WO2011024360A1 - 高分子形燃料電池の運転方法 - Google Patents
高分子形燃料電池の運転方法 Download PDFInfo
- Publication number
- WO2011024360A1 WO2011024360A1 PCT/JP2010/003930 JP2010003930W WO2011024360A1 WO 2011024360 A1 WO2011024360 A1 WO 2011024360A1 JP 2010003930 W JP2010003930 W JP 2010003930W WO 2011024360 A1 WO2011024360 A1 WO 2011024360A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- electrolyte membrane
- catalyst layer
- fuel cell
- cathode
- height
- Prior art date
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04082—Arrangements for control of reactant parameters, e.g. pressure or concentration
- H01M8/04089—Arrangements for control of reactant parameters, e.g. pressure or concentration of gaseous reactants
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
- H01M4/8636—Inert electrodes with catalytic activity, e.g. for fuel cells with a gradient in another property than porosity
- H01M4/8642—Gradient in composition
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04298—Processes for controlling fuel cells or fuel cell systems
- H01M8/04694—Processes for controlling fuel cells or fuel cell systems characterised by variables to be controlled
- H01M8/04828—Humidity; Water content
- H01M8/04835—Humidity; Water content of fuel cell reactants
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/10—Fuel cells with solid electrolytes
- H01M8/1004—Fuel cells with solid electrolytes characterised by membrane-electrode assemblies [MEA]
- H01M8/1006—Corrugated, curved or wave-shaped MEA
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04082—Arrangements for control of reactant parameters, e.g. pressure or concentration
- H01M8/04089—Arrangements for control of reactant parameters, e.g. pressure or concentration of gaseous reactants
- H01M8/04119—Arrangements for control of reactant parameters, e.g. pressure or concentration of gaseous reactants with simultaneous supply or evacuation of electrolyte; Humidifying or dehumidifying
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/50—Fuel cells
Definitions
- the present invention relates to a power generation method for a polymer fuel cell using hydrogen or a hydrocarbon such as alcohol as a fuel, which can be used as a power source for electric vehicles or a home power system.
- Patent Document 1 discloses a method of forming a concavo-convex structure on the surface of the electrolyte membrane by pressing a mold (template) having a concavo-convex structure formed from a material having a hardness higher than that of the electrolyte membrane on the surface of the electrolyte membrane. ing.
- Patent Document 2 an uneven structure is provided in advance on the surface of a base film that also serves as protection of the electrolyte membrane, a polymer film-forming material is applied on the base film and dried, and then the base film is A method is disclosed in which an uneven structure is formed on the surface of an electrolyte membrane by peeling it from the electrolyte membrane.
- Non-Patent Document 1 a precursor liquid of an electrolyte material that is cured by ultraviolet rays is poured onto a template film formed from polycyanomethyl acrylate and subjected to microfabrication on the surface. A method of peeling from a sheet is disclosed.
- FIG. 3 of Patent Document 1 shows a flowchart for explaining each step of forming microprotrusions on the electrolyte membrane surface.
- the electrolyte membrane 201 placed on the metal table 204 is pressed by a molding die 203 having a predetermined concave shape to form columnar microprojections 104 on the surface of the electrolyte membrane.
- Two types of structures are disclosed as the shape of the microprotrusions (represented as pillars in the table of Patent Document 1). That is, a so-called rod-shaped microprojection (FIGS.
- Patent Document 1 and 2 of Patent Document 1 having a diameter of about 0.3 ⁇ m and a length of 3 ⁇ m, and a length (height) of 0.5 to 5 ⁇ m and a length (height) of 0. These are 25-2.6 ⁇ m disk-shaped minute projections (FIGS. 5, 7, and 8 of Patent Document 1).
- a carbonized layer is formed on the surface of microprotrusions by heating at 100 ° C. for 2 minutes in a nitrogen atmosphere or by sputtering, and a metal catalyst such as platinum is formed on the carbonized layer.
- a method for precipitating is disclosed.
- Patent Document 1 does not disclose a feasible manufacturing method.
- the effectiveness of the rod-shaped microprotrusions is unknown.
- an example in which a concave mold is pressed against a sulfomethylated polyethersulfone membrane is disclosed.
- the height of the microprojections was 0.5 to 1 ⁇ m, and the diameter of the microprojections was 2.6 ⁇ m at the maximum.
- the thickness of the catalyst layer formed on the surface of the electrolyte membrane having minute protrusions is considerably thick at 160 ⁇ m on the cathode side and 55 ⁇ m on the anode side.
- FIG. 2 of Patent Document 2 shows a flowchart for explaining each step of forming a micro uneven structure on the electrolyte membrane surface by cast molding.
- the microprojections 4a on the roller 10 are transferred onto the protective sheet by pressing the protective sheet 3a (3b) with the two rollers 10 and 11.
- the hydrocarbon-based polymer film-forming material 12 is discharged from the nozzle 13 onto the protective sheet, spreads uniformly with the doctor blade 14, and dried to form an electrolyte film.
- the shape of the micro uneven structure on the electrolyte membrane only the same contents as those disclosed in Patent Document 1 are disclosed. Furthermore, no sufficient disclosure has been made regarding power generation conditions, particularly humidification conditions of the supplied gas.
- Patent Document 3 discloses a method of forming a convex portion by attaching a particulate electrolyte to a flat film and a method of dissolving a part of the flat film.
- the power generation performance when an anode gas and a cathode gas having a relative humidity of 26% are used is disclosed.
- a fuel cell having a convex portion on the electrolyte membrane gives a high voltage under the same conditions, there is no suggestion about the relationship between the shape of the convex portion and suitable humidification conditions (in particular, Patent Document 3). In paragraphs 0020 and 0036).
- Non-Patent Document 1 3 ⁇ m ⁇ 3 ⁇ m fine insertion portions (concave portions) regularly arranged are formed on the electrolyte membrane surface, and the depth is gradually deepened to 1.4 ⁇ m, 1.9 ⁇ m, 3.7 ⁇ m. Then, it is disclosed that the performance is improved at a low current density, but the performance is decreased at a high current density.
- the desirable shape of the microstructure on the electrolyte membrane surface and the humidification conditions of the supply gas are not mentioned.
- Patent Document 4 can be cited as a document related to the present invention.
- JP-A-2005-108822 (especially 0025, 0037 to 0040, 0049 to 0057, FIG. 8 (a)), 0045 to 0048, FIG. 8 (b), 0062, 0068, 0069, FIG. 8 (c)) JP 2006-331720 A (0022-0025, FIG. 9) Japanese Patent Laying-Open No. 2005-085544 JP 2008-004486 A
- Patent Documents 1 and 2 and Non-Patent Document 1 disclose that the effect of improving the output density can be obtained by forming microprotrusions on the electrolyte membrane and increasing the surface area. However, it has not been clarified which parameter dominantly affects the performance of the fuel cell among various parameters related to the shape of the uneven portion. In addition, the power density improvement shown in each document is small, and a great effect of changing the practical value of the fuel cell has not been achieved.
- the inventors proceeded with research on the shape of the convex and concave portions in the electrolyte membrane having a concave and convex structure, identified a factor that dominantly improves the performance of the fuel cell, and combined with this, the relative humidity of the oxygen-containing gas used As a result, it was found that the polymer fuel cell continues to exhibit excellent current-voltage characteristics in a stable manner.
- the present invention is as follows.
- a method for generating electric power using a polymer electrolyte fuel cell comprising the following steps (A) and (B): Preparing the polymer electrolyte fuel cell (A), wherein the polymer electrolyte fuel cell comprises a cathode, an anode, and an electrolyte membrane sandwiched between the cathode and the anode;
- the surface of the electrolyte membrane facing the cathode includes a plurality of convex portions having a height of 5 ⁇ m or more and 15 ⁇ m or less or a plurality of concave portions having a depth of 5 ⁇ m or more and 15 ⁇ m or less
- the cathode is composed of a catalyst layer formed in close contact with the surface, and the thickness of the catalyst layer is 1 to 3 times the height of the convex portion or the depth of the concave portion,
- the battery performance improvement effect due to the unevenness of the membrane surface is mainly interpreted as an increase in the contact area between the electrolyte membrane and the catalyst layer. It is described as existing. As a result, a structure for increasing the surface area of the electrolyte membrane has been proposed regardless of the thickness of the catalyst layer.
- the present inventors succeeded in obtaining data on the cathode side that the proton bypass transport effect is an essential factor for improving battery performance.
- the structure which controlled the thickness of the catalyst layer by making the depth of a recessed part large and the cathode side thin was employ
- reaction gas is generally humidified so as to obtain high power generation performance in a flat electrolyte membrane.
- this humidified reaction gas is supplied to the electrolyte membrane having a concavo-convex structure and the fuel cell is operated, the generated water condenses and stays in the deep part of the catalyst layer. Will fall. The performance deterioration due to the retention of water becomes more noticeable when the operation is performed at a high current density.
- a fuel cell in which the height of the convex portion or the depth of the concave portion provided on the surface of the electrolyte membrane on the cathode side is large and the thickness of the catalyst layer on the cathode side is adjusted to be thin is adjusted with the oxygen-containing gas supplied to the cathode side.
- the relative humidity By setting the relative humidity to 10% or less, the produced water or condensed water does not stay, and it is possible to continuously exhibit high performance that has not been achieved in the past.
- Example 1 Schematic diagram showing the shape of the cathode side surface of the electrolyte membrane in the first embodiment of the present invention
- Example 1 the current-voltage characteristic diagram which MEA in which the diameter (phi) of the convex part and the space
- the humidified dew point of the supply gas is 90 ° C. (relative humidity 100%).
- the humidified dew point of the supply gas is 80 ° C. (relative humidity 67%).
- the current-voltage characteristic figure immediately after the evaluation start which MEA in which the height of the convex part was variously changed shows.
- the humidified dew point of the supply gas is 90 ° C.
- Example 1 The humidified dew point of the supply gas is 80 ° C. (relative humidity 67%).
- the MEA by which the height of the convex part was changed variously shows the current-voltage characteristic diagram after 5 hours from the start of evaluation.
- the humidified dew point of the supply gas is 90 ° C. (relative humidity 100%).
- the humidified dew point of the supply gas is 80 ° C. (relative humidity 67%).
- Example 1 the MEA by which the height of the convex part was changed variously shows the current-voltage characteristic diagram after 5 hours from the start of evaluation.
- the humidification dew point of the supply gas is 70 ° C. (relative humidity 44%).
- the humidification dew point of the supply gas is 40 ° C. (relative humidity 10%).
- the MEA having a convex portion height of 10 ⁇ m or 15 ⁇ m shows 5 from the start of evaluation.
- Current-voltage characteristics after time In Example 2 the current-voltage characteristic diagram after the elapse of 5 hours from the start of evaluation, indicated by the MEA having a convex portion height of 10 ⁇ m or 15 ⁇ m.
- Voltage characteristics Cross-sectional conceptual diagram showing the configuration of a polymer fuel cell used in the present invention
- a fuel cell containing Nafion (trade name, DuPont) made of a fluorine-based polymer as an electrolyte membrane will be described as an example of a method of generating power by supplying hydrogen gas to the anode side.
- the present invention is not limited to the case of using a fuel cell including an electrolyte made of a fluorine-based polymer, and can be widely applied to fuel cells having a gas diffusing electrode.
- FIG. 1 is a conceptual diagram illustrating the surface of an electrolyte membrane 3 having an uneven structure in the present invention.
- a flat bottom base 1 is formed continuously, and a structure in which a plurality of discontinuous protrusions (convex parts) are formed on the flat bottom base 1 is projected in the present invention. Called a type.
- a structure in which the planar upper base 2 is continuously formed and a plurality of discontinuous holes (concaves) are formed in the planar upper base 2 is referred to as a concave mold.
- a cylindrical shape is shown as a representative example of the shape of the convex portion and the concave portion, but it may be a polygonal column such as a quadrangular column or a triangular column.
- a cone or a polygonal pyramid may be used, and convex portions or concave portions having various shapes can be applied.
- This uneven structure is provided on the cathode side, and a cathode catalyst layer is provided on the surface of the electrolyte membrane having the uneven structure.
- this invention is described mainly about a convex type, this invention is applicable also to a concave type.
- the area where the catalyst layer contacts the electrolyte membrane is increased compared to the case of a flat electrolyte membrane.
- this increase in the contact area can be expected to contribute to the improvement of proton conductivity and adhesion between the catalyst layer and the electrolyte membrane, protons are easily and easily reduced to every corner of the catalyst layer. It does not contribute to the bypass transport effect of protons supplied by resistance.
- the catalyst layer and the electrolyte membrane are The contact area.
- the contact area can be changed.
- the power generation performance of the fuel cell is not greatly improved.
- the cross-sectional area ( ⁇ ) and the interval (S) of the convex portions are set to be constant and the height (h) of the convex portions is changed variously, the higher the height (h), the higher the performance of the fuel cell. Become.
- the maximum thickness of the catalyst layer is set to be 1 to 3 times as thin as the height of the convex portion in combination with the control of the height (h), the degree of improvement in performance increases.
- the proton in the electrolyte membrane constitutes the convex portion instead of the proton conduction path in the catalyst layer that has entered the concave portion.
- the maximum thickness of the catalyst layer As thin as 30 ⁇ m or less. Thereby, the performance of the fuel cell is remarkably improved.
- the maximum thickness of the catalyst layer exceeds 30 ⁇ m, sufficient supply of protons to every corner of the catalyst layer cannot be secured, and the battery performance is not sufficiently improved.
- the maximum thickness of the catalyst layer is too thin, it becomes difficult to form the catalyst layer uniformly when a general coating method such as screen coating or spray coating is used to form the catalyst layer. That is practical.
- the height (h) of the convex portion is 5 to 15 ⁇ m, and the maximum thickness of the catalyst layer is 1 to 3 times the height (h) of the convex portion.
- the maximum thickness of the catalyst layer is preferably 10 to 30 ⁇ m. In this case, the maximum thickness of the catalyst layer is not less than the height of the convex portion.
- the present invention since the maximum thickness of the catalyst layer is adjusted to be thin, the amount of catalyst used can be reduced, which is extremely advantageous in terms of fuel cell manufacturing costs. In other words, the present invention is extremely useful because it can continuously exhibit excellent current-voltage characteristics, and can suppress the manufacturing cost of the fuel cell. Furthermore, since the maximum thickness of the catalyst layer is adjusted to be thin, the fuel cell can be made compact.
- the current density is adjusted to less than 0.5 A / cm 2 .
- the current density is 0.5 A / cm 2 or more, the suppression of the performance deterioration due to the low current density is not sufficient.
- the dry or wet state of the catalyst layer and the electrolyte membrane is mainly determined by the relative humidity of the supplied oxygen-containing gas at the battery operating temperature. Since the drying conditions and the wetting conditions of the catalyst layer and the electrolyte membrane are determined not by temperature but by the relative humidity to which they are exposed, the operating conditions can be represented by the relative humidity.
- the relative humidity of the oxygen-containing gas By reducing the relative humidity of the oxygen-containing gas to be greater than the relative humidity of the conventionally used oxygen-containing gas, it is possible to suppress the clogging of the concave portion due to the generated water, and to avoid deterioration in performance over time. Specifically, using an oxygen-containing gas having a relative humidity of 10% or less at the operating temperature of the fuel cell can avoid deterioration in performance over time.
- an oxygen-containing gas having a low relative humidity when the current density is 0.5 A / cm 2 or more, the electrolyte membrane can be kept wet by the water generated in the catalyst layer on the cathode side. It is preferable that the electrolyte membrane is not excessively dried to deteriorate the battery performance.
- a fuel having an electrolyte membrane provided with a convex portion having a height of 5 to 15 ⁇ m on the cathode side surface and a cathode made of a catalyst layer having a maximum thickness of 1 to 3 times the convex portion height By operating the battery mainly by supplying an oxygen-containing gas having a relative humidity of 10% or less, the effect of proton bypass transport due to uneven surface of the electrolyte membrane can be sufficiently and stably extracted. . As a result, higher performance, that is, higher voltage can be achieved, and performance deterioration with time can be avoided.
- FIG. 1 illustrates a structure in which the shape and size of each convex portion is constant and has regularity in a plane, but the regularity of the convex portion is required to exert the proton bypass transport effect. It is not always necessary. For example, convex portions of various shapes may be mixed, or the size and interval may be distributed or varied. In such a case, the height of the convex portion is considered as an average value.
- FIG. 9 is a conceptual cross-sectional view showing the configuration of the polymer fuel cell used in the present invention.
- a cathode catalyst layer 12 and an anode catalyst layer 13 are provided on both surfaces of the electrolyte membrane 11, respectively.
- a gas diffusion layer 14 is provided on the cathode catalyst layer 12 and the anode catalyst layer 13.
- separators 16 each having a gas flow path 15 are installed.
- An uneven structure is formed on both surfaces of the electrolyte membrane 11, and the cathode catalyst layer 12 and the anode catalyst layer 13 are formed in close contact with the uneven structure.
- Such a catalyst layer can be formed, for example, by applying a coating liquid containing a catalyst onto an electrolyte membrane having a concavo-convex structure.
- the maximum thickness of the catalyst layer refers to the thickness from the surface of the catalyst layer to the deepest portion of the catalyst layer (the portion in contact with the concave portion of the electrolyte membrane).
- FIG. 9 shows a state in which the concavo-convex structure is formed on both surfaces of the electrolyte membrane 11, but in the present invention, it is essential to provide the concavo-convex structure on the surface on the side where the cathode catalyst layer 12 is provided. It is not always necessary to provide an uneven structure on the surface on the side where the anode catalyst layer 13 is provided.
- oxygen-containing gas is supplied to the cathode catalyst layer 12 via the cathode-side separator and diffusion layer
- hydrogen gas is supplied to the anode catalyst layer 13 via the anode-side separator and diffusion layer.
- Example 1 A convex electrolyte membrane was produced by casting a fluoropolymer electrolyte solution using a concave mold.
- the concave mold was created by plasma etching after masking various patterns on a silicon wafer.
- the cross-sectional shape and spacing of the protrusions were adjusted by the mask pattern, and the height of the protrusions was adjusted by the time and intensity of plasma etching.
- Nafion liquid water / alcohol solvent, solid content ratio adjusted to about 20%
- a Nafion solution was coated on a silicon ferrule whose surface was unevenly processed in various shapes and dried. During drying, the temperature of the atmosphere and the humidification conditions were adjusted.
- the coating and drying of Nafion liquid were repeated several times as necessary. After drying, heat treatment was performed at 130 ° C. to 200 ° C. in air so that Nafion was not redissolved in water. The heat treatment time was adjusted in the range of 1 to 100 minutes according to the heat treatment temperature.
- the heat-treated film was peeled off from the silicon mold using a jig such as tweezers so that the uneven portion was not damaged. When it was difficult to peel off the film, the silicon mold was treated with a release agent in advance to facilitate release.
- the cross section of the convex portion was set to a standard shape with a diameter of 5 ⁇ m, the height (h) of the convex portion was 3 ⁇ m, and the interval (S) between the convex portions was 5 ⁇ m.
- a shape with a fixed shape factor and various other shape factors was prototyped.
- a Nafion solution solid content ratio 20% as an electrolyte binder is added to and mixed with TEC10E50E (manufactured by Tanaka Kikinzoku Co., Ltd., ketjen carrier, Pt amount is about 45% by weight), which is Pt / C powder, and the catalyst layer ink is mixed.
- the catalyst layer ink was applied on the convex electrolyte membrane by screen coating and dried to form a catalyst layer. The coating amount was controlled so that the loading amount of the Pt catalyst was 0.5 ⁇ 0.05 mg / cm 2 .
- the gas diffusion layer carbon paper having a thickness of 180 to 270 ⁇ m treated with water repellent and having a microporous layer formed on the surface thereof was used.
- the microporous layer was formed by kneading carbon powder and a fluororesin dispersion, coating the carbon paper, and heat-treating it.
- the obtained gas diffusion layers were stacked so as to be sandwiched from both the anode side serving as the fuel electrode and the cathode side serving as the air electrode so that the microporous layer was positioned on the catalyst layer side.
- the thickness of the catalyst layer was 15 ⁇ m.
- a small cell was produced for performance evaluation of the catalyst layer.
- the shape of the catalyst layer was set to 6 cm square.
- a seal sheet was disposed around the gas diffusion layer with the thickness adjusted.
- the gas diffusion layer was sandwiched between two separators each having a meandering gas flow path on the surface in contact with the gas diffusion layer, and the structure was adjusted to ensure the gas sealing property and electrical conductivity between the members by the fastening plate.
- the separator a composite type separator made of carbon powder and resin was used.
- a catalyst layer is formed on the surface of the planar electrolyte membrane made by cast molding so that the amount of Pt is also 0.5 mg / cm 2, and the other parts including the gas diffusion layer are made in the same configuration for comparison.
- a small cell was prepared.
- the height of the convex portion is fixed at 3 ⁇ m, and as shown in Table 1, the diameter ( ⁇ ) of the convex portion is set to 2 ⁇ m, 5 ⁇ m, or 10 ⁇ m, and the interval (S) between the convex portions is 3 ⁇ m.
- Table 1 the diameter ( ⁇ ) of the convex portion is set to 2 ⁇ m, 5 ⁇ m, or 10 ⁇ m, and the interval (S) between the convex portions is 3 ⁇ m.
- FIGS. 2 (a) and 2 (b) The above results are shown in FIGS. 2 (a) and 2 (b). However, each figure shows the current-voltage characteristics immediately after the start of evaluation.
- the characteristics of the electrolyte membrane are greatly improved even though the surface area of the electrolyte membrane is more than twice the surface area of the planar membrane. I wouldn't. From this, it was found that the characteristic improvement effect due to the unevenness is not dominant due to the increase in the area of the portion where the catalyst layer is in contact with the electrolyte membrane. Thus, it has been found that it is easy to supply protons to the catalyst layer portion far from the electrolyte membrane due to the unevenness, that is, the effect of proton bypass transport is important for improving the characteristics.
- 3 (a) and 3 (b) show current-voltage characteristics immediately after the start of evaluation. From each figure, the current-voltage characteristics were hardly improved when the height of the convex portion was 1 ⁇ m or 3 ⁇ m, but the output voltage was improved at the same current density when the height was 5 ⁇ m, 10 ⁇ m or 15 ⁇ m. It can be seen that the current density is greatly improved, and the characteristics are greatly improved as compared with the conventional one using the planar electrolyte membrane.
- FIG. 4 (a) and 4 (b) show the current-voltage characteristics after 5 hours from the start of evaluation. From comparison between FIG. 3 (a) and FIG. 4 (a), and comparison between FIG. 3 (b) and FIG. 4 (b), when the height of the convex portion is 5 ⁇ m or more, any humidification condition It can be seen from FIG. 4 that the performance is greatly reduced. That is, it has been found that the performance decreases with time. However, when the relative humidity was 67% (dew point 80 ° C.), the degree of performance deterioration over time was small compared to the case where the relative humidity was 100% (dew point 90 ° C.). On the other hand, in a comparative small cell using a conventional planar electrolyte membrane, such a decrease in performance over time was hardly observed.
- the same performance evaluation was performed assuming an operation that does not use a humidifier such as a bubbler (operation that is practically referred to as a non-humidifying operation). Specifically, the same performance evaluation was performed by supplying ambient air at a room temperature of 30 ° C. and a humidity of 50% as a cathode gas. When such ambient air is supplied to a fuel cell having an operating temperature of 90 ° C., the relative humidity of the supplied gas is about 3%.
- FIG. 6 shows the case where the height of the convex portion is 10 ⁇ m or 15 ⁇ m among the results shown in FIGS. 4 (a), 4 (b), 5 (a), and 5 (b).
- the current-voltage characteristics after 5 hours from the start of evaluation under the four humidification conditions are shown. From this figure, it can be seen that the performance is higher under high humidification conditions in the low current density region, but the performance is higher under low humidification conditions in the high current density region.
- the shape of the current-voltage characteristic curve is a downwardly convex curve when the humidification dew point of the supply gas is lower than 40 ° C. (relative humidity is 10%), whereas the humidification dew point of the supply gas is 80 ° C. ( When the relative humidity is higher than 67%), it has been newly found that the curve becomes a convex curve upward, and greatly varies depending on the degree of humidification of the supply gas.
- FIG. 5 shows that when the humidification dew point of the supply gas is lower than 70 ° C. (relative humidity is 44%), the height of the convex portion is 15 ⁇ m, and the performance is higher than that of the height of 10 ⁇ m. From this, it has been newly found that the performance improvement effect by increasing the height of the convex portion appears more prominently as the supply gas is less humidified.
- Example 2 In Example 1, the current-voltage characteristics of a small cell including a convex electrolyte membrane were evaluated. On the other hand, in Example 2, the current-voltage characteristics of a small cell including a concave electrolyte membrane are evaluated.
- the diameter ( ⁇ ) of the concave portion was set to 10 ⁇ m.
- the interval between the recesses, that is, the rib width is set to 5 ⁇ m corresponding to the diameter ( ⁇ ) of the protrusion of the convex film, and the depth of the recess is set to 10 ⁇ m corresponding to the height of the convex part of the convex film. Or it set to 15 micrometers.
- the same structure as the convex film of Example 1 was used, a small cell was produced, and the current-voltage characteristics were evaluated.
- FIG. 7 shows current-voltage characteristics after 5 hours from the start of evaluation, which are exhibited under various humidification conditions by a membrane electrode assembly using a concave membrane with a concave depth of 10 ⁇ m or 15 ⁇ m.
- FIG. 7 shows the same tendency as in FIG. That is, it was found that the concave film showed the same current-voltage characteristics as the convex film under each humidification condition.
- Example 3 In Example 1, an improvement in current-voltage characteristics was found when the height of the convex portion was 5 ⁇ m or more, but in Example 3, the relationship between the thickness of the catalytic reaction layer and the current-voltage characteristics was evaluated.
- the in this example in the convex film, the diameter ( ⁇ ) of the convex part is fixed to 5 ⁇ m, the distance (S) between the convex part and the convex part is fixed to 5 ⁇ m, and the height (h) is fixed to 10 ⁇ m.
- a small cell for evaluation similar to that of Example 1 was produced by changing the thickness to 20, 30, 50, 100, or 150 ⁇ m. Regardless of the thickness of the catalyst layer, the same catalyst layer ink as used in Example 1 was used for forming the catalyst layer.
- the loading amount of Pt was about 0.25 mg / cm 2 , 1.25 mg / cm 2 , or 2.5 mg / cm 2 , respectively.
- the method for coating the catalyst layer an optimum method was adopted according to the thickness of the catalyst layer from screen coating, spray coating, and transfer method.
- the MEA having a catalyst layer thickness of 10 to 30 ⁇ m exhibited higher performance than the MEA using a conventional planar membrane, but the catalyst layer having a thickness of 50 ⁇ m or more exhibited lower performance.
- the power generation method of the polymer fuel cell of the present invention it is possible to greatly increase the output density so far, and to bring the polymer fuel cell to a much smaller size and lower cost.
- market acceptance of stationary fuel cells and automotive fuel cells is dramatically increased, enabling CO 2 emissions to be reduced and contributing to reducing the global environmental load.
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Sustainable Development (AREA)
- Sustainable Energy (AREA)
- Fuel Cell (AREA)
Abstract
Description
前記固体高分子形燃料電池を準備する工程(A)、および
ここで、前記固体高分子形燃料電池は、カソード、アノード、および前記カソードおよび前記アノードに挟まれた電解質膜を具備し、
前記電解質膜の、前記カソードに対向する表面は、5μm以上15μm以下の高さを有する複数の凸部または5μm以上15μm以下の深さを有する複数の凹部を具備し、
前記カソードは前記表面に密着して形成された触媒層から構成され、前記触媒層の厚みは前記凸部の高さまたは前記凹部の深さの1倍以上3倍以下であり、
10%以下の相対湿度を有する酸素含有ガスを前記カソードに供給し、前記固体高分子形燃料電池を用いて電力を発生させる工程(B)。
図1は、本発明において凹凸構造を有する電解質膜3の表面を図示する概念図を示す。図1(a)に示すように、平面下底部1が連続的に形成されており、その平面下底部1上に不連続な突起(凸部)が複数形成された構造を、本発明では凸型と呼ぶ。逆に、図1(b)に示すように、平面上底部2が連続的に形成されており、平面上底部2に不連続な孔(凹部)が複数形成された構造を凹型と呼ぶ。図1では、凸部及び凹部の形状の代表例として円柱状のものを示しているが、四角柱、三角柱等の多角柱であってもよい。円錐、又は、多角錐であってもよく、様々な形状の凸部又は凹部を適用できる。この凹凸構造はカソード側に設けられ、凹凸構造を有する電解質膜表面にカソード触媒層が設けられる。以下では、主に凸型について本発明の実施形態を説明するが、本発明は凹型にも適用できる。
凸型の電解質膜が、フッ素系ポリマー電解質の溶液を、凹型モールドを用いてキャスト成形することによって製造された。凹型モールドは、シリコンウエハー上に種々のパターンをマスク形成した後、プラズマエッチングによって作成された。凸部の断面形状及び間隔の設計はマスクパターンによって、凸部の高さはプラズマエッチングの時間及び強度によって調節された。ポリマー電解質の溶液としてはナフィオン液(水/アルコール溶媒、固形分比を約20%に調整)が用いられた。表面に種々の形状の凸凹加工が施されたシリコンフェハー上にナフィオン液をコートし乾燥させた。乾燥の際には雰囲気の温度及び加湿条件を調節した。必要に応じてナフィオン液のコートと乾燥を複数回繰り返した。乾燥後、空気中130℃~200℃で熱処理を施し、ナフィオンが水に再溶解しないようにした。熱処理の時間は1分~100分の範囲で熱処理温度に応じて調節した。熱処理された膜を、ピンセット等のジグを用いて凹凸部が損傷しないようにシリコンモールドから引き剥がした。膜の引き剥がしが困難な場合は、シリコンモールドを予め離型剤で処理しておき、離型しやすいようにした。凸型膜では、凸部の断面は径5μm、凸部の高さ(h)は3μm、凸部と凸部の間隔(S)は5μmを標準の形状に設定した。凸部の直径及び高さ、並びに、凸部の間隔が発電性能に与える影響を調べるため、注目する形状因子を固定し、その他の形状因子を種々変更した形状を試作した。
実施例1では凸型の電解質膜を含む小型セルの電流-電圧特性が評価された。これに対し、本実施例2では凹型の電解質膜を含む小型セルの電流-電圧特性が評価される。この凹型電解質膜では凹部の径(φ)を10μmに設定した。凹部と凹部の間隔、すなわちリブ幅は、凸型膜の凸部の径(φ)と対応させて5μmに設定し、凹部の深さは、凸型膜の凸部の高さと対応させて10μm又は15μmに設定した。触媒層及びガス拡散層を含む他の構成としては、実施例1の凸型膜と同様のものを用い、小型セルを作製し、電流-電圧特性を評価した。
実施例1では凸部の高さを5μm以上とした際の電流-電圧特性の改善が見出されたが、本実施例3では触媒反応層の厚みと電流-電圧特性との関係が評価される。本実施例では、凸型膜において凸部の径(φ)を5μm、凸部と凸部の間隔(S)を5μm、高さ(h)を10μmに固定し、触媒層の厚みを10、20、30、50、100又は150μmに変更して実施例1と同様の評価用小型セルを作製した。触媒層の厚みに関わらず、触媒層形成のために用いられた触媒層インクは実施例1と同様のものを用いた。例えば、触媒層厚みが10μm、50μm又は100μmである時、Ptのローディング量はそれぞれ、約0.25mg/cm2、1.25mg/cm2、又は、2.5mg/cm2であった。触媒層の塗工方法は、スクリーン塗工、スプレー塗工、及び、転写法から、触媒層の厚みに応じて最適な方法を採用した。
2 平面上底部
3 電解質膜
4 凸部
5 間隔(S)
11 電解質膜
12 カソード触媒層
13 アノード触媒層
14 ガス拡散層
15 ガス流路
16 セパレータ
Claims (1)
- 固体高分子形燃料電池を用いて電力を発生させる方法であって、以下の工程(A)および(B)を具備する:
前記固体高分子形燃料電池を準備する工程(A)、および
ここで、前記固体高分子形燃料電池は、カソード、アノード、および前記カソードおよび前記アノードに挟まれた電解質膜を具備し、
前記電解質膜の、前記カソードに対向する表面は、5μm以上15μm以下の高さを有する複数の凸部または5μm以上15μm以下の深さを有する複数の凹部を具備し、
前記カソードは前記表面に密着して形成された触媒層から構成され、前記触媒層の厚みは前記凸部の高さまたは前記凹部の深さの1倍以上3倍以下であり、
10%以下の相対湿度を有する酸素含有ガスを前記カソードに供給し、前記固体高分子形燃料電池を用いて電力を発生させる工程(B)。
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201080034117.1A CN102473934B (zh) | 2009-08-26 | 2010-06-14 | 高分子型燃料电池的运转方法 |
JP2011528619A JP4920799B2 (ja) | 2009-08-26 | 2010-06-14 | 高分子形燃料電池の運転方法 |
US13/359,248 US8404391B2 (en) | 2009-08-26 | 2012-01-26 | Method of operating polymer electrolyte fuel cell |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2009194937 | 2009-08-26 | ||
JP2009-194937 | 2009-08-26 |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/359,248 Continuation US8404391B2 (en) | 2009-08-26 | 2012-01-26 | Method of operating polymer electrolyte fuel cell |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2011024360A1 true WO2011024360A1 (ja) | 2011-03-03 |
Family
ID=43627483
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2010/003930 WO2011024360A1 (ja) | 2009-08-26 | 2010-06-14 | 高分子形燃料電池の運転方法 |
Country Status (4)
Country | Link |
---|---|
US (1) | US8404391B2 (ja) |
JP (1) | JP4920799B2 (ja) |
CN (1) | CN102473934B (ja) |
WO (1) | WO2011024360A1 (ja) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2018055791A (ja) * | 2016-09-26 | 2018-04-05 | 日産自動車株式会社 | 膜電極接合体 |
KR20220147326A (ko) * | 2021-04-27 | 2022-11-03 | 인천대학교 산학협력단 | 연료전지용 고분자 전해질막, 이의 제조 방법, 및 이를 포함하는 연료전지 |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP7220368B2 (ja) * | 2017-12-01 | 2023-02-10 | パナソニックIpマネジメント株式会社 | 水素供給システム |
KR102204304B1 (ko) * | 2017-12-27 | 2021-01-18 | 주식회사 엘지화학 | 리튬 메탈 이차전지 및 그 제조 방법 |
WO2023101305A1 (ko) * | 2021-12-03 | 2023-06-08 | 코오롱인더스트리 주식회사 | 막-전극 어셈블리 및 이를 포함하는 연료전지 |
CN114551951A (zh) * | 2022-01-10 | 2022-05-27 | 杭州电子科技大学 | 一种用于燃料电池的制绒阴离子交换膜及其制备方法 |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2004296176A (ja) * | 2003-03-26 | 2004-10-21 | Toray Ind Inc | 固体高分子型燃料電池 |
JP2007026836A (ja) * | 2005-07-14 | 2007-02-01 | Nissan Motor Co Ltd | 燃料電池の触媒層形成方法及び膜電極接合体 |
JP2007157572A (ja) * | 2005-12-07 | 2007-06-21 | Toyota Motor Corp | 燃料電池 |
JP2008004486A (ja) * | 2006-06-26 | 2008-01-10 | Toyota Motor Corp | 燃料電池用電解質膜および膜電極接合体の製造方法 |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6835488B2 (en) * | 2000-05-08 | 2004-12-28 | Honda Giken Kogyo Kabushiki Kaisha | Fuel cell with patterned electrolyte/electrode interface |
US6663994B1 (en) * | 2000-10-23 | 2003-12-16 | General Motors Corporation | Fuel cell with convoluted MEA |
US7691518B2 (en) * | 2003-05-15 | 2010-04-06 | Nissan Motor Co., Ltd. | Prevention of flooding of fuel cell stack |
JP4576813B2 (ja) | 2003-09-05 | 2010-11-10 | 株式会社豊田中央研究所 | 高分子電解質膜及び膜電極接合体 |
US8309265B2 (en) | 2003-09-12 | 2012-11-13 | Hitachi, Ltd. | Electrolyte membrane for fuel cells, its production and fuel cell using the same |
JP4826075B2 (ja) | 2003-09-12 | 2011-11-30 | 株式会社日立製作所 | 燃料電池用電解質膜とその製造方法及びそれを用いた燃料電池 |
JP4824946B2 (ja) | 2005-05-24 | 2011-11-30 | 株式会社日立製作所 | 保護フィルム付き電解質膜およびその製造方法。 |
-
2010
- 2010-06-14 JP JP2011528619A patent/JP4920799B2/ja not_active Expired - Fee Related
- 2010-06-14 CN CN201080034117.1A patent/CN102473934B/zh not_active Expired - Fee Related
- 2010-06-14 WO PCT/JP2010/003930 patent/WO2011024360A1/ja active Application Filing
-
2012
- 2012-01-26 US US13/359,248 patent/US8404391B2/en not_active Expired - Fee Related
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2004296176A (ja) * | 2003-03-26 | 2004-10-21 | Toray Ind Inc | 固体高分子型燃料電池 |
JP2007026836A (ja) * | 2005-07-14 | 2007-02-01 | Nissan Motor Co Ltd | 燃料電池の触媒層形成方法及び膜電極接合体 |
JP2007157572A (ja) * | 2005-12-07 | 2007-06-21 | Toyota Motor Corp | 燃料電池 |
JP2008004486A (ja) * | 2006-06-26 | 2008-01-10 | Toyota Motor Corp | 燃料電池用電解質膜および膜電極接合体の製造方法 |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2018055791A (ja) * | 2016-09-26 | 2018-04-05 | 日産自動車株式会社 | 膜電極接合体 |
KR20220147326A (ko) * | 2021-04-27 | 2022-11-03 | 인천대학교 산학협력단 | 연료전지용 고분자 전해질막, 이의 제조 방법, 및 이를 포함하는 연료전지 |
KR102654013B1 (ko) * | 2021-04-27 | 2024-04-02 | 인천대학교 산학협력단 | 연료전지용 고분자 전해질막, 이의 제조 방법, 및 이를 포함하는 연료전지 |
Also Published As
Publication number | Publication date |
---|---|
US20120189924A1 (en) | 2012-07-26 |
CN102473934B (zh) | 2014-09-03 |
JP4920799B2 (ja) | 2012-04-18 |
JPWO2011024360A1 (ja) | 2013-01-24 |
CN102473934A (zh) | 2012-05-23 |
US8404391B2 (en) | 2013-03-26 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP4920799B2 (ja) | 高分子形燃料電池の運転方法 | |
JP4977945B2 (ja) | 膜電極接合体及びその製造方法、並びに燃料電池 | |
WO2002073721A1 (en) | Gas diffusion electrode and fuel cell using this | |
WO2011013711A1 (ja) | 固体高分子形燃料電池用ガス拡散層部材および固体高分子形燃料電池 | |
JP2011008940A (ja) | 膜電極接合体および燃料電池 | |
JP4861025B2 (ja) | 固体高分子電解質型燃料電池用電極及びその製造方法 | |
JP2007080776A (ja) | 固体高分子型燃料電池、固体高分子型燃料電池スタック及び携帯用電子機器 | |
JP5362008B2 (ja) | 燃料電池 | |
JP5430079B2 (ja) | 膜電極接合体の製造方法 | |
JP2005294175A (ja) | 電極触媒層およびその製造方法 | |
JP4880131B2 (ja) | ガス拡散電極およびこれを用いた燃料電池 | |
KR102654013B1 (ko) | 연료전지용 고분자 전해질막, 이의 제조 방법, 및 이를 포함하는 연료전지 | |
JP5870643B2 (ja) | 固体高分子形燃料電池用膜電極接合体の製造方法 | |
JP4686992B2 (ja) | 固体高分子型燃料電池およびその発電方法 | |
JP2010021114A (ja) | 直接酸化型燃料電池 | |
JP2008198516A (ja) | 燃料電池 | |
JP2006210345A (ja) | 膜電極接合体,膜電極接合体の製造方法,燃料電池 | |
JP5619841B2 (ja) | 固体高分子形燃料電池の製造方法 | |
JP2010225560A (ja) | 燃料電池用セパレータ、燃料電池、および燃料電池用セパレータの製造方法 | |
JP2008234941A (ja) | 多孔質触媒層の製造方法、膜電極接合体の製造方法および固体高分子型燃料電池の製造方法 | |
JP5736232B2 (ja) | 固体高分子形燃料電池 | |
JP2002329501A (ja) | ガス拡散電極およびそれを用いた高分子電解質型燃料電池 | |
JP6048015B2 (ja) | 膜電極接合体の製造方法 | |
JP2006344426A (ja) | 固体高分子型燃料電池 | |
JP2011192593A (ja) | 膜電極接合体および燃料電池 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 201080034117.1 Country of ref document: CN |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 10811419 Country of ref document: EP Kind code of ref document: A1 |
|
DPE1 | Request for preliminary examination filed after expiration of 19th month from priority date (pct application filed from 20040101) | ||
WWE | Wipo information: entry into national phase |
Ref document number: 2011528619 Country of ref document: JP |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 10811419 Country of ref document: EP Kind code of ref document: A1 |