WO2013127085A1

WO2013127085A1 - Nonpiezoelectric stack for planar anode-supported solid oxide fuel cell

Info

Publication number: WO2013127085A1
Application number: PCT/CN2012/071851
Authority: WO
Inventors: 王蔚国; 金乐; 官万兵; 翟惠娟; 刘武; 谢光华
Original assignee: 中国科学院宁波材料技术与工程研究所
Priority date: 2012-03-02
Filing date: 2012-03-02
Publication date: 2013-09-06

Abstract

A nonpiezoelectric stack for a planar anode-supported solid oxide fuel cell comprises a plurality of cell units which are stacked together. Each cell unit comprises a lower connecting component (1), an anode-side metal mesh (2), an anode-supported single cell (5), a cathode-side metal mesh (7) and an upper connecting component (13) which are arranged from bottom to top in sequence. A spacing board (4) is arranged around both the anode-side metal mesh (2) and the cathode-side metal mesh (7). The spacing board (4) around the anode-side metal mesh (2) is connected to the anode-side of the lower connecting component (1) and the anode of the anode-supported single cell (5) through a sealing material (3), and the spacing board (4) around the cathode-side metal mesh (7) is connected to the cathode-side of the upper connecting component (13) and the cathode of the anode-supported single cell (5) through the sealing material (3). The same connecting component is shared between two adjacent cell units. The nonpiezoelectric stack for a planar anode-supported solid oxide fuel cell has the advantages of a simple operation process and convenient system integration.

Description

Anode-supported flat solid oxide fuel cell without piezoelectric stack

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of solid oxide fuel cell technology, and more particularly to an anode-supported flat-plate solid oxide fuel cell piezoelectric stack.

BACKGROUND OF THE INVENTION Solid Oxide Fuel Cell (SOFC) is an all-solid-state device that converts the chemical energy of a fuel into electrical energy through an electrochemical oxidation process. Due to its simple system design, energy conversion efficiency of 70%~80%, large scale flexibility, environmental friendliness, fuel adaptability and long life, it is widely used, including: providing backup energy for residential and hospitals. , providing auxiliary power for the car.

Solid oxide fuel cells are generally stacked from a plurality of cells and are therefore also referred to as solid oxide fuel cell stacks or stacks. Solid oxide fuel cell stacks mainly have two basic types of flat and tubular types. Among them, flat-type stacks are favored by researchers because of their high power density and small size. The flat solid oxide fuel cell stack is mainly composed of a single cell, a connecting member and a sealing material. According to the conventional anode-supported solid oxide fuel cell stack at room temperature, the anode side is soft contact at a high temperature, and the cathode side is a soft contact. The connector is in direct hard contact with the cathode, so the contact effect is poor. Moreover, due to the difference in deformation between the single cell and the connecting member at a high temperature, the thermal expansion coefficients of the two cells are not matched during the cooling process, so that the screw and the nut need to be fixed at room temperature, so that the components of the stack are not dispersed. This type of piezoelectric stack also needs to be removed before the use of the fixed screw, which complicates the operation process; at the same time, the piezoelectric stack is not convenient for system integration.

Although Bloom Energy has developed a standardized electrolyte-supported piezoelectric stack module, the method for manufacturing the piezoelectric stack-free module has higher requirements on the connector, and is only applicable to the electrolyte supporting stack, requiring the connector and the electrolyte to support the battery. The thermal expansion coefficient is highly matched, so this method is not suitable for making an anode-supported piezoelectric stack. Anode-supported solid oxide fuel cell without piezoelectric stack is currently in the world SUMMARY OF THE INVENTION In view of this, an embodiment of the present invention provides a piezoelectric-free solid-state fuel cell anode-less stack, which solves the problem that the existing piezoelectric stack operation process is complicated and system integration is inconvenient.

To achieve the above object, the present invention provides the following technical solutions:

An anode-supported flat-plate solid oxide fuel cell without piezoelectric stack, the piezoelectric stack comprising: a plurality of battery cells stacked together, wherein each battery cell comprises:

a lower connecting member, an anode side metal mesh, an anode supporting unit cell, a cathode side metal mesh, and an upper connecting member disposed in order from bottom to top; and a spacer plate is disposed around the anode side metal mesh and the cathode side metal mesh, the anode a spacer plate around the side metal mesh is connected to the anode side of the lower connecting member and the anode of the anode supporting unit cell through a sealing material, and the spacer plate around the cathode side metal mesh passes through the sealing material and the cathode side of the upper connecting member Connected to the cathode of the anode supporting unit cell;

The same connector is shared between two adjacent battery cells.

Preferably, the above-mentioned piezoelectric stack further comprises: a protective coating disposed on the cathode side metal mesh toward the cathode supporting the cathode of the single cell.

Preferably, in the piezoelectric stack, the spacer has a thickness of 0.1 to 2 mm.

Preferably, in the above-mentioned piezoelectric stack, the lower connecting member and the upper connecting member have the same shape, and the anode side of the lower connecting member is a flat plate type, and the anode side metal mesh is a wave type or a dovetail metal mesh. .

Preferably, in the above-mentioned piezoelectric stack, the lower connecting member and the upper connecting member have the same shape, and the anode side of the lower connecting member is provided with a convex groove or a linear groove, and the anode side metal The net is a flat metal mesh.

Preferably, in the above-mentioned piezoelectric transformer, the lower connecting member and the upper connecting member have the same shape, and the cathode side of the upper connecting member is a flat plate type, and the cathode side metal mesh is a wave type or a dovetail metal mesh. .

Preferably, in the above-mentioned piezoelectric stack, the lower connecting member and the upper connecting member have the same shape, and the cathode side of the upper connecting member is provided with a convex groove or a linear groove, and the cathode side metal The net is a flat metal mesh.

Preferably, the above non-piezoelectric stack further comprises: a cathode current collecting layer disposed on a cathode surface of the anode supporting unit cell.

Preferably, in the above non-piezoelectric stack, the cathode current collecting layer is a dry state set formed by a spraying process. A flow layer or a wet current collecting layer formed by a screen printing process.

Preferably, in the above non-piezoelectric stack, the current collecting layer has a thickness of 20 to 500 μm.

It can be seen from the above technical solution that the anode supporting flat solid oxide fuel cell provided by the invention has no piezoelectric stack, and a cathode side metal mesh is disposed between the anode supporting unit cell and the upper connecting member, and the anode supporting cell is provided at the anode. An anode-side metal mesh is disposed between the lower connecting member and the lower connecting member, so that the anode and the cathode of the anode supporting unit are in soft contact with the connecting member, and the anode-side metal mesh and the cathode-side metal mesh are disposed around the anode-side metal mesh. The spacer plate can adjust the thickness of the anode side metal mesh and the cathode side metal mesh by adjusting the thickness of the spacer plate, thereby ensuring that the connecting member is in sufficient contact with the anode supporting unit cell; and the spacer plate is also supported by the anode The thermal expansion coefficient matching between the single cell and the connecting member plays a certain buffering role, so that the stack component can be tightly combined at room temperature without external pressure, thereby forming a piezoelectric-free stack, and the piezoelectric stack is not only operated. Simple, but also convenient for system integration.

BRIEF DESCRIPTION OF THE DRAWINGS In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below, and obviously, in the following description The drawings are merely examples of the invention, and other figures can be obtained from those of ordinary skill in the art in light of the inventive drawings.

1 is a schematic structural view of a battery unit in a piezoelectric stack of an anode-supported flat-plate solid oxide fuel cell according to the present invention;

2 is a schematic structural view of an anode side of a connecting member provided by the present invention;

3 is a schematic structural view of another anode side of the connecting member provided by the present invention;

4 is a schematic structural view of an anode side metal mesh provided by the present invention;

FIG. 5 is a schematic structural view of another anode side metal mesh provided by the present invention; FIG.

6 is a schematic structural view of an anode side of a third connecting member provided by the present invention;

7 is a schematic structural view of a cathode side of a connecting member provided by the present invention;

8 is a schematic structural view of a cathode side metal mesh provided by the present invention;

9 is a schematic structural view of a partition plate provided around an anode side metal mesh provided by the present invention; FIG. 10 is a schematic structural view of a partition plate provided around a cathode side metal mesh provided by the present invention; 11 is a schematic structural view showing the assembly of a plurality of battery cells into an anode-supported flat-plate solid oxide fuel cell stack according to the present invention;

Fig. 12 is a physical diagram of the piezoelectric stack of the anode-supported flat-plate solid oxide fuel cell formed by heating, holding and cooling the battery stack shown in Fig. 11. The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. example. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without the creative work are all within the scope of the present invention.

In the following description, numerous specific details are set forth in order to provide a full understanding of the present invention, but the invention may be practiced in other ways other than those described herein, and those skilled in the art may, without departing from the scope of the invention. The invention is not limited by the specific embodiments disclosed below. The anode-supported flat-plate solid oxide fuel cell non-piezoelectric stack provided by the present invention comprises a plurality of battery cells stacked together, wherein the structure of each battery cell is as shown in FIG. 1 , and each of the battery cells comprises: The lower connecting member 1, the anode side metal net 2, the anode supporting unit cell 5, the cathode side metal net 7 and the upper connecting member 13 are disposed in order from the bottom to the top; and the partition plate 4 is disposed around the anode side metal net 2 (Fig. 1 is The partitioned structure 4 is a hollow structure, wherein the empty portion just accommodates the anode-side metal mesh 2, and similarly, the periphery of the cathode-side metal mesh 7 is also provided with a partition plate 6 The hollow portion of the partition plate 6 accommodates the cathode side metal mesh 7; the lower connecting member 1 and the upper connecting member 13 have two sides, and the upward facing side of the two connecting members is the anode side, that is, The side facing the anode supporting the anode of the unit cell 5, the downward facing side is the cathode side, that is, the side supporting the cathode of the unit cell 5 toward the anode, the anode supporting the unit cell 5 having the anode facing downward and the cathode facing upward; Anode side metal 4 2 around the upper and lower spacer plates are provided with a shape identical thereto a sealing material 3, the spacer plate 4 by a sealing material supporting single anode side and the anode 3 is electrically connected to the lower member 1 of the The anodes of the cells 5 are connected to each other. Similarly, the upper and lower partition plates 6 around the cathode side metal mesh 7 are also provided with sealing materials of the same shape, and the spacers 6 pass through the sealing material and the upper connecting members. The cathode side of 13 is connected to the cathode of the anode supporting unit cell 5.

After a plurality of battery cells are stacked on each other, an anode-supported flat-plate solid oxide fuel cell non-piezoelectric stack can be formed by heating, heat preservation and cooling, and two adjacent battery cells in the non-piezoelectric stack are formed. Share the same connector.

The piezoelectric stack provided by the invention has the following advantages: a cathode side metal mesh is disposed between the anode supporting unit cell and the upper connecting member, and an anode side metal mesh is disposed between the anode supporting unit cell and the lower connecting member, thereby The anode supporting single cells are made soft contact on both sides, which ensures sufficient contact between the connecting member and the battery, and improves the output power of the stack; and a spacer plate is arranged around the anode side metal mesh and the cathode side metal mesh. Adjusting the thickness of the spacer, adjusting the thickness of the anode side metal mesh and the cathode side metal mesh, eliminating the matching process of the battery and the sealing material thickness, simplifying the testing and production process, and increasing the sealing effect; and the partitioning plate The thermal expansion coefficient matching of the anode supporting unit cell and the connecting member has a certain buffering effect, so that the stack component can be tightly combined at room temperature without external pressure, thereby forming a piezoelectric stack without the piezoelectric stack. Compared to a piezoelectric stack, there is no need to remove the screw and nut when operating, so the operation process is simple, and since the piezoelectric stack does not need to rely on the screw and To give its parent outside the pressure, therefore, no piezoelectric stack volume made smaller and more compact, the production process is simpler and more conducive to integration system. The structure of each component in each of the battery cells of the anode-supported flat-plate solid oxide fuel cell pressureless reactor provided by the present invention will be described in detail below.

The anode support flat solid oxide fuel cell provided by the present invention has no piezoelectric stack, and each of the battery cells thereon includes the structure shown in FIG. 1, and the lower connecting member 1 and the upper connecting member 13 in FIG. There are two sides, and the lower side of the two connecting members are the cathode side, the upward facing side is the anode side, and the air flow path is formed between the cathode side and the cathode side metal mesh 7, and the anode side and the anode side metal are formed. A fuel gas flow path is formed between the nets 2.

2 and FIG. 3, FIG. 2 and FIG. 3 are two schematic views of the anode side of the connecting member provided by the present invention. The oppositely disposed holes 8 and 9 are the inlet and outlet of the fuel gas, respectively, and the fuel gas flow path. 10 is formed by an etching process, the fuel gas channel etching depth is 0.3 to 1.5 mm, the flow channel structure may be a bump type groove structure as shown in FIG. 2, or a linear groove structure as shown in FIG.

The anode side metal mesh 2 can improve the contact effect between the anode side of the lower connecting member 1 and the anode supporting the single cell 5, wherein the anode side metal mesh 2 has a thickness of 0.1 to 3 mm, and the anode side metal mesh 2 Can be stamped into a wave shape, see Figure 4, or flat plate, see Figure 5. The flat anode side metal mesh is generally used for the joint of the structure shown in Figs. 2 and 3. If a wave-shaped anode side metal mesh is used, a flat structural joint as shown in Fig. 6 is used. The anode side metal mesh is welded to the anode side of the connector to form a fuel gas flow path.

Referring to FIG. 7, FIG. 7 is a schematic structural view of a cathode side of a connecting member according to the present invention. The cathode side of the connecting member is an air semi-open structure, and is etched into a flat plate having a depth of 0.3 to 1.5 mm, and the hole 11 is air. The inlet, rectangular opening 12 is an air outlet, and air is discharged directly from the inlet 11 through the connector. The hole 11 is disposed opposite to the rectangular opening 12, and the side of the connecting member corresponding to the hole 11 and the rectangular opening 12 is different from the side of the connecting member corresponding to the anode side fuel gas inlet and outlet of the connecting member, and therefore, the fuel The air flow path intersects the air flow path. Of course, the cathode side of the connector may also be etched to the structure shown in Fig. 2 or Fig. 3, but it is to be ensured that an air flow path is formed between the cathode side and the cathode side metal mesh of the connector.

When the cathode side of the connecting member is the structure shown in FIG. 7, the cathode side metal mesh may be stamped into a wave-shaped structure as shown in FIG. 8, or may be stamped into a dovetail structure, and the height of the cathode side metal mesh after punching. It is 0.1~3mm. The air flow path is formed by pre-welding the cathode side metal mesh to the cathode side of the connector. The cathode side metal mesh is a high temperature resistant alloy such as a Ni-Cr alloy, a Hyness 230 alloy, or the like. In order to prevent the cathode side metal mesh from being oxidized by the air or the Cr-containing metal mesh to form Cr volatilization on the anode supporting single cell cathode, the connecting member soldered with the cathode side metal mesh may be sprayed with a protective coating on the surface of the cathode side metal mesh. The layer, for example, is plasma sprayed with a Ni-Cr/LSM composite coating.

9 and FIG. 10, FIG. 9 is a schematic structural view of a spacer provided around the anode side metal mesh according to the present invention, and FIG. 10 is a schematic structural view of a spacer disposed around the cathode side metal mesh provided by the present invention. The thickness of the intermediate partition plate of FIG. 9 and FIG. 10 should be between 0.1 and 2 mm, and the partition plate can be made of ferritic stainless steel such as 430. The thickness of the spacer can be based on the gas flow path at room temperature The etching depth and the thickness of the metal mesh are selected. If the metal mesh is easily deformed at a high temperature, the thickness of the spacer may be arbitrarily selected so that the metal mesh matches the thickness of the spacer at a high temperature. The spacers are sealed with a sealing material to form a sealed composite assembly, and the sealing material structure is matched with the corresponding spacer structure.

In order to increase the cathode current collecting effect in the embodiment of the present invention, a cathode current collecting layer may be coated on the surface of the cathode supporting unit cell cathode, and the current collecting layer may spray a cathode powder of a certain quality and thickness by spraying to form a dry layer. The current collector layer may also be formed into a cathode slurry by using an organic solvent such as alcohol or terpineol, and printed on the surface of the cathode of the battery by screen printing or the like to form a wet current collecting layer. The thickness of the collector layer can be between 20 and 500 μm.

The above components can be assembled according to the structure shown in Fig. 1 to form a battery unit, and a plurality of battery cells are repeatedly combined to form an anode-supported flat-plate solid oxide fuel cell stack, as shown in Fig. 11. For example, 组装 30 battery cells are assembled into a 30-unit standard anode-supported stack module. The stack is heated to a suitable temperature at a certain heating rate. The temperature should be higher than the softening temperature of the sealing material. After the sealing material is softened for more than 2 hours, a certain pressure (50~500kg) is applied and the temperature is kept for a certain period of time ( > 4 hours), cooled to room temperature at a rate of rC/min. The residual pressure is removed to form an anode-supported piezoelectric stack module. The fabrication process of the anode-supported flat-plate solid oxide fuel cell without piezoelectric stack provided by the present invention is described in detail below with reference to a specific embodiment. The manufacturing process specifically includes the following steps:

1. The anode side of the connecting member is etched into a bump-like groove structure having a depth of 0.3 mm, and 0.09 mm thick foamed nickel is used as the anode side metal mesh, and a 0.4 mm thick spacer plate is disposed around the anode-side metal mesh. The partition plate and the connecting member and the partition plate and the battery are sealed and connected by a sealing material.

2. The cathode side of the connecting member is etched into a flat-plate structure having a depth of 0.5 mm, and a Ni-Cr alloy mesh is used as a cathode-side metal mesh, and the cathode-side metal mesh is punched into a wave shape having a height of 1.5 mm. The cathode side metal mesh is circumferentially matched with a 0.4 mm thick spacer, the cathode side metal mesh is stamped and welded to the cathode side of the connecting member, and a plasma process is used to spray Ni-Cr/LSM on the cathode side metal mesh. Composite coating.

3. The single cell used is a flat-plate anode-supported NiO-Ni/YSZ/LSM battery with a cell size of 10 cm X 10 cm. 4. The terpineol and LSM powder are formulated into a LSM slurry in a certain ratio, and the LSM slurry is screen printed on the cathode surface of the battery as a cathode current collecting layer by screen printing, and the collector layer mass is 3.5 to 4.5 g. . The battery is applied to the stack assembly under wet conditions in the collector layer.

5. Assemble the components of each stack into a 30-unit stack according to the structure shown in Figure 1. Pre-pressurize 50 kg at room temperature to make the wet collector layer and the cathode side metal mesh fully contact.

6. Place the assembled electric reactor in an electric furnace, raise the temperature to 850 °C at a heating rate of rC/min, pressurize for 2 hours, pressurize 200kg, and then keep it for 4 hours, cool down to room temperature at rC/min, unload The residual pressure of the reactor is reduced, and an anode-supported piezoelectric stack is fabricated.

The fabricated piezoelectric stack is shown in Fig. 12. The stack does not need to be fixedly pressurized at room temperature, and the components of the stack are tightly combined, and no gap is seen in the periphery of the stack.

As can be seen from the above description, the anode-supported flat-plate solid oxide fuel cell provided by the present invention has no piezoelectric stack, and the anode supporting single cell in the stack is a double-sided full-soft contact, and the connecting member and the anode support the single battery. A spacer is disposed between the two sides. By adjusting the thickness of the spacer, the thickness of the anode side metal mesh and the cathode side metal mesh can be quantitatively adjusted, thereby ensuring sufficient contact between the connector and the battery; and the spacer plate is also connected to the battery and the connection. The thermal expansion coefficient matching of the two members acts as a buffering effect, so that the stack components can be tightly combined at room temperature without external pressure to form a piezoelectric stack. The various parts of this manual are described in a progressive manner. Each part focuses on the differences between the other parts. The same similar parts between the parts can be referred to each other.

The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments are obvious to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded to the broadest scope of the principles and novel features disclosed herein.

Claims

Rights request

An anode-supported flat-plate solid oxide fuel cell non-piezoelectric stack, characterized in that it comprises: a plurality of battery cells stacked together, wherein each battery cell comprises:

The same connector is shared between two adjacent battery cells.

2. The piezoelectric transformer according to claim 1, further comprising: a protective coating disposed on the cathode side metal mesh toward the cathode supporting unit cell cathode.

The piezoelectric transformer stack according to claim 1, wherein the spacer has a thickness of 0.1 to 2 mm.

4. The piezoelectric transformer according to claim 1, wherein the lower connecting member and the upper connecting member have the same shape, and the anode side of the lower connecting member is a flat plate type, and the anode side metal mesh It is a wave or dovetail metal mesh.

5. The piezoelectric transformer according to claim 1, wherein the lower connecting member and the upper connecting member have the same shape, and the anode side of the lower connecting member is provided with a convex groove or a straight type. The groove, the anode side metal mesh is a flat metal mesh.

The piezoelectric transformer stack according to claim 1, wherein the lower connecting member and the upper connecting member have the same shape, and the cathode side of the upper connecting member is a flat plate type, and the cathode side metal mesh It is a wave or dovetail metal mesh.

7. The piezoelectric transformer according to claim 1, wherein the lower connecting member and the upper connecting member have the same shape, and the cathode side of the upper connecting member is provided with a convex groove or a straight type. a groove, the cathode side metal mesh is a flat metal mesh.

The piezoelectric transformer according to any one of claims 1 to 7, further comprising: a cathode current collecting layer provided on a cathode surface of the anode supporting unit cell.

9. The piezoelectric transformer according to claim 8, wherein the cathode current collecting layer is a dry current collecting layer formed by a spray coating process or a wet current collecting layer formed by a screen printing process.

The piezoelectric transformer according to claim 8, wherein the current collecting layer has a thickness of 20 to 500 μm.