18 and 19 are also poor.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit the scope of protection 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 may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present application.

Claims

1. A glass-ceramic material for a fuel cell connection component, characterized in that: The microcrystalline glass material is composed of a crystalline phase and a glass phase, and the mass percentage of the crystalline phase in the microcrystalline glass material is ≥30%; the main crystalline phase in the crystalline phase includes at least one of magnesia chalcedony, feldspar, olivine, calcite, silica, cerium dioxide, lanthanum aluminum borate and calcium lanthanum borate.

2. The microcrystalline glass material for fuel cell connection components according to claim 1, characterized in that: The mass percentage of the crystalline phase in the microcrystalline glass material is ≥60%.

3. The glass-ceramic material for fuel cell connection components according to claim 1, characterized in that: The mass percentage of the crystalline phase in the microcrystalline glass material is ≥85%.

4. The microcrystalline glass material for fuel cell connection components according to claim 1, characterized in that: The main crystalline phase in the crystalline phase includes magnesia chalcedony and silicon dioxide, wherein the mass ratio of magnesia chalcedony to silicon dioxide is magnesia chalcedony: silicon dioxide=0.3-8:

1.

5. The microcrystalline glass material for fuel cell connection components according to claim 4, characterized in that: The microcrystalline glass material comprises the following components in percentage by mass: 5%-60% of magnesia feldspar and 3%-10% of silicon dioxide.

6. The glass-ceramic material for fuel cell connection components according to claim 1, characterized in that: The main crystalline phase in the crystalline phase includes feldspar and silicon dioxide, and the mass ratio of feldspar to silicon dioxide is feldspar:silicon dioxide=0.3-5:

1.

7. The glass-ceramic material for fuel cell connection components according to claim 6, characterized in that: The microcrystalline glass material comprises the following components in percentage by mass: 20%-65% of feldspar and 10%-30% of silicon dioxide.

8. The glass-ceramic material for fuel cell connection components according to claim 1, characterized in that: The main crystalline phase in the crystalline phase includes magnesia and olivine, wherein the mass ratio of magnesia to olivine is magnesia:olivine=0-15:

1.

9. The microcrystalline glass material for fuel cell connection components according to claim 8, characterized in that: The microcrystalline glass material comprises the following components in percentage by mass: 0%-50% of forsterite and 5%-50% of olivine.

10. A connecting component for a fuel cell, characterized in that: The connecting component comprises a microcrystalline glass portion and an alloy portion made of the microcrystalline glass material according to any one of claims 1 to 9; Preferably, the glass-ceramic part and the alloy part in the connecting component are sealed end to end.

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