KR20150010165A - Flat-type solid oxide fuel cell with multi-cell structure and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a solid oxide fuel cell of a multi-cell structure, and more specifically, to a flat-type solid oxide fuel cell comprising: a supporter; and at least one multi-cell end cell including a plurality of cell units equipped on an upper part of the supporter, wherein the cell units comprise an anode, an electrolyte, a cathode, and a connecting material, and the supporter is non-conductive. According to the present invention, the solid oxide fuel cell can implement high voltage, low price of the end cell, and high endurance.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a flat-type solid oxide fuel cell having a multi-cell structure and a method of manufacturing the same.

The present invention relates to a planar solid oxide fuel cell having a multi-cell structure and a method of manufacturing the same.

Recently, as the exhaustion of existing energy resources such as oil and coal is predicted, interest in energy that can replace them is increasing. As one of such alternative energies, fuel cells are attracting particular attention due to their advantages such as high efficiency, emission of pollutants such as NO _x and SO _x , and abundant fuel.

A fuel cell is a power generation system that converts the chemical reaction energy of a fuel and an oxidizer into electric energy. Hydrogen, hydrocarbons such as methanol and butane are used as fuel, and oxygen is used as an oxidant. Unlike conventional power generation technologies that involve fuel, combustion, steam generation, and turbine driving, fuel cells have a new concept of power generation technology that does not cause environmental problems as well as high efficiency because there is no process of fuel combustion or turbine drive .

The fuel cell can be classified into a polymer electrolyte membrane fuel cell (PEMFC), a phosphoric acid fuel cell (PAFC), a molten carbonate fuel cell (MCFC), a solid oxide fuel And a solid oxide fuel cell (SOFC).

A typical solid oxide fuel cell is composed of an oxygen ion conductive electrolyte, an air electrode and a fuel electrode located on both sides thereof, and its operation principle is as follows. The oxygen atoms in the air electrode are converted into oxygen ions by the reduction reaction of receiving two electrons, and the oxygen ions move to the fuel electrode through the electrolyte. In the fuel electrode, water is generated by reacting with oxygen ions and hydrogen supplied. At this time, electrons are generated in the fuel electrode and electrons are consumed in the air electrode. Therefore, when the two electrodes are connected to each other through an external circuit, It is the principle of the cell reaction.

On the other hand, the solid oxide fuel cell can be classified into a cylindrical type and a flat plate type. Plate-type solid oxide fuel cells are mainly composed of one unit cell, and are being widely used to facilitate distributed generation or large-capacity power generation.

On the outer circumferential surface in the case of the cylindrical support, on the upper and lower surfaces in the case of the flat plate-like support, a power generation portion having a laminated structure of the fuel electrode, the electrolyte and the air electrode is formed.

Since the plate-type single cell has lower internal resistance and higher power density than cylindrical type, it is suitable for high-efficiency power generation and has a high productivity. In addition, it is relatively easy to thin the electrolyte. In order to build a large-area stack suitable for power generation, The number of unit cells is required, and there is also a problem due to the limitation of the durability of the support.

Korean Patent Publication No. 2005-0099558

Accordingly, there is a need in the art for a solid oxide fuel cell that increases the efficiency of a single cell, lowers manufacturing cost, and increases the durability of a support.

According to an embodiment of the present invention, there is provided a battery pack comprising at least one multi-cell unit cell comprising a support and a plurality of cell units provided on the support,

Wherein the cell unit includes a fuel electrode, an electrolyte, an air electrode, and a connection member,

Wherein the support is non-conductive.

Further, in one embodiment of the present disclosure, a method of manufacturing a multi-cell unit cell including a step of laminating a plurality of cell units on a support,

Wherein the cell unit comprises a fuel electrode, an electrolyte, an air electrode and a connecting material.

The planar solid oxide fuel cell having the multi-cell structure according to the present invention can realize a low voltage and a high durability of a unit cell with a minimum unit index.

1 is a cross-sectional view of a planar solid oxide fuel cell having a multi-cell structure according to an embodiment of the present invention.
2 is a plan view of a planar solid oxide fuel cell having a multi-cell structure.
3 is a cross-sectional view and a plan view of a structure in which a current collector is coupled to a multi-cell single cell, and a fuel electrode and an air electrode are connected to a current collector, respectively.
4 is a cross-sectional view and a plan view showing a structure in which a sealant is stacked on a collecting cell.

Hereinafter, the present invention will be described in detail.

In one embodiment of the present disclosure, the support is a nonconductive support.

In one embodiment of the present disclosure, the support is a ceramic support.

For example, the ceramic support may be alumina (Al ₂ O ₃ ). Specifically, it is not limited to zirconia (Doped ZrO ₂ ) doped with magnesia alumina (spinel, MgLa ₂ O ₄ ), zirconia (ZrO ₂ ), CaO or Y ₂ O ₃ or Sc ₂ O ₃ .

The ceramic support according to the present invention comprises a porous structure. In this case, gas supply to the electrode side can be smooth.

When the support is non-conductive, current does not flow to the support and the current collector, so that a current can be generated in series between the cell units.

1 is a cross-sectional view of a planar solid oxide fuel cell having a multi-cell structure according to an embodiment of the present invention.

2 is a plan view of a planar solid oxide fuel cell having a multi-cell structure.

A planar solid oxide fuel cell according to one embodiment of the present invention includes a multi-cell unit cell including a support 1, a fuel electrode 2, an electrolyte 3, an air electrode 4, and a connection member 5.

In one embodiment of the present invention, the planar solid oxide fuel cell includes at least two multi-cell unit cells, and further includes a current buffer layer between the at least two multi-unit cells.

In one embodiment of the present invention, the multi-cell unit cell includes a support and a plurality of cell units.

The plurality of cell units each comprising a fuel electrode; Electrolyte; Air electrode and connecting member.

In the plurality of cell units, the meaning of the "plurality" is n, and n is an integer of 2 or more. The n may be arbitrarily changed by a person skilled in the art according to the size of the multi-cell single cell to be used. Specifically, n is an integer of 2 to 100. In another embodiment, n is an integer from 10 to 80. In another embodiment, n is an integer from 20 to 30. [

In one embodiment of the present disclosure, the multi-cell unit cell comprises 2 to 10 cell units per 10 cm of the length of the support.

In one embodiment of the present specification, the plurality of cell units are connected in series with each other.

In one embodiment of the present invention, the planar solid oxide fuel cell further includes at least two multi-cell unit cells, and further includes a current buffer layer disposed between the multi-unit unit cells.

In one embodiment of the present invention, the at least two multi-cell unit cells are connected in parallel with each other.

In one embodiment of the present invention, the planar solid oxide fuel cell includes at least two multi-cell unit cells, the at least two multi-cell unit cells are stacked and connected in parallel, and the plurality of cell units are connected in series with each other .

In an embodiment of the present invention, when the cell units are connected in series to each other, the multi-cell unit cell including a plurality of cell units may include a plurality of cell units, And has a high voltage.

Therefore, the battery has a high voltage with a minimum number of unit cells, and thus a compact flat plate type solid oxide fuel cell can be provided.

In one embodiment of the present invention, the multi-cell unit cell includes a plurality of cell units provided on the support, the cell unit including a fuel electrode; An air electrode opposed to the fuel electrode; An electrolyte disposed between the fuel electrode and the air electrode; And a coupling member provided on the air electrode.

In one embodiment of the present invention, the electrolyte of the mth cell unit of the cell unit is provided between the fuel electrode of the mth cell unit and the air electrode of the mth cell unit, and between the mth fuel electrode and the m + 1th fuel electrode do.

In one embodiment of the present invention, the connector connects the plurality of cell units in series.

In one embodiment of the present invention, the connecting material of the mth cell unit among the plurality of cell units serially connects the mth air electrode and the (m + 1) th fuel electrode.

In one embodiment of the present invention, the connecting material of the mth cell unit is provided between one region of the mth air electrode and the mth electrolyte and the (m + 1) th electrolyte.

The unit cells included in the multi-cell structure may be connected to each other through a series connection of a planar electrode structure via the connection member.

According to an embodiment of the present invention, a current collector is provided in contact with both sides of the surface of the support having the plurality of cell units and both sides of the support.

In one embodiment of the present invention, the current collector contacts at least a part of the anode of the first cell unit, and contacts at least part of the cathode of the nth cell unit.

The meaning of "tangent" includes not only being directly tangent but also indirect tangent through the tangent.

In this specification, the current collector plays a role of facilitating the stacking of the multi-cell single cell as well as collecting the electrons of the fuel electrode and the air electrode. The collector may be made of a material used in the related art such as a metal.

In this specification, since electricity is extracted at both ends of the cells connected in series, the coupling members of the first and nth cell units are respectively provided in one region of the fuel electrode of one unit and in one region of the air electrode of the other unit do.

In one embodiment of the present invention, the connecting material of the first cell unit is provided in one area of the upper portion of the anode, and the connecting material of the nth cell unit is provided in one area of the upper portion of the air electrode.

In one embodiment of the present disclosure, the sealant is further provided on one side and one side of the upper portion of the connector.

The sealant separates the fuel gas and oxygen to maintain the performance of the fuel cell and prevent the formation of oxyhydrogen. As the sealant, generally known materials such as glass materials can be used.

In another embodiment, the air electrode of the (m + 1) th cell unit of the cell unit is spaced apart from the connecting material of the mth cell unit by a predetermined distance.

In this case, it is possible to prevent the mth air electrode and the (m + 1) th air electrode from contacting each other, and in the case of a dense structure, the air can be introduced into the air electrode.

In one embodiment of the present invention, the air electrode of the (m + 1) th cell unit and the connecting material of the mth cell unit of the cell unit are disposed in contact with each other. In the case of a porous structure, air can be introduced into the air electrode even if the air electrode and the connection member are in contact with each other.

In one embodiment of the present invention, gas channel segments are further provided on both sides of the at least two stacked multi-cell single cells, and the gas channel segments connect the at least two stacked multi-cell unit cells to each other in parallel.

In this specification, the gas channel segment can be used with the same material as the current collector, and serves as a gas passage as well as a parallel connection of the stacked multi-cell single cells.

In the present specification, m is an integer of 1 to n, and n is an integer of 2 or more.

Further, when using a multi-cell unit cell stacked with two or more layers, the output density per unit volume can be increased as compared with a single-layered multi-cell unit cell.

In one embodiment of the present invention, a current buffer layer is provided between the stacked multi-cell unit cells of two or more layers. In this case, sequential stacking is possible.

The cathode may be lanthanum or calcium-doped strontium doped lanthanum manganite (LSM); Lanthanum strontium cobalt iron oxide (LSCF ((La, Sr) (Co, Fe))); BSCF ((Ba, Sr) (Co, Fe)); Ceria doped with at least one of gadolinium, samarium, lanthanium, ytterbium and neodymium; And perovskite doped with at least one of platinum, nickel, palladium, silver, lanthanum, strontium, barium and cobalt, but the present invention is not limited thereto.

The fuel electrode may be made of a mixed material of nickel oxide (NiO) and yttria stabilized zirconia (YSZ), but is not limited thereto.

The electrolyte is a hydrocarbon-based polymer, fluorinated polymer, yttria stabilized zirconia, (La, Sr) (Ga , Mg) O 3, Ba (Zr, Y) O 3, GDC (Gd doped CeO 2), YDC (Y 2 O _3- doped CeO ₃ ), YSZ (Yttrium stabilized zirconia), Scandium stabilized zirconia (ScSZ), and the like.

The connecting material may be a noble metal having good conductivity such as silver (Ag), platinum (Pt), nickel (Ni) or the like, or a mixture of these noble metals and a glass sealing material, or an air electrode (perovskite structure having high- Stainless steel (SUS), superalloys and the like are used, but the present invention is not limited thereto.

In one embodiment of the present disclosure, the current buffer layer is insulating.

In the present specification, the current buffer layer is silicon oxide (SiO _x), silicon nitride (Si _x N _y), aluminum oxide (Al _x O _y), magnesium oxide (Mg _x O _y), titanium oxide (Ti _x O _y ), Zirconium oxide (Zr _x O _y ), cerium oxide (Ce _x O _y ), lanthanum gallate, barium cerate, barium zirconate, Phase, but is not limited thereto.

The buffer layer serves as a buffer layer for insulation and thermal expansion. Here, the buffer layer for thermal expansion means a buffer layer for suppressing stress due to thermal expansion. Accordingly, since the current buffer layer is provided between the multi-cell unit cell and the connecting material, it is possible to prevent a short-circuit occurring vertically between the multi-cell unit.

In the present invention, both ends of the multi-cell structure are connected by using ceramic segments, metal segments, or the like for current collection.

The segment is formed of a conductive ceramic or metal segment, and preferably has a reduction resistance and oxidation resistance because it is in contact with a fuel gas containing hydrogen and air.

Specifically, the segment may be a lanthanum chromite-based perovskite-type oxide (LaCrO ₃ -based oxide) or a conductive ceramic connecting material doped with calcium, strontium, magnesium, cobalt, aluminum or the like; Based ferrite based ferrite (STS), austenitic stainless steel (Austenitic STS), Fe-based superalloy (FeBSA), Ni based on Cr Ni-base superalloy (NiBSA), and the like, but is not limited thereto.

The segment serves to supply the gas flow path, and has a groove in which the gas flow path can be supplied. The shape of the groove is not limited.

In this specification, a manufacturing method of a planar solid oxide fuel cell is as follows.

According to an embodiment of the present disclosure, there is provided a method of manufacturing a multi-cell unit comprising the step of laminating a plurality of cell units on a support,

The cell unit includes a fuel electrode, an electrolyte, an air electrode, and a connection member.

In the present specification, in the step of manufacturing two or more of the multi-cell unit cells, the cell unit may include stacking an electrolyte on the fuel electrode; Stacking an air electrode on the electrolyte; And laminating a coupling material on the air electrode.

According to an embodiment of the present invention, there is provided a method of manufacturing a multi-cell unit comprising the steps of: And a current buffer layer between the at least two multi-cell single cells.

In one embodiment of the present invention, in the step of manufacturing two or more of the multi-cell unit cells, the plurality of cell units are stacked to be connected in series.

In one embodiment of the present invention, the step of fabricating the multi-cell unit cell includes connecting the plurality of cell units in series with the connector.

In one embodiment of the present invention, the method further includes connecting the at least two multi-cell unit cells in parallel.

According to an embodiment of the present invention, the method includes stacking two or more layers of the multi-cell unit cells, and further providing a current buffer layer between the multi-cell unit cells of two or more layers. And further includes gas channel segments on both sides of the stacked multi-cell single cells.

In one embodiment of the present disclosure, the method further comprises parallelly connecting both sides of the at least two multi-cell single cells to a gas channel segment.

3 is a cross-sectional view and a plan view of a structure in which a current collector is coupled to a multi-cell single cell, and a fuel electrode and an air electrode are connected to a current collector, respectively. Specifically, the multi-cell unit cell and the current collector having the gas passage are combined to collect the fuel electrode and the air electrode respectively with the current collector.

4 is a cross-sectional view and a plan view showing a structure in which a sealant is stacked on a collecting cell. Specifically, the collector can be manufactured by laminating a sealant of a glass material for separating the fuel gas and the air gas from the collecting cell by combining the current collector.

In one embodiment of the present invention, the support of the cell unit is nonconductive.

In this specification, the support can be produced using a general molding method, which is a cheap non-conductive ceramic. In the present specification, the support can be manufactured using a general molding method. For example, it can be manufactured by a method such as tape-casting, extrusion molding, or pressing, but is not limited thereto.

In this specification, the negative electrode (anode) may be manufactured using a film coating method. For example, it can be produced by a method such as tape-casting, screen-printing, spray coating or ink-jet printing, but is not limited thereto.

In this specification, the cathode (cathode) may be manufactured using a film coating method. For example, it can be produced by a method such as tape-casting, screen-printing, spray coating or ink-jet printing, but is not limited thereto.

In this specification, the electrolyte may be prepared using a film coating method. For example, it can be produced by a method such as tape-casting, screen-printing, spray coating or ink-jet printing, but is not limited thereto.

The solid oxide fuel cell has low overvoltage based on the activation polarization and low irreversible loss, so the power generation efficiency is high. In addition, since the reaction rate at the electrode is high, expensive noble metal is not required as an electrode catalyst.

Since the solid oxide fuel cell operates at a high temperature of 600 to 1000 ° C., the power conversion efficiency is the highest among the conventional fuel cells.

Unlike a phosphoric acid fuel cell or a polyelectrolyte fuel cell, which is operated at a temperature of 200 ° C or lower, due to the high-temperature operation, the reaction can be accelerated without using expensive platinum catalyst, and the reforming reaction of the fuel at the fuel electrode side at high temperature It is possible to directly use fuel such as natural gas and coal gas in addition to hydrogen.

In addition, it is possible to improve the efficiency of the entire power generation system by performing the arrangement recovery and the combined power generation using the discharged waste heat.

In particular, unlike a molten carbonate fuel cell, a liquid electrolyte is not used, so there is no problem of corrosion of materials, loss of electrolytes, and thus no problem of replenishment.

Another embodiment is characterized in that one support and a plurality of cell units are provided on the support.

And a current collector of the cell unit, wherein the current collector connects the plurality of cell units in series.

By virtue of this feature, the advantages of the planar solid oxide single cell are maintained, but the low voltage and high durability of the unit cell can be realized by using a high-voltage material with a minimum number of unit cells, .

In addition, two or more multi-cell unit cells are laminated, and a current buffer layer is provided between the multi-cell unit cells. The current buffer layer has an insulating property. Due to this characteristic, it is possible to prevent a short circuit occurring between the cell units included in the multi-cell single cell in the vertical direction between the series-connected multi-cell units.

Further, two or more multi-cell unit cells are stacked, and each multi-cell unit cell is connected in parallel with a connecting member. Because of this feature, there is an effect that the connection between the disconnected multi-cell unit due to the insulating current buffer layer is maintained.

In addition, compared with the flat tubular fuel cell, the stack can be fastened in a simple laminated form, and a compact fuel cell can be provided even if the lamination is large.

In particular, the compact single cell design has features suitable for easy stacking applications in residential distributed generation systems.

1 support
2 cathode (anode, anode)
3 Electrolyte
4 anode (cathode, cathode)
5 Interconnector
6 Current buffer layer
7 current colloector
8 sealant
9 gas channel segment
10 cell unit

Claims (23)

And at least one multi-cell unit cell comprising a support and a plurality of cell units provided on the support,
Wherein the cell unit includes a fuel electrode, an electrolyte, an air electrode, and a connection member,
Wherein the support is non-conductive. The method according to claim 1,
Wherein the plurality of cell units are connected in series with each other. The method according to claim 1,
Wherein the planar solid oxide fuel cell includes at least two multi-cell unit cells,
And further comprising a current buffer layer between said at least two multi-cell single cells. The method of claim 3,
Wherein the at least two multi-cell unit cells are connected in parallel with each other. The method according to claim 1,
The cell unit includes a fuel electrode;
An air electrode opposed to the fuel electrode;
An electrolyte disposed between the fuel electrode and the air electrode; And
And a connection member provided on the upper portion of the air electrode. The method according to claim 1,
The electrolyte of the mth cell unit of the cell unit
Between the anode of the m-th cell unit and the cathode of the m-th cell unit and
Th fuel electrode and the (m + 1) th fuel electrode,
M is an integer of 1 to n,
Wherein n is an integer greater than or equal to 2. The method according to claim 1,
And the connecting member connects the plurality of cell units in series. The method according to claim 1,
The connecting material of the mth cell unit of the cell unit
(M + 1) th fuel electrode in series,
M is an integer of 1 to n,
And n is an integer of 2 or more. The method of claim 8,
The connector of the m < th >
The m < th >
And the electrolyte is disposed between the mth electrolyte and the (m + 1) th electrolyte. The method according to claim 1,
Further comprising a current collector provided in contact with both sides of the surface of the support having the plurality of cell units and both sides of the support. The method of claim 10,
Wherein the current collector contacts at least a part of the anode of the first cell unit,
and at least a part of the air electrode of the nth cell unit,
and n is an integer of 2 or more. The method according to claim 1,
The connecting material of the first cell unit is provided in one region of the upper portion of the anode,
The connecting material of the nth cell unit is provided in one region above the air electrode,
and n is an integer of 2 or more. The method of claim 12,
Further comprising a sealant on one side and one side of the upper portion of the connecting member. The method according to claim 1,
The air electrode of the (m + 1) th cell unit of the cell unit is spaced apart from the connecting material of the mth cell unit at a predetermined interval,
M is an integer of 1 or more and n or less,
And n is an integer of 2 or more. The method of claim 3,
Wherein a gas channel segment is further provided on both sides of the at least two multi-cell single cells,
Wherein the gas channel segment connects the two or more multi-cell unit cells in parallel with each other. The method according to claim 1,
Wherein the support is a ceramic support. The method of claim 3,
Wherein the current buffer layer is insulative. And a step of laminating a plurality of cell units on top of the support,
Wherein the cell unit includes a fuel electrode, an electrolyte, an air electrode, and a connection member,
Wherein the support is nonconductive. ≪ RTI ID = 0.0 > 11. < / RTI > 19. The method of claim 18,
Wherein the cell unit comprises: stacking an electrolyte on the anode;
Stacking an air electrode on the electrolyte; And
And laminating a connecting material on the air electrode. ≪ RTI ID = 0.0 > 11. < / RTI > 19. The method of claim 18,
Manufacturing two or more of the multi-cell unit cells; And
Further comprising the step of providing a current buffer layer between said at least two multi-cell single cells. 19. The method of claim 18,
Wherein the step of fabricating the multi-
And connecting the plurality of cell units in series with the coupling member. The method of claim 20,
And connecting the at least two multi-cell unit cells in parallel. 19. The method of claim 18,
Wherein the support is a ceramic support.

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