JP2008234910A - Ink for fuel cell electrode catalyst layer, and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable to draw out excellent battery performance by having a catalyst-supporting carbon in full contact with an ion exchange resin and to have dispersion stability capable of corresponding to a contiguous automatic coating, in ink for a fuel cell electrode catalyst layer. <P>SOLUTION: Pt50%-supporting carbon black, 20%-Nafion dispersion, distilled water and ethanol are mixed (S10), and mixture is added to a beads mill to carry out mixing and dispersing as a first dispersion process (S11). Then, by using a three-one motor +5 cm-square churning wing as a fluid treatment device, a flow treatment is carried out at 150 rpm to 300 rpm (S12). As a second dispersing process, a dispersion treatment is carried out (S13) by using the beads mill or an ultrasonic homogenizer. The obtained ink for a fuel cell electrode catalyst layer 1 includes dispersion stability capable of corresponding to a contiguous automatic coating, a churning-proof property and a share-proof property. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fuel cell electrode catalyst layer ink for forming a catalyst layer of an electrode used in a polymer electrolyte fuel cell, and a method for producing the same, and more particularly to a fuel cell electrode catalyst having high dispersion stability and capable of continuous automatic coating. The present invention relates to a layer ink and a method for producing the same.

  In a polymer electrolyte fuel cell, a cathode side electrode and an anode side electrode are formed on both sides of a polymer electrolyte membrane. Usually, the cathode side electrode and the anode side electrode are carbon carrying a catalyst such as platinum. Electrocatalyst layer composed of black and ion exchange resin, carbon black powder for imparting conductivity to carbon substrate such as carbon cloth and carbon paper, and polytetrafluoroethylene dispersion for imparting water repellency The gas diffusion layer is formed by applying a kneaded water repellent paste.

  Here, in order to put the polymer electrolyte fuel cell to practical use, it is necessary to mass-produce the electrode catalyst layer. However, in order to continuously produce the electrode catalyst layer, the catalyst layer ink is continuously applied automatically. Conventional inks for catalyst layers have poor stability and have problems in coating workability.

Therefore, in the invention disclosed in Patent Document 1, the dispersion stability of the ink for the catalyst layer is improved by using a polymer dispersant. In the invention disclosed in Patent Document 2, the dispersion stability of the ink for the catalyst layer is improved by adding the ion exchange resin in two stages at the time of preparing the ink for the catalyst layer.
Japanese Patent Laid-Open No. 2003-077479 Japanese Patent Laid-Open No. 2003-197205

  However, in the technique described in Patent Document 1, a polymer dispersant is used. When the fuel cell performance is compared with the case of dispersing to the same level without using the dispersant, the catalyst-supported carbon and the polymer dispersant are compared. However, there is a portion that is preferentially in contact, and the catalyst of that portion is not used, so the battery performance is degraded. Further, in the technique described in Patent Document 2, even if the ion exchange resin is added in two portions, the dispersion step is only once, and there is a portion where the ion exchange resin is not in contact with the catalyst-supporting carbon. There were many problems, and sufficient catalyst performance could not be obtained.

  Therefore, the present invention provides an ink for a fuel cell electrode catalyst layer that has sufficient dispersion stability that can be used for continuous automatic coating, while the ion-exchange resin is sufficiently in contact with the catalyst-supporting carbon to bring out good battery performance. It is an object to provide a manufacturing method thereof.

  The ink for a fuel cell electrode catalyst layer according to the invention of claim 1 is an ink for a fuel cell electrode catalyst layer for forming a catalyst layer of a solid polymer fuel cell composed mainly of a polymer electrolyte membrane. The mixture liquid containing the catalyst-supporting carbon, the ion exchange resin, and the solvent is dispersed, and the obtained dispersion liquid is allowed to flow for 1 hour to 30 hours, followed by further dispersion treatment.

  A fuel cell electrode catalyst layer ink according to a second aspect of the present invention is the ink according to the first aspect, wherein a mixed liquid containing the catalyst-supporting carbon, the ion-exchange resin, and the solvent is dispersed using a bead mill. is there.

  The fuel cell electrode catalyst layer ink according to a third aspect of the present invention is the fuel cell electrode catalyst layer ink according to the first or second aspect, wherein the fluidized time is in the range of 3 to 20 hours.

  According to a fourth aspect of the present invention, there is provided a fuel cell electrode catalyst layer ink comprising: a fuel cell electrode catalyst layer ink for forming a catalyst layer of a polymer electrolyte fuel cell having a polymer electrolyte membrane as a center; A first dispersion step in which a mixed solution containing a catalyst-supporting carbon, an ion exchange resin, and a solvent is dispersed using a bead mill; and the dispersion obtained in the first dispersion step is treated for 1 hour. It includes a fluid state maintaining step for maintaining the fluid state for 30 hours and a second dispersion step for further performing a dispersion treatment.

  According to a fifth aspect of the present invention, there is provided the method for producing an ink for a fuel cell electrode catalyst layer according to the fourth aspect, wherein the time during which the fluid state is maintained in the fluid state maintaining step is in the range of 3 hours to 20 hours. It is.

  The ink for a fuel cell electrode catalyst layer according to the invention of claim 1 is an ink for a fuel cell electrode catalyst layer for forming a catalyst layer of a solid polymer fuel cell composed mainly of a polymer electrolyte membrane. Then, a mixed liquid containing the catalyst-supporting carbon, the ion exchange resin, and the solvent is dispersed, and the obtained dispersion is fluidized for 1 hour to 30 hours, followed by further dispersion treatment.

  As a result of accumulating earnest experimental research, the present inventor dispersed a mixed liquid containing catalyst-carrying carbon, an ion exchange resin, and a solvent, and kept the obtained dispersion in a fluid state for 1 hour or more. Further, by carrying out a dispersion treatment, the catalyst-carrying carbon and the ion exchange resin are sufficiently uniformly mixed, and furthermore, a fuel cell having storage stability, agitation resistance, and shear resistance to cope with continuous automatic coating. The present inventors have found that an ink for an electrode catalyst layer can be obtained, and have completed the present invention based on this finding.

  Here, it is particularly important that the dispersion once obtained is once retained in a fluid state and then dispersed again. The time for maintaining the fluidized state is insufficient if it is less than 1 hour, and if it exceeds 30 hours, the productivity deteriorates, and therefore it is preferably in the range of 1 hour to 30 hours.

  In this way, the ion-exchange resin can be sufficiently brought into contact with the catalyst-supporting carbon to bring out good battery performance, and it becomes a fuel cell electrode catalyst layer ink having dispersion stability that can be applied to continuous automatic coating. .

  In the fuel cell electrode catalyst layer ink according to the second aspect of the invention, a mixed liquid containing the catalyst-supporting carbon, the ion exchange resin, and the solvent is dispersed using a bead mill.

  As a result of accumulating extensive experimental research, the present inventor has first dispersed a mixed liquid containing catalyst-supporting carbon, ion exchange resin and solvent using a bead mill, and the resulting dispersion is in a fluid state for 1 hour or longer. The catalyst-supporting carbon and the ion exchange resin are sufficiently uniformly mixed, and storage stability, agitation resistance, and shear resistance to support continuous automatic coating. The present inventors have found that an ink for a fuel cell electrode catalyst layer having properties can be obtained, and have completed the present invention based on this finding.

  In this way, the ion-exchange resin can be sufficiently brought into contact with the catalyst-supporting carbon to bring out good battery performance, and it becomes a fuel cell electrode catalyst layer ink having dispersion stability that can be applied to continuous automatic coating. .

  In the fuel cell electrode catalyst layer ink according to the third aspect of the invention, the time for the fluidized state is in the range of 3 to 20 hours. By maintaining the fluidized state for 3 hours or longer, an ink for a fuel cell electrode catalyst layer having storage stability, agitation resistance, and shear resistance to more reliably support continuous automatic coating can be obtained. Therefore, productivity is improved by setting it within 20 hours.

  In this way, the ion-exchange resin can be sufficiently brought into contact with the catalyst-supporting carbon to bring out good battery performance, and it becomes a fuel cell electrode catalyst layer ink having dispersion stability that can be applied to continuous automatic coating. .

  According to a fourth aspect of the present invention, there is provided a method for producing an ink for a fuel cell electrode catalyst layer, comprising: A first dispersion step in which a mixed solution containing a catalyst-supporting carbon, an ion exchange resin, and a solvent is dispersed using a bead mill; and the dispersion obtained in the first dispersion step is treated for 1 hour to A fluid state maintaining step of maintaining the fluid state for 30 hours, and a second dispersion step of further performing a dispersion treatment.

  As a result of accumulating extensive experimental research, the present inventor has first dispersed a mixed liquid containing catalyst-supporting carbon, ion exchange resin and solvent using a bead mill, and the resulting dispersion is in a fluid state for 1 hour or longer. The catalyst-supporting carbon and the ion exchange resin are sufficiently uniformly mixed, and storage stability, agitation resistance, and shear resistance to support continuous automatic coating. The present inventors have found that an ink for a fuel cell electrode catalyst layer having properties can be obtained, and have completed the present invention based on this finding.

  Here, it is particularly important that the dispersion once obtained is once retained in a fluid state and then dispersed again. The time for maintaining the fluidized state is insufficient if it is less than 1 hour, and if it exceeds 30 hours, the productivity deteriorates, and therefore it is preferably in the range of 1 hour to 30 hours.

  In this way, the ion-exchange resin can be sufficiently brought into contact with the catalyst-supporting carbon to bring out good battery performance, and at the same time, manufacture of an ink for a fuel cell electrode catalyst layer having dispersion stability that can be applied to continuous automatic coating Become a method.

  In the method for producing an ink for a fuel cell electrode catalyst layer according to the invention of claim 5, the time for maintaining the fluid state in the fluid state maintaining step is in the range of 3 hours to 20 hours.

  Fuel cell electrode catalyst having storage stability, agitation resistance, and shear resistance for more reliably supporting continuous automatic coating by setting the time for maintaining the fluid state in the fluid state maintaining step to 3 hours or more. A layer ink can be obtained, and the productivity can be further improved by setting the ink within 20 hours.

  In this way, the ion-exchange resin can be sufficiently brought into contact with the catalyst-supporting carbon to bring out good battery performance, and at the same time, manufacture of an ink for a fuel cell electrode catalyst layer having dispersion stability that can be applied to continuous automatic coating Become a method.

  Hereinafter, an ink for a fuel cell electrode catalyst layer and a method for producing the same according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a flowchart showing a method for producing an ink for a fuel cell electrode catalyst layer according to an embodiment of the present invention.

Embodiment 1
First, the method for producing the ink for the fuel cell electrode catalyst layer according to the first embodiment of the present invention will be described. The fuel cell electrode catalyst layer ink according to the first embodiment is an air electrode (anode electrode) catalyst layer ink.

  The air electrode catalyst layer ink as the fuel cell electrode catalyst layer ink according to the first embodiment includes Pt (platinum) 50% supported carbon black as catalyst supported carbon, and Wako Pure Chemical Industries, Ltd. as ion exchange resin. ) 20% Nafion dispersion, distilled water as a solvent and ethanol. Table 1 shows the composition of the air electrode catalyst layer ink according to the first embodiment.

  Next, a method for producing the fuel cell electrode catalyst layer ink according to the first embodiment will be described with reference to the flowchart of FIG. First, Pt 50% -supported carbon black, 20% Nafion dispersion, distilled water and ethanol are mixed according to the composition shown in Table 1 (step S10). And as a 1st dispersion | distribution process, a mixture is put into a bead mill and mixing and dispersion | distribution are performed (step S11).

  As the bead mill, PCM-L 0.5 mm zirconia bead mill (disperser A) manufactured by Asada Tekko Co., Ltd. or batch SG · 2 mm zirconia bead mill (disperser B) was used. Subsequently, the dispersion was subjected to flow treatment for a predetermined time using a flow treatment apparatus. As a flow treatment apparatus, a flow treatment was performed at 150 rpm to 300 rpm using a three-one motor + 5 cm square stirring blade (step S12).

  And as a 2nd dispersion | distribution process, the dispersion process was performed using the said disperser A or the ultrasonic homogenizer UH-300 (disperser C) made from SMT (step S13). Through the above steps, the fuel cell electrode catalyst layer ink 1 according to the first embodiment was manufactured. The batch scale is 300 g for the first dispersion step, 200 g for the flow treatment step, and 200 g for the second dispersion step. Table 2 summarizes the dispersers used.

  In such a production process, the fuel cell electrode catalyst layer ink 1 according to Examples 1 to 5 was produced by changing the dispersion conditions or the flow treatment time. For comparison, the fuel cell electrode catalyst layer inks according to Comparative Examples 1 to 6 were manufactured by a manufacturing process partially different from the manufacturing process shown in the flowchart of FIG. The production conditions of the ink for the fuel cell electrode catalyst layer according to Examples 1 to 5 and Comparative Examples 1 to 6 are collectively shown in the upper part of Table 3.

  As shown in the upper part of Table 3, in the manufacturing process of the fuel cell electrode catalyst layer ink 1 according to Examples 1 to 5, all the first dispersion treatment was performed by a bead mill (disperser A or disperser B). The flow process is performed for 3 hours or more, and the second dispersion process is always performed. Therefore, the fuel cell electrode catalyst layer ink 1 according to Examples 1 to 5 and the method for producing the same satisfy all the conditions according to claims 1 to 4 of the present invention.

  On the other hand, as shown in the upper part of Table 3, in the manufacturing process of the fuel cell electrode catalyst layer ink according to Comparative Examples 1 to 6, the first dispersion treatment is performed by ultrasonic dispersion (disperser C). Or the flow treatment is performed for less than 1 hour or not at all, or the second dispersion treatment is not performed. From the conditions according to claims 1 and 3 of the present invention, either The condition is not met.

  The characteristics of the fuel cell electrode catalyst layer inks according to Examples 1 to 5 and Comparative Examples 1 to 6 were evaluated. Specifically, in order to evaluate the median diameter at the time of completion of production and storage stability, the median diameter after standing at 20 ° C. for 2 weeks is measured, and as an appropriate evaluation for continuous automatic coating, stirring resistance is evaluated. In order to check the shear resistance in the liquid feed pump, the increase in viscosity was measured.

  The median diameter was measured using HORIBA LA-910 manufactured by Horiba, Ltd. Stir resistance is determined by stirring 150 g of fuel cell electrode catalyst layer ink with PTFE 5 cm square feathers at 150 rpm for 10 hours, and checking for the presence or absence of aggregation and increase in viscosity. The case where aggregation or viscosity increase was observed was evaluated as x. The shear resistance was measured by using an E-type viscometer at 200 s-1 (1 ° 34'R24 rotor 53 rpm) for 3 minutes, where no increase in viscosity was observed, and when increase in viscosity was observed × It was evaluated. Each evaluation result is summarized in the lower part of Table 3.

  As shown in the lower part of Table 3, in the fuel cell electrode catalyst layer ink 1 according to Examples 1 to 5, the median diameter after standing at 20 ° C. for 2 weeks is the same as the median diameter at the time of completion of production. However, it was found that the dispersion stability was excellent. In addition, both the stirring resistance after 1 day of manufacturing and the stirring resistance after 2 weeks of manufacturing are both evaluated as “good”, and both the shear resistance after 1 day of manufacturing and the shear resistance after 2 weeks of manufacturing are evaluated as “good”. Yes, the overall judgment was rated as ○.

  On the other hand, in the fuel cell electrode catalyst layer inks according to Comparative Examples 1 to 6, as shown in the lower part of Table 3, except for Comparative Example 4, the inks were allowed to stand at 20 ° C. for 2 weeks. The median diameter was increased more than the median diameter at the completion of production, and in Comparative Example 4, undispersed particles of about 20 μm remained. Furthermore, except for Comparative Example 3 and Comparative Example 4, both the stirring resistance after 1 day of manufacturing and the stirring resistance after 2 weeks of manufacturing were evaluated as x, and the shear resistance after 1 day of manufacturing was 2 weeks after manufacturing. Each share resistance was evaluated as x. As a result, all the comprehensive judgments were evaluated as Δ or ×.

  In this way, in the fuel cell electrode catalyst layer ink 1 produced by the manufacturing method of Examples 1 to 5 according to the first embodiment, the ion-exchange resin is sufficiently in contact with the catalyst-supporting carbon, and a good battery is obtained. It was revealed that the performance can be extracted, the dispersion stability can be applied to continuous automatic coating, the stirring resistance indicating the appropriateness for continuous automatic coating, and the shear resistance in the liquid feed pump.

Embodiment 2
Next, the manufacturing method of the fuel cell electrode catalyst layer ink according to the second embodiment of the present invention will be described. The fuel cell electrode catalyst layer ink according to the second embodiment is a fuel electrode (cathode electrode) catalyst layer ink.

  The fuel electrode catalyst layer ink as the fuel cell electrode catalyst layer ink according to the second embodiment includes Pt (platinum) 50% supported carbon black as catalyst supported carbon, and Wako Pure Chemical Industries, Ltd. as ion exchange resin. ) 20% Nafion dispersion, distilled water as a solvent and ethanol. Table 4 shows the composition of the fuel electrode catalyst layer ink according to the second embodiment.

  The manufacturing procedure is the same as the manufacturing procedure of the first embodiment shown in the flowchart of FIG. The batch scale is 300 g for the first dispersion step, 200 g for the flow treatment step, and 200 g for the second dispersion step. The dispersers used are summarized in Table 5.

  In such a production process, the fuel cell electrode catalyst layer inks according to Examples 6 to 10 were produced by changing the dispersion conditions or the flow treatment time. For comparison, the fuel cell electrode catalyst layer inks according to Comparative Examples 7 to 10 were manufactured by a manufacturing process partially different from the manufacturing process shown in the flowchart of FIG. The production conditions of the fuel cell electrode catalyst layer inks according to Examples 6 to 10 and Comparative Examples 7 to 10 are collectively shown in the upper part of Table 6.

  As shown in the upper part of Table 6, in the manufacturing process of the fuel cell electrode catalyst layer ink according to Examples 6 to 10, all the first dispersion treatment was performed by a bead mill (disperser A or disperser B). The flow process is performed for 3 hours or more, and the second dispersion process is always performed. Therefore, the fuel cell electrode catalyst layer inks according to Examples 6 to 10 and the method for producing the same satisfy all the conditions according to claims 1 to 4 of the present invention.

  On the other hand, as shown in the upper part of Table 6, in the manufacturing process of the fuel cell electrode catalyst layer ink according to Comparative Example 7 to Comparative Example 10, the first dispersion treatment is performed by ultrasonic dispersion (disperser C). Or the flow treatment is performed for less than 1 hour or not at all, or the second dispersion treatment is not performed. From the conditions according to claims 1 and 3 of the present invention, either The condition is not met.

  The characteristics of the inks for fuel cell electrode catalyst layers according to Examples 6 to 10 and Comparative Examples 7 to 10 were evaluated. Specifically, in order to evaluate the median diameter at the time of completion of production and storage stability, the median diameter after standing at 20 ° C. for 2 weeks is measured, and as an appropriate evaluation for continuous automatic coating, stirring resistance is evaluated. In order to check the shear resistance in the liquid feed pump, the increase in viscosity was measured.

  The median diameter was measured using HORIBA LA-910 manufactured by Horiba, Ltd. Stir resistance is determined by stirring 150 g of fuel cell electrode catalyst layer ink with PTFE 5 cm square feathers at 150 rpm for 10 hours, and checking for the presence or absence of aggregation and increase in viscosity. The case where aggregation or viscosity increase was observed was evaluated as x. The shear resistance was measured by using an E-type viscometer at 200 s-1 (1 ° 34'R24 rotor 53 rpm) for 3 minutes, where no increase in viscosity was observed, and when increase in viscosity was observed × It was evaluated. Each evaluation result is summarized in the lower part of Table 6.

  As shown in the lower part of Table 6, in the fuel cell electrode catalyst layer inks according to Examples 6 to 10, the median diameter after standing at 20 ° C. for 2 weeks is the same as the median diameter at the completion of production. It was found that the dispersion stability was excellent without any change. In addition, both the stirring resistance after 1 day of manufacturing and the stirring resistance after 2 weeks of manufacturing are both evaluated as “good”, and both the shear resistance after 1 day of manufacturing and the shear resistance after 2 weeks of manufacturing are evaluated as “good”. Yes, the overall judgment was rated as ○.

  On the other hand, in the fuel cell electrode catalyst layer inks according to Comparative Examples 7 to 10, as shown in the lower part of Table 6, except for Comparative Examples 9 and 10, the inks were kept at 20 ° C. for 2 weeks. The median diameter after standing was larger than the median diameter at the completion of production, and in Comparative Example 10, undispersed particles of about 20 μm remained. Further, in any of Comparative Examples 7 to 10, both the stirring resistance after 1 day of manufacture and the stirring resistance after 2 weeks of manufacture are evaluated as x, and the shear resistance after 1 day of manufacture is also evaluated after 2 weeks of manufacture. The share resistance was also evaluated as x. As a result, the overall judgment was evaluated as x.

  In this way, in the fuel cell electrode catalyst layer inks produced by the production methods of Examples 6 to 10 according to the second embodiment, the ion-exchange resin is sufficiently in contact with the catalyst-supporting carbon, and the battery performance is good. As a result, it has been revealed that it has dispersion stability that can be applied to continuous automatic coating, agitation resistance indicating appropriateness for continuous automatic coating, and share resistance in a liquid feed pump.

Embodiment 3
Next, the manufacturing method of the fuel cell electrode catalyst layer ink according to the third embodiment of the present invention will be described. The fuel cell electrode catalyst layer ink according to the third embodiment is an air electrode (anode electrode) catalyst layer ink similar to the first embodiment.

  The air electrode catalyst layer ink as the fuel cell electrode catalyst layer ink according to the third embodiment includes Pt (platinum) 50% supported carbon black as catalyst supported carbon, and Wako Pure Chemical Industries, Ltd. as ion exchange resin. ) 20% Nafion dispersion, distilled water as a solvent and ethanol. Table 7 shows the composition of the fuel electrode catalyst layer ink according to the third embodiment.

  The manufacturing procedure is the same as the manufacturing procedure of the first embodiment shown in the flowchart of FIG. The batch scale and the used disperser A and disperser C are the same as those in the first embodiment and the second embodiment.

  In such a production process, the flow treatment time was changed for comparison, and the fuel cell electrode catalyst layer inks according to Example 11 and Comparative Example 11 were produced. The production conditions of the ink for the fuel cell electrode catalyst layer according to Example 11 and Comparative Example 11 are summarized in the upper part of Table 8.

  As shown in the upper part of Table 8, in the manufacturing process of the fuel cell electrode catalyst layer ink according to Example 11 and Comparative Example 11, the first dispersion treatment is performed by a bead mill (dispersing machine A), and the flow treatment is performed. And the second distributed processing is also performed (dispersing machine C). The difference between Example 11 and Comparative Example 11 is that the flow treatment time of Example 11 is 10 hours, whereas the flow treatment time of Comparative Example 11 is 0.5 hours. And the point which does not satisfy | fill the conditions concerning Claim 3 is only.

  The characteristics of the ink for the fuel cell electrode catalyst layer according to Example 11 and Comparative Example 11 were evaluated. Specifically, in order to evaluate the median diameter at the time of completion of production and storage stability, the median diameter after standing at 20 ° C. for 2 weeks is measured, and as an appropriate evaluation for continuous automatic coating, stirring resistance is evaluated. In order to check the shear resistance in the liquid feed pump, the increase in viscosity was measured.

  The median diameter was measured using HORIBA LA-910 manufactured by Horiba, Ltd. Stir resistance was determined by stirring 150 g of fuel cell electrode catalyst layer ink with PTFE 5 cm square feathers at 150 rpm for 10 hours and checking for the presence of aggregation and viscosity increase. The case where aggregation or viscosity increase was observed was evaluated as x. The shear resistance was measured with an E-type viscometer at 200 s-1 (1 ° 34'R24 rotor 53 rpm) for 3 minutes, where no increase in viscosity was observed, and when an increase in viscosity was observed × It was evaluated. The evaluation results are summarized in the lower part of Table 8.

  As shown in the lower part of Table 8, in the fuel cell electrode catalyst layer ink according to Example 11, the median diameter after standing at 20 ° C. for 2 weeks was completely different from the median diameter at the completion of production. It was found that the dispersion stability was excellent. In addition, the agitation resistance after 1 day of production and the agitation resistance after 2 weeks of production are evaluated as “good”, and the share resistance after 1 day of production and the share resistance after 2 weeks of production are also evaluated as “good”. All were evaluated as ○.

  On the other hand, in the fuel cell electrode catalyst layer ink according to Comparative Example 11, as shown in the lower part of Table 8, the median diameter after standing at 20 ° C. for 2 weeks is larger than the median diameter at the completion of production. The agitation resistance after 1 day of production and the agitation resistance after 2 weeks of production were evaluated as x, and the share resistance after 1 day of production and the shear resistance after 2 weeks of production were evaluated as x. It was. As a result, the overall judgment was evaluated as x.

  In this way, in the fuel cell electrode catalyst layer ink according to the manufacturing method of Example 11 according to the third embodiment, the ion-exchange resin sufficiently contacts the catalyst-supporting carbon, and good battery performance can be obtained. As a result, it became clear that it has dispersion stability that can be applied to continuous automatic coating, agitation resistance indicating appropriateness for continuous automatic coating, and shear resistance in a liquid feed pump.

  In each of the above embodiments, Pt (platinum) 50% supported carbon black is used as catalyst-supported carbon, 20% Nafion dispersion manufactured by Wako Pure Chemical Industries, Ltd. is used as an ion exchange resin, and distilled water and ethanol are used as solvents. However, the catalyst-supporting carbon, the ion exchange resin, and the solvent are not limited to these.

In practicing the present invention, other configurations, components, materials, blends, shapes, sizes, manufacturing methods, etc. of the fuel cell electrode catalyst layer ink are also included in the fuel cell electrode catalyst layer ink manufacturing method. The process is not limited to the above embodiments.
In addition, since the numerical value raised in the embodiment of the present invention does not indicate a critical value but indicates a preferable value suitable for implementation, even if the numerical value is slightly changed, implementation is not denied. Absent.

FIG. 1 is a flowchart showing a method for producing an ink for a fuel cell electrode catalyst layer according to an embodiment of the present invention.

Explanation of symbols

  1 Ink for fuel cell electrode catalyst layer

Claims (5)

An ink for a fuel cell electrode catalyst layer for forming a catalyst layer of a solid polymer fuel cell composed mainly of a polymer electrolyte membrane,
A fuel cell obtained by dispersing a mixed liquid containing a catalyst-supporting carbon, an ion exchange resin, and a solvent, and allowing the obtained dispersion to be in a fluid state for 1 to 30 hours, followed by further dispersion treatment. Ink for electrode catalyst layer.   2. The fuel cell electrode catalyst layer ink according to claim 1, wherein a mixed liquid containing the catalyst-supporting carbon, the ion-exchange resin, and the solvent is dispersed using a bead mill.   3. The fuel cell electrode catalyst layer ink according to claim 1, wherein the time for the fluidized state is within a range of 3 hours to 20 hours. 4. A method for producing an ink for a fuel cell electrode catalyst layer for forming a catalyst layer of a solid polymer fuel cell composed mainly of a polymer electrolyte membrane,
A first dispersion step in which a mixed solution containing a catalyst-supporting carbon, an ion exchange resin, and a solvent is dispersed using a bead mill;
A fluid state maintaining step of maintaining the dispersion obtained in the first dispersion step in a fluid state for 1 to 30 hours;
A method for producing an ink for a fuel cell electrode catalyst layer, further comprising a second dispersion step for performing a dispersion treatment.   5. The method for producing an ink for a fuel cell electrode catalyst layer according to claim 4, wherein the time for maintaining the fluid state in the fluid state maintaining step is in the range of 3 hours to 20 hours.

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