Solid oxide fuel cell with triangular tube type anode substrate and electric pile

Abstract

The invention relates to a solid oxide fuel cell with a triangular tube type anode substrate and an electric pile, and belongs to the technical field of solid oxide fuel cells. The battery sequentially comprises a triangular tube type anode base body and anode functional layers from inside to outside, the outer surface of the triangular tube type anode base body is completely coated with the anode functional layers, a first barrier layer, an electrolyte layer, a second barrier layer and a cathode functional layer are sequentially arranged on the surfaces of the two anode functional layers, and a connecting layer is arranged on the other surface of each anode functional layer; the hollow structure of the triangular tube type anode base body is a fuel gas channel; the triangular tube type anode matrix, the anode functional layer and the cathode functional layer are all of porous structures, and the electrolyte layer, the first barrier layer, the second barrier layer and the connecting layer are all of compact structures. The power divider is simple in structure and convenient to produce and assemble, has high mass power density and volume power density, and meanwhile has the advantages of being high in structural strength, small in size and easy to integrate.

Description

Technical Field

[0001] The present invention relates to a solid oxide fuel cell and a stack with a triangular tube-shaped anode substrate, belonging to the technical field of solid oxide fuel cells. Background Art

[0002] A solid oxide fuel cell (SOFC) is an all-solid-state chemical power generation device that directly and efficiently converts the chemical energy stored in fuels and oxidants into electrical energy at medium and high temperatures in an environmentally friendly manner, and is the most promising energy conversion and storage technology in the future. Tubular solid oxide fuel cells are considered ideal prime movers for distributed energy supply systems because they are easy to assemble into high-power stacks and can operate under pressure.

[0003] Traditional circular tubular solid oxide fuel cells have advantages such as relatively simple cell unit assembly and easy sealing, which enable their relatively wide application. However, during the production process of their substrates, they are prone to deformation. At the same time, when forming a stack, due to ohmic losses, the overall power is not high, and a large amount of space is lost, resulting in a low power per unit volume of circular tubular solid oxide fuel cells; while flat tubular solid oxide fuel cells have too small fuel gas channels, and the power of a single cell is not as high as that of circular tubular solid oxide fuel cells. The above problems limit the development of solid oxide fuel cells. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a solid oxide fuel cell and a stack with a triangular tube-shaped anode substrate. The cell and stack have a simple structure, are convenient for production and assembly, have high mass power density and volume power density, and at the same time have the characteristics of high structural strength, small volume, and easy integration.

[0005] To achieve the above purpose, the technical solution of the present invention is as follows.

[0006] A solid oxide fuel cell with a triangular tube-shaped anode substrate, the cell sequentially includes a triangular tube-shaped anode substrate and an anode functional layer from the inside to the outside. The anode functional layer completely covers the outer surface of the triangular tube-shaped anode substrate. A first barrier layer, an electrolyte layer, a second barrier layer, and a cathode functional layer are sequentially provided on the surfaces of the two anode functional layers. A connection layer is provided on the other surface of the anode functional layer; the hollow structure of the triangular tube-shaped anode substrate is a fuel gas channel;

[0007] The triangular tube-shaped anode substrate, the anode functional layer, and the cathode functional layer are all porous structures, and the electrolyte layer, the first barrier layer, the second barrier layer, and the connection layer are all dense structures.

[0008] Furthermore, the cross-section of the triangular tube-shaped structure is an equilateral triangle.

[0009] Further, the main material of the anode substrate is a cermet of nickel oxide - yttria - stabilized zirconia (YSZ) or nickel oxide - gadolinium - doped ceria (SDC).

[0010] Further, the material of the anode functional layer is a perovskite material with high electrochemical activity; preferably, the anode functional material is nickel oxide - yttria - stabilized zirconia, LaCrO 3 - based perovskite material or SrTiO 3 - based perovskite material.

[0011] Further, the material of the electrolyte layer is an oxide with oxygen ion conduction ability at high temperatures; preferably, the electrolyte material is ytterbium - stabilized zirconia, and the mole fraction of ytterbium is 3% - 8%.

[0012] Further, the material of the cathode functional layer is a perovskite material with high catalytic reaction activity; preferably, the material of the cathode functional layer is a perovskite material containing cobalt and nickel, or a composite material composed of a perovskite material containing cobalt and gadolinium - doped ceria.

[0013] Further, the materials of the first barrier layer and the second barrier layer are ceria doped with metal elements; preferably, the materials of the first barrier layer and the second barrier layer are gadolinium - doped ceria, and the mole fraction of gadolinium is 10% - 30%.

[0014] Further, the material of the connecting layer is a cermet material with excellent electrical conductivity at high temperatures; preferably, the material of the connecting layer is lanthanum chromite cermet.

[0015] Further, the length of the triangular - tube - type anode substrate is 100 mm - 250 mm, the outer - diameter side length of the triangular tube is 10 mm - 20 mm, and the wall thickness is 0.4 mm - 1.2 mm;

[0016] The thickness of the anode functional layer is 20 μm - 30 μm;

[0017] The thickness of the first barrier layer is 1 μm - 5 μm;

[0018] The thickness of the electrolyte layer is 10 μm - 30 μm;

[0019] The thickness of the second barrier layer is 1 μm - 5 μm;

[0020] The thickness of the cathode functional layer is 20 μm - 120 μm;

[0021] The thickness of the connecting layer is 20 μm - 40 μm.

[0022] A preparation method of a solid oxide fuel cell with a triangular - tube - type anode substrate according to the present invention, the method steps include:

[0023] (1) Prepare the anode substrate paste, extrude and mold it to obtain a triangular tube-shaped anode substrate.

[0024] (2) Prepare the anode functional layer paste. Seal one end of the triangular tube-shaped anode substrate with hot melt adhesive. After the hot melt adhesive completely solidifies, immerse the triangular tube-shaped anode substrate in the anode functional layer paste. After immersion, sinter it to obtain an anode functional layer on the outer surface of the triangular tube-shaped anode substrate.

[0025] (3) Prepare the first barrier layer on each of the two surfaces of the anode functional layer by screen printing.

[0026] (4) Prepare the electrolyte layer on each of the two first barrier layers by plasma spraying.

[0027] (5) Prepare the second barrier layer on each of the two electrolyte layers by screen printing.

[0028] (6) Prepare the cathode functional layer on each of the two second barrier layers by screen printing.

[0029] (7) Prepare the connection layer on the other surface of the anode functional layer by plasma spraying.

[0030] A solid oxide fuel cell stack with a triangular tube-shaped anode substrate. Connect multiple cells in series in the way that the connection layer side of one cell is connected to the cathode functional layer of another cell according to the present invention to obtain an efficient triangular tube-shaped solid oxide fuel cell stack.

[0031] Further, the current collecting metal is made of stainless steel material.

[0032] Beneficial effects

[0033] The present invention provides a solid oxide fuel cell with a triangular tube-shaped anode substrate. The triangular tube-shaped anode substrate is located at the structural center, and a fuel gas channel is arranged inside it. The anode functional layer covers the entire outer side of the triangular tube-shaped anode substrate. The electrolyte layer is coated on both sides of the triangular tube-shaped substrate and has a dense structure, which can prevent gas mixing on both sides of the electrode and conduct oxygen ions at the same time. The cathode functional layer is arranged outside the electrolyte layer. At the same time, the first barrier layer and the second barrier layer are respectively arranged between the anode functional layer and the electrolyte layer, and between the electrolyte layer and the cathode functional layer to prevent the electrolyte material from reacting with the electrode material. The connection layer is arranged on the other side of the triangular tube-shaped substrate and is used to connect single cells in series to form a stack. The structure of this cell is simple. Using both sides of the triangular tube as the cathode increases the reaction area, making the cell have a higher power density. Further, using YSZ or SDC as the anode material can enhance the mechanical strength of the cell.

[0034] The reaction process of the battery includes an anodic oxidation reaction and a cathodic reduction reaction. The reaction process is that the fuel gas enters the fuel gas channel and diffuses longitudinally to the interface between the functional layer and the electrolyte layer. On the cathode side, oxygen is catalytically reduced to oxygen ions, which are conducted through the electrolyte to the interface to undergo an electrochemical reaction; the reaction process generates water and a large amount of electrical energy.

[0035] The present invention provides a method for preparing a solid oxide fuel cell with a triangular tube-shaped anode substrate. Different methods are used to prepare each structure. Among them, the anode substrate is prepared by an extrusion molding method, which is convenient for production and assembly into a stack. At the same time, the stability of the triangular tube shape can prevent the deformation of the battery substrate after extrusion molding.

[0036] The present invention provides a solid oxide fuel cell stack with a triangular tube-shaped anode substrate. Two or more of the triangular tube-shaped solid oxide fuel cells are provided, and the single cells are connected in series through a current collector metal and a connection layer to form a battery stack. The triangular tube-shaped single cells are assembled into a stack more closely, saving space, thereby enhancing the volumetric power density of the stack. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic structural diagram of the triangular tube-shaped solid oxide fuel cell in the present invention.

[0038] Figure 2 It is a top view interface diagram of the triangular tube-shaped solid oxide fuel cell in the present invention.

[0039] Figure 3 It is a structural diagram of the triangular tube-shaped solid oxide fuel cell stack in the present invention.

[0040] Figure 4 It is a current collection schematic diagram of the triangular tube-shaped solid oxide fuel cell stack in the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0041] The present invention will be further described in detail below with reference to specific embodiments.

[0042] A solid oxide fuel cell with a triangular tube-shaped anode substrate, as Figure 1-2 shown, the triangular tube-shaped solid oxide fuel single cell mainly includes a fuel gas channel (1), a triangular tube-shaped anode substrate (2), an anode functional layer (3), a first barrier layer (4), an electrolyte layer (5), a second barrier layer (6), and a cathode functional layer (7). When the temperature reaches the discharge temperature of the solid oxide fuel cell, a certain amount of fuel gas and oxygen are respectively introduced on the anode and cathode sides. The fuel gas enters the fuel gas channel and diffuses radially to the interface between the functional layer and the electrolyte layer. On the cathode side, oxygen is catalytically reduced to oxygen ions, which are conducted through the electrolyte to the interface to undergo an electrochemical reaction; the reaction process generates water and a large amount of electrical energy.

[0043] A triangular tube type solid oxide fuel cell stack for efficient energy conversion, as Figure 3-4 shown, the fuel cell stack is composed of a plurality of single cells connected in series through a connection layer (8) and a current collecting metal (9).

[0044] Example 1

[0045] In this example, the anode substrate is prepared by extrusion of a mud material, has a porous structure, and the material is nickel oxide - yttria - stabilized zirconia; the anode functional layer has a porous structure, is impregnated onto the anode substrate by preparing a slurry, and the thickness of the anode functional layer is adjusted to 20 μm to 30 μm by the number of impregnations and time, and the material is LaCrO 3 based perovskite material with high electrochemical activity; the first barrier layer and the second barrier layer have a dense structure, with a thickness of 1 μm to 5 μm, to prevent the functional layer from reacting with the electrolyte and the electrolyte from reacting with the cathode, and the material is gadolinium - doped ceria, and the molar fraction of gadolinium is 10% to 30%; the electrolyte layer has a dense structure, is sprayed onto the anode by a spraying method, with a thickness of 10 μm to 30 μm, and the material is ytterbium - stabilized zirconia with oxygen ion conduction ability at high temperatures, and the molar fraction of ytterbium is 3% to 8%; the cathode functional layer has a porous structure, with a thickness of 20 μm to 120 μm, and the material is a cobalt - and nickel - containing perovskite material with high catalytic reaction activity; the connection layer has a dense structure, with a thickness of 20 μm to 40 μm, and the material is a lanthanum chromate cermet material with excellent electrical conductivity at high temperatures; the material used for the current collecting metal is a stainless steel material.

[0046] Specifically, it can be prepared according to the following method:

[0047] The preparation method steps of the anode functional layer include: mixing the anode functional layer raw materials, and putting them into a sand mill for sanding for 12 h to obtain mixed fine powder, and then adding an appropriate amount of ethanol for dispersion. The above slurry is put into the sand mill again for sanding for 12 h to obtain the anode functional layer slurry. The anode substrate is immersed in the anode functional layer slurry, the immersion time is 15 s, and then it is dried, the temperature is set to 50 °C to 60 °C, and the drying time is set to 10 min. Repeat the above operations twice. The anode with the impregnated functional layer is transferred to a muffle furnace for sintering, the sintering temperature is 1000 °C, the sintering time is 2 h, and the heating rate is 0.5 °C / min. After sintering, the anode functional layer is obtained on the surface of the anode substrate.

[0048] The preparation method of the first barrier layer is specifically to add the raw materials of the first barrier layer to an appropriate amount of terpineol, put them into a ball mill and ball mill for 2 h to obtain the first barrier layer slurry. The slurry is printed on the anode functional layer by the screen printing method, the drying time is set to 10 min, and then the anode with the first barrier layer is transferred to a muffle furnace for sintering. The sintering temperature is 1300 °C, the sintering time is 5 h, and the heating rate is 1 °C / min. After sintering, the anode with the first barrier layer is obtained.

[0049] The steps of the preparation method of the connecting layer include: adding the raw materials of the connecting layer to an appropriate amount of ethanol, putting them into a ball mill and ball milling for 24 h to obtain the connecting layer slurry. The slurry is sprayed on the surface of the anode functional layer by a plasma spraying machine, the spraying pressure is 0.3 MPa, and drying is carried out after each spraying. The temperature is set to 50 °C to 60 °C, the drying time is set to 10 min, and spraying-drying is carried out 8 times. The anode with the sprayed functional layer is transferred to a muffle furnace for sintering. The sintering temperature is 1300 °C, the sintering time is 3 h, and the heating rate is 1 °C / min. After sintering, an electrolyte layer is obtained on the surface of the anode functional layer.

[0050] The steps of the preparation method of the electrolyte layer include: adding the raw materials of the electrolyte layer to an appropriate amount of ethanol, putting them into a ball mill and ball milling for 24 h to obtain the electrolyte layer slurry. The slurry is sprayed on the surface of the first barrier layer by a plasma spraying machine, the spraying pressure is 0.4 MPa, and drying is carried out after each spraying. The temperature is set to 50 °C to 60 °C, the drying time is set to 10 min, and spraying-drying is carried out 8 times. The anode with the sprayed functional layer is transferred to a muffle furnace for sintering. The sintering temperature is 1450 °C, the sintering time is 3 h, and the heating rate is 1 °C / min. After sintering, an electrolyte layer is obtained on the surface of the first barrier layer.

[0051] The preparation method of the second barrier layer is the same as that of the first barrier layer.

[0052] The steps of the preparation method of the cathode functional layer include: adding 15% soluble starch, 8% ethyl cellulose and an appropriate amount of terpineol to the raw materials of the cathode functional layer, putting them into a ball mill and ball milling for 2 h to obtain the cathode functional layer slurry. The slurry is printed on the second barrier layer of the half-cell by the screen printing method, the drying time is set to 10 min, and the above operation is repeated 1 time. After the cathode functional layer is completely dried, the half-cell with the cathode functional layer is transferred to a muffle furnace for sintering. The sintering temperature is 1100 °C, the sintering time is 2 h, and the heating rate is 2 °C / min. After sintering, a full cell is obtained.

[0053] This embodiment also provides a series connection method and current collection method for a triangular tubular solid oxide fuel cell stack. Specifically, the stack connects a cathode surface of a single cell and a current collection layer through a current collection metal, such that the other cathode surface of the single cell is located on both sides of the stack, oxygen is purged on both sides of the stack, each fuel gas pore channel of the stack is connected to a fuel gas supply pipe, and fuel gas is introduced from bottom to top. A connection layer and a cathode surface at both ends of the entire stack are respectively connected to wires to collect current.

[0054] In summary, the invention includes but is not limited to the above embodiments. Any equivalent replacement or partial improvement made under the spirit and principle of the present invention will be regarded as being within the protection scope of the present invention.

Claims

1. A solid oxide fuel cell having a triangular tubular anode substrate, characterized in that: The battery comprises a triangular tubular anode substrate and an anode functional layer from the inside to the outside, wherein the anode functional layer is completely coated on the outer surface of the triangular tubular anode substrate, and a first barrier layer, an electrolyte layer, a second barrier layer and a cathode functional layer are sequentially arranged on the two surfaces of the anode functional layer, and a connecting layer is arranged on the other surface of the anode functional layer; the hollow structure of the triangular tubular anode substrate is a fuel gas channel; The triangular tube anode substrate, the anode functional layer, and the cathode functional layer are all porous structures, and the electrolyte layer, the first barrier layer, the second barrier layer, and the connecting layer are all dense structures; Preferably, the cross section of the triangular tube structure is an equilateral triangle.

2. A solid oxide fuel cell having a triangular tubular anode substrate as claimed in claim 1, characterized in that: The main material of the anode substrate is nickel oxide-yttria-stabilized zirconium oxide or nickel oxide-gadolinium oxide-doped cerium oxide metal ceramic.

3. A solid oxide fuel cell having a triangular tubular anode substrate as claimed in claim 1, characterized in that: The material of the anode functional layer is a perovskite material with high electrochemical activity; preferably, the anode functional material is nickel oxide-yttria stabilized zirconia, LaCrO3-based perovskite material or SrTiO3-based perovskite material.

4. A solid oxide fuel cell having a triangular tubular anode substrate as claimed in claim 1, characterized in that: The electrolyte layer material is an oxide having oxygen ion conductivity at high temperature; preferably, the electrolyte material is ytterbium oxide stabilized zirconium oxide, and the molar fraction of ytterbium oxide is 3% to 8%.

5. A solid oxide fuel cell having a triangular tubular anode substrate as claimed in claim 1, characterized in that: The cathode functional layer material is a perovskite material with high catalytic reaction activity; preferably, the cathode functional layer material is a perovskite material containing cobalt and nickel, or a composite material consisting of a cobalt-containing perovskite material and gadolinium oxide-doped cerium oxide.

6. A solid oxide fuel cell having a triangular tubular anode substrate as claimed in claim 1, characterized in that: The materials of the first barrier layer and the second barrier layer are cerium oxide doped with metal elements respectively; preferably, the materials of the first barrier layer and the second barrier layer are cerium oxide doped with gadolinium oxide, and the molar fraction of gadolinium oxide is 10% to 30%.

7. A solid oxide fuel cell having a triangular tubular anode substrate as claimed in claim 1, characterized in that: The connecting layer material is a metal ceramic material with excellent high-temperature electrical conductivity; preferably, the connecting layer material is lanthanum chromate metal ceramic.

8. A solid oxide fuel cell having a triangular tubular anode substrate according to any one of claims 1 to 7, characterized in that: The length of the triangular tube anode substrate is 100mm to 250mm, the side length of the triangular tube outer diameter is 10mm to 20mm, and the wall thickness is 0.4mm to 1.2mm; The thickness of the anode functional layer is 20 μm to 30 μm; The thickness of the first barrier layer is 1 μm to 5 μm; The thickness of the electrolyte layer is 10 μm to 30 μm; The thickness of the second barrier layer is 1 μm to 5 μm; The thickness of the cathode functional layer is 20 μm to 120 μm; The thickness of the connection layer is 20 μm to 40 μm.

9. A method for preparing a solid oxide fuel cell having a triangular tubular anode substrate according to any one of claims 1 to 8, characterized in that: The method steps include: (1) preparing an anode substrate slurry, extruding and molding, and preparing a triangular tube anode substrate; (2) preparing an anode functional layer slurry, sealing one end of a triangular tubular anode substrate with a hot melt adhesive, and after the hot melt adhesive is completely solidified, dipping the triangular tubular anode substrate in the anode functional layer slurry, and sintering after the dipping is completed to obtain an anode functional layer on the outer surface of the triangular tubular anode substrate; (3) preparing a first barrier layer on two surfaces of the anode functional layer by screen printing; (4) preparing electrolyte layers on the two first barrier layers respectively by plasma spraying; (5) preparing a second barrier layer on each of the two electrolyte layers by screen printing; (6) preparing cathode functional layers on the two second barrier layers respectively by screen printing; (7) A connecting layer is prepared on the other surface of the anode functional layer by a plasma spraying method.

10. A solid oxide fuel cell stack having a triangular tubular anode substrate, characterized in that: According to any one of claims 1 to 8, a connection layer of a battery is connected to the cathode functional layer of another battery via a collector metal, and multiple batteries are connected in series to obtain a highly efficient triangular tube solid oxide fuel cell stack.

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