KR101364131B1 - Cylindrical solid oxide fuel cell - Google Patents

Abstract

A cylindrical solid oxide fuel cell module by an embodiment of the present invention comprises the following: a fuel electrode supporter; an electrolyte layer located on the outer circumference of the fuel electrode supporter; an air electrode layer located on the electrolyte layer; and an inner current collector located inside the fuel electrode supporter. The fuel electrode supporter includes: a metal felt layer passing through fuel gas by being formed into a porous structure, and functioning as a current collector; and a metallic wire located on the inner circumference of the metal felt layer with constant intervals for collecting internal current. The inner current collector is inserted into the fuel electrode supporter with the outer circumference contacting the metallic wire for reducing resistance.

Description

Cylindrical Solid Oxide Fuel Cell {CYLINDRICAL SOLID OXIDE FUEL CELL}

The present invention relates to a solid oxide fuel cell, and more particularly to a cylindrical solid oxide fuel cell that can reduce the internal resistance and increase the output by reducing the nickel (Ni) resistance in the unit cell.

Demand for electricity is gradually increasing due to the economic growth due to industrial development, and environmental problems such as pollution problems caused by the use of fossil fuels such as petroleum and coal required for electric power generation and abnormal weather are getting serious.

Moreover, various environmental pollution problems such as global warming due to carbon dioxide generation due to the use of fossil fuels are emerging. As a clean energy source to replace fossil fuels, solar, solar energy, bio energy, wind energy, and hydrogen energy Development is underway.

Among them, active research is being conducted in the fuel cell sector using hydrogen as a fuel. The fuel cell sector is evaluated as a future power generation technology because there is no emission of pollutants due to power generation, and it requires land, power transmission, and substation facilities for power plant construction. It is not suitable for our country.

A fuel cell is a device that directly converts chemical energy of fuel (hydrogen, LNG, LPG, etc.) and air into electricity and heat by an electrochemical reaction. Unlike the existing power generation technology that takes fuel combustion process, steam generation, turbine drive, and generator drive process, there is no combustion process or drive device, so it is a new concept of power generation technology that not only causes high efficiency but also causes environmental problems. Such a fuel cell has almost no emissions of air pollutants such as SOx and NOx, generates little carbon dioxide, and is a pollution-free power generation. It has advantages such as low noise and no vibration.

There are various types of fuel cells such as phosphate fuel cell (PAFC), alkaline fuel cell (AFC), polymer electrolyte fuel cell (PEMFC), direct methanol fuel cell (DMFC), and solid oxide fuel cell (SOFC). Medium solid oxide fuel cell (SOFC) has high power generation efficiency due to low overvoltage and low irreversible loss based on activation polarization. In addition, it is possible to use not only hydrogen but also carbon or hydrocarbon-based fuels, so that the fuel selection range is wide and the reaction rate at the electrode is high, thus eliminating the need for expensive precious metals as electrode catalysts. In addition, the use of heat is high because the temperature of the heat emitted by the generation is very high. The heat generated from solid oxide fuel cells is not only used for reforming fuel, but also for industrial or cooling energy sources in cogeneration. Therefore, the solid oxide fuel cell is an essential power generation technology for entering the hydrogen economy society in the future.

Looking at the basic operation principle of the solid oxide fuel cell (SOFC), the solid oxide fuel cell is basically a device that generates by the oxidation reaction of hydrogen and CO, the electrode reaction in the anode and cathode as shown in Reaction 1 below This is going on.

Scheme 1

_{^{Anode: H 2 + O 2 - →}} H 2 O + 2e

_{^{CO + O 2 - → CO 2}} + 2e

_{Cathode: O 2 + 4e → 2O 2} -

Total reaction: H ₂ + CO + O ₂ → H ₂ 0 + CO ₂

That is, electrons reach the cathode via an external circuit, and at the same time, oxygen ions generated at the cathode are transferred to the anode through the electrolyte, whereby hydrogen or CO combines with oxygen ions to generate electrons, water, or CO ₂ .

Accordingly, many studies have been made on the improvement of the internal current collecting method of the battery when the cylindrical solid oxide fuel cell is collected in the solid oxide fuel cell.

In the conventional cylindrical solid oxide fuel cell, the nickel fuel or nickel mesh is welded to the nickel felt or the nickel mesh for the internal current collecting of the cylindrical fuel cell. It is formed into a shape that can be located inside. Subsequently, a nickel ink is applied onto the rounded nickel felt and then put into a fuel cell to collect current.

However, in the above configuration, when the unit resistance of the cylindrical solid oxide fuel cell module is connected in series, the resistance value of the entire stack is calculated. Difficulty collecting or distributing

The problem to be solved by the present invention is to provide a cylindrical solid oxide fuel cell that can reduce the internal resistance and obtain a high output by reducing the nickel (Ni) resistance.

Another object of the present invention is to provide a cylindrical solid oxide fuel cell that can be applied to all types of solid oxide fuel cells using internal current collectors, and can be used in portable and military small stacks of high voltage and low current types. There is.

The various problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

Cylindrical solid oxide fuel cell module according to an embodiment of the present invention, the anode support; An electrolyte layer positioned on an outer circumferential surface of the anode support; A cathode layer positioned on the electrolyte layer; And an internal current collector positioned inside the anode support, wherein the anode support includes a metal felt layer formed to be porous to allow fuel gas to pass therethrough and function as a current collector; And a metallic wire spaced apart from the inner surface of the metal felt layer by a predetermined interval and collecting an internal current, wherein the inner current collector is inserted into the anode support, and an outer circumferential surface contacts the metallic wire to reduce resistance. You can.

The internal current collector may have a plurality of rod shapes.

The internal current collector may have a plurality of wire shapes.

The internal current collector may be formed of a conductive metal material.

The conductive metal material may include any one of nickel (Ni), stainless steel, or steel.

The metal felt layer may be a nickel (Ni) felt layer mainly containing nickel (Ni).

The metallic wire may comprise any one of metals, alloys, mixtures of metals and alloys, or mixtures of metal oxides and metals.

The metallic wire may be a nickel (Ni) wire mainly containing nickel (Ni).

The metallic wire may include any one of Au, Pd, Pt, Ni, Ru, Rh, Ir, or an alloy thereof.

The internal current collector may be electrically connected to the anode support to collect current generated from the anode support.

The internal current collector may serve to compress the metallic wire to the inner circumferential surface of the metal felt layer and also function as a current collector.

Cylindrical solid oxide fuel cell according to an embodiment of the present invention, a unit cell; An internal current collector located inside the unit cell, wherein the unit cell comprises: a fuel cell support including a metal felt layer functioning as a current collector and a metallic wire collecting internal current; An electrolyte layer positioned on an outer circumferential surface of the anode support; And a cathode layer disposed on the electrolyte layer, wherein the internal current collector may include a plurality of rods or wires which are in contact with the metallic wire and formed of a conductive metal material.

The various problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

Cylindrical solid oxide fuel cell according to an embodiment of the present invention can reduce the internal resistance and obtain a high output by reducing the nickel (Ni) resistance.

In addition, the cylindrical solid oxide fuel cell according to an embodiment of the present invention is applicable to all types of solid oxide fuel cells using internal current collectors, and may be used in portable and military small stacks of high voltage and low current types.

It will be appreciated that various embodiments of the inventive concepts of the present invention can provide various effects not specifically mentioned.

1 is a view schematically showing a cylindrical solid oxide fuel cell module according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along line AA ′ of FIG. 1.
3 is an enlarged cross-sectional view of a portion B of FIG. 2.
4 is a longitudinal cross-sectional view of an internal current collector according to a modified example of the technical idea of the present invention.
FIG. 5 is a graph for comparing a performance curve for each temperature according to whether an internal current collector is present in a cylindrical solid oxide fuel cell according to an embodiment of the inventive concept.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and how to accomplish them, will become apparent by reference to the embodiments described in detail below with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, the embodiments disclosed herein are provided so that the disclosure can be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the thickness or size of each layer may be exaggerated for convenience and clarity of description and may differ from the thickness or size of the actual layer.

Terms such as top, bottom, top, bottom, or top, bottom, etc. are used to distinguish relative positions in components. For example, in the case of naming the upper part of the drawing as upper part and the lower part as lower part in the drawings for convenience, the upper part may be named lower part and the lower part may be named upper part without departing from the scope of right of the present invention .

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprises", "having", and the like are used to specify that a feature, a number, a step, an operation, an element, a part or a combination thereof is described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the meaning in the context of the relevant art and are to be construed as ideal or overly formal in meaning unless explicitly defined in the present application Do not.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the cylindrical solid oxide fuel cell according to an embodiment of the present invention.

1 is a view schematically showing a cylindrical solid oxide fuel cell according to an embodiment of the inventive concept, FIG. 2 is a cross-sectional view taken along line AA ′ of FIG. 1, and FIG. 3 is a portion B of FIG. 2. Figure 4 is an enlarged cross-sectional view, Figure 4 is a conceptual longitudinal sectional view of the internal current collector according to a modification of the technical idea of the present invention, Figure 5 is a cylindrical solid oxide fuel cell according to an embodiment of the present invention This is a graph for comparing the performance curve for each temperature according to the presence or absence of internal current collector.

1 to 4, a cylindrical solid oxide fuel cell module 100 according to an embodiment of the inventive concept may include a unit cell 80 and an internal current collector located inside the unit cell 80. 700).

The unit cell 80 may include an anode support 10, an electrolyte layer 30 disposed on an outer circumferential surface of the anode support 10, and an anode layer 50 located on the electrolyte layer 30. .

The anode support 10 may have a cylindrical shape and may support the unit cell 80 of the cylindrical solid oxide fuel cell submodule 100 as a whole. The anode support 10 may be manufactured using a slurry prepared by mixing nickel oxide (NiO) powder, yttria stabilized zirconia (YSZ) powder, a binder, a homogeneous agent, a dispersant, a plasticizer and a solvent. Since the anode support 10 is formed of a mixture of nickel oxide (NiO) and yttria stabilized zirconia (YSZ), the anode support 10 may have conductivity. The anode support 10 may be formed of a porous material so that fuel gas including hydrogen may pass therethrough. The anode support 10 forms a frame of the unit cell 80 and serves as a flow path of the fuel / reactant, and since two or more unit cells are connected, the anode support 10 may be made of a material having no electrical conductivity. The anode support 10 may further include a metal felt layer 12 on an inner circumferential surface thereof.

The metal felt layer 12 may be formed to be porous to allow the fuel gas to pass therethrough and to function as a current collector to improve current collection efficiency. For example, the metal felt layer 12 may be a nickel (Ni) felt layer mainly containing nickel (Ni).

An inner circumferential surface of the metal felt layer 12 may be provided with a metallic wire 16 spaced apart at a predetermined interval. The metallic wire 16 may be a nickel (Ni) wire mainly containing nickel (Ni). However, the metallic wire 16 may be formed of silver (Ag) wire containing silver (Ag) as a main component in a highly corrosive environment. The metallic wire 16 may be any one of a metal, an alloy, a mixture of metals and alloys, or a mixture of metal oxides and metals to collect internal current of the cylindrical solid oxide fuel cell 100. For example, the metallic wire 16 may be any one of Au, Pd, Pt, Ni, Ru, Rh, Ir, or an alloy thereof. Preferably, the metallic wire 16 may be nickel (Ni).

The electrolyte layer 30 may be located on an outer circumferential surface of the anode support 10. The electrolyte layer 30 may be formed by coating a slurry prepared by mixing zirconia (ZrO ₂ ) -based powder, a binder, a homogeneous agent, a dispersant, a plasticizer, and a solvent on the anode support 10. The electrolyte layer 30 may be coated on the anode support 10 using dip coating, painting, or the like, or may be formed by a vacuum deposition method including a chemical vapor deposition method, a physical vapor deposition method, and the like. The electrolyte layer 30 may contact the fuel gas that has passed through the anode support 10. The electrolyte layer 30 may generate electrons through the fuel gas of the anode support 10 from the oxygen of the air to generate a current to the anode support 10. In this case, the anode support 10 may generate water by reacting oxygen ions transferred through the electrolyte layer 30 with hydrogen ions of the fuel gas.

The cathode layer 50 may be located on the electrolyte layer 30. The cathode layer 50 may be formed in a multilayer structure. For example, the cathode layer 50 may be formed of an LSM-YSZ layer, an LSM layer, and an LSCF layer sequentially. The cathode layer 50 may be coated by the same dip coating or painting method as the electrolyte layer 30 or may be coated by screen printing. The cathode layer 50 may be formed of a porous material so that air containing oxygen may pass therethrough. Air passing through the cathode layer 50 may contact the electrolyte layer 30. The electrolyte layer 30 may have a dense structure to prevent the air and the fuel gas from being mixed.

The internal current collector 70 may have a plurality of rod shapes and may be located inside the anode support 10. The internal current collector 70 may be electrically connected to the anode support 10 to collect current generated from the anode support 10. The internal current collector 70 may be formed of a metal material having high conductivity to reduce the conductive resistance inside the unit cell 80 and to reduce the contact resistance between the unit cell 80 and the internal current collector 70. Can be. For example, the internal current collector 70 may be formed of nickel (Ni), stainless steel, steel, or the like in consideration of structural stability and electrical conductivity. The internal current collector 70 may have a plurality of rod shapes corresponding to the shape of the unit cell 80. The internal current collector 70 may compress the metallic wire 16 to the inner circumferential surface of the metal felt layer 12 and may also function as a current collector. The internal current collector 70 may reduce the resistance of the nickel (Ni) wire, thereby reducing internal resistance of the solid oxide fuel cell unit cell 80 and improving power generation efficiency.

In one embodiment according to the spirit of the present invention, the internal current collector 70 may be variously modified. The internal current collector 70 which can be variously modified as described above will be described with reference to FIG. 4. Here, the modified portion will be mainly described in comparison with the above-described embodiment.

4 is a conceptual longitudinal cross-sectional view of an internal current collector according to a modified example of the technical idea of the present invention.

Referring to FIG. 4, in another embodiment of the inventive concept, the internal current collector 70 ′ may include a plurality of wires. The plurality of wires may be located inside the anode support 10. The internal current collector 70 ′ may be electrically connected to the anode support 10 to collect current generated from the anode support 10. The internal current collector 70 ′ may be formed of nickel (Ni), stainless steel, steel, or the like in consideration of structural stability and electrical conductivity.

Meanwhile, in one embodiment and one modified example of the technical concept of the present invention, the internal current collectors 70 and 70 'are each composed of a plurality of rods or a plurality of wires, but the present invention is not limited thereto. Alternatively, the internal current collectors 70 and 70 'may be configured with a plurality of rods or wires inside the anode support 10.

Using the anode support 10 of the same cylindrical solid oxide fuel cell module 100, the unit cell 80 having the internal current collector 70 and the unit cell 80 having no internal current collector 70 are provided. The kind was produced.

As a result of comparing the performance of the unit cell 80, as shown in FIG. 5, it can be seen that the performance of the unit cell 80 provided with the internal current collector 70 is high.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood that the invention may be practiced. It is therefore to be understood that one embodiment described above is illustrative in all aspects and not restrictive.

100; Cylindrical solid oxide fuel cell module 10; Anode support
12; Metal felt layer 16; Metallic wire
30; An electrolyte layer 50; Cathode layer
70, 70 '; Internal current collector 80; Unit cell

Claims (13)

An anode support;
An electrolyte layer positioned on an outer circumferential surface of the anode support;
A cathode layer positioned on the electrolyte layer; And
Including an internal current collector located inside the anode support,
The fuel electrode support,
A metal felt layer formed to be porous to allow fuel gas to pass therethrough and function as a current collector; And
It is provided on the inner circumferential surface of the metal felt layer spaced apart from each other, and comprises a metallic wire for collecting the internal current,
The internal current collector,
A cylindrical solid oxide fuel cell module inserted into the anode support and having an outer circumferential surface in contact with the metallic wire to reduce resistance.
The method of claim 1,
The internal current collector is a cylindrical solid oxide fuel cell module consisting of a plurality of rod (rod) shape.
The method of claim 1,
The internal current collector is a cylindrical solid oxide fuel cell module consisting of a plurality of wire (wire) shape.
The method of claim 1,
The internal current collector is a cylindrical solid oxide fuel cell module formed of a conductive metal material.
5. The method of claim 4,
The conductive metal material is a cylindrical solid oxide fuel cell module comprising any one of nickel (Ni), stainless or steel.
The method of claim 1,
Wherein the metal felt layer is a nickel (Ni) felt layer cylindrical solid oxide fuel cell module.
The method of claim 1,
The metallic wire is a cylindrical solid oxide fuel cell module comprising any one of a metal, an alloy, a mixture of metal and alloy, or a mixture of metal oxide and metal.
8. The method of claim 7,
The metallic wire is a nickel (Ni) wire cylindrical solid oxide fuel cell module.
The method of claim 1,
The metallic wire is a cylindrical solid oxide fuel cell module comprising any one of Au, Pd, Pt, Ni, Ru, Rh, Ir or alloys thereof.
The method of claim 1,
And the internal current collector is electrically connected to the anode support to collect current generated from the anode support.
The method of claim 1,
The internal current collector serves to compress the metallic wire to the inner peripheral surface of the metal felt layer and at the same time function as a current collector of the cylindrical solid oxide fuel cell module.
Unit cell;
Including an internal current collector that is located inside the unit cell,
The unit cell includes:
A fuel cell support including a metal felt layer functioning as a current collector and a metallic wire collecting internal current;
An electrolyte layer positioned on an outer circumferential surface of the anode support; And
It includes a cathode layer located on the electrolyte layer,
The internal current collector,
A cylindrical solid oxide fuel cell comprising a plurality of rods or wires in contact with the metallic wire and formed of a conductive metal material.
13. The method of claim 12,
The conductive metal material is a cylindrical solid oxide fuel cell comprising any one of nickel (Ni), stainless steel or steel.

Images