KR102129651B1 - Cathod green sheet for solid oxide fuel cell and solid oxide fuel cell - Google Patents

Abstract

The present specification relates to an anode green sheet for a solid electrolyte fuel cell and a solid oxide fuel cell.

Description

Cathode green sheet and solid oxide fuel cell for solid electrolyte fuel cells {CATHOD GREEN SHEET FOR SOLID OXIDE FUEL CELL AND SOLID OXIDE FUEL CELL}

The present specification relates to an anode green sheet for a solid electrolyte fuel cell and a solid oxide fuel cell.

Recently, as the depletion of existing energy resources such as oil and coal is predicted, interest in energy that can replace them is increasing. As one of these alternative energies, fuel cells are particularly attracting attention due to advantages such as high efficiency, no emission of pollutants such as NOx and SOx, and abundant fuel used.

A fuel cell is a power generation system that converts the chemical reaction energy of a fuel and an oxidant into electrical energy, and hydrogen, hydrocarbons such as methanol and butane, and oxygen are typically used as the fuel.

Fuel cells include polymer electrolyte fuel cells (PEMFC), direct methanol fuel cells (DMFC), phosphoric acid fuel cells (PAFC), alkaline fuel cells (AFC), molten carbonate fuel cells (MCFC), and solid oxide fuel And SOFCs.

On the other hand, it is also necessary to study a metal air secondary battery that manufactures an air electrode of a metal secondary battery as an air electrode by applying the principle of the air electrode of a fuel cell.

Republic of Korea Patent Publication No. 2016-0059419 (released May 26, 2016)

The present specification relates to an anode green sheet for a solid electrolyte fuel cell and a solid oxide fuel cell.

This specification describes an anode green sheet for a solid electrolyte fuel cell having a color in the range of 9.59 ≤ X ≤ 17.81, 10.178 ≤ Y ≤ 18.902 and 7.735 ≤ Z ≤ 14.365 on the CIE (Commossion international de l'Eclairage) color chart. to provide.

In addition, the present specification is a solid oxide fuel cell including an anode, an anode, and an electrolyte provided between the anode and the cathode, wherein the anode includes a layer in which the anode green sheet is sintered according to one embodiment of the present specification. Provided is a solid oxide fuel cell.

The anode green sheet for a solid electrolyte fuel cell according to an exemplary embodiment of the present specification has an advantage of being distinguished by a different color from other layers of the solid electrolyte fuel cell.

Since the anode functional layer for a solid electrolyte fuel cell according to an exemplary embodiment of the present specification forms a structure in which nanoparticles are provided on the microparticles (Nano on microstructure), the activation area is widened and the efficiency of the fuel cell is high.

1 is a schematic view showing the principle of electricity generation of a solid oxide fuel cell.
2 is a view schematically showing an embodiment of a battery module including a fuel cell.
3 is an electron scanning microscope image of the core-shell particles of the embodiment.
4 is an electron scanning microscope image of the core-shell particles of the comparative example.
5 is a photograph of the anode green sheet prepared in Examples and Comparative Examples.
6 is a graph of the relative amount of light reflected in response to each wavelength when irradiating a light source to the anode green sheet prepared in Examples and Comparative Examples.
7 is a scanning electron microscope image of a cross-section of a cell to which the anode green sheet prepared in Example is applied.
8 is a scanning electron microscope image of a cross section of a cell to which an anode green sheet prepared in a comparative example is applied.
9 is a graph showing an open circuit voltage (OCV) and a power density (OPD) of a cell to which an anode green sheet manufactured in Examples and Comparative Examples is applied.
10 is a current density comparison graph of a cell to which an anode green sheet prepared in Examples and Comparative Examples is applied.

Hereinafter, the present specification will be described in detail.

This specification describes an anode green sheet for a solid electrolyte fuel cell having a color in the range of 9.59 ≤ X ≤ 17.81, 10.178 ≤ Y ≤ 18.902 and 7.735 ≤ Z ≤ 14.365 on the CIE (Commossion international de l'Eclairage) color chart. to provide.

The anode green sheet may have a color in a region of 10 ≤ X ≤ 17, 11 ≤ Y ≤ 19 and 8 ≤ Z ≤ 15 on a CIE (Commossion international de l'Eclairage) color chart.

The anode green sheet may have a color in a region of 11 ≤ X ≤ 16, 12 ≤ Y ≤ 17 and 8 ≤ Z ≤ 14 on a CIE (Commossion international de l'Eclairage) color chart.

In the present specification, the green sheet refers to a film-type film that can be processed in the next step, not a complete final product. In other words, the green sheet is coated with a coating composition containing inorganic particles and a solvent and dried in a sheet form, and the green sheet refers to a sheet in a semi-dry state that can maintain a sheet form while containing a little solvent.

The anode green sheet may include at least one of an anode functional layer green sheet and an anode support green sheet. Specifically, the anode green sheet may include at least one of one or more anode functional layer green sheets and one or more anode support green sheets.

The thickness of the green sheet for the anode functional layer may be 10 μm or more and 30 μm or less, 20 μm or more and 30 μm or less, and 21 μm or more and 26 μm or less.

The thickness of the green sheet for the anode support may be 80 μm or more and 120 μm or less, and specifically, 90 μm or more and 110 μm or less.

The anode green sheet may include a core including NiO; And core-shell particles having a shell provided on the core and including a ceria-based metal oxide.

Based on the total weight of the core-shell particles, the content of NiO may be 35% by weight or more and 60% by weight or less, and the content of the ceria-based metal oxide may be 40% by weight or more and 65% by weight or less.

The weight ratio of the NiO and the ceria-based metal oxide may be 3.5: 6.5 or more and 6: 4 or less.

The content of NiO may be 53.8 wt% or more and 150 wt% or less of the ceria-based metal oxide.

The average diameter of the core may be 0.1 μm or more and 2 μm or less, and specifically, 0.5 μm or more and 1 μm or less.

The ceria-based metal oxide may include at least one of samarium-doped ceria and gadolinium-doped ceria, and may specifically include gadolinium-doped ceria, and more specifically, gadolinium-doped ceria.

The ceria-based metal oxide of the shell is in the form of particles, and the average diameter of the ceria-based metal oxide particles may be several nm or more and hundreds or less, and specifically 10 nm or more and 100 nm or less.

At this time, the diameter means the length of the longest line among the lines connecting two points on the circumference of the particle.

This specification is an anode green sheet according to an exemplary embodiment of the present specification; And an additional green sheet provided on one surface of the anode green sheet.

The additional green sheet may be an electrolyte green sheet provided on the anode green sheet, or an electrolyte green sheet and a cathode green sheet sequentially provided on the anode green sheet.

The present specification is a solid oxide fuel cell including an anode, an anode, and an electrolyte provided between the anode and the anode, wherein the anode comprises a layer in which the anode green sheet is sintered according to one embodiment of the present specification. Provide a fuel cell.

FIG. 1 schematically shows the principle of electricity generation of a solid oxide fuel cell, and the solid oxide fuel cell is composed of an electrolyte layer and an anode and a cathode formed on both sides of the electrolyte layer. do. Referring to FIG. 1, which shows the principle of electricity generation of a solid oxide fuel cell, oxygen ions are generated while air is electrochemically reduced at the cathode, and the generated oxygen ions are transferred to the anode through the electrolyte layer. At the anode, fuel such as hydrogen, methanol, butane, etc. is injected, and the fuel is combined with oxygen ions to electrochemically oxidize, releasing electrons and generating water. The reaction causes electron movement to occur in the external circuit.

The cathode may include an inorganic material having oxygen ion conductivity to be applied to an anode for a solid oxide fuel cell. The type of the inorganic material is not particularly limited, but the inorganic material is yttria stabilized zirconium oxide (YSZ: (Y ₂ O ₃ ) _x (ZrO ₂ ) _1-x , x = 0.05 to 0.15), Scandia Stabilized zirconium oxide (ScSZ: (Sc ₂ O ₃ ) _x (ZrO ₂ ) _1-x , x = 0.05 ~ 0.15), samarium dop ceria(SDC: (Sm ₂ O ₃ ) _x (CeO ₂ ) _{1- x} , x = 0.02 to 0.4), gadolinium dope ceria (GDC: (Gd ₂ O ₃ ) _x (CeO ₂ ) _1-x , x = 0.02 to 0.4), lanthanum strontium manganese oxide: LSM), Lanthanum strontium cobalt ferrite (LSCF), Lanthanum strontium nickel ferrite (LSNF), Lanthanum calcium nickel ferrite (LCNF), Lanthanum strontium cobalt oxide (Lanthanum cobalt oxide) oxide: LSC) Gadolinium strontium cobalt oxide (GSC), Lanthanum strontium ferrite (LSF), Samarium strontium cobalt oxide (SSC), Barium strontium cobalt Sium barium ferrite: BSCF) and lanthanum strontium gallium magnesium oxide (LSGM).

The cathode comprises at least one of Lanthanum strontium cobalt ferrite (LSCF), Lanthanum strontium cobalt oxide (LSC) and Barium Strontium cobalt ferrite (BSCF), electrolyte It may further include the same inorganic material as the metal oxide. Specifically, when the electrolyte contains a ceria-based metal oxide, the cathode may further include a ceria-based metal oxide. More specifically, when the electrolyte includes gadolinium dope ceria, the cathode may further include gadolinium dope ceria.

The thickness of the air electrode may be 10 μm or more and 100 μm or less. Specifically, the thickness of the air electrode may be 20 μm or more and 50 μm or less.

The porosity of the cathode may be 10% or more and 50% or less. Specifically, the porosity of the cathode may be 10% or more and 30% or less.

The pore diameter of the cathode may be 0.1 μm or more and 10 μm or less. Specifically, the pore diameter of the air electrode may be 0.5 μm or more and 5 μm or less. More specifically, the pore diameter of the air electrode may be 0.5 μm or more and 2 μm or less.

The method of manufacturing the cathode is not particularly limited, for example, coating and drying and firing the slurry for the cathode, or coating and drying the cathode slurry on a separate release paper to prepare a green sheet for the cathode, and at least one cathode For the green sheet alone or calcined with a neighboring heterogeneous green sheet, an air cathode can be produced.

The thickness of the green sheet for the cathode may be 10 μm or more and 100 μm or less.

The cathode slurry includes inorganic particles having oxygen ion conductivity, and if necessary, the cathode slurry may further include at least one of a binder resin, a plasticizer, a dispersant, and a solvent. The binder resin, plasticizer, dispersant and solvent are not particularly limited, and conventional materials known in the art may be used.

Based on the total weight of the slurry for the cathode, the content of the inorganic particles having oxygen ion conductivity is 40% by weight or more and 70% by weight or less, the content of the solvent is 10% by weight or more and 30% by weight or less, and the content of the dispersant is 5% by weight or more and 10% by weight or less, the content of the plasticizer is 0.5% by weight or more and 3% by weight or less, and the binder may be 10% by weight or more and 30% by weight or less.

The anode may include an inorganic material having oxygen ion conductivity to be applied to the anode for a solid oxide fuel cell. The type of the inorganic material is not particularly limited, but the inorganic material is yttria stabilized zirconium oxide (YSZ: (Y ₂ O ₃ ) _x (ZrO ₂ ) _1-x , x = 0.05 to 0.15), Scandia Stabilized zirconium oxide (ScSZ: (Sc ₂ O ₃ ) _x (ZrO ₂ ) _1-x , x = 0.05 ~ 0.15), samarium dop ceria(SDC: (Sm ₂ O ₃ ) _x (CeO ₂ ) _{1- x} , x = 0.02 to 0.4) and gadolinium dope ceria (GDC: (Gd ₂ O ₃ ) _x (CeO ₂ ) _1-x , x = 0.02 to 0.4).

The anode may include the same inorganic material as the metal oxide of the electrolyte. Specifically, when the electrolyte contains a ceria-based metal oxide, the anode may include a ceria-based metal oxide. More specifically, when the electrolyte contains gadolinium dope ceria, it may include gadolinium dope ceria as the anode.

The anode may further include NiO. In other words, the anode may include an inorganic material having oxygen ion conductivity and NiO, and specifically may include the same inorganic material and NiO as the metal oxide of the electrolyte, and more specifically, include a ceria-based metal oxide and NiO. Can.

According to one embodiment of the present specification, the anode may include gadolinium dope ceria and NiO.

The thickness of the anode may be 10 μm or more and 1000 μm or less. Specifically, the thickness of the anode may be 20 μm or more and 900 μm or less.

The porosity of the anode may be 10% or more and 50% or less. Specifically, the porosity of the anode may be 10% or more and 30% or less.

The pore diameter of the anode may be 0.1 μm or more and 10 μm or less. Specifically, the pore diameter of the anode may be 0.5 μm or more and 5 μm or less. More specifically, the pore diameter of the anode may be 0.5 μm or more and 2 μm or less.

The manufacturing method of the anode is not particularly limited, for example, coating and drying and firing the slurry for the anode, or coating and drying the anode slurry on a separate release paper to prepare a green sheet for the anode, and at least one anode For the green sheet alone or by firing with neighboring heterogeneous green sheets, an anode can be produced.

The slurry for the anode includes inorganic particles having oxygen ion conductivity, and if necessary, the slurry for the anode may further include at least one of a binder resin, a plasticizer, a dispersant, and a solvent. The binder resin, plasticizer, dispersant and solvent are not particularly limited, and conventional materials known in the art may be used.

The inorganic particle having oxygen ion conductivity includes a core including NiO; And core-shell particles having a shell provided on the core and including a ceria-based metal oxide.

Based on the total weight of the core-shell particles, the content of NiO may be 35% by weight or more and 60% by weight or less, and the content of the ceria-based metal oxide may be 40% by weight or more and 65% by weight or less.

Based on the total weight of the slurry for the anode, the content of the core-shell particles having oxygen ion conductivity is 40% by weight or more and 70% by weight or less, and the content of the solvent is 10% by weight or more and 30% by weight or less, and a dispersant The content may be 5 wt% or more and 10 wt% or less, the content of the plasticizer may be 0.5 wt% or more and 3 wt% or less, and the binder may be 10 wt% or more and 30 wt% or less.

The anode may be provided on a separate porous ceramic support or porous metal support, or may include an anode support and an anode functional layer. At this time, the anode support includes the same inorganic material as the anode functional layer, but has a higher porosity and relatively thicker thickness than the anode functional layer, and is a layer that supports another layer, and the anode functional layer is provided between the anode support and the electrolyte layer. It may be a layer that plays a major role as an anode.

When the anode is provided on the porous ceramic support or the porous metal support, the green sheet for the prepared anode can be laminated on the fired porous ceramic support or the porous metal support and fired to produce the anode.

When the anode includes an anode support and an anode functional layer, the prepared green sheet for the anode functional layer can be laminated on a calcined anode support and fired to produce an anode.

When the anode includes an anode support and an anode functional layer, the thickness of the anode support may be 350 µm or more and 1000 µm or less, and the thickness of the anode functional layer may be 5 µm or more and 50 µm or less.

The electrolyte may include a ceria-based metal oxide.

The ceria-based metal oxide is not particularly limited as long as it is a ceria-based metal oxide having oxygen ion conductivity, but may specifically include at least one of samarium-doped ceria and gadolinium-doped ceria, and more specifically, may include gadolinium-doped ceria. .

The thickness of the electrolyte may be 10 μm or more and 100 μm or less. Specifically, the thickness of the electrolyte may be 20 μm or more and 50 μm or less.

The manufacturing method of the electrolyte is not particularly limited, for example, by coating and drying and calcining the electrolyte slurry, or by coating and drying the electrolyte slurry on a separate release paper to prepare a green sheet for electrolyte, and one or more electrolytes For the green sheet alone or calcined with a neighboring heterogeneous green sheet, an electrolyte can be prepared.

The thickness of the green sheet for electrolyte may be 10 μm or more and 100 μm or less.

The electrolyte slurry includes ceria-based metal oxide particles, and if necessary, the slurry for the anode can further include at least one of a binder resin, a plasticizer, a dispersant, and a solvent. The binder resin, plasticizer, dispersant and solvent are not particularly limited, and conventional materials known in the art may be used.

Based on the total weight of the slurry for the electrolyte layer, the content of the ceria-based metal oxide particles may be 40% by weight or more and 70% by weight or less.

Based on the total weight of the slurry for the electrolyte layer, the content of the solvent is 10% by weight or more and 30% by weight or less, the content of the dispersant is 5% by weight or more and 10% by weight or less, and the content of the plasticizer is 0.5% by weight or more and 3% by weight Below, the binder may be 10% by weight or more and 30% by weight or less.

The shape of the fuel cell is not limited, and may be, for example, coin, flat, cylindrical, horn, button, sheet or stacked.

The fuel cell may be specifically used as a power source for electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, or power storage devices.

The present specification provides a battery module including a fuel cell as a unit cell.

2 schematically shows an embodiment of a battery module including a fuel cell, and the fuel cell includes a battery module 60, an oxidizing agent supply unit 70, and a fuel supply unit 80.

The battery module 60 includes one or two or more of the fuel cells described above as a unit cell, and when two or more unit cells are included, includes a separator interposed therebetween. The separator prevents the unit cells from being electrically connected and transfers fuel and oxidant supplied from the outside to the unit cell.

The oxidizing agent supply unit 70 serves to supply the oxidizing agent to the battery module 60. Oxygen is typically used as the oxidizing agent, and oxygen or air may be injected into the oxidizing agent supply unit 70 to be used.

The fuel supply unit 80 serves to supply fuel to the battery module 60, a fuel tank 81 for storing fuel, and a pump 82 for supplying fuel stored in the fuel tank 81 to the battery module 60 ). As the fuel, gaseous or liquid hydrogen or hydrocarbon fuels may be used. Examples of hydrocarbon fuels include methanol, ethanol, propanol, butanol or natural gas.

Hereinafter, the present specification will be described in more detail through examples. However, the following examples are only intended to illustrate the present specification and are not intended to limit the present specification.

[Example]

The anode functional layer slurry ((AFL slurry) was an inorganic material and used core-shell particles with GDC particles on the surface of NiO particles, wherein GDC had an average diameter of about 50 nm and NiO had an average diameter of about 0.75 µm, The weight ratio of GDC and NiO will be 50:50.

An electron scanning microscope image of the core-shell particles is shown in FIG. 3.

The AFL slurry comprises a dispersant, a plasticizer, and a binder resin together with a solvent, based on the total weight of the slurry, 50.2 wt% of core-shell particles, 18.2 wt% of a solvent, 6.2 wt% of a dispersant, 1.2 wt% of a plasticizer, and 24.2 wt% of a binder. Added. The AFL slurry was tape-casted to obtain an AFL Green Sheet having a thickness of 22 μm to 25 μm.

[Comparative example]

Examples and all the conditions are the same, in Comparative Example, GDC having an average diameter of about 50 nm and NiO having an average diameter of about 0.75 µm in an AFL slurry, and the weight ratio of GDC and NiO is 50:50. Green sheet was obtained by applying wt%.

An electron scanning microscope image of a state in which the GDC and NiO are simply mixed is illustrated in FIG. 4.

[Experimental Example 1]

The photographs of the anode green sheets prepared in Examples and Comparative Examples are shown in FIG. 5, and it can be seen that colors are different from each other.

[Experimental Example 2]

Color analysis was performed on the anode green sheet prepared in Examples and Comparative Examples using a tungsten halogen lamp as a light source using a spectrophotometer (Spectrophotometer, CM-2600d).

The results are shown in Table 1 and FIG. 6.

X(D65) Y (D65) Z(D65) Example High value 15.880 16.830 13.480 Low value 11.520 12.250 8.620 Comparative example High value 28.950 32.560 29.160 Low value 25.450 28.910 25.410

6 shows a relative amount of light reflected in response to each wavelength when a light source is irradiated to the specimen. Through this, it can be confirmed that the amount of the specimen reflected in each example is smaller than the comparative example.

[Experimental Example 3]

Cells were prepared in the following manner using an anode functional layer green sheet to which Examples and Comparative Examples were applied.

The solid oxide fuel cell used for the measurement was prepared with an anode support layer (ASL), an anode functional layer (AFL), an electrolyte layer (EL), and an anode (CL, cathode layer).

The ASL slurry uses GDC and NiO as inorganic materials, and the ratio of GDC and NiO is 50:50 vol%.

In addition, the ASL slurry was added with a dispersant, a plasticizer, and a binder resin as a solvent, based on the total weight of the slurry, 18.2 wt% of a solvent, 6.2 wt% of a dispersant, 1.2 wt% of a plasticizer, and 24.2 wt% of a binder. The ASL slurry was tape-casted to obtain an ASL Green Sheet having a thickness of 100 μm to 200 μm.

As an anode functional layer (AFL) green sheet, green sheets prepared in Examples and Comparative Examples were used, respectively.

The EL slurry was the same as the ASL slurry and the organic material, but constituted an inorganic material only by GDC without NiO, and was used to cast an EL green sheet having a thickness of 20 μm.

ASL green sheets, AFL green sheets, and EL green sheets were sequentially laminated, and then sintered at 1400°C to produce a half cell. At this time, the thickness of the ASL, AFL, and EL after sintering was 800 μm, 20 μm, and 20 μm, respectively.

The total composition, based on the total _{weight, LSCF6428 (La 0. 6 Sr} 0. 4 Co 0. 2 Fe 0. 8 O 3 -δ) to 60wt%, the binder composition is ESL441 a three-roll mill to the air electrode LSCF compositions comprising 40wt% (Roll Mill) was used to prepare an LSCF cathode composition in paste form.

On the electrolyte layer of the half cell prepared above, the LSCF cathode composition was applied by a screen printing method and dried, followed by heat treatment at 1000°C to form an anode.

The scanning electron microscope for the cross section of the prepared cell was measured, and the results are shown in FIGS. 7 (Example) and 8 (Comparative Example). 7 and 8, it can be seen that the particles of the functional layer to which the green sheet of the embodiment was applied were more even.

While supplying 500 cc of air per minute to the cathode and supplying 200 cc of hydrogen to the anode while measuring the potential of the cell while increasing the applied current (consumption current), the output (power) was calculated by multiplying the current density and voltage. The results are shown in Figs. 9 and 10, through which the examples showed better performance than the comparative examples, and the open circuit voltage (OCV) was improved by about 10% and the power density (OPD) was improved by about 12%.

At this time, an open circuit voltage (OCV) means a voltage in a state where no current is applied, and an operating power density (OPD) means power at a current density of 500 mA/cm ² .

60: battery module
70: oxidizing agent supply unit
80: fuel supply
81: fuel tank
82: Pump

Claims (9)

On the CIE (Commossion international de l'Eclairage, International Lighting Commission) color chart has a color in the region of 9.59 ≤ X ≤ 17.81, 10.178 ≤ Y ≤ 18.902 and 7.735 ≤ Z ≤ 14.365,
A core having an average diameter of 0.1 μm or more and 2 μm or less and containing NiO; And a core-shell particle provided on the core and having a shell comprising gadolinium dope ceria particles having an average diameter of 10 nm or more and 100 nm or less. The anode green sheet for a solid electrolyte fuel cell according to claim 1, wherein the anode green sheet is at least one of a green sheet for an anode functional layer and a green sheet for an anode support. The anode green sheet for a solid electrolyte fuel cell according to claim 2, wherein the thickness of the green sheet for the anode functional layer is 10 μm or more and 30 μm or less. The anode green sheet for a solid electrolyte fuel cell according to claim 2, wherein the thickness of the green sheet for the anode support is 80 μm or more and 120 μm or less. delete delete delete delete A solid oxide fuel cell comprising an anode, an anode, and an electrolyte provided between the anode and the anode,
The anode is a solid oxide fuel cell comprising a layer sintered anode green sheet according to any one of claims 1 to 4.

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