KR20140020065A - Solid oxide fuel cell anode metal support and method for manufacturing the same - Google Patents

Abstract

The present invention provides a method for manufacturing an anode metal support for a fuel cell, comprising: a step for supplying a flexible and conductive base plate, which is provided as an anode, to an electrolyte including metal ions in one horizontal direction; an electro-deposition step for forming an electro-deposition layer on the base plate by electro-depositing metal ions in an electrolyte on one surface or both surfaces of the base plate via the reaction of the base plate and a cathode which is installed on one surface or both surfaces of the base plate to be separated from each other; and an exfoliation step for obtaining a metal foil by exfoliating the electro-deposition layer from the base plate, wherein the metal foil has a porous structure. Further, the present invention provides an anode metal support for a fuel cell manufactured thereby, having a thickness of 30 to 200 μm. The present invention can reduce the production costs of the metal support and can facilitate mass production by using the method for manufacturing an anode metal support for a solid oxide fuel cell. Also, the present invention can provide a metal support for a solid oxide fuel cell having excellent strength and impact characteristics because the pore size and distribution of the metal support can be adjusted easily and cracks on the surface of the metal support can be reduced.

Description

Solid oxide fuel cell anode metal support and method for manufacturing the same}

The present invention relates to an anode metal support for a solid oxide fuel cell.

A solid oxide fuel cell includes a fuel cell / electrolyte / air electrode as a basic unit cell, and a power generation capacity obtained from one cell per unit area is about 1V. Therefore, in order to produce the output required for the actual power generation facility, a plurality of unit cells are connected in series and in parallel, and a stack is formed by inserting a separator and a current collector between the cells and the cells. However, as the area of the unit cell increases, the efficiency of the unit cell decreases, and the fracture toughness against sealing, thermal shock, and physical shock is low, making it difficult to commercialize fuel cells. In particular, in the case of the ceramic support type solid oxide, it is very vulnerable to impact because of its fundamentally low fracture toughness, and to solve this problem, a metal support type solid oxide fuel cell has been developed.

The anode metal support used in the solid oxide fuel cell is required to have high electrical conductivity, to secure a fuel injection path to the anode, to have excellent impact characteristics, and to have a similar thermal expansion coefficient to that of the solid electrolyte material. Metal support manufacturing methods currently being researched include laser drilling and sintering of metal powders, which are difficult to mass-produce due to the formation of pores for each of the metal supports. In this case, it is difficult to uniformize the distribution of pores, and there is a fear of causing microcracks at the grain boundaries and causing brittle fracture.

One aspect of the present invention provides a method for manufacturing a cathode metal support for a solid oxide fuel cell, which is easy to control the pore size and distribution of the metal support, and is capable of cost reduction and mass production, and provides an anode metal support for a solid oxide fuel cell having excellent strength and impact characteristics. I would like to.

According to an embodiment of the present invention, a horizontal supply of a flexible and conductive mother plate which is provided as a negative electrode and is provided as a negative electrode to an electrolyte solution including metal ions in one direction; The electrodeposition step and the electrodeposition layer in which an electrode layer is spaced on one side or both sides of the mother plate and the metal ions of the electrolyte are electrolytically deposited on one side or both sides of the mother plate to form an electrodeposition layer on the mother plate. And a peeling step of peeling from the mother plate to obtain a metal foil, wherein the metal foil is provided with a method of manufacturing a fuel cell metal support for a fuel cell having a porous structure.

The mother plate may be made of stainless steel or titanium, and an oxide film may be formed on one surface or both surfaces.

The mother plate may be a hole pattern formed on the surface.

The hole pattern may be formed through the surface of the mother plate.

The hole pattern may be formed by laser drilling.

The hole pattern may form an intaglio on the surface of the mother plate, and the intaglio may be filled with a non-conductive material.

The intaglio may be formed by an etching process.

The nonconductive material may be any one of an epoxy resin, alumina, silica, and mixtures thereof.

The electrolyte may be one containing 40-50g of Ni precursor or 40-50g of Ni precursor and 6-12g of Fe precursor per liter of water.

The Ni precursor may be any one of nickel sulfate, nickel chloride, nickel nitrate, nickel sulfamate, and mixtures thereof.

The Fe precursor may be any one of iron sulfate, iron chloride, iron nitrate, iron sulfamate, and mixtures thereof.

The electrolyte may further include at least one of boric acid, ammonia, and any one of a pH buffer and sodium dodecyl sulfate, sodium lauryl sulfate, saccharin, and a mixture of these.

The pH buffer may be included in 15 ~ 35g per 1L electrolyte.

Stress relieving agent may be included in 0.05 ~ 4g per 1L of electrolyte.

According to another embodiment of the present invention, a fuel cell anode metal support for a fuel cell manufactured by the above method is provided with a fuel cell anode metal support having a thickness of 30 ~ 200㎛.

The fuel cell metal support for the fuel cell may have a thermal expansion coefficient of 5 to 15 X 10 ^-6 / K.

The anode metal support for the fuel cell may have pores having an average diameter of 5 ~ 50㎛.

The anode metal support for the fuel cell may have an opening ratio of 10 to 90%.

By using the method of manufacturing the anode metal support for the solid oxide fuel cell of the present invention, mass production can be facilitated while reducing the manufacturing cost of the metal support. In addition, it is possible to easily control the size and distribution of the pores of the metal support, it is possible to reduce the cracks on the surface of the metal support to obtain the anode metal support for a solid oxide fuel cell excellent in strength and impact characteristics.

Figure 1 schematically shows a horizontal type electric casting apparatus for producing a cathode metal support for a solid oxide fuel cell of the present invention.
2 is a SEM photograph (80 magnification) of the surface of the metal oxide support of the solid oxide fuel cell of the present invention.
Figure 3 shows a SEM photograph (1500 magnification) of the surface of the metal oxide support of the solid oxide fuel cell of the present invention.

The present invention relates to an anode metal support for a solid oxide fuel cell and a method of manufacturing the same. When using the method of manufacturing a fuel cell metal support for a fuel cell of the present invention, it is possible to easily adjust the size and distribution of the pores, and to improve the strength and impact characteristics of the metal support, while reducing the defects caused by the destruction of the material, It can be easier to produce.

FIG. 1 schematically illustrates a horizontal type electroforming apparatus for manufacturing a metal support of a solid oxide fuel cell of the present invention, and will be described in detail with reference to the drawing.

According to an embodiment of the present invention, a horizontal supply of a flexible and conductive mother plate which is provided as a negative electrode and is provided as a negative electrode to an electrolyte solution including metal ions in one direction; The metal ions of the electrolyte are electrolytically deposited on one side or both sides of the mother plate 1 by the action of the anode 53 and the mother plate 1, which are spaced apart from one side or both sides of the mother plate 1, and thus the mother plate 1. And a peeling step of peeling the electrodeposited layer from the mother plate 1 to obtain a metal foil 74, wherein the metal foil has a porous structure. do.

Brief description of the horizontal type electric casting device of Figure 1 as follows. When the mother plate 1 is put into the horizontal type electric casting device, the mother plate can be joined by the bonding device 2 and supplied continuously. In the mother board 1 bonded by the bonding apparatus, a hole pattern is formed on the surface of the processing apparatus 3, and the remaining workpiece, processing liquid or processing residues, etc., remaining on the surface of the mother board are removed by the pre-cleaning apparatus 4 thereafter. do. The washed base plate 1 receives a current from the current supply device 51 through a conductor roll 52 which is transferred into a horizontal cell and functions as a cathode. The electrolyte solution in the electrolyte reservoir 57 heated by the electrolyte heater 58 is supplied to the mother plate 1 through the electrolyte supply nozzle 54 through the electrolyte filter 56 and the electrolyte pump 55, and to the electrolyte solution. The electrodeposition layer is formed on the surface of the mother plate by the action of the immersed mother plate 1 and the anode 53. The base plate in which the electrodeposition layer is formed may pass through the post-cleaning apparatus 5 to remove impurities on the electrodeposition layer. The base plate on which the electrodeposition layer is formed is separated into the base plate 1 and the metal foil 74 by the metal foil separation device 71, and the metal foil 74 is cut and wound up by the metal foil cutting device 72. The separated base plate 1 is cut by the base plate cutting device 73 and then wound up by the winding device 6.

Electroforming method is to deposit a metal on a model to which a peeling film has been applied, and then remove the electrodeposited metal to obtain a product having an uneven surface opposite to the model surface, or to separate the electrodeposited metal surface by separating and coating the metal. It is a method of obtaining a product having the same irregularities as the first model by electrodeposition and separation. In forming the metal foil by electroforming, the base plate 1 that can be used for forming the metal foil can be used without particular limitation as long as it is flexible and has conductivity. For example, stainless steel, titanium, or the like can be applied. It is preferable that the oxide film is formed in the surface of such a base plate 1. The present invention seeks to obtain a metal foil. When the metal foil 74 formed by electrodeposition on the base plate 1 has a rigid bond with the base plate 1, it is not easy to separate the metal foil from the base plate 1. Therefore, it is preferable that the oxide film is formed on the base plate 1. By the oxide film on the mother board 1, even if the metal foil is electrodeposited on the mother board 1, since the adhesion to the surface of the mother board 1 is weak, the metal foil can be easily peeled from the mother board 1.

The surface of the mother plate 1 may be a hole pattern formed on the surface, it may be subjected to the step of processing the surface of the mother plate 1 to give the hole pattern. When providing a hole pattern to the surface of the mother board 1, the metal foil 74 obtained by electrodeposition can transfer the hole pattern formed in the mother board 1 as it is, and can provide a constant pore to the metal foil 74 obtained. Since the processing of the mother plate 1 can be carried out on both sides of the mother plate 1, it is possible to give a hole pattern through the processing on both sides of the mother plate (1).

The hole pattern formed on the base plate 1 may be formed to penetrate the surface of the base plate, and the processing means is not particularly limited, and any suitable processing means known in the art may be applied. For example, the hole pattern may be formed by laser drilling.

In addition, the hole pattern formed on the mother plate 1 may form an intaglio on the surface of the mother plate, and the intaglio may be filled with a non-conductive material. The means for forming the intaglio is not particularly limited, but any suitable processing means known in the art may be applied. For example, the intaglio may be formed by an etching process.

The non-conductive material is not particularly limited, and materials having low electrical conductivity known in the art may be used. For example, the non-conductive material may be any one of an epoxy-based polymer resin, an oxide such as alumina or silica, and a mixture thereof. . In addition, any other insulating polymer material that can be easily used by those skilled in the art can be used in the present invention.

In the case of electroforming by supplying an electrolyte solution to the mother plate formed by the above-described method to form a hole pattern, the electrode pattern is not formed in the formed hole pattern, the hole pattern is transferred to form pores to form the metal foil 74 of the porous structure You can get it. When manufacturing the metal support by the manufacturing method of the present invention, there is no need to perform a process for forming pores separately in the resulting anode metal support, mass production is easy, and manufacturing cost can be reduced.

In the case where the surface of the mother plate is processed as described above, in order to obtain a uniform metal foil, it is sometimes necessary to remove the processing material, processing liquid or processing residues remaining on the surface of the mother plate from the surface of the mother plate. It may include. The washing of the surface of the mother plate is not particularly limited and can be removed using an acidic solution and water. Thereafter, the mother board can be dried by blowing high pressure air, hot gas, or heating the mother board.

The base plate is continuously supplied into the pole cell, and is supplied in a constant direction. Here, the "electrode cell" may be defined as a unit cell in which a mother plate is supplied into an electrolyte solution and metal ions are electrodeposited onto the mother plate surface by an electrolytic precipitation reaction to form an electrodeposition layer. In addition, the term “constant direction” means that the mother plate proceeds in one direction without changing the advancing direction of the mother plate until the mother cell is supplied into the pole cell and at least exits the horizontal cell. In this specification, the advancing direction of the mother plate may be referred to as 'horizontal direction' or simply 'horizontal' in some cases. Furthermore, the mother plate may advance the pole cell in the horizontal direction so that metal ions in the electrolyte are electrolytically deposited on the mother plate. In order to indicate that the pole cell is also referred to as a 'horizontal cell'.

For the continuous supply of the base plate 1, the base plate is not necessarily limited to this, but can be supplied into the horizontal cell to the base plate 1 wound in the form of a coil, furthermore, if such a base plate 1 is supplied The base plate 1 wound in the form of a coil can be continuously supplied following the previously supplied base plate. At this time, if necessary, the rear end of the preceding base plate 1 and the front end of the subsequent base plate can be joined by a predetermined bonding device 2 such as welding and continuously supplied. Furthermore, in order to easily join, each terminal joined can also be processed to a suitable shape.

The base plate is supplied horizontally into the horizontal cell by a pair of conductor rolls 52 which contact the widthwise edge portion of the base plate to transfer the base plate into the horizontal cell. At this time, it is possible to perform one side electric pole by installing an anode on one side of the mother plate supplied into the horizontal cell, and by installing the anode on both sides to increase the production rate of the metal foil by electrolytic deposition of metal on both sides of the mother plate. You can.

When the mother plate 1 is supplied into the horizontal cell as described above, the electrolyte is supplied to one or both sides of the mother plate 1 through the electrolyte supply nozzle 54, and the mother plate 1 and the anode 53 are immersed in the electrolyte. do. As the electrolyte moves through the horizontal flow path formed by the base plate 1 and the positive electrode 53, metal ions are deposited on the surface of the base plate by electrolytic deposition by the base plate 1 and the positive electrode 53, which serve as negative electrodes. Form a layer.

The electrolyte solution may include 40-50 g of Ni precursor or 40-50 g of Ni precursor and 6-12 g of Fe precursor per 1 L of water, and the electrolyte may more preferably include both Ni precursor and Fe precursor. Since Ni is excellent in electrical conductivity and Fe has excellent strength or hardness and is flexible at the same time, cracking or breaking due to physical impact does not occur well, which is advantageous in terms of securing heat dissipation and durability. In addition, manufacturing costs are low, mass production is possible, and storage and substrate size control are easy.

The Ni or Fe precursor contained in the electrolyte is not particularly limited, and suitable ones known in the art may be used. For example, the Ni precursor may use any one of nickel sulfate, nickel chloride, nickel nitrate, nickel sulfamate, and mixtures thereof. In addition, the Fe precursor may be any one of iron sulfate, iron chloride, iron nitrate, iron sulfamate and mixtures thereof.

The electrolyte solution may further include a pH buffer which is any one of boric acid, ammonia, and mixtures thereof. However, the pH buffer is not limited thereto, and those known in the art may be appropriately used. The pH buffer may be effectively electrodeposited Fe and Ni ions to the cathode during electroforming by adjusting the pH of the electrolyte to 1.5 ~ 3.5. In order to obtain such an effect, the pH buffer is preferably contained in 15 ~ 35g per 1L of electrolyte.

The electrolyte may further include a stress relieving agent which is any one of a surfactant such as sodium dodecyl sulfate and sodium lauryl sulfate, saccharin and mixtures thereof. The stress relaxation agent is not limited thereto, and those known in the art may be appropriately used. The stress relieving agent reduces the stress of the metal foil so that the metal foil can be easily detached from the mother plate. In order to obtain such an effect, the stress relaxation agent is preferably contained in an amount of 0.05 to 4 g per 1 L of the electrolyte.

Preferably, the electrolyte solution further includes at least one of the pH buffer and the stress buffer. Moreover, it is preferable to manage the temperature of electrolyte solution at 50-60 degreeC.

The method of manufacturing a fuel cell metal support for a fuel cell includes a step of peeling the electrodeposition layer from the mother plate 1 to obtain a metal foil 74. In order to separate an electrodeposition layer from the mother board 1, it can isolate using the difference of the shear stress of the mother board 1 and an electrodeposition layer. Since the electrodeposition layer formed by electrodeposition on the mother board 1 is bonded by surface tension with respect to the mother board which has an oxide film, it can isolate easily by this. Separation of the electrodeposition layer by such a shear stress difference can be carried out by passing through a plurality of rollers. Furthermore, a difference in the moving speed of the metal foil 74 and the moving speed of the base plate 1 may be generated to separate and generate a shear force. On the other hand, when electrodeposition is performed on both sides of the mother board 1, the upper and lower metal foils 74 may be separated at the same time or may be separated by giving a time difference.

Although the metal foil 74 obtained in this way can be wound up and obtained, it can cut | disconnect appropriately according to the winding amount. Furthermore, the electrode plate 1 from which the electrodeposition layer is separated can also be wound up and reused as the mother plate 1. However, the separated base plate 1 may have an electrolyte solution or other impurities in the electrodeposition process, and it is preferable that the surface of the base plate 1 is kept clean by drying after washing. Furthermore, when the mother plate 1 is bonded for continuous supply of the mother plate 1, the mother plate 1 can be cut to an appropriate length according to the winding amount of the mother plate 1, and at this time, it is preferable to cut based on the bonding portion.

As another embodiment of the present invention, a fuel cell anode metal support for a fuel cell manufactured by the above method is provided with a fuel cell anode metal support having a thickness of 30 ~ 200㎛.

Preferably, the anode metal support has a thickness of 30 to 200 μm. When the anode metal support is less than 30 μm, the metal support may not secure sufficient structural stability, may be difficult to handle in the process, and absorb the occurrence of tolerances in the stack configuration. There is a difficulty. If it exceeds 200㎛ has a disadvantage in that the productivity is lowered when compared to the technology for manufacturing the metal support by rolling after processing.

The anode metal support is Ni or Fe-Ni alloy composition, when the Fe-Ni alloy composition, the Ni content is preferably 40 to 90% by weight. The thermal expansion coefficient may be optimized by controlling the Ni content, and the thermal expansion coefficient is not particularly limited, but the thermal expansion coefficient is preferably 5 to 15 × 10 ⁻⁶ / K. The metal support should be controlled to a level similar to the coefficient of thermal expansion of the cell components, which is dependent on the difference in stress applied to the metal support or the materials deposited thereon as the temperature rises or falls. This may be due to cracks or fractures. When the Ni content is out of the above range, the difference in thermal expansion coefficient becomes large, which may cause deterioration of characteristics of the cell electrode due to thermal stress.

The metal support may have pores having an average diameter of 5 to 50 μm. When the metal support is out of the above range, it is difficult to manufacture a cell by collapsing in the process of raising the positive electrode and the electrolyte on the metal support. The lower layer portion in contact with the current collector may be 50 µm or more. In addition, the pore size and distribution should be uniformly controlled, otherwise the power generation efficiency is lowered and it is difficult to secure stable power.

The metal support is preferably formed so that the opening ratio is 10 to 90%. If the opening ratio is less than 10%, power generation efficiency required for the fuel cell may not be obtained, and if the opening ratio is higher than 90%, the strength of the metal support may be inferior.

Hereinafter, the present invention will be described more specifically by way of specific examples. The following examples are provided to aid understanding of the present invention, and the scope of the present invention is not limited thereto.

[Example]

50 g of nickel chloride, 12 g of iron chloride, 20 g of boric acid and 0.4 g of saccharine were added per liter of water to prepare an electrolytic solution of the present invention. The electrolytic solution was electroformed at pH 2.0 and 55 ° C.

A stainless steel mirror steel sheet was used as the mother plate, and the hole was processed by laser drilling in the thickness direction, and the hole pattern was formed by engraved epoxy resin. The formed hole pattern had an average diameter of pores of 30 μm and a pore distribution density of 1%.

The mother plate was placed in the horizontal electroforming apparatus of FIG. 1 and electroformed at a current density of 5 A / dm 2 to form Fe—Ni electrodeposition layers on both sides of the mother plate. The formed Fe—Ni electrodeposition layer was separated to obtain a Fe—Ni metal foil having a thickness of 50 μm.

SEM photographs were taken of the prepared metal foil surface at 80 times and 1500 times, respectively, and are shown in FIGS. 2 and 3, respectively.

With reference to the control of the uniform size and distribution of pores from the above Figures 2 and 3, it can be seen visually that the metal support produced using the present invention has uniform and even pores.

As can be seen from this, using the solid oxide fuel cell metal support manufacturing method of the present invention, it is possible to produce a metal support having a uniform size and distribution of pores, and excellent strength and impact characteristics.

1: bed
2: splicer
3: processing equipment
4: pre-washing device
5: after washing device
6: winding device
51: current supply device (rectifier)
52: conductor roll
53: anode
54: electrolyte supply nozzle
55: electrolyte pump
56: electrolyte filter
57: electrolyte reservoir
58: electrolyte burner
71: metal foil separator
72: metal foil cutting device
73: bed cutting device
74: Metal foil

Claims (18)

Horizontally supplying a flexible and conductive mother plate in one direction to the electrolyte solution including the metal ions as a cathode;
An electrodeposition step in which metal ions of the electrolyte are electrolytically deposited on one or both surfaces of the mother plate by the action of the anode and the mother plate spaced apart from one or both sides of the mother plate to form an electrodeposition layer on the mother plate;
And a peeling step of peeling the electrodeposited layer from the mother plate to obtain a metal foil, wherein the metal foil has a porous structure. The method of claim 1, wherein the mother plate is made of stainless steel or titanium, and an oxide film is formed on one surface or both surfaces. The method of claim 1, wherein the mother plate has a hole pattern formed on a surface thereof. The method of claim 3, wherein the hole pattern is formed through the surface of the mother plate. The method of claim 4, wherein the hole pattern is formed by laser drilling. The method of claim 3, wherein the hole pattern is formed on the surface of the mother plate, and the negative electrode is filled with a non-conductive material. The method of claim 6, wherein the intaglio is formed by an etching process. The method of claim 6, wherein the nonconductive material is any one of an epoxy resin, alumina, silica, and a mixture thereof. The method of claim 1, wherein the electrolyte solution comprises 40-50 g of Ni precursor or 40-50 g of Ni precursor and 6-12 g of Fe precursor per liter of water. 10. The method of claim 9, wherein the Ni precursor is any one of nickel sulfate, nickel chloride, nickel nitrate, nickel sulfamate, and a mixture thereof. The method of claim 9, wherein the Fe precursor is any one of iron sulfate, iron chloride, iron nitrate, iron sulfamate, and a mixture thereof. The method of claim 9, wherein the electrolyte further comprises at least any one of boric acid, ammonia and mixtures thereof, pH buffer and any one of sodium dodecyl sulfate, sodium lauryl sulfate, saccharin and mixtures thereof. Method for producing a fuel cell metal support for a fuel cell. 13. The method of claim 12, wherein the pH buffer is contained in an amount of 15 to 35 g per 1 L of the electrolyte. 13. The method of claim 12, wherein the stress relaxation agent is contained in an amount of 0.05 to 4 g per 1 L of the electrolyte. A fuel cell anode metal support for a fuel cell manufactured by the method of any one of claims 1 to 14, having a thickness of 30 to 200㎛. The anode metal support for a fuel cell according to claim 15, wherein the coefficient of thermal expansion is 5 to 15 X 10 ^-6 / K. 16. The anode metal support for a fuel cell according to claim 15, wherein the fuel cell has pores having an average diameter of 5 to 50 µm. 16. The anode metal support for fuel cell according to claim 15, wherein the aperture ratio is 10 to 90%.

Images