JP2017134941A - Fuel battery single cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel battery single cell which can improve the efficiency in supplying and discharging fuel gas.SOLUTION: A fuel battery single cell 1 comprises an anode 2, a solid electrolyte layer 3, and a cathode 5. The anode 2 internally has a plurality of thickness direction passages 21 and a plurality of surface direction passages 22. The thickness direction passages 21 are arranged along an anode thickness direction, and each of them has a layer surface opening 212 on a layer surface 211 which is on the opposite side to the solid electrolyte layer 3 side. The surface direction passages 22 are arranged along an anode surface direction, and each of them has a lateral surface opening 222 on a lateral surface 221 of the anode 2. In the fuel battery single cell 1, the lateral surface 221 of the anode 2 excluding the lateral surface opening 222 is covered with a dense body 6 capable of sealing gas.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a fuel cell single cell.

  Conventionally, a flat plate fuel cell unit cell having an anode, a solid electrolyte layer, and a cathode is known.

  For example, Patent Document 1 discloses a solid oxide fuel cell unit cell including a plurality of gas flow paths penetrating in a plane direction in a pattern having a predetermined opening width in an anode.

JP 2012-252963 A

  However, the conventional fuel cell unit cell needs to perform supply and discharge of the fuel gas through the same flow path, and the fuel gas leaks from the side surface of the anode, so that the efficiency of supply and discharge of the fuel gas is poor. Therefore, the conventional fuel cell single cell is disadvantageous for operation under high-density current.

  This invention is made | formed in view of this subject, and it aims at providing the fuel cell single cell which can improve the efficiency of supply and discharge | emission of fuel gas.

One aspect of the present invention is a flat plate fuel cell single cell (1) having an anode (2), a solid electrolyte layer (3), and a cathode (5), and using the anode as a support,
The anode is arranged along the anode thickness direction, and has a plurality of thickness direction channels (21) having a layer surface opening (212) on the layer surface (211) opposite to the solid electrolyte layer side, and the anode surface direction. A plurality of planar flow paths (22) provided with side openings (222) on the side surface (221) of the anode,
The fuel cell single cell (1) has a side surface of the anode excluding the side surface opening covered with a gas-tight dense body (6).

  In the fuel cell unit cell, the side surface of the anode excluding the side surface opening is covered with a dense body capable of gas sealing. Therefore, the fuel cell unit cell can suppress the fuel gas from leaking from the portion of the side surface of the anode other than the side surface opening. As a result, in the fuel cell single cell, the flow of the fuel gas in the thickness direction flow path and the flow of the fuel gas in the plane direction flow path are rectified. Therefore, the fuel cell unit cell supplies the fuel gas from the layer surface opening and discharges the fuel gas from the side surface opening, or supplies the fuel gas from the side surface opening and discharges the fuel gas from the layer surface opening. Gas supply and discharge efficiency can be improved. Further, the fuel cell single cell can efficiently discharge water vapor generated by power generation together with the fuel gas. Therefore, the fuel cell single cell is advantageous for operation under a high current density.

  In addition, the code | symbol in the parenthesis described in the means to solve a claim and a subject shows the correspondence with the specific means as described in embodiment mentioned later, and limits the technical scope of this invention. It is not a thing.

1 is a front view schematically showing a single fuel cell according to Embodiment 1. FIG. 2 is a plan view schematically showing a single fuel cell according to Embodiment 1. FIG. 1 is a right side view schematically showing a single fuel cell according to Embodiment 1. FIG. It is the IV-IV sectional view taken on the line of FIG. It is the VV sectional view taken on the line of FIG. It is the VI-VI sectional view taken on the line of FIG. It is the VII-VII sectional view taken on the line of FIG. FIG. 5 is an explanatory view schematically showing a single fuel cell according to Embodiment 2 in correspondence with FIG. 4. FIG. 6 is an explanatory diagram schematically showing a single fuel cell according to Embodiment 3 corresponding to FIG. 5.

(Embodiment 1)
The fuel cell single cell of Embodiment 1 is demonstrated using FIGS. As illustrated in FIGS. 1 to 7, the fuel cell single cell 1 of this embodiment includes an anode 2, a solid electrolyte layer 3, and a cathode 5. The fuel cell single cell 1 can be operated in a temperature range of 500 ° C. to 900 ° C., for example. The fuel cell using solid oxide ceramics as the solid electrolyte of the solid electrolyte layer 3 is referred to as a solid oxide fuel cell (SOFC).

  The fuel cell single cell 1 can further include an intermediate layer 4 between the solid electrolyte layer 3 and the cathode 5. The intermediate layer 4 is a layer mainly for suppressing the reaction between the solid electrolyte layer material and the cathode material. In the present embodiment, specifically, in the fuel cell single cell 1, the anode 2, the solid electrolyte layer 3, the intermediate layer 4, and the cathode 5 are laminated in this order and joined to each other. The fuel cell single cell 1 is an anode support type in which an anode 2 as an electrode is a support. Therefore, the fuel cell single cell 1 has a sufficiently thick anode 2 as compared with other layers, and is excellent in the formation of a thickness direction channel 21 and a surface direction channel 22 described later. In each figure, an example is shown in which the outer shape of the fuel cell single cell 1 is rectangular. In addition, the outer shape of the single fuel cell 1 may be a circular shape or the like.

  The anode 2 has a plurality of thickness direction channels 21 and a plurality of surface direction channels 22 therein. The thickness direction flow path 21 is arranged along the anode thickness direction, and includes a layer surface opening 212 on the layer surface 211 opposite to the solid electrolyte layer 3 side. The surface direction flow path 22 is disposed along the anode surface direction, and includes a side surface opening 222 on the side surface 221 of the anode 2. The anode 2 usually includes a hole (not shown). The thickness direction flow path 21 and the surface direction flow path 22 are formed larger than the diameter of the hole, and are different from the hole.

  Specifically, the anode 2 can include a diffusion layer 201 and an active layer 202. The diffusion layer 201 is a layer that diffuses the fuel gas F supplied to the anode 2 into the layer surface. The active layer 202 is a layer that is disposed on the solid electrolyte layer 3 side of the diffusion layer 201 and serves as an anode reaction field. Note that the diffusion layer 201 and the active layer 202 are bonded to each other. The thickness direction flow path 21 and the surface direction flow path 22 can be included in the diffusion layer 201. In this case, the active layer 202 is not lost due to the formation of the thickness direction flow path 21 and the surface direction flow path 22. Therefore, it is possible to obtain the single fuel cell 1 capable of improving the efficiency of supply and discharge of the fuel gas F while sufficiently securing the anode reaction field.

  In the present embodiment, as shown in FIG. 4, the layer surface 211 of the anode 2 is a supply surface for the fuel gas F, and a part of the side surface 221 of the anode 2 is a discharge surface for the fuel gas F. Has been. In addition, the fuel cell single cell 1 may have a part of the side surface 221 of the anode 2 as a supply surface for the fuel gas F and a layer surface 211 of the anode 2 as a discharge surface for the fuel gas F. .

  Specifically, the plurality of thickness direction flow paths 21 can be arranged in a state of being separated from each other. In this case, it becomes easy to uniformly supply the fuel gas F to the anode reaction site. In addition, when it is set as the structure which discharges | emits the fuel gas F from the layer surface 211 of the anode 2, it becomes easy to discharge | emit the fuel gas F containing water vapor | steam uniformly from the field | area of an anode reaction.

  Specifically, the diffusion layer 201 has thickness direction flow paths 21 arranged in a plurality of rows and a plurality of columns. More specifically, FIGS. 1 to 7 show an example in which the diffusion layer 201 includes the thickness direction flow path 21 arranged in 6 rows × 6 columns (36 in total).

  Specifically, the end of the thickness direction flow path 21 on the solid electrolyte layer 3 side may be in contact with the active layer 202 as illustrated in FIGS. 1 to 7, or may not be in contact with the active layer 202. May be. When the end of the thickness direction flow path 21 on the solid electrolyte layer 3 side is in contact with the active layer 202, the fresh fuel gas F can be supplied to the anode reaction site earlier. When the end of the thickness direction flow path 21 on the solid electrolyte layer 3 side is not in contact with the active layer 202, diffusion between the end of the thickness direction flow path 21 on the solid electrolyte layer 3 side and the active layer 202 is diffused. The hole of the layer 201 is interposed. Therefore, in this case, the fuel gas F supplied through the thickness direction flow path 21 is once diffused by the diffusion layer 201 and then enters the active layer 202. Therefore, in this case, the fuel gas F can be supplied to the active layer 202 more uniformly.

  When the fuel gas F is discharged from the layer surface 211 of the anode 2 and the end of the thickness direction flow path 21 on the solid electrolyte layer 3 side is in contact with the active layer 202, the anode reaction occurs. The fuel gas F containing water vapor can be discharged to the outside of the cell more quickly.

  Specifically, the plurality of planar flow paths 22 can be arranged in a state of being separated from each other. In this case, it becomes easy to uniformly discharge the fuel gas F containing water vapor from the anode reaction field. In addition, when it is set as the structure which supplies the fuel gas F from a part of the side surface 221 of the anode 2, it becomes easy to supply the fuel gas F uniformly to the field of an anode reaction.

  Specifically, the diffusion layer 201 has a plurality of planar flow paths 22 arranged in a state of being separated from each other in the same plane. More specifically, FIGS. 1 to 7 show an example in which the diffusion layer 201 has five planar flow paths 22 arranged at a predetermined interval in the same plane. 1 to 7, one end of the planar flow path 22 penetrates the side surface 221 of the anode 2, and the other end of the planar flow path 22 penetrates the side surface 221 of the anode 2. Without being shown, an example of being present in the anode 2 is shown. In the present embodiment, since the outer shape of the single fuel cell 1 is a square shape, the side surface 221 of the anode 2 is composed of four surfaces. And the example which one edge part of the surface direction flow path 22 has penetrated to one of the four surfaces is shown. In addition, it can also be set as the structure which the both ends of the surface direction flow path 22 penetrate to the side surface 221 of the anode 2.

  Specifically, the planar flow path 22 may be in contact with the active layer 202 as illustrated in FIGS. 1 to 7 or may not be in contact with the active layer 202. When the planar flow path 22 is in contact with the active layer 202, the fuel gas F containing water vapor generated by the anode reaction can be discharged to the outside of the cell earlier.

  Note that the fuel gas F is supplied from a part of the side surface 221 of the anode 2, and when the planar flow path 22 is in contact with the active layer 202, the fresh fuel gas F is subjected to an anode reaction. It is possible to supply faster than before. On the other hand, when the fuel gas F is supplied from a part of the side surface 221 of the anode 2 and the planar channel 22 is not in contact with the active layer 202, the solid electrolyte of the planar channel 22. Between the wall surface on the layer 3 side and the active layer 202, the hole of the diffusion layer 201 is interposed. Therefore, in this case, the fuel gas F supplied through the planar flow path 22 is once diffused by the diffusion layer 201 and then enters the active layer 202. Therefore, in this case, the fuel gas F can be supplied to the active layer 202 more uniformly.

  When the thickness direction flow path 21 and the surface direction flow path 22 are arranged so as not to cross each other from the viewpoint of avoiding the mixing of the fuel gas F flowing in each flow path and making it easy to ensure the anode strength. Good. Moreover, both the thickness direction flow path 21 and the surface direction flow path 22 can be made into linear form. In this case, it is possible to obtain the single fuel cell 1 in which the efficiency of supplying and discharging the fuel gas F can be easily improved as compared with the case where the thickness direction flow path 21 and the surface direction flow path 22 are not linear.

  The channel widths of the thickness direction channel 21 and the surface direction channel 22 are preferably 20 μm or more, more preferably from the viewpoints of improving the supply of the fuel gas F, improving the discharge of the fuel gas F, forming the channel, and the like. The thickness can be 100 μm or more, more preferably 400 μm or more. Further, the channel widths of the thickness direction channel 21 and the surface direction channel 22 are preferably 1500 μm or less, more preferably 800 μm or less, and even more preferably 500 μm or less, from the viewpoint of ensuring anode strength and the like. The channel pitch of the thickness direction channel 21 and the surface direction channel 22 is preferably 20 μm or more, more preferably 100 μm, from the viewpoint of suppressing strength deterioration due to short circuit between the channels and reducing manufacturing difficulty. More preferably, it can be 400 μm or more. Further, the channel pitch of the thickness direction channel 21 and the surface direction channel 22 is preferably 1000 μm or less, more preferably 800 μm or less, from the viewpoint of improving the supply performance of the fuel gas F, improving the discharge performance of the fuel gas F, etc. More preferably, it can be 500 μm or less.

  Here, in the fuel cell single cell 1, the side surface 221 of the anode 2 excluding the side surface opening 222 is covered with a dense body 6 that can be gas-sealed. Specifically, in this embodiment, both side surfaces of the diffusion layer 201 and the active layer 202 are covered with the dense body 6.

Specifically, the dense body 6 may be any material that does not allow gas components contained in the fuel gas F supplied to the anode 2 and the fuel gas F discharged from the anode 2 to pass therethrough. More specifically, examples of the gas component include gases such as H ₂ , CH ₄ , CO, CO ₂ , and H ₂ O (water vapor). In the present embodiment, the fuel cell single cell 1 reforms methane gas into fuel gas F. Therefore, specifically, the gas component of the fuel gas F includes H ₂ , CH ₄ , CO, CO ₂ , H ₂ O (water vapor), and the like.

Specifically, as the material of the dense body 6, for example, glass such as crystallized glass, zirconium oxide oxide such as yttria stabilized zirconia (YSZ), scandia stabilized zirconia (ScSZ), CeO ₂ , or Examples include cerium oxides such as ceria solid solutions in which CeO ₂ is doped with one or more elements selected from Gd, Sm, Y, La, Nd, Yb, Ca, and Ho. can do. The material of the dense body 6 can be the same material as the material of the solid electrolyte layer 3 described later from the viewpoint of easily reducing the difference in thermal expansion. In the present embodiment, the material of the dense body 6 is crystallized glass.

The linear thermal expansion coefficient of the dense body 6 can be in the range of 5 × 10 ^{−6 to} 20 × 10 ⁻⁶ / K. In this case, the dense body 6 is unlikely to be damaged due to thermal stress generated when the temperature of the fuel cell unit cell 1 is increased or decreased. Therefore, in this case, the possibility that the fuel gas F leaks from the side surface of the anode 2 due to the breakage of the dense body 6 is further reduced, and the fuel cell unit cell 1 advantageous for improving the supply and discharge efficiency of the fuel gas F is obtained. It is done.

The linear thermal expansion coefficient of the dense body 6 is preferably 6 × 10 ⁻⁶ / K or more, more preferably 7 × 10 ⁻⁶ / K or more, and even more preferably 8 × 10 from the viewpoint of suppressing breakage of the dense body 6. ^-6 / K or more, even more preferably 9 × 10 ^-6 / K or more. In addition, the linear thermal expansion coefficient of the dense body 6 is preferably 18 × 10 ⁻⁶ / K or less, more preferably 15 × 10 ⁻⁶ / K or less, and further preferably 14 from the viewpoint of suppressing breakage of the dense body 6. × 10 ⁻⁶ / K or less, even more preferably 13 × 10 ⁻⁶ / K or less. The linear thermal expansion coefficient of the dense body 6 is basically measured in accordance with JIS R1618: 2002 “Method of measuring thermal expansion by thermomechanical analysis of fine ceramics”. Specifically, the dense body 6 of the sample is set in a fully expanded thermomechanical analyzer, and the temperature is increased at a rate of temperature increase of 10 ° C./min. By the time T rises from T ₀ (= 100 ° C.) to T ₁ (= 700 ° C.), the sample expands from length L ₀ to L ₁ . The linear thermal expansion coefficient at this time (/ K), calculated from calculation formula _{(dL / dT) T = T1} / L 0. _{However, (dL / dT) T =} T1 , the temperature T is the slope of the long curve at the time of _{T 1.}

  Specifically, the thickness of the dense body 6 can be equal to or greater than the thickness of the solid electrolyte layer 3. In this case, it becomes easy to ensure the bonding strength between the dense body 6 and the anode 2. The thickness of the dense body 6 is preferably larger than the thickness of the solid electrolyte layer 3 from the viewpoint of easily obtaining the above effect.

  The thickness of the dense body 6 is preferably 3 μm or more, more preferably 4 μm or more, and even more preferably 5 μm or more, from the viewpoint of easily ensuring the bonding strength between the dense body 6 and the anode 2. The thickness of the dense body 6 is preferably 20 μm or less, more preferably 15 μm or less, and even more preferably 10 μm or less, from the viewpoints of adhesion between materials, gas sealability, and the like.

  In the single fuel cell 1, the material of the solid electrolyte layer 3 is zirconium oxide based oxidation such as yttria stabilized zirconia (YSZ) and scandia stabilized zirconia (ScSZ) from the viewpoint of excellent strength and thermal stability. A thing can be used conveniently. The material of the solid electrolyte layer 3 is preferably yttria-stabilized zirconia from the viewpoints of ion conductivity, mechanical stability, compatibility with other materials, and chemical stability from an air atmosphere to a fuel gas atmosphere. is there. In the present embodiment, specifically, yttria-stabilized zirconia can be used as the material of the solid electrolyte layer 3.

  The thickness of the solid electrolyte layer 3 is preferably 3 to 20 μm, more preferably 4 to 15 μm, and still more preferably 5 to 10 μm from the viewpoint of reducing ohmic resistance. In the present embodiment, the thickness of the solid electrolyte layer 3 can be specifically set to 5 μm.

  In the fuel cell single cell 1, examples of the material of the anode 2 include a mixture of a catalyst such as Ni or NiO and a solid electrolyte such as the above-described zirconium oxide-based oxide. NiO becomes Ni in a reducing atmosphere during power generation. In the present embodiment, Ni or a mixture of NiO and yttria-stabilized zirconia can be used as the material of the anode 2, specifically, the material of the diffusion layer 201 and the material of the active layer 202.

  In addition, the thickness of the diffusion layer 201 is preferably 100 μm or more, more preferably 200 μm or more, and more preferably 300 μm or more, from the viewpoint of securing strength as a support. The thickness of the diffusion layer 201 is preferably 800 μm or less, more preferably 700 μm or less, from the viewpoint of improving gas diffusibility. The thickness of the active layer 202 is preferably 10 μm or more, more preferably 15 μm or more, from the viewpoints of reaction persistence, handleability, workability, and the like. The thickness of the active layer 202 is preferably 30 μm or less, more preferably 25 μm or less, from the viewpoint of reducing electrode reaction resistance. In the present embodiment, the thickness of the diffusion layer 201 can be specifically 400 μm, and the thickness of the active layer 202 can be specifically 25 μm.

In the fuel cell single cell 1, examples of the material of the cathode 5 include transition metal perovskite oxides. The transition metal perovskite oxide, specifically, for _{example, La x Sr 1-x CoO} 3 based _{oxide, La x Sr 1-x Co} y Fe 1-y O 3 based oxide, _Sm x Sr ₁ Examples include _-x CoO ₃ oxides (wherein 0 ≦ x ≦ 1, 0 ≦ y ≦ 1). These can be used alone or in combination of two or more. In the present embodiment, as the material of the cathode 5, in _particular, be used _{La x Sr 1-x Co y} Fe 1-y O 3 based oxide (0 ≦ x ≦ 1,0 ≦ y ≦ 1) it can.

  Further, the thickness of the cathode 5 is preferably 20 to 100 μm, more preferably 30 to 80 μm, from the viewpoints of gas diffusibility, electrode reaction resistance, current collection, and the like. In the present embodiment, specifically, the thickness of the cathode 5 can be set to 50 μm.

In the fuel cell unit cell 1, the material of the intermediate layer 4 is, for example, CeO ₂ or CeO ₂ or one or two selected from Gd, Sm, Y, La, Nd, Yb, Ca, and Ho. Examples thereof include cerium oxide-based oxides such as ceria-based solid solutions doped with more than one element. These can be used alone or in combination of two or more. In this embodiment, specifically, a ceria-based solid solution in which CeO ₂ is doped with Gd can be used as the material of the intermediate layer 4.

  Further, the thickness of the intermediate layer 4 is preferably 1 to 20 μm, more preferably 2 to 5 μm, from the viewpoints of reducing ohmic resistance and suppressing element diffusion from the cathode. In the present embodiment, the thickness of the intermediate layer 4 can be specifically set to 3 μm.

  In the fuel cell single cell 1, the side surface 221 of the anode 2 excluding the side surface opening 222 is covered with a dense body 6 capable of gas sealing. Therefore, the fuel cell single cell 1 can suppress leakage of the fuel gas F from the portion other than the side surface opening 222 in the side surface 221 of the anode 2. As a result, in the single fuel cell 1, the flow of the fuel gas F in the thickness direction flow path 21 and the flow of the fuel gas F in the plane direction flow path 22 are rectified. Therefore, the fuel cell single cell 1 supplies the fuel gas F from the layer surface opening 212 and discharges the fuel gas F from the side surface opening 222, or supplies the fuel gas F from the side surface opening 222 and supplies the fuel from the layer surface opening 212. The efficiency of supply and discharge of the fuel gas F when the gas F is discharged can be improved. Further, the single fuel cell 1 can efficiently discharge the water vapor generated by the power generation together with the fuel gas F. Therefore, the single fuel cell 1 is advantageous for operation under a high current density.

(Embodiment 2)
The fuel cell single cell of Embodiment 2 is demonstrated using FIG. Of the reference numerals used in the second and subsequent embodiments, the same reference numerals as those used in the above-described embodiments represent the same components as those in the above-described embodiments unless otherwise indicated.

  As illustrated in FIG. 8, in the fuel cell single cell 1 of the present embodiment, the dense body 6 covers the side surface of the solid electrolyte layer 3. In this case, it becomes easy to suppress leakage of the fuel gas F from the portion other than the side surface opening 222 in the side surface 221 of the anode 2. The dense body 6 may cover all of the side surfaces of the solid electrolyte layer 3 or may cover a part of the side surfaces of the solid electrolyte layer 3. FIG. 8 shows the latter case.

  Further, the diffusion layer 201 can include a plurality of sub-direction channels 23 arranged along the anode surface direction in addition to the plurality of surface-direction channels 22. In this case, when the fuel gas F is supplied from the layer surface 211 of the anode 2, the fuel gas F easily diffuses uniformly in the anode surface direction through the surface direction sub-channel 23. In the present embodiment, specifically, the plurality of planar flow paths 22 are in contact with the active layer 202, but the multiple planar flow paths 23 are not in contact with the active layer 202. Further, the plurality of surface direction sub-channels 23 are arranged in a different plane from the plurality of surface direction channels 22. More specifically, the plurality of planar sub-channels 23 are arranged in a plurality of planes (two planes in FIG. 8) that are separated from each other in the thickness direction. The arrangement and number of flow paths in each plane are the same as those of the planar flow path 22. Further, FIG. 8 shows an example in which both end portions of the plurality of planar sub-channels 23 do not penetrate the side surface 221 of the anode 2 and exist in the anode 2. Other configurations and operational effects are the same as those of the first embodiment.

(Embodiment 3)
The fuel cell single cell of Embodiment 3 is demonstrated using FIG.

  As illustrated in FIG. 9, in the single fuel cell 1 of the present embodiment, the dense body 6 covers the layer surface 211 of the anode 2 excluding the layer surface opening 212. That is, in the present embodiment, the portion of the outer surface of the anode 2 excluding the side surface opening 222 and the layer surface opening 212 is covered with the dense body 6. In this case, the fuel gas F can be prevented from leaking not only from the side surface 221 of the anode 2 excluding the side surface opening 222 but also from the layer surface 211 of the anode 2 excluding the layer surface opening 212. Other configurations and operational effects are the same as those of the first embodiment.

(Experimental example)
Hereinafter, it demonstrates more concretely using an experiment example.
<Single fuel cell of sample 1>
-Material preparation-
NiO powder (average particle size: 1.0 μm), 8YSZ powder (average particle size: 0.5 μm), carbon (pore forming agent), polyvinyl butyral, isoamyl acetate and 1-butanol are mixed in a ball mill. A slurry was prepared. At this time, the mass ratio of the NiO powder and the 8YSZ powder was set to 65:35. The average particle diameter is the particle diameter (diameter) d50 when the volume-based cumulative frequency distribution measured by the laser diffraction / scattering method shows 50% (hereinafter the same). The slurry was applied in a layer form on a resin carrier sheet using a doctor blade method and dried. This prepared the square-shaped raw sheet | seat with a carrier sheet. The thickness of the raw sheet is 100 μm.

  Using a mold consisting of a lower mold having a protrusion for forming a through hole and an upper mold having a fitting hole into which the tip of the protrusion is fitted, the lower mold and the upper mold are placed so that the carrier sheet is on the lower mold side. The raw sheet was sandwiched between the mold and the raw sheet was punched out together with the carrier sheet, which was separated from the mold. Thus, a through hole forming sheet having a plurality of through holes was formed. The plurality of through holes are arranged in a plurality of rows × a plurality of columns, specifically, 70 rows × 70 columns. The diameter of the through holes is 100 μm, and the pitch between the through holes is 0.9 mm. The lower mold protrusion in the used mold is tapered so that the cross-sectional area becomes smaller upward in order to facilitate demolding after sheet punching.

  Next, the punched carrier sheet is peeled off from the through hole forming sheet, and a slightly adhesive sheet is attached to the surface opposite to the peeling side of the carrier sheet, and the slightly adhesive sheet is placed on the lower side. did.

Next, after the acrylic beads, ethyl cellulose, terpineol, dispersant, leveling agent, and anti-settling agent were stirred with a planetary mixer, they were mixed with three rolls to prepare a vanishing agent paste. Note that the loss paste, _{Additional, Ag, Fe 2 O 3,} CuO, may contain _MoO 3, _Co 3 O 4, at least one selected from the group consisting of ZnO. In this case, it becomes possible to capture the S component that can be contained in the fuel gas F by the elements and compounds deposited on the channel wall surface, and to suppress the deactivation of the anode due to catalyst poisoning. Become. In addition, the extinguishing agent paste may contain at least one selected from the group consisting of TiO ₂ , SiO ₂ , and fluorine compounds. In this case, the compound deposited on the channel wall surface can impart a water repellency effect, and it is easy to suppress blockage of the channel due to water vapor generated by the anode reaction.

  Subsequently, the vanishing agent paste was filled into each through-hole in the through-hole forming sheet on the slightly adhesive sheet using a screen printing method and dried. Thereafter, the slightly adhesive sheet was peeled off. Thereby, the square-shaped processed sheet A was formed.

  A processed sheet B was formed on the surface of the processed sheet A by pattern printing of the disappearing agent paste using a screen printing method. The printed pattern formed on the processed sheet B is a linear pattern composed of 70 linear pastes arranged at equal intervals, and is for forming a planar flow path. In addition, each linear paste is arrange | positioned between each through-hole so that it may not overlap with each through-hole. Each linear paste has a line width of 125 μm, a line-to-line pitch of 0.9 mm, and a line thickness of 55 μm. Moreover, the one side edge part of each linear paste is not in contact with the end surface of the processed sheet B, and the other side edge part of each linear paste is in contact with the end surface on the opposite side to the end surface of the processed sheet B.

  NiO powder (average particle size: 1.0 μm), 8YSZ powder (average particle size: 0.2 μm), carbon, polyvinyl butyral, isoamyl acetate and 1-butanol (mixed solvent) are mixed in a ball mill. A slurry was prepared. At this time, the mass ratio of the NiO powder and the 8YSZ powder was set to 65:35. Using the doctor blade method, the slurry was applied in layers on a resin sheet, dried, and then the resin sheet was peeled off to prepare a square active layer forming sheet. The thickness of the active layer forming sheet was 30 μm. Note that the amount of carbon in the active layer forming sheet is smaller than that of the processed sheet A.

  A slurry was prepared by mixing 8YSZ powder (average particle size: 0.5 μm), polyvinyl butyral, isoamyl acetate and 1-butanol with a ball mill. Using the doctor blade method, the slurry was applied in layers on a resin sheet, dried, and then the resin sheet was peeled off to prepare a rectangular solid electrolyte layer forming sheet. The thickness of the solid electrolyte layer forming sheet was 5 μm.

A slurry was prepared by mixing CeO ₂ (10GDC) powder (average particle size: 0.3 μm) doped with 10 mol% Gd, polyvinyl butyral, isoamyl acetate, 2-butanol and ethanol with a ball mill. . Using the doctor blade method, the slurry was applied in layers on a resin sheet, dried, and then the resin sheet was peeled off to prepare a rectangular intermediate layer forming sheet. The thickness of the intermediate layer forming sheet was 4 μm.

A cathode forming paste was prepared by mixing LSC (La _0.6 Sr _0.4 CoO ₃ ) powder (average particle size: 2.0 μm), ethyl cellulose, and terpineol with three rolls.

-Cell fabrication-
By laminating processed sheet A, processed sheet A, processed sheet A, processed sheet B, active layer forming sheet, solid electrolyte layer forming sheet, and intermediate layer forming sheet in this order, and press-bonding, a laminate is obtained. Obtained. Each processed sheet was laminated with the positions of the through holes aligned. This is because the thickness direction flow path is constituted by the stacked through holes. Moreover, the edge part of a linear paste is exposed to one of the four end surfaces of a laminated body. This is because a side opening is formed on the side surface of the diffusion layer. In addition, a CIP molding method was used for pressure bonding. The CIP molding conditions were a temperature of 80 ° C., a pressing force of 50 MPa, and a pressing time of 10 minutes. Moreover, the laminated body was degreased after the pressure bonding.

  Next, the laminate was fired at 1350 ° C. for 2 hours. As a result, a sintered body was obtained in which a diffusion layer (350 μm), an active layer (25 μm), a solid electrolyte layer (4 μm), and an intermediate layer (3 μm) were laminated in this order. In addition, by the said baking, a vanishing agent paste lose | disappears, and the surface corresponding to the thickness direction flow path corresponding to the laminated | stacked through-hole, and a linear pattern in a diffused layer so that it may be illustrated in FIGS. Each directional flow path was formed.

Next, a crystallized glass material was applied to the side surface of the anode excluding the side surface opening in the sintered body and the side surface of the solid electrolyte layer using a dip coating method. Thereafter, this was baked at 850 ° C. for 2 hours to form a dense body made of crystallized glass. The thickness of the dense body is 8 μm, and the linear thermal expansion coefficient of the dense body is in the range of 5 × 10 ^{−6 to} 20 × 10 ⁻⁶ / K.

  Next, a cathode forming paste was applied to the surface of the intermediate layer in the sintered body by a screen printing method and baked at 950 ° C. for 2 hours to form a layered cathode (50 μm). Thus, a fuel cell single cell of Sample 1 was obtained.

  The present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Moreover, each structure shown by each embodiment can be combined arbitrarily. In the second embodiment, the diffusion layer 201 may not have the surface direction sub-channel 23. In the third embodiment, the dense body 6 may cover the side surface of the solid electrolyte layer 3.

DESCRIPTION OF SYMBOLS 1 Fuel cell single cell 2 Anode 21 Thickness direction flow path 211 Layer surface 212 Layer surface opening 22 Surface direction flow path 221 Side surface 222 Side surface opening 3 Solid electrolyte layer 5 Cathode 6 Dense body

Claims (6)

A flat fuel cell unit cell (1) having an anode (2), a solid electrolyte layer (3), and a cathode (5), and using the anode as a support,
The anode is arranged along the anode thickness direction, and has a plurality of thickness direction channels (21) having a layer surface opening (212) on the layer surface (211) opposite to the solid electrolyte layer side, and the anode surface direction. A plurality of planar flow paths (22) provided with side openings (222) on the side surface (221) of the anode,
A fuel cell single cell (1) in which the anode side surface excluding the side opening is covered with a gas-sealable dense body (6). 2. The fuel cell single cell according to claim 1, wherein the dense body has a linear thermal expansion coefficient in a range of 5 × 10 ^{−6 to} 20 × 10 ⁻⁶ / K.   3. The fuel cell single cell according to claim 1, wherein a thickness of the dense body is equal to or greater than a thickness of the solid electrolyte layer.   The fuel cell unit cell according to any one of claims 1 to 3, wherein the dense body further covers a side surface of the solid electrolyte layer.   The fuel cell unit cell according to any one of claims 1 to 4, wherein the dense body further covers a layer surface of the anode excluding the layer surface opening. The anode includes a diffusion layer (201) for diffusing the fuel gas (F) supplied to the anode in a layer surface, and an active layer (disposed on the solid electrolyte layer side of the diffusion layer) and serving as an anode reaction field ( 202)
The fuel cell single cell according to any one of claims 1 to 5, wherein the thickness direction flow path and the planar direction flow path are included in the diffusion layer.

Images