CN111403768A - Integrated structure, battery/electrolytic cell and preparation method of battery stack - Google Patents

Abstract

The invention provides an integrated structure, a battery/electrolytic cell and a preparation method of a battery stack. The method comprises the following steps: the self-sealing connector and support integrated structure is prepared by designing pore-forming agents with different flow passage shapes, then spreading powder layer by layer and then utilizing a compression molding and powder metallurgy preparation method. And sequentially preparing an anode, an electrolyte and a cathode on the metal porous area of the support body and the connector integrated structure by using tape casting, wet process or spraying, so that the anode covers the metal porous area, the electrolyte covers the anode area, and finally preparing the self-sealing monocell/electrolytic cell. The preparation method effectively simplifies the manufacturing process of the cell stack, reduces the sealing workload of the cell stack, is beneficial to reducing the manufacturing cost of the cell, and is beneficial to the commercial popularization of the solid oxide cell.

Description

Integrated structure, battery/electrolyte cell and method for preparing battery stack

technical field

The present invention relates to the field of energy technology, in particular to a method for preparing an integrated structure, a battery/electrolytic cell and a battery stack.

Background technique

Solid oxide fuel cell (SOFC for short) is an energy conversion device, which directly converts the chemical energy of fuel into electrical energy, and has the advantages of high power generation efficiency, no environmental pollution, and no noise. A traditional SOFC single cell consists of an anode, an electrolyte, and a cathode. According to the type of support that provides battery strength, it can be divided into anode-supported SOFC, cathode-supported SOFC, and electrolyte-supported SOFC, each of which provides support by thickening one of the components (about 1 mm). Due to the inherent brittleness of ceramic materials, the mechanical strength of the above-mentioned supported SOFCs is still not high, and thickening of the electrode or electrolyte components will lead to a decrease in battery performance.

Metal-supported SOFC is a new type of SOFC structure. Using porous metal as a support, the anode, electrolyte and cathode are sequentially prepared on it. Due to the use of the metal support, the structure has good mechanical strength and thermal shock resistance, and the electrode and electrolyte components can be made into thin films, which not only reduces the cost but also improves the output performance of the battery.

SOFC single cells must be fixed on metal connectors, which can provide gas flow channels and conduct current. The traditional anode-supported SOFC, cathode-supported SOFC, electrolyte-supported SOFC, and the connector are mainly connected and sealed by glass sealing materials, which are not only expensive but also poor in stability. Since the metal support SOFC uses a metal support, the traditional welding technology can be used to realize the connection between the support and the connecting body. The welding methods in the related art include brazing and laser welding.

However, the working temperature of SOFC is between 600-800 °C. Under such a high temperature, there are problems such as uneven stress and uneven composition at the welded joint, as well as weak sealing and oxidation resistance of the weld. , will affect the long-term stability of the battery, resulting in battery performance degradation.

Therefore, the problem of connection and sealing between the connecting body and the supporting body is still a key problem in the art, and if it can be solved, it will greatly promote the development of the art. Likewise, solid oxide electrolysis cells suffer from similar sealing issues.

SUMMARY OF THE INVENTION

The present invention provides an integrated structure, a battery/electrolytic cell and a method for preparing a battery stack, so as to solve the connection and sealing problems between the metal support and the connector in the above problems.

In a first aspect, the present invention provides a method for preparing an integrated structure of a support body and a connecting body, the method comprising:

Using the pore-forming agent powder, a first pore-forming agent block and a second pore-forming agent block are prepared, and a plurality of pores are distributed inside each of the first pore-forming agent block and the second pore-forming agent block. ;

Mixing metal powder and pore-forming agent powder to prepare porous metal support precursor powder;

placing the first pore-forming agent block in a mold, and laying the metal powder on the first pore-forming agent block to form a first metal powder layer;

on the first metal powder layer, placing the second pore former block;

Filling the metal powder inside the plurality of pores of the second pore-forming agent block to obtain a filled second pore-forming agent block;

Spreading the porous metal support precursor powder on the filled second pore-forming agent block to form a second metal powder layer to obtain a multi-layer structure system;

Filling the metal powder in the gap between the multi-layer structure system and the mold to obtain a filled structure system in which the metal powder surrounds the second metal powder layer;

Pressing the filling structure system to obtain a green body;

removing the pore-forming agent in the shaped green body to obtain a processed green body;

The treated green body is fired to obtain an integrated structure of the connecting body and the supporting body.

Preferably, the shape of the plurality of pores distributed inside the first pore-forming agent block is different from the shape of the plurality of pores distributed inside the second pore-forming agent block; the determining factor of the shape is at least Including the incoming gas and the flow rate of the gas.

Preferably, the pressing of the filling structure system to obtain a green body, comprising:

The filling structure system is pressed by means of pressure pressing to obtain a green body; wherein, the pressing pressure ranges from 100 MPa to 1000 MPa; the content of the pore-forming agent in the porous metal support precursor powder is 0～20%wt.

The value of the pressing pressure corresponds to the content of the pore-forming agent in the porous metal support precursor powder, and the value of the pressing pressure corresponds to the value of the porous support in the integrated connector-support structure. The porosity of the part corresponds.

Preferably, the removal of the pore-forming agent in the shaped green body to obtain a processed green body, comprising:

The pore-forming agent in the green compact is removed by heating to obtain a processed green compact; the heating temperature ranges from 100° C. to 400° C.; and the removal time is 1 h to 4 h.

Preferably, in the process of roasting the treated green body, the roasting environment includes at least one of a low pressure vacuum, a reducing atmosphere and an inert atmosphere; the roasting temperature ranges from 1000°C to 1400°C; The roasting time is 4h-6h.

Preferably, the particle size of the metal powder is 10-80 μm, and the metal powder includes at least one of iron-chromium alloy, nickel-chromium alloy and pure chromium.

Preferably, the content of the pore-forming agent in the porous metal support precursor powder is 0-20% wt.

Preferably, the pore-forming agent includes at least one of ammonium bicarbonate, soluble starch, sucrose, sodium chloride and carbon powder.

Preferably, the preparation method for preparing the first pore-forming agent block and the second pore-forming agent block includes: die pressing or screen printing.

In a second aspect, the present invention provides a method for preparing a solid oxide fuel cell/electrolyzer, the method comprising:

Using the method described in the first aspect above, an integrated structure of the connecting body and the supporting body is prepared;

Coating the anode material on the surface area of the integrated structure of the connector and the support to obtain an anode layer;

Coating the electrolyte material on the surface of the anode layer to obtain an electrolyte layer;

Coating the cathode material on the surface of the electrolyte layer to obtain a solid oxide fuel cell/electrolyte;

the second pore former block is removed to form an anode gas channel through which anode gas flows into the anode;

The first porogen mass is removed to form a cathode gas channel through which cathode gas flows into the cathode.

Preferably, the coating method includes at least one of tape casting and sintering, and atmospheric plasma spraying.

In a third aspect, the present invention provides a solid oxide fuel cell stack, wherein the solid oxide fuel cell stack comprises two or more of the solid oxide fuel cells described in the second aspect;

The solid oxide fuel cell stack is prepared by the following steps:

The cathode of the first solid oxide fuel cell and the anode of the second solid oxide fuel cell are bonded by a binder to obtain a cumulative plurality of solid oxide cells;

The accumulated plurality of solid oxide cells are sintered to obtain a solid fuel cell stack.

The integrated structure, the battery/electrolytic cell and the structure and the method for preparing the battery stack provided by the embodiments of the present invention effectively simplify the manufacturing process of the battery stack and reduce the sealing workload of the battery stack through the preparation method of the present invention. It is beneficial to reduce the manufacturing cost of the battery, and is beneficial to the commercialization of the solid oxide battery. And, the preparation method provided by the invention also includes the following advantages:

1. By designing the pore-forming agent block with two flow channel shapes, after removing the pore-forming agent, the pore-forming agent block of the two flow channel shapes is removed at low temperature to form a flow channel, that is, the anode and the cathode are automatically formed. The anode gas channel and the cathode gas channel are formed to achieve the purpose of forming the integrated structure of the connecting body and the supporting body at one time. However, traditional methods such as mechanical processing need to prepare the connector first, then prepare the support, and finally connect the connector and the support. This traditional method will generate a connection interface, and the two ends of the support also need additional sealing, and the corresponding sealing There are disadvantages of uneven stress and uneven composition at high temperature at the joint and the joint.

2. The preparation method provided in the embodiment of the present invention can adjust different flow channel forms, that is, prepare pore-forming agent blocks with different flow channel forms, so that when the cathode or anode gas reaches the cathode or anode, the gas can be evenly distributed. At the cathode or anode, the purpose of regulating the uniform distribution of the cathode or anode gas inside the respective electrodes is achieved, thereby reducing the potential difference inside the electrodes, reducing the internal resistance of the battery, and improving the performance of the battery. The potential difference refers to one side of the anode or the cathode. Since the gas concentration at the pores is higher, the potential there is higher, while the potential at other parts is lower, thereby forming a potential difference.

In addition, in the preparation method provided by the embodiment of the present invention, when preparing pore-forming agent blocks with different flow channel forms, the flow channel forms of the pore-forming agent blocks are determined by the gas and/or the flow rate of the gas introduced into the air channel, When reaching the conditioning gas at the anode or cathode, a uniform distribution can be achieved.

3. The preparation method of the present invention achieves the purpose of preparing the cathode gas channel and the anode gas channel in a non-machining manner by designing two flow-to-shape pore-forming agent blocks, which overcomes the problem of preparing the flow channel (gas channel) by machining. (Dao) processing technology complexity, to achieve the purpose of simplifying the preparation process.

4. In the present invention, the structure of the integrated structure of the connecting body and the supporting body is obtained by the preparation method of one pressing and one sintering. Because the connecting body and the supporting body are formed and sintered by powder metallurgy at one time, the welding seam caused by the welding connection is avoided. The problem of non-uniformity makes it unnecessary to consider the sealing and connection of the support body and the connecting body when preparing the battery stack, which greatly improves the stability of the combination between the support body and the connecting body.

5. In the preparation method of the present invention, by designing two pore-forming agent blocks whose length and width are smaller than the preset mold, the prepared structure has the feature that the connecting body wraps the supporting body, avoiding the use of welding technology to connect the connecting body and the supporting body. When connecting, the sealing performance and the stability of the connection point are both poor.

6. In the preparation method of the present invention, due to the one-time molding and firing method, the obtained connector-support integrated structure has no welding seam, and has uniform material composition, high temperature resistance and strong oxidation resistance in each area of the structure. It solves the problems of poor sealing and anti-oxidation ability of the welding seam at high temperature due to the uneven stress and uneven composition of the welding joint in the welding method, and improves the long-term stability of the battery. , to overcome the problem of battery performance degradation.

7. In the preparation method of the present invention, by filling each layer in the mold in turn, and the space between the pore-forming agent block and the mold is filled with metal powder as a connecting body, the connecting body surrounding the supporting body is realized by the connecting body. The integrated structure with the support body achieves the purpose of self-sealing, and does not need to use traditional methods such as mechanical welding.

Description of drawings

Fig. 1 shows a schematic cross-sectional view of the integrated structure of the support body and the connecting body prepared in the embodiment of the present invention;

Figure 2 shows a schematic cross-sectional view of the integrated structure of the support body and the connecting body prepared in Example 2 of the present invention;

3 shows a schematic cross-sectional view of the integrated structure of the support body and the connector prepared in Example 3 of the present invention;

Figure 4 shows a schematic structural diagram of a pore-forming agent block with a first flow channel structure prepared in an embodiment of the present invention;

Figure 5 shows a schematic structural diagram of a pore-forming agent block with a first flow channel structure prepared in an embodiment of the present invention;

FIG. 6 shows a scanning electron microscope schematic diagram of the positional relationship between the connector, the support and the anode gas channel in the integrated structure of the connector and the support prepared in the embodiment of the present invention;

FIG. 7 shows a flow chart of an embodiment of a method for preparing an integrated structure of a support body and a connecting body according to the present invention;

FIG. 8 shows a schematic cross-sectional view of a battery stack having an integrated structure of a support body and a connecting body prepared in Example 7 of the present invention;

9 shows a schematic diagram of a conventional connection of a metal-supported solid oxide fuel cell in an embodiment of the present invention;

FIG. 10 shows the schematic diagram of the scanning electron microscope shown in FIG. 6 corresponding to the specific position in FIG. 1 .

Detailed ways

In order to make the above objects, features and advantages of the present invention more clearly understood, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments. The embodiments of the present invention are described in detail below. This embodiment is implemented on the premise of the technical solution of the present invention, and provides a detailed implementation manner and a specific operation process, but the protection scope of the present invention is not limited to the following implementation. example.

In the prior art, the metal support SOFC uses a metal support body, so the connection and sealing of the support body and the connecting body can be realized by traditional welding technology, and the welding technology adopted in the related art includes brazing and laser welding. However, the operating temperature of the existing SOFC is between 600-800°C. Under such a high temperature, the stress at the welded joint is uneven, the composition is uneven, and the sealing performance and oxidation resistance of the welding seam may affect the battery. long-term stability, resulting in battery performance degradation. Therefore, the problem of connection and sealing between the connecting body and the supporting body is still a key problem in the art, and if it can be solved, it will greatly promote the development of the art. Likewise, solid oxide electrolysis cells suffer from similar sealing issues. The welding technology operating area in the related art is shown in FIG. 9 .

The implementation process of the method for preparing the integrated structure of the support body and the connecting body, the battery stack and the electrolytic cell of the present invention will be described in detail below by way of examples.

First, take the solid oxide fuel cell as an example to explain Figure 1-Figure 3:

Referring to FIG. 1 , it shows a cross-sectional schematic diagram of an integrated structure of a support body and a connecting body prepared in an embodiment of the present invention. As shown in the figure: 1-1 is a metal connector, 1-2 is a porous metal support, 1-3 is an anode gas channel, and 1-4 is a cathode gas channel. As shown in Figure 1, the cathode gas channel and the The anode gas channels are separated by the dense transverse cross-section of the connector, and in the electrodes on the same side (as shown in the cathode below in Figure 1), the flow channels are also separated by the longitudinal dense metal of the connector, so that the gas can only flow in the channel circulation. In addition, the support body is wrapped by the connecting body to achieve the purpose of sealing, so that the connecting body and the support body do not need to be connected by welding.

FIG. 2 shows a schematic cross-sectional view of the integrated structure of the support body and the connecting body prepared in Example 2 of the present invention. As shown in the figure: 2-1 is a metal connector, 2-2 is a porous metal support, 2-3 is an anode, 2-4 is an electrolyte layer, 2-5 is a cathode, and 2-6 is a gas channel. Among them, the support body has only a very thin layer, which is used to support the electrode. A part of the connecting body forms an air channel, and the other part separates the cathode gas channel from the anode gas channel to prevent the anode gas and the cathode gas from mixing flow.

FIG. 3 shows a schematic cross-sectional view of the integrated structure of the support body and the connecting body prepared in Example 3 of the present invention. As shown in the figure: 3-1 is the metal connector, 3-2 is the anode side porous metal support, 3-3 is the anode, 3-4 is the electrolyte layer, 3-5 is the cathode, 3-6 is the gas channel, 3-7 is the cathode side porous metal support. Among them, the connector only has the function of separating the cathode gas channel from the anode gas channel, and the support body not only has the function of supporting the electrode, but also has the function of constructing the air channel, as shown in the constructed anode gas channel 3-6, and, When a support is used to construct an air channel, since the porous metal support precursor powder used to prepare the support contains a pore-forming agent, after the pore-forming agent is removed, the support is composed of porous metal, and the pores in the porous metal are also With the function of flow channel, the gas can flow in the pores in the porous metal, so that when the gas reaches the electrode, it can be more evenly distributed on the electrode surface, reducing the potential difference in the electrode, and improving the battery performance.

FIG. 4 and FIG. 5 respectively show the schematic structural diagrams of the pore-forming agent blocks with two flow channel structures prepared in the embodiment of the present invention. As shown in the figure: The pore-forming agent block with this runner structure is pressed by a forming mold. The length, width, thickness and runner shape of the pore-forming agent block can be made according to actual needs. The adjustment is made by pre-preparing a mold corresponding to the pore-forming agent block with the desired flow channel shape, and then preparing the pore-forming agent with the desired flow channel shape by pressing. And, as shown in Fig. 4 and Fig. 5 , the right side of the pore-forming agent block in the shape of the flow channel is designed with a gas channel, so that after the entire integrated structure of the sealed connecting body and the support body is successfully prepared, the gas channel can be used for this channel. Pass in anode gas or cathode gas.

FIG. 6 shows a scanning electron microscope schematic diagram of the positional relationship between the connector, the support and the anode air channel in the integrated structure of the connector and the support prepared in the embodiment of the present invention. As shown in FIG. 6 , the connecting body in the present invention wraps the support body, the edge of the support body forms a self-sealing, and the anode gas channel is a flow channel formed by removing the pore-forming agent block with the shape of a flow channel at a low temperature. It should be noted that since Fig. 6 was photographed by a scanning electron microscope, only a part of the entire integrated structure of the connecting body and the supporting body can be cut and photographed. Therefore, Fig. 6 shows a part of the entire integrated structure. , as shown in Figure 10.

In the first aspect, an embodiment of the present invention provides a method for preparing an integrated structure of a support body and a connecting body, as shown in FIG. 7 , the method is as follows:

S101, using a pore-forming agent powder to prepare a first pore-forming agent block and a second pore-forming agent block, wherein the inner distribution of the first pore-forming agent block and the second pore-forming agent block is multiple a pore;

Description: The pore-forming agent powder is prepared into a block with a flow channel shape through a preparation process. In the later roasting process, the pore-forming agent can be removed to form an intermediate flow channel; and the first pore-forming agent block prepared. and the second pore former block size is smaller than the mold. Wherein, the shape of the plurality of pores distributed inside the first pore-forming agent block is different from the shape of the plurality of pores distributed inside the second pore-forming agent block; the shape is passed through the pores The flow rate of the gas and/or the gas is determined.

S102, mixing metal powder and pore-forming agent powder to prepare porous metal support precursor powder;

Description: In the present invention, the integration of the connector and the support includes a dense connector part and a porous support part, and an anode, an electrolyte, and a cathode are prepared on the support in sequence. The precursor powder formed by mixing the metal powder and the pore-forming agent is used to prepare the porous metal support body, and the porous metal support body can be formed after the powder spreading, pressing and sintering process in the later stage.

S103, placing the first pore-forming agent block in a mold, and laying the metal powder on the first pore-forming agent block to form a first metal powder layer;

Wherein, the width of the first pore-forming agent block is smaller than the width of the used mold, so that there is a space between the pore-forming agent block and the mold, which serves as the metal powder filling area of the connecting body. Therefore, after the metal powder completely covers the pore-forming agent block, the gap between the mold and the pore-forming agent block can continue to be filled, thereby obtaining a dense structure;

It is explained that the first metal powder layer obtained in this step is the connector part below the anode gas flow channel 1-3 in Fig. 1; the pore-forming agent with the metal powder covering the shape of the flow channel is laid to make the anode gas flow after sintering. The channel is separated from the cathode gas channel (the cross section between 1-3 and 1-4 in Figure 1); the pore-forming agent in the shape of the flow channel laid in this step is to form the cathode flow channel for later sintering (1 in Figure 1). -4),

S104, placing the second pore-forming agent block on the first metal powder layer;

It is explained that the function of the placed second pore-forming agent block is to obtain the anode gas flow channel after the pore-forming agent removal operation.

S105, filling the metal powder in the interior of the plurality of pores of the second pore-forming agent block to obtain a filled second pore-forming agent block;

It is explained that the metal powder filled here is to prepare the protruding part in the connecting body, and the protruding part is connected with the supporting body (such as the protruding part connected with the supporting body in the connecting body 2-1 in FIG. 2 ).

S106, laying the porous metal support precursor powder on the filled second pore-forming agent block to form a second metal powder layer to obtain a multi-layer structure system;

In the specific implementation, the laid porous metal support precursor powder is used to prepare an anode support, and when laying the porous metal support precursor powder, attention should be paid to the width of the porous metal support precursor powder layer and the pore formation. The width of the agent block is equal (as shown by the width of 1-2 in Figure 1, the width of 2-2 in Figure 2, and the width of 3-2 in Figure 3), and then filled with metal powder as a connecting body. (as shown by the two ends of 1-1 in FIG. 1 , the two ends of 2-1 in FIG. 2 , and the two ends of 3-1 in FIG. 3 ), a metal powder surrounding the porous metal support precursor powder layer is obtained , and then an integrated structure in which the connected body wraps the support body (the parts at both ends of the connected body as shown in Figures 1 , 2 and 3 ) is obtained, so that a self-sealing structure is formed after sintering at a later stage. (That is, it is not necessary to seal both sides of the support body by welding, but directly fill the space between the support body and the mold with metal powder when laying the metal powder as the connecting body to form a packaged integrated structure , automatically seal the support to prevent it from leaking)

S107, filling the metal powder in the gap between the multi-layer structure system and the mold to obtain a filled structure system in which the metal powder surrounds the second metal powder layer;

It should be noted that, in the preparation method provided by the present invention, regarding the filling of the metal powder in the gap between the multi-layer structure system and the mold described in step S107, the filling method is not limited to this step. It is recorded that in step S103, the gap between the mold and the first pore-forming agent block can be directly filled completely, and the thickness of the first metal powder layer obtained on the first pore-forming agent block is 1-3 mm .

S108, pressing the filling structure system to obtain a green body;

Description: Pressing the above structure under a certain pressure to form a green compact, on the one hand, is convenient for taking out the mold, and on the other hand, it is to improve the sintering and molding performance of the integrated structure of the connector and the support body. During specific implementation, the filling structure system is pressed by means of pressure pressing to obtain a green body; wherein, the pressing pressure ranges from 100 MPa to 1000 MPa; the porous metal support precursor powder is made of The pore-forming agent content is 0-20% wt; wherein, the value of the pressing pressure corresponds to the content of the pore-forming agent in the porous metal support precursor powder, and the value of the pressing pressure is the value of the integrated connection The porosity of the porous support part in the body-support structure corresponds to, for example, when the content of the pore-forming agent in the porous metal support precursor powder is 0% wt, the value of the pressure should be a small pressure (such as 100MPa~ 400MPa), and the metal powder should be a metal powder with a larger particle size (such as 60-80 μm) to ensure that the porosity in the prepared porous metal support reaches the required value of voids as gas channels.

S109, removing the pore-forming agent in the molding green body to obtain a processed green body;

During the specific implementation, the pore-forming agent in the green compact is removed by heating to obtain a processed green compact; the heating temperature ranges from 100°C to 400°C; the removal time ranges from 1 hour to 1 hour. 4h.

Note: Since a large amount of gas will be generated when the pore-forming agent in the form of a flow channel is removed, it needs to be removed before the green compact is sintered to ensure the integrated sintering and molding performance of the connecting body and the support body. Because the pore-forming agent in the form of a flow channel has a large volume, if it is directly operated in S110, a large amount of substances (the pore-forming agent will volatilize rapidly at high temperature) will volatilize, which may affect the integrated structure. formability.

S110, calcining the treated green body to obtain an integrated structure of the connecting body and the supporting body.

Wherein, the sintering environment includes at least one of low pressure vacuum, reducing atmosphere and inert atmosphere; the sintering temperature range is 1000°C～1400°C; the sintering time is 4h～6h;

Description: The compact formed by powder pressing is sintered to form a structure in which the connecting body and the supporting body are integrated.

During specific implementation, the particle size of the metal powder is 10-80 μm, and the metal powder includes at least one of iron-chromium alloy, nickel-chromium alloy and pure chromium;

During specific implementation, the content of the pore-forming agent in the porous metal support precursor powder is 0-20% wt;

During specific implementation, the pore-forming agent includes at least one of: ammonium bicarbonate, soluble starch, sucrose and carbon powder;

In a specific implementation, the preparation method for preparing the first pore-forming agent block and the second pore-forming agent block includes: die pressing or screen printing.

In a second aspect, the present invention provides a method for preparing a solid oxide fuel cell/electrolyzer, the method comprising:

Using the method described in the first aspect above, an integrated structure of the connecting body and the supporting body is prepared;

Coating the anode material on the surface area of the integrated structure of the connector and the support to obtain an anode layer;

Coating the electrolyte material on the surface of the anode layer to obtain an electrolyte layer;

Coating the cathode material on the surface of the electrolyte layer to obtain a solid oxide fuel cell/electrolyte;

the second pore former block is removed to form an anode gas channel through which anode gas flows into the anode;

the first pore former block is removed to form a cathode gas channel through which the cathode gas flows into the cathode;

Wherein, the coating method includes at least one of tape casting and sintering, and atmospheric plasma spraying.

In a third aspect, the present invention provides a solid oxide fuel cell stack, wherein the solid oxide fuel cell stack comprises two or more of the solid oxide fuel cells described in the second aspect;

The solid oxide fuel cell stack is prepared by the following steps:

The cathode of the first solid oxide fuel cell and the anode of the second solid oxide fuel cell are bonded by a binder to obtain a cumulative plurality of solid oxide cells;

The accumulated plurality of solid oxide cells are sintered to obtain a solid fuel cell stack.

Through the preparation method of the integrated structure of the connecting body and the supporting body provided by the embodiment of the present invention, the connecting body and the supporting body are prepared into an integrated structure (without welding) by one-time molding. Porous, partially hollow and partially dense structure, that is, the method of combining with pore-forming agent and then removing the pore-forming agent, has a wide range of applications in the preparation of solid oxide fuel cells, and solves the problems of poor sealing at high temperature and battery performance in welding technology. attenuation, etc.

Among them, partially porous refers to parts 1-2 in Fig. 1 (that is, porous metal support), and partially hollow refers to parts 1-3 and 1-4 in Fig. 1 (anode gas flow channel and cathode gas flow channel), local densification refers to part 1-1 of Figure 1 (metal connector). The reason why it is said to be partially porous, partially hollow, and partially dense is because the support and connector structure are an integrated structure formed by pressing and sintering. It is partially hollow, partially porous, and partially dense.

In order for those skilled in the art to better understand the present invention, the integrated structure, the battery/electrolytic cell and the preparation method of the battery stack of the present invention will be described below through a plurality of specific embodiments.

Example 1

The ammonium bicarbonate block with the two runner shapes as shown in Figure 4 and Figure 5 is prepared by pressing the mold corresponding to the ammonium bicarbonate block with the flow channel shape as shown in Figure 4 and Figure 5 in advance. , the ammonium bicarbonate block is 8cm╳8cm ammonium bicarbonate block. The iron-chromium alloy metal powder is mixed with ammonium bicarbonate to obtain a porous metal support precursor powder, wherein the content of ammonium bicarbonate is 20% wt.

Place the ammonium bicarbonate block in the shape of the flow channel as shown in Figure 4 on the bottom of the mold with a diameter of 10cm╳10cm, and place the iron-chromium alloy metal powder with a particle size of about 20μm on the flow channel shape shown in Figure 4. Above the ammonium bicarbonate, and completely cover the ammonium bicarbonate with a runner shape as shown in Figure 4 (including filling the space between the mold and the ammonium bicarbonate block) with iron-chromium alloy metal powder to form a first metal powder layer ; Place the ammonium bicarbonate with the shape of the flow channel as shown in Figure 5 on the first metal powder layer, and continue to fill the iron-chromium alloy metal powder with the ammonium bicarbonate in the shape of the flow channel as shown in Figure 5 to obtain The filled ammonium bicarbonate block with the flow channel shape as shown in Figure 5; then, the pre-prepared porous metal region precursor powder is placed on the filled ammonium bicarbonate block with the flow channel shape as shown in Figure 5 and finally filling the space between the ammonium bicarbonate block and the mold with iron-chromium alloy metal powder to obtain a complete filling structure system in which the iron-chromium alloy metal powder surrounds the powder layer of the precursor powder in the porous metal region. The structural system was pressed with a pressure of 500 MPa to form a green body, and a green body was obtained, and then the pore-forming agent ammonium bicarbonate in the green body was removed at 100 ° C for 4 h to obtain a green body after treatment; The treated green body was sintered for 6 h in a vacuum environment at a high temperature of ℃ to form an integrated structure of the connecting body and the supporting body.

A Ni/YSZ anode with a thickness of 30 μm was prepared on the surface area of the integrated structure of the connector and the support by means of tape casting and sintering, so that it completely covered the surface porous area, and a YSZ electrolyte layer with a thickness of 10 μm was covered on the anode, and The YSZ electrolyte layer is in contact with the dense area on the edge of the connector (as shown in the positional relationship between 2-4 and 2-1 in Figure 2), and after sintering, a 20 μm thick LSCF cathode is sprayed to obtain a solid oxide fuel cell. Exhibits good voltage and power output.

Among them, YSZ refers to yttrium oxide partially stabilized zirconia; LSCF refers to lanthanum strontium cobalt iron electrode material. It should be noted that the cathode, anode and electrolyte materials in the subsequent examples are the same as those in Example 1, and the cathode, anode and electrolyte materials used in the present invention can be selected from commonly used materials, which are not made in the present invention. limited.

Example 2

The pure chromium metal powder is mixed with ammonium bicarbonate to obtain a porous metal support precursor powder, wherein the content of ammonium bicarbonate is 9% wt. In this embodiment, the ammonium bicarbonate block is 8cm╳16cm ammonium bicarbonate block.

Prepare a pore-forming agent (ammonium bicarbonate) with a flow channel shape as shown in Figure 4 and place it at the bottom of a 10cm╳20cm mold, and place pure chromium metal powder with a particle size of about 40 μm on the pore-forming agent ( ammonium bicarbonate) and cover it, and then place the pore-forming agent (ammonium bicarbonate) with the shape of the flow channel as shown in Figure 5 on it and lay down pure chromium metal powder, then, the porous metal region precursor The powder is laid on the uppermost layer, and finally the space around the mold and the precursor powder layer of the porous metal region is filled with metal powder, and the precursor powder layer of the porous metal region is surrounded to obtain a filling structure system. The obtained filling structure system was pressed with a pressure of 1000MPa to form a green body, and then the pore-forming agent ammonium bicarbonate in the green body was removed at 110°C for 2 hours to obtain a green body after treatment; in an inert atmosphere environment of 1400°C Among them, the treated green body 6h is sintered to form an integrated structure of the connecting body and the supporting body.

A 30μm thick Ni/YSZ anode was prepared on the surface area by atmospheric plasma spraying to completely cover the surface porous area, a 15μm thick YSZ electrolyte layer was covered on the anode and contacted with the edge dense area, and then sprayed with a thickness of 30μm after sintering LSCF cathodes, solid oxide fuel cells were obtained, and the cells exhibited good voltage and power output.

Example 3

The iron-nickel alloy metal powder is mixed with ammonium bicarbonate to obtain a porous metal support precursor powder, wherein the content of ammonium bicarbonate is 12% wt. In this embodiment, the ammonium bicarbonate blocks are 4cm╳4cm ammonium bicarbonate blocks.

Prepare the pore-forming agent with the shape of the flow channel as shown in Figure 5 and place it at the bottom of the mold of 5cm╳5cm, and fill the obtained porous metal support precursor powder into the void of the pore-forming agent with the shape of the flow channel as shown in Figure 5 (obtained). It is the cathode metal support structure 3-7), and the iron-nickel alloy metal powder with a particle size of about 15 μm is placed on the pore-forming agent with the shape of the flow channel, and it is covered (the metal powder is placed to cover the flow channel). The channel-shaped pore-forming agent is to separate the anode gas channel from the cathode gas channel after sintering (the part that is transverse between 3-2 and 3-7 in Figure 3), and then the pore-forming agent with the flow channel shape as shown in Figure 4 is used. The pore-forming agent is placed on it (the pore-forming agent in the shape of the flow channel laid in this step is to form an anode gas flow channel for later sintering (as shown in 3-6 in Figure 3)), and iron is used around the pore-forming agent. The nickel alloy metal powder is filled (to obtain the structure of 3-1 wrapping 3-2), and then, the precursor powder of the porous metal region is placed in the void of the pore-forming agent in the shape of the flow channel in Figure 4 (to obtain the anode metal support structure) 3-2), and lay the precursor powder of the porous metal region on the top layer, and finally fill the space around the mold and the precursor powder layer of the porous metal region with metal powder, and surround the precursor powder layer of the porous metal region to obtain a filling structure system. Press the filling structure system with a pressure of 500MPa to form a green body to obtain a green body; remove the pore-forming agent ammonium bicarbonate in the green body at 200 ° C for 1 h to obtain a green body after treatment; In a reducing atmosphere at ℃, the green body was sintered for 4 h to form an integrated structure of the connecting body and the supporting body.

A 20μm thick Ni/YSZ anode was prepared on the surface area by atmospheric plasma spraying to completely cover the surface porous area, a 20μm thick YSZ electrolyte layer was covered on the anode and contacted with the edge dense area, and then 20μm thick LSCF was sprayed The cathode, a solid oxide fuel cell was obtained, and the cell exhibited good voltage and power output.

Example 4

The alloy powder selected in this embodiment is an iron-chromium alloy metal powder with a particle size of about 30 μm, and the carbon powder block is a carbon powder block with a size of 12cm╳12cm.

Prepare the pore-forming agent with the shape of the flow channel as shown in Figure 5 and place it at the bottom of the mold of 15cm╳15cm, and mix the iron-chromium alloy metal powder with the carbon powder to obtain the porous metal support precursor powder, wherein the content of the carbon powder is 15% wt. Lay the iron-chromium alloy metal powder on the pore-forming agent with the shape of the flow channel, and cover it, and then place the pore-forming agent with the flow channel shape as shown in Figure 4 on it and lay the iron-chromium alloy metal powder, Then, the porous metal region precursor powder is placed on the uppermost layer, and finally the space around the mold and the porous metal region precursor powder layer is filled with metal powder, and the porous metal region precursor powder layer is surrounded to obtain a filling structure system. Press the filling structure system with a pressure of 350MPa to form a green body to obtain a green body; remove the pore-forming carbon powder in the green body at 400°C for 3 hours to obtain a treated green body; then heat the green body at 1300°C In the reducing atmosphere, the green body is sintered for 6h to form an integrated structure of the connecting body and the supporting body.

A 25μm thick Ni/YSZ fuel electrode was prepared on the surface area by atmospheric plasma spraying or tape casting and sintering, so that it completely covered the surface porous area, and a 10μm thick YSZ electrolyte layer was covered on the anode and dense with the edge. Area contact, sintered and then sprayed with a 20 μm thick LSM air electrode to obtain a solid oxide fuel electrolytic cell, which showed good voltage and power output.

Example 5

The soluble starch blocks in the two channel shapes shown in Figures 4 and 5 were pre-prepared by screen printing, and the soluble starch blocks were 8cm╳8cm soluble starch blocks. Chromium powder with a particle size of 40 μm is mixed with soluble starch to obtain a porous metal support precursor powder, wherein the content of soluble starch is 15% wt.

Place the soluble starch block in the shape of the flow channel as shown in Figure 4 on the bottom of the mold of 10cm╳10cm, and place the chromium powder with a particle size of 40μm on the soluble starch with the shape of the flow channel as shown in Figure 4. And the soluble starch with the flow channel shape as shown in Figure 4 is completely covered with chromium powder with a particle size of 40 μm to form the first metal powder layer; then the soluble starch block with the flow channel shape as shown in Figure 5 is placed to form the first metal powder layer. On a metal powder layer and continue to lay chromium powder with a particle size of 40 μm, a second metal powder layer is formed; then, the pre-prepared porous metal region precursor powder is laid on the second metal powder layer, and finally the metal The powder fills the space around the mold and the precursor powder layer of the porous metal region, and surrounds the precursor powder layer of the porous metal region to obtain a filled structure system. Press the filling structure system with a pressure of 100 MPa to form a green body to obtain a green body, and then remove the pore-forming agent soluble starch in the green body at 400 ° C for 4 hours to obtain a processed green body; The treated green body is sintered at a high temperature of ℃ for 6 h to form an integrated structure of the connecting body and the supporting body.

A Ni/YSZ anode with a thickness of 30 μm was prepared on the surface area of the integrated structure of the connector and the support by means of tape casting and sintering, so that it completely covered the surface porous area, and a YSZ electrolyte layer with a thickness of 10 μm was covered on the anode, and The YSZ electrolyte layer is in contact with the dense area on the edge of the connector (as shown in the positional relationship between 2-4 and 2-1 in Figure 2), and after sintering, a 20 μm thick LSCF cathode is sprayed to obtain a solid oxide fuel cell. Exhibits good voltage and power output.

Example 6

Sodium chloride blocks with two flow channel shapes as shown in Figures 4 and 5 were pre-prepared by screen printing, and the sodium chloride blocks were 3cm╳3cm sodium chloride blocks. The iron-nickel alloy metal powder with a particle size of about 80 μm is mixed with sodium chloride to obtain a porous metal support precursor powder, wherein the content of ammonium bicarbonate is 0%wt.

Prepare the pore-forming agent with the shape of the flow channel as shown in Figure 5 and place it at the bottom of the mold of 5cm╳5cm, fill the porous metal support precursor powder into the void of the pore-forming agent with the shape of the flow channel as shown in Figure 5, and place the particles Iron-nickel alloy metal powder with a diameter of about 10 μm The iron-nickel alloy metal powder is placed on the pore-forming agent with a flow channel shape, and covers it, and then the pore-forming agent with a flow channel shape as shown in Figure 4 is placed on it And lay the iron-nickel alloy metal powder, then, lay the precursor powder of the porous metal region in the void of the pore-forming agent in the shape of the flow channel in Figure 4, and finally lay the precursor powder of the porous metal region on the top layer, and finally The space around the mold and the precursor powder layer of the porous metal region is filled with metal powder, and the precursor powder layer of the porous metal region is surrounded to obtain a filling structure system. Press the structural system with a pressure of 1000MPa to form a green body to obtain a green body; remove the pore-forming agent sodium chloride in the green body at 200°C for 2 hours to obtain a green body after treatment; then at 1050°C In a reducing atmosphere, the green body is sintered for 6 h to form an integrated structure of the connecting body and the supporting body.

A 20μm thick Ni/YSZ anode was prepared on the surface area by atmospheric plasma spraying to completely cover the surface porous area, a 20μm thick YSZ electrolyte layer was covered on the anode and contacted with the edge dense area, and then 20μm thick LSCF was sprayed The cathode, a solid oxide fuel cell was obtained, and the cell exhibited good voltage and power output.

Example 7

The ammonium bicarbonate blocks in the two flow channel shapes shown in Figures 4 and 5 were pre-prepared by screen printing, and the ammonium bicarbonate blocks were 7cm╳7cm ammonium bicarbonate blocks. The nickel-chromium alloy metal powder with a particle size of 50 μm is mixed with sucrose to obtain a porous metal support precursor powder, wherein the content of sucrose is 20% wt.

Place the sucrose block in the shape of the flow channel as shown in Figure 4 on the bottom of the mold with a diameter of 10cm╳10cm, and lay the nickel-chromium alloy metal powder with a particle size of 10μm on the sucrose with the shape of the flow channel as shown in Figure 4. , and completely cover the sucrose with a flow channel shape as shown in Figure 4 with a nickel-chromium metal powder with a particle size of 10 μm to form a first metal powder layer; On the metal powder layer, continue to lay nickel-chromium metal powder with a particle size of 10 μm to form a second metal powder layer; The metal powder fills the space around the mold and the precursor powder layer of the porous metal region, and surrounds the precursor powder layer of the porous metal region to obtain a filling structure system. The structural system was pressed with a pressure of 100 MPa to form a green body, and a green body was obtained, and then the pore-forming agents ammonium bicarbonate and sucrose in the green body were removed at 400 ° C for 4 hours to obtain a processed green body; The treated green body was sintered at a high temperature of 1400° C. for 4 hours to form an integrated structure of the connecting body and the supporting body.

A Ni/YSZ anode with a thickness of 30 μm was prepared on the surface area of the integrated structure of the connector and the support by means of tape casting and sintering, so that it completely covered the surface porous area, and a YSZ electrolyte layer with a thickness of 10 μm was covered on the anode, and The YSZ electrolyte layer is in contact with the dense area on the edge of the connector (as shown in the positional relationship between 2-4 and 2-1 in Figure 2), and after sintering, a 20 μm thick LSCF cathode is sprayed to obtain a solid oxide fuel cell. Exhibits good voltage and power output.

Two or more prepared solid oxide fuel single cells are accumulated to form a cell stack, and each cell is connected by manganese cobalt oxide (MCO), that is, manganese cobalt oxide can be prepared into slurry at room temperature, and then Smear on the surface of the cathode, then bond the cells layer by layer, and sinter and solidify to obtain a solid oxide fuel cell stack, as shown in Figure 8. The figure shows the battery obtained by accumulating 4 single cells heap.

It should be noted that, in the preparation method provided by the present invention, a pore-forming agent block with the same flow channel shape can also be used to prepare an integrated structure of the connector and the support body, so as to obtain a cathode gas channel and an anode gas with the same flow channel shape The preparation method is similar to the above-mentioned embodiment 1-7; and in the preparation method of the present invention, the particle size of the metal powder of the support and the connector can be the same or different, and the selected particle size can be selected according to actual needs. And the pore-forming agent used in the preparation process of the present invention can be the same (such as Example 1-6, using one pore-forming agent), or can be different (such as Example 7, using two pore-forming agents) ).

The core of the present invention is to use powder metallurgy technology to prepare an integrated structure of the connecting body and the supporting body at one time. Since the metal powder used will become an integral structure after sintering, there is no need to use additional connecting means for connecting.

The method embodiments are described as a series of action combinations for the sake of simple description, but those skilled in the art should know that the present invention is not limited by the described action sequence, because according to the present invention, some steps Other sequences or concurrently may be used. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and components involved are not necessarily required by the present invention.

The integrated structure, the battery/electrolyte cell and the method for preparing the battery stack provided by the present invention have been introduced in detail above. Specific examples are used in this paper to illustrate the principles and implementations of the present invention. The description of the above examples is only used for In order to help understand the method of the present invention and its core idea; at the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation and application scope. In summary, this specification The contents should not be construed as limiting the present invention.

Claims (10)

1. A preparation method of an integrated structure of a support body and a connecting body, wherein the method comprises: Using the pore-forming agent powder, a first pore-forming agent block and a second pore-forming agent block are prepared, and a plurality of pores are distributed inside each of the first pore-forming agent block and the second pore-forming agent block. ; Mixing metal powder and pore-forming agent powder to prepare porous metal support precursor powder; placing the first pore-forming agent block in a mold, and laying the metal powder on the first pore-forming agent block to form a first metal powder layer; on the first metal powder layer, placing the second pore former block; Filling the metal powder in the interior of the plurality of pores of the second pore-forming agent block to obtain a filled second pore-forming agent block; Spreading the porous metal support precursor powder on the filled second pore-forming agent block to form a second metal powder layer to obtain a multi-layer structure system; Filling the metal powder in the gap between the multi-layer structure system and the mold to obtain a filled structure system in which the metal powder surrounds the second metal powder layer; Pressing the filling structure system to obtain a green body; removing the pore-forming agent in the shaped green body to obtain a processed green body; The treated green body is fired to obtain an integrated structure of the connecting body and the supporting body. 2 . The method according to claim 1 , wherein the shape of the plurality of pores distributed in the first pore-forming agent block is the same as the shape of the plurality of pores distributed in the second pore-forming agent block. 3 . The shape of the pores is different; The shape-determining factors include at least the gas introduced and the flow rate of the gas. 3. The method according to claim 1, wherein the pressing of the filling structure system to obtain a green body, comprising: The filling structure system is pressed by means of pressure pressing to obtain a green body; wherein, the pressing pressure ranges from 100 MPa to 1000 MPa; the content of the pore-forming agent in the porous metal support precursor powder is 0～20%wt; The value of the pressing pressure corresponds to the content of the pore-forming agent in the porous metal support precursor powder, and the value of the pressing pressure corresponds to the value of the porous support in the integrated connector-support structure. The porosity of the part corresponds. 4. The method according to claim 1, wherein the removing the pore-forming agent in the green compact to obtain the processed green compact comprises: The pore-forming agent in the green compact is removed by heating to obtain a processed green compact; the heating temperature ranges from 100° C. to 400° C.; and the removal time is 1 h to 4 h. 5. The method according to claim 1, wherein, in the process of calcining the treated green body, the calcining environment comprises at least one of a low pressure vacuum, a reducing atmosphere and an inert atmosphere; The roasting temperature ranges from 1000°C to 1400°C; the roasting time ranges from 4h to 6h. 6 . The method according to claim 1 , wherein the particle size of the metal powder is 10-80 μm, and the metal powder comprises at least one of iron-chromium alloy, nickel-chromium alloy and pure chromium. 7 . 7. The method according to claim 1, wherein the pore-forming agent comprises at least one of ammonium bicarbonate, soluble starch, sucrose, sodium chloride and carbon powder. 8 . The method according to claim 1 , wherein the preparation method for preparing the first pore-forming agent block and the second pore-forming agent block comprises: mold pressing or screen printing. 9 . 9. A method for preparing a solid oxide fuel cell/electrolyte, wherein the method comprises: Adopt the method described in any one of the above claims 1-8 to prepare the integrated structure of the connecting body and the supporting body; Coating the anode material on the surface area of the integrated structure of the connector and the support to obtain an anode layer; Coating the electrolyte material on the surface of the anode layer to obtain an electrolyte layer; Coating the cathode material on the surface of the electrolyte layer to obtain a solid oxide fuel cell/electrolyte; Wherein, the coating method includes at least one of tape casting and sintering, and atmospheric plasma spraying. 10. A solid oxide fuel cell stack, wherein the solid oxide fuel cell stack comprises two or more of the solid oxide fuel cells according to claim 9; The solid oxide fuel cell stack is prepared by the following steps: The cathode of the first solid oxide fuel cell and the anode of the second solid oxide fuel cell are bonded by a binder to obtain a cumulative plurality of solid oxide cells; The accumulated plurality of solid oxide cells are sintered to obtain a solid fuel cell stack.

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