CN1947291A - Membrane-electrode assembly for fuel cell and fuel cell using same - Google Patents

Abstract

Disclosed is a membrane-electrode assembly for fuel cells which is improved in durability to repeated starting and stopping operations. Specifically disclosed is a membrane-electrode assembly for fuel cells comprising a cathode catalyst layer containing a cathode catalyst composed of platinum or an platinum alloy, a conductive carbon material for supporting the cathode catalyst and a proton conductive polymer electrolyte; a solid polymer electrolyte membrane; and an anode catalyst layer containing an anode catalyst, a conductive carbon material for supporting the anode catalyst and a proton conductive polymer electrolyte. In this membrane-electrode assembly for fuel cells, the average thickness (Ya) of the anode catalyst layer is smaller than the average thickness (Yc) of the cathode catalyst layer.

Description

Fuel cell is with film-electrode bond and the fuel cell that uses it

Technical field

The present invention relates to the fuel cell film-electrode bond, more particularly, relate to the electrode catalyst layer of fuel cell with film-electrode bond.

Background technology

In recent years, echo mutually with the social desirability and the trend that with the energy environment problem are background, fuel cell just is being subjected to people's attention as vehicle with drive source and fixed power supply.Fuel cell can be divided into all kinds according to the kind of electrolytical kind or electrode, as representational example, comprises alkaline type, phosphatic type, fused carbonate type, solid electrolyte type, solid polymer type.Wherein, can be of greatest concern at the polymer electrolyte fuel cell (PEFC) that low temperature (being generally below 100 ℃) is worked down, and constantly developed practicability (the Japan Patent spy opens the 2004-79457 communique) as automobile with low public hazards power source in recent years.

The formation of PEFC is generally the structure by dividing plate clamping film-electrode bond (MEA).MEA has the structure that stacked gas diffusion layers, cathode catalyst layer, solid polyelectrolyte membrane, anode catalyst layer and gas diffusion layers form usually.

In MEA, following electrochemical reaction takes place.At first, it is oxidized by catalyst to be fed to the hydrogen that is comprised in the fuel gas of anode (fuel electrodes) side, produces proton and electronics.Then, the proton that is generated is by the polyelectrolyte that anode side catalyst layer comprised, and then the solid polyelectrolyte membrane by contacting with anode side catalyst layer, arrives negative electrode (air pole) side catalyst layer.In addition, at electronics that anode side catalyst layer produced by constituting the conductive carrier of anode side catalyst layer, and then by arriving cathode-side catalytic layer with gas diffusion layers, gas barrier and the external circuit of the opposite side contacts of solid polyelectrolyte membrane of anode side catalyst layer.Then, proton and the electronics that arrives cathode-side catalytic layer be fed to the oxygen reaction generation water that is comprised in the oxidant gas of cathode-side catalytic layer.In fuel cell,, electric energy can be discharged into the outside by above-mentioned electrochemical reaction.

As the purposes of PEFC, vehicle is studied with drive source or fixed power supply, and, required in long-time, to have durability in order to be applied to these purposes.Wherein, using in the situation of drive source, requiring not stop to cause battery behavior to reduce owing to frequent starting as vehicle.

Particularly in the electrode catalyst layer that comprises conductivity raw material of wood-charcoal material such as the catalyst of forming by platinum or platinum alloy, the carbon black of supported catalyst and proton-conducting polyelectrolyte, exist easily since repeatedly starting stop to cause that the gas diffusibility and the drainage of decomposition deterioration, the electrode of the corrosion of conductivity raw material of wood-charcoal material and polyelectrolyte reduce, concentration overvoltage increases, the tendency of battery behavior reduction.

Therefore, all the time, carried out the trial of the corrosion resistance of a large amount of raising conductivity raw material of wood-charcoal material.For example, open in the 2005-26174 communique, disclose the conductivity raw material of wood-charcoal material that has improved corrosion resistance by the crystallinity of Heat Treatment Control charcoal at Japanese patent laid-open 05-129023 communique and Japan Patent spy.

Summary of the invention

As mentioned above, PEFC is required to demonstrate higher power generation performance in long-time.But, in existing film-electrode bond, even the conductivity raw material of wood-charcoal material that passes through heat treatment raising corrosion resistance that utilizes patent documentation 2 and 3 etc. to be put down in writing can not obtain sufficient power generation performance.

Owing to starting repeatedly stop one of reason that the power generation characteristics of the film-electrode bond that caused reduces can think when stopping, remaining in anode one side hydrogen caused.In anode one side, supply of hydrogen acts as a fuel, and when film-electrode bond stopped, gases such as anode one side supply air remained in the hydrogen of anode one side with displacement.But if hydrogen is not removed and at the hydrogen of the residual amount to a certain degree of anode one side, then formed local cell in anode one side when starting from anode, negative electrode one side is exposed under the high potential state.The result is, at the platinum place as catalyst cupport the electrolysis of water takes place and produces oxygen, and the raw material of wood-charcoal material passes through Reaction generation oxide etch.Because the raw material of wood-charcoal material corrodes, the electrode catalyst layer of the film-electrode bond deterioration that deforms, the concentration overvoltage increase, the performance of PEFC significantly reduces.In addition, in film-electrode bond, because starting stops to cause platinum to fuse in the solid polyelectrolyte membrane, causes the decomposition of polyelectrolyte repeatedly, these all are the reasons that causes the performance of PEFC to reduce.

Therefore, the objective of the invention is to improve the durability that fuel cell stops starting repeatedly with film-electrode bond.

The present inventor has carried out positive research in view of the above problems, found that, and is thin than cathode catalyst layer by making anode catalyst layer, can improve the durability of the cathode catalyst layer that fuel cell stops starting with film-electrode bond.

That is, above-mentioned problem solves by following (1)～(3).

(1) a kind of fuel cell film-electrode bond, it comprises:

Cathode catalyst layer, it contains the conductivity raw material of wood-charcoal material and the proton-conducting polyelectrolyte of platinum or the formed cathod catalyst of platinum alloy, the described cathod catalyst of load;

Solid polyelectrolyte membrane;

Anode catalyst layer, it contains the conductivity raw material of wood-charcoal material and the proton-conducting polyelectrolyte of anode catalyst, the described anode catalyst of load,

Wherein,

The average thickness of described anode catalyst layer (Ya) is littler than the average thickness (Yc) of described cathode catalyst layer.

(2) use the polymer electrolyte fuel cell of above-mentioned fuel cell with film-electrode bond.

(3) vehicle of the above-mentioned polymer electrolyte fuel cell of lift-launch.

Embodiment

Be elaborated at embodiment of the present invention below.

First aspect of the present invention is a kind of fuel cell film-electrode bond, and it comprises:

Cathode catalyst layer, it contains the conductivity raw material of wood-charcoal material and the proton-conducting polyelectrolyte of platinum or the formed cathod catalyst of platinum alloy, the described cathod catalyst of load;

Solid polyelectrolyte membrane;

Anode catalyst layer, it contains the conductivity raw material of wood-charcoal material and the proton-conducting polyelectrolyte of anode catalyst, the described anode catalyst of load,

Wherein,

The average thickness of described anode catalyst layer (Ya) is littler than the average thickness (Yc) of described cathode catalyst layer.

With in the film-electrode bond, make the average thickness (Ya) of anode catalyst layer littler at fuel cell of the present invention than the average thickness (Yc) of cathode catalyst layer.Like this, the hydrogen that remains in anode one side when stopping can be replaced by other gas effectively.The result is at anode one side formation local cell, can prevent the deterioration of film-electrode bond in the time of can suppressing to start.

In addition, if anode catalyst layer is thin, then when stopping, during gases such as purging air, reduce the amount of moisture of anode catalyst layer easily for the hydrogen of replacing anode one side.That is, anode catalyst layer is dry easily.The result is in order to replenish the moisture that anode catalyst layer reduces, to cause that moisture moves relative to higher solid polyelectrolyte membrane from amount of moisture.Simultaneously, cause that moisture moves from cathod catalyst course solid polyelectrolyte membrane, the amount of moisture of cathode catalyst layer reduces.When starting,,, just can not produce oxygen as long as near platinum catalyst, there is not water even cathode catalyst layer is exposed under the high potential.Thereby, can suppress the charcoal corrosion of following starting to stop to take place.

But the above-mentioned mechanism between formation of the present invention and the effect infers that technical scope of the present invention is not restricted to utilize the execution mode of above-mentioned mechanism.

As mentioned above, in film-electrode bond of the present invention, the average thickness of anode catalyst layer (Ya) is littler than the average thickness (Yc) of cathode catalyst layer.Specifically, Ya and Yc are preferably and satisfy Ya/Yc=0.01～0.9, more preferably satisfy the relation of Ya/Yc=0.03～0.86.By the THICKNESS CONTROL with catalyst layer is such relation, the film-electrode bond that can obtain having favorable durability.

The average thickness of anode catalyst layer (Ya) is preferably 0.3 μ m～10 μ m, and more preferably 0.3 μ m～8 μ m are preferably 2 μ m～6 μ m especially.In addition, the average thickness of cathode catalyst layer (Yc) is preferably 7 μ m～20 μ m, more preferably 7 μ m～15 μ m.By being controlled in this scope, can effectively suppress to start when stopping or the corrosion of the charcoal during load variations and platinum fuse.Catalyst layer is thin more, and then the discharge of the diffusivity of gas and permeability and humidification water and generation water is also just good more, still, if catalyst layer is thin excessively, then is difficult to keep durability, therefore, should obtain both balances and decide preferred thickness.

In addition, in the present invention, the thickness of each catalyst layer of anode and negative electrode is to use in the electron micrograph (multiplication factor: 3000 times) of the catalyst layer section that scanning electron microscope takes under the condition of the accelerating voltage of 3kV, measure the thickness of the catalyst layer at 20～50 positions, get its mean value.

Then, the component parts to PEFC of the present invention describes.

Cathode catalyst layer comprises platinum or the formed cathod catalyst of platinum alloy, the conductivity raw material of wood-charcoal material of load cathod catalyst and the polyelectrolyte of proton-conducting.In cathode catalyst layer, cathod catalyst can load on the conductivity raw material of wood-charcoal material as cathode electrode catalyst.

Cathod catalyst is the material of the reaction on a kind of negative electrode one side (air pole) that promotes film-electrode bond, can use platinum or platinum alloy at least.As platinum alloy, not special restriction from accessing the angle of high catalytic activity, preferably can list the alloy of alloy, platinum and the rhodium of platinum and iridium.In addition, as above-mentioned platinum alloy, from improve thermal endurance, to purposes such as toxicity carbon monoxide anti-, preferably can list the base metal more than at least a kind that is selected from chromium, manganese, iron, cobalt and the nickel and the alloy of platinum.The preferred by quality ratio platinum/base metal of the mixed proportion of above-mentioned platinum and above-mentioned base metal is 1/1～5/1 in the above-mentioned platinum alloy, is preferably 2/1～4/1 especially.Like this, can make when keeping high catalytic activity, have the cathod catalyst of anti-middle toxicity, corrosion resistance etc.

The not special restriction of the average grain diameter of target catalyst is preferably 1～20nm, more preferably 2～10nm.Though infer that the average grain diameter of catalyst granules is more little, thereby then the big more catalyst activity of specific area is improved, in fact,, can not obtains the catalytic activity that the increase degree with specific area matches even the catalyst granules particle diameter is minimum.

In addition, in the present invention, the average grain diameter of cathod catalyst and anode catalyst is represented is the mean value of the particle diameter of the crystallite particle diameter of being tried to achieve by the half breadth of the diffraction maximum of cathod catalyst in the X-ray diffraction or anode catalyst or cathod catalyst that obtains by the transmission electron microscope image or anode catalyst.

So-called conductivity raw material of wood-charcoal material is meant to have as the function of the carrier of cathod catalyst and the raw material of wood-charcoal material with conductivity, is also referred to as the conductivity charcoal.Actual giving and accepting of electronics of carrying out the position of electrode reaction undertaken by conductivity raw material of wood-charcoal material.The not special restriction of the conductivity raw material of wood-charcoal material of target catalyst layer, the preferred carbon black that uses through graphitization processing.Its hydrophobicity of common carbon black is more contour than oxide, but has functional groups such as a spot of hydroxyl or carboxyl thereby possess hydrophilic property on the surface.In contrast, because the hydrophilic functional group reduces, thereby hydrophobicity improves through the carbon black of graphitization processing.Improved hydrophobic carbon black by use, the drainage of electrode catalyst layer is improved, and then the battery performance of PEFC is improved.

As above-mentioned carbon black,, preferably can list channel black, furnace black, pyrolytic carbon black, Ketjen black or BlackPearl etc. so long as existing common carbon black just has no particular limits.In addition, as above-mentioned carbon black, commercially available product can be used, the Ketjen Black EC that Vulcan XC-72, Vulcan P, Black Pearls880, Black Pearls 1100, Black Pearls 1300, Black Pearls 2000, Regal400, Lion company that Cabot company makes make, the oil oven method carbon blacks such as #3150, #3250 that Mitsubishi Chemical Ind makes can be listed; The acetylene blacks such as electrochemistry carbon black that Denki Kagaku Kogyo kabushiki makes etc.

As above-mentioned graphitization processing, so long as existing normally used processing such as heat treatment gets final product not special restriction.Above-mentioned heat treatment is preferably carried out in inert gas atmospheres such as nitrogen, argon gas, helium.In addition, heat treatment temperature, heat treatment time as long as suitably set so that the carbon black of resulting graphitization processing has desirable BET surface area etc., can carry out under 2000～3000 ℃ 5～20 hours according to employed raw material of wood-charcoal material and different.

The graphitization rate of the carbon black of above-mentioned graphitization processing can be more than 75%, be preferably 80～95%.Like this, not only can guarantee water proofing property, and can improve corrosion resistance and conductance by changing crystal structure by the surface functional group that reduces carbon black.

It is 1.80～2.11g/cm that the carbon black of above-mentioned graphitization processing preferably uses real density ³, interplanar distance d ₀₀₂It is the carbon black of 3.36～3.55 .

In the present invention, the interplanar distance d of the carbon black of above-mentioned graphitization processing ₀₀₂Be meant interplanar crystal spacing, the mean value of 1/2 interlamellar spacing of the axial lattice constant of vertical direction c of expression hexagonal wire side based on the hexagonal wire side of carbon black graphite-structure.

The carbon black of having implemented graphitization processing by heat treatment etc. forms the graphitization layer that three-dimensional lattice constituted of approximate graphite-structure in its surface, and carry out along with graphited, reduce trickle gap between lattice, and the crystal structure of conductivity raw material of wood-charcoal material is similar to the crystal structure of graphite.If except water proofing property, also consider corrosion resistance etc., then be preferably the degree of crystallization height of employed conductivity raw material of wood-charcoal material.

When the real density of the carbon black of above-mentioned graphitization processing less than 1.80g/cm ³, interplanar distance d ₀₀₂When surpassing 3.55 , in most cases graphite-structure can not fully develop, and may can not get highly corrosion resistant, electronic conductivity.In addition, when real density greater than 2.11g/cm ³, interplanar distance d ₀₀₂During less than 3.36 , the graphite-structure excessive development may can not get sufficient specific area as a rule.

Therefore, preferably to use real density be 1.80～2.11g/cm to the carbon black of above-mentioned graphitization processing ³, interplanar distance d ₀₀₂Be 3.36～3.55 carbon black, more preferably using real density is 1.90～2.11g/cm ³, interplanar distance d ₀₀₂Be the carbon black of 3.38～3.53 , especially preferably using real density is 1.90～2.11g/cm ³, interplanar distance d ₀₀₂It is the carbon black of 3.40～3.51 .

In addition, in the present invention, real density is the value of measuring by the vapor-phase replacement method of using helium, interplanar distance d ₀₀₂For " shake method (in a few days standard law-translator that this science development can authorization annotates) " (rice wall doffer, the plain No.36,25～34 (1963) of the charcoal) mensuration by using X-ray diffraction method.

In addition, can to use conductance be the carbon black of 50～1000S/cm, preferred 100～1000S/cm to the carbon black of above-mentioned graphitization processing.

In addition, the carbon black of above-mentioned graphitization processing is in order to be used for the electrode catalyst of high performance fuel cell, not only require the load cathod catalyst, and require to have and be used for that electronics outputed to external circuit or from the function of the collector body of external circuit input electronics.If the conductance of the carbon black of above-mentioned graphitization processing is less than 50S/cm, the then internal resistance of fuel cell rising, battery performance reduce, if surpass 1000S/cm, crystallization, BET surface area that charcoal then takes place reduce.

In the present invention, the conductance of the carbon black of above-mentioned graphitization processing is for using the method identical with conventional method, under the pressure of 14～140MPa,, under nitrogen atmosphere gas, carry out heat treated, then 25 ℃ of values of measuring down with 1000 ℃ with the carbon black compression forming of graphitization processing.

In the present invention, the carbon black of graphitization processing can comprise the BET surface area and is preferably 100m ²More than/the g, more preferably 100～300m ²/ g, preferred especially 120～250m ²The carbon black of the graphitization processing of/g (A).Use the carbon black (A) of above-mentioned graphitization processing, not only drainage is good but also corrosion resistance is also good, and then the dispersed height of the cathod catalyst of institute's load, therefore can obtain the good cathode electrode catalyst of catalytic activity.

To the not special restriction of the catalyst loadings of the carbon black (A) of graphitization processing.Can suitably determine load capacity, so that obtain desirable power generation characteristics according to kind of the carbon black (A) of the performance of the kind of cathod catalyst, film-electrode bond, graphitization processing etc.Specifically, when working load the carbon black (A) of above-mentioned graphitization processing of above-mentioned cathod catalyst during as cathode electrode catalyst (C), the total amount of the above-mentioned relatively cathode electrode catalyst of the load capacity of above-mentioned cathod catalyst (C) is preferably 20～80 quality %, 40～60 quality % more preferably in the above-mentioned cathode electrode catalyst (C).If the catalyst loadings of the carbon black of graphitization processing (A) in this scope, when being in high potential, can being suppressed near the oxygen that produces the platinum catalyst and contacting with carbon surface and oxide etch takes place.

As the conductivity raw material of wood-charcoal material of cathode catalyst layer, except the carbon black (A) of above-mentioned graphitization processing, be preferably and further comprise the BET surface area and be preferably less than 100m ²/ g, 80～100m more preferably ²The carbon black of the graphitization processing of/g (B).Not only water proofing property is good for the carbon black of above-mentioned graphitization processing (B), corrosion resistance is especially good.Therefore, the carbon black (A) by using graphitization processing and the carbon black (B) of graphitization processing are as the carrier of cathod catalyst, can utilize the carbon black (A) of graphitization processing to obtain high catalytic activity and utilize the carbon black (B) of graphitization processing further to improve corrosion resistance, obtain the good film-electrode bond of power generation performance and durability.

To the not special restriction of the catalyst loadings of the carbon black (B) of graphitization processing, specifically, at working load the carbon black (B) of above-mentioned graphitization processing of above-mentioned cathod catalyst during as cathode electrode catalyst (D), the total amount of the above-mentioned relatively cathode electrode catalyst of the load capacity of above-mentioned cathod catalyst (D) is preferably 10～50 quality %, 10～30 quality % more preferably in the above-mentioned cathode electrode catalyst (D).If the catalyst loadings of the carbon black of graphitization processing (B) can obtain having concurrently the cathod catalyst of corrosion resistance and catalytic activity in this scope.

When the carbon black (B) of carbon black (A) that uses above-mentioned graphitization processing and graphitization processing during as the conductivity raw material of wood-charcoal material of cathode catalysis agent carrier, for durability and the catalytic activity of taking into account cathode electrode catalyst, and further reduce catalytic activity reduction amplitude in time, the cathod catalyst of institute's load on the carbon black (B) of the carbon black (A) of graphitization processing and graphitization processing is preferably adjusted average grain diameter and load respectively.

Specifically, the average grain diameter of cathod catalyst can be 2～8nm in the carbon black of graphitization processing (A), is preferably 3～6nm.If above-mentioned average grain diameter less than 2nm, then can not obtain high catalytic activity at the generating beginning initial stage, if greater than 8nm, then the particle diameter of the cathod catalyst of institute's load becomes excessive, and active surface area diminishes, and catalytic activity reduces on the contrary.In addition, the average grain diameter of cathod catalyst is 4～10nm in the carbon black of graphitization processing (B), is preferably 4～8nm.When above-mentioned average grain diameter during less than 4nm, can not fully reduce catalytic activity reduction in time, if greater than 8nm, then the particle diameter of the cathod catalyst of institute's load becomes excessive, and active surface area reduces, and catalytic activity reduces on the contrary.

In cathode catalyst layer, in order further to improve the durability and the power generation performance of film-electrode bond, the above-mentioned cathode electrode catalyst (D) that forms of carbon black (B) the load cathod catalyst of the above-mentioned cathode electrode catalyst (C) that forms of carbon black (A) the load cathod catalyst of the above-mentioned graphitization processing of mixed according to the rules and above-mentioned graphitization processing more preferably.

Promptly, in cathode catalyst layer, above-mentioned cathode electrode catalyst (C) can be with mass ratio (C)/(D) with above-mentioned cathode electrode catalyst (D), be preferably more than 60/40, more preferably 60/40～99/1, be preferably 80/20～99/1 especially, more preferably 85/15～95/5 mixed.If the mixing quality of electrode catalyst (C) and electrode catalyst (D) less than 60/40, then may cause power generation performance to reduce than (C)/(D), thereby be preferably and be controlled in the above-mentioned scope.

In cathode catalyst layer, the moisture that carrying out generated that is accompanied by electrode reaction is easily along with institute's supplied fuel gas stream moves.Under service conditionss such as high current density and high humidification, a large amount of water that generate rest near the gas discharge section of cathode catalyst layer, hindered the carrying out of electrode reaction, owing to these reasons, the deterioration of swimming over to the downstream cathode electrode catalyst from gas flow path in cathode catalyst layer becomes violent.Therefore, when comprising above-mentioned cathode electrode catalyst (C) and cathode electrode catalyst (D) in cathode catalyst layer, the composition of preferred target electrode catalyst carries out optimization from the downstream of swimming over to of gas flow path.

Promptly, can be so that at the mass ratio (C)/(D) of above-mentioned cathode electrode catalyst (C) with the above-mentioned cathode electrode catalyst (D) in the downstream of the gas flow path of cathode catalyst layer, littler than the mass ratio (C)/(D) of the upstream side of the gas flow path of cathode catalyst layer.

Specifically, mass ratio (C)/(D) (=R of the above-mentioned cathode electrode catalyst (C) of the upstream side of the gas flow path of cathode catalyst layer and above-mentioned cathode electrode catalyst (D) _Up) with mass ratio (C)/(D) (=R of above-mentioned cathode electrode catalyst (C) with the above-mentioned cathode electrode catalyst (D) in the downstream of the gas flow path of cathode catalyst layer _Down) ratio be R _Up/ R _DownMore than=1/1, be preferably 2/1～9/1, be preferably 3/1～6/1 especially.

Like this, can make electrode reaction indifference in cathode catalyst layer, can be in long-time the cathode catalyst layer of the desirable performance of maintenance.

In addition, the upstream side of the gas flow path of cathode catalyst layer is meant near the fuel gas introducing port that the downstream of the gas flow path of cathode catalyst layer is meant that each concrete scope etc. can consider that the characteristic of cathode catalyst layer decides near the fuel gas outlet.

In addition, in the present invention,, can use further and carry out the carbon black that hydrophobization is handled with fluorine compounds as the conductivity raw material of wood-charcoal material of cathode catalyst layer.Like this, can further improve the hydrophobicity of cathode catalyst layer.The gross mass of the conductivity raw material of wood-charcoal material of the relative cathode catalyst layer of use amount of the carbon black that use fluorine compounds enforcement hydrophobization is handled is preferably 1～20 quality %.By mixing the amount of this scope, can realize from the initial stage to through after long-time, and in the scope of low current density～high current density, show high power generation performance, improve durability, realize the high life characteristic.In addition, the example as hydrophobization is handled can list the method for carbon black being handled by polytetrafluoroethylene.

In addition, as the conductivity raw material of wood-charcoal material of cathode catalyst layer, more preferably use carbon nano-tube, carbon nano-fiber or Carbon Nanohorn (Carbon Nanohorn).By adding degree of graphitization carbon nano-tube, carbon nano-fiber or the Carbon Nanohorn higher than carbon black, can improve the hydrophobicity in the cathode catalyst layer, inhibition causes the destruction of the three-phase structure of deterioration.According to circumstances, can mix use with 2 kinds in carbon nano-tube, carbon nano-fiber or the Carbon Nanohorn or 3 kinds.The gross mass of the conductivity raw material of wood-charcoal material of the relative cathode catalyst layer of use amount of carbon nano-tube, carbon nano-fiber or Carbon Nanohorn is 1～20 quality %.By mixing the amount of this scope, from the initial stage to through after long-time, and in the scope of low current density～high current density, show high power generation performance, improve durability, realize the high life characteristic.

Employed proton-conducting polyelectrolyte has the effect of the mobility of the proton of migration between negative electrode (air pole) anode (fuel electrodes) in the generating that improves PEFC in cathode catalyst layer and the anode catalyst layer.

As polyelectrolyte, so long as normally used polyelectrolyte in the catalyst layer just has no particular limits.Specifically, can list Nafion ^TMThe hybrid polymer that (E.I.Du Pont Company's manufacturing) etc. has sulfonic perfluorocarbon polymer, the hydro carbons macromolecular compound of the inorganic acids such as phosphoric acid that mixed, part are replaced by proton-conducting functional group, the macromolecule electrolyte such as proton conductor that in macromolecule matrix, flooded phosphoric acid solution or sulfuric acid solution.

Solid polyelectrolyte membrane is a kind of ionic conductivity film that is present between cathode catalyst layer and the anode catalyst layer.To the not special restriction of solid polyelectrolyte membrane, can use with electrode catalyst layer in the formed film of employed identical proton-conductive electrolyte.For example, the various Nafion that can use E.I.Du Pont Company to make ^TM, or with Flemion ^TMCommon commercially available solid polymer type dielectric films such as perfluoro sulfonic acid membrane for representative.Also can use in the macromolecule micro-porous film the electrolytical film of steeping liq, electrolytical film of filled high polymer etc. in porous plastid.In the solid polyelectrolyte membrane in employed polyelectrolyte and the electrode catalyst layer employed proton-conductive electrolyte can be the same or different, from the viewpoint of the adaptation that improves electrode catalyst layer and solid polyelectrolyte membrane, preferably use identical material.

The thickness of solid polyelectrolyte membrane can consider that the characteristic of resulting MEA suitably determines, the viewpoint of the durability when intensity during from the system film and use is preferably only thin, and the viewpoint of the power characteristic during from use is preferably not blocked up.Specifically, the thickness of the dielectric film of solid macromolecule is preferably 5～300 μ m, and more preferably 10～200 μ m are preferably 15～100 μ m especially.

Anode catalyst layer comprises the conductivity raw material of wood-charcoal material and the proton-conducting polyelectrolyte of anode catalyst, load anode catalyst.

Anode catalyst is the material of effect with reaction of anode one side (fuel electrodes) that promotes PEFC.As long as have the effect of anode catalyst, its kind is just had no particular limits.The same with cathod catalyst, can use platinum or platinum alloy, also can use other catalyst.For example, can use catalyst in metals such as being selected from platinum, ruthenium, iridium, rhodium, palladium, osmium, tungsten, lead, iron, chromium, cobalt, nickel, manganese, vanadium, molybdenum, gallium, aluminium and their alloy etc.The catalyst that can be mixed with two or more.

To the conductivity raw material of wood-charcoal material as anode catalyst layer, carbon black is preferably used in not special restriction, more preferably uses the carbon black of graphitization processing.Owing in anode catalyst layer, corrode than the more difficult generation charcoal of cathode catalyst layer, even thereby without the carbon black of graphitization processing, also can from the initial stage to through long-time back and under low current density～high current density, show electrical property occurred frequently, improve durability, realize the high life characteristic.Because the hydrophilic functional group of graphited carbon black reduces, thereby hydrophobicity is improved.When the carbon black that uses hydrophobicity to improve, when stopping, PEFC carries out the operating period of anode catalyst layer purging air, and the amount of moisture in the anode catalyst layer reduces easily, that is, dry easily.

The not special restriction of the catalyst loadings of conductivity raw material of wood-charcoal material in the antianode catalyst layer.Can suitably determine load capacity according to the kind of anode catalyst, the performance of film-electrode bond, the kind of conductivity raw material of wood-charcoal material etc., so that obtain desirable power generation characteristics.For example, the conductivity raw material of wood-charcoal material that anode catalyst is arranged when working load is during as the anode electrode catalyst agent, and the total amount of the above-mentioned relatively anode electrode catalyst agent of above-mentioned anode catalyst load capacity is preferably 30～70 quality % in the above-mentioned anode electrode catalyst agent.If this catalyst loadings is in this scope, then the utilization ratio of platinum improves, thereby can be with the anode catalyst layer slimming.

As the basic structure of film-electrode bond of the present invention, preferably can list the structure that the arranged in order according to cathode catalyst layer, solid polyelectrolyte membrane and anode catalyst layer forms.Preferred structure as above-mentioned film-electrode bond, preferably the outside of any one in cathode catalyst layer and anode catalyst layer disposes gas diffusion layers, more preferably disposes gas diffusion layers in the outer survey of cathode catalyst layer and anode catalyst layer.Like this, the gas from the outside supply can be fed on the electrode catalyst layer more equably, can further improve the power generation performance of film-electrode bond.

Constituent material to gas diffusion layers has no particular limits.Can list, for example, the fabric of charcoal system, paper shape papermaking body, felt, nonwoven fabrics etc. have the lamellar material of conductivity and porous matter.More particularly, can list carbon paper (carbonpaper), charcoal cloth, charcoal nonwoven fabrics etc.The preferred carbon paper that uses through water-proofing treatment.

The flaky material through water-proofing treatment as be suitable for gas diffusion layers through the carbon paper of water-proofing treatment etc. can list the flaky material that comprises waterproofing agent.As described waterproofing agent, preferably can list the macromolecular material of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyhexafluoropropylene, tetrafluoraoethylene-hexafluoropropylene copolymer fluorine such as (FEP) system, polypropylene, polyethylene etc.

The preferred used thickness of gas diffusion layers is the following carbon paper of 400 μ m or through the carbon paper of water-proofing treatment, can consider the characteristic of resulting gas diffusion layer and suitably decision.If consider the water proofing property of gas diffusion layers, more preferably used thickness is the following gas diffusion layers of 200 μ m.To the not special restriction of the lower limit of the thickness of gas diffusion layers, if but thin excessively, then can not obtain sufficient mechanical, thereby thickness is to be suitable more than the 100 μ m.

In addition, in order to prevent the liquid flooding of film-electrode bond, mil layer (mil layer) can be set between gas diffusion layers and cathode catalyst layer and anode catalyst layer.So-called mil layer is meant the surface that is formed at gas diffusion layers, the mixture layer that is formed by water proofing property fluororesin such as carbon and polytetrafluoroethylene.

Second aspect of the present invention is the polymer electrolyte fuel cell (PEFC) of a kind of fuel cell of first aspect of having used the invention described above with film-electrode bond.PEFC of the present invention, the catalyst layer of its film-electrode bond are difficult for deterioration takes place, and durability is good.That is, PEFC of the present invention, even under the situation of long-time use PEFC, voltage reduces also very little.Such characteristic is useful especially in requiring to have for a long time the purposes of durability.As such purposes, can list vehicle purposes such as automobile.Because PEFC of the present invention can keep power generation characteristics in long-time, therefore can realize carrying the raising of long-term and vehicle value in life-span of the vehicle of PEFC of the present invention.PEFC of the present invention is preferably used as various power sources, is preferably used as the power source of vehicle especially.

To the formation as PEFC, existing known technology can be suitably used in not special restriction, has the structure by dividing plate clamping MEA usually.Specifically, can list formation according to the arranged in order of dividing plate, gas diffusion layers, cathode catalyst layer, solid polyelectrolyte membrane, anode catalyst layer, gas diffusion layers and dividing plate.But the present invention is not limited to so basic formation, and the PEFC with other formation is also applicable to the present invention.

To the not special restriction of the material of dividing plate, can use known dividing plates such as metal separator such as charcoal system dividing plate, stainless steel such as fine and close carbon graphite, carbon slab.To the not special restrictions such as shape of the thickness of dividing plate and size, flow passage groove, can consider that the power characteristic etc. of resulting fuel cell is suitably determined.

In addition, in order to make fuel cell obtain desirable voltage etc., can also form by piling up that the stacked a plurality of MEA of dividing plate are connected in series.To not special restriction such as the shape of fuel cell etc., can suitably determine so that obtain battery behavior such as desirable voltage.

Embodiment

Embodiment 1

1. the preparation of anode electrode catalyst agent

Prepare 4.0g carbon black (the Ketjen Black that Ketjen Black International company makes ^TMEC, BET surface area=800m ²/ g) as conductivity raw material of wood-charcoal material, to wherein adding the 400g dinitro two ammino platinum aqueous solution (Pt concentration 1.0%) and stirring 1 hour.And then, mix 50g methyl alcohol as reducing agent, stirred 1 hour.In 30 minutes, be heated to 80 ℃ and stirred 6 hours down then, in 1 hour, be cooled to room temperature then at 80 ℃.Filtering precipitate, then under reduced pressure under 85 ℃ with dry 12 hours of resulting solids, use mortar to pulverize, obtain anode electrode catalyst agent (average grain diameter of Pt particle is 2.6nm, and Pt load concentration is 50 quality %).

2. the preparation of cathode electrode catalyst

By under 2700 ℃ to carbon black (the Ketjen Black that Ketjen Black International company makes ^TMEC) carry out 10 hours graphitization processing, obtain carbon black (the Ketjen Black EC of graphitization processing, the BET surface area=130m of graphitization processing ²/ g, real density 1.93g/cm ³, interplanar distance d ₀₀₂3.51 , conductance 200S/cm).In the Ketjen black of 4.0g graphitization processing, the adding 400g dinitro two ammino platinum aqueous solution (Pt concentration 1.0%) also stirred 1 hour.And then mix 50g formic acid as reducing agent, stirred 1 hour.Then, in 30 minutes, be heated to 40 ℃ and stirred 6 hours down at 40 ℃.In 30 minutes, be heated to 60 ℃, stirred 6 hours down at 60 ℃ again, in 1 hour, be cooled to room temperature then.Filtering precipitate, then under reduced pressure under 85 ℃ with dry 12 hours of resulting solids, use mortar to pulverize, obtain cathode electrode catalyst (average grain diameter of Pt particle is 4.8nm, and Pt load concentration is 50 quality %).

3. the manufacturing of anode catalyst layer

With respect to the quality of anode electrode catalyst agent, add the Purified Water of 5 times of amounts, carry out 5 minutes decompression degassing operation.To the normal propyl alcohol that wherein adds 0.5 times of amount, further add the solution that comprises the proton-conducting polyelectrolyte and (comprise the 20wt% Nafion that DuPont company makes ^TM).The content of the polyelectrolyte in the solution is: the solid constituent mass ratio with respect to anode electrode catalyst agent carbonaceous amount is carbon/ionomer=1.0/0.9.

By Soniprep resulting mixed slurry is fully disperseed, catalyst pulp is made in degassing operation by reducing pressure.By silk screen print method it is printed onto on the face of ptfe sheet, the catalyst pulp of printing and desirable thickness respective amount, drying is 24 hours under 60 ℃.Formed anode catalyst layer is of a size of 5cm * 5cm.In addition, adjust the coating layer on the ptfe sheet so that the Pt amount becomes 0.05mg/cm ²

4. the manufacturing of cathode catalyst layer

With respect to the quality of cathode electrode catalyst, add the Purified Water of 5 times of amounts, carry out 5 minutes decompression degassing operation.To the normal propyl alcohol that wherein adds 0.5 times of amount, further add the solution that comprises the proton-conducting polyelectrolyte and (comprise the 20wt% Nafion that DuPont company makes ^TM).The content of the polyelectrolyte in the solution is: the solid constituent mass ratio with respect to the carbonaceous amount of cathode electrode catalyst is carbon/ionomer=1.0/0.9.

By Soniprep resulting mixed slurry is fully disperseed, catalyst pulp is made in degassing operation by reducing pressure.By silk screen print method it is printed onto on the face of ptfe sheet, the catalyst pulp of printing and desirable thickness respective amount, drying is 24 hours under 60 ℃.Formed cathode catalyst layer is of a size of 5cm * 5cm.In addition, adjust the coating layer on the ptfe sheet so that the Pt amount becomes 0.35mg/cm ²

5. the making of membrane-electrode assembly (MEA)

Will be as the Nafion of solid polyelectrolyte membrane ^TMFormed electrode catalyst layer is piled up on 111 (thickness 25 μ m) and the previous ptfe sheet of making.At this moment, carry out stacked according to the order of anode catalyst layer, solid polyelectrolyte membrane, cathode catalyst layer.Then, hot pressing is 10 minutes under 130 ℃, the condition of 2.0MPa, only peels off ptfe sheet, obtains MEA.

The thickness that is transferred to the cathode catalyst layer on the solid polyelectrolyte membrane is about 12 μ m, and the Pt load capacity is every 1cm ²Apparent electrode area 0.35mg, electrode area be 25cm ²The thickness of anode catalyst layer is about 1.5 μ m, and the Pt load capacity is every 1cm ²Apparent electrode area 0.05mg, electrode area be 25cm ²

6. the performance evaluation of membrane-electrode assembly (MEA)

On two faces of the above-mentioned MEA that obtains, be provided as the carbon paper (size: 6.0cm * 5.5cm, thickness 320 μ m) of gas diffusion layers and the gas barrier of band gas flow path,, obtain estimating and use monocell then with gold-plated stainless steel collector plate clamping.Act as a fuel at the anode one side supply of hydrogen of estimating with monocell, supply air as oxidant in negative electrode one side.The supply pressure of two kinds of gases is atmospheric pressure, and hydrogen is that 58.6 ℃ and relative humidity are 60%, and air is that 54.8 ℃ and relative humidity are 50%, and battery temperature is made as 70 ℃.In addition, hydrogen utilization ratio is 67%, and air utilization ratio is 40%.Under this condition, measure with 1.0A/cm ²The cell voltage in current density when generating as initial cell voltage.

Then, after generating 60 seconds, generation outage.After stopping, stop supplies hydrogen and air were with air displacement monocell and standby 50 seconds.Then with 10 seconds of 1/5 anode, one side supply of hydrogen of above-mentioned utilance.Anode one side supply of hydrogen under above-mentioned the same terms is supplied air to negative electrode one side, once more with 1.0A/cm then ²Current density generating 60 seconds.In addition, load current at this moment in 30 seconds from 0A/cm ²Be increased to 1A/cm ²Implement this generating and stop action, measure cell voltage, estimate power generation performance.With 1.0A/cm ²Current density under the period of cell voltage when reaching 0.45V as the value of durability evaluation.Formation and result are shown in table 1-1.In addition, the heat treatment temperature of the graphitization processing of employed conductivity raw material of wood-charcoal material, BET specific area, real density, interplanar distance d in the cathode electrode catalyst ₀₀₂, conductance gathers and is shown in table 4.

Embodiment 2～25, reference example 1～5

Except the formation that shown in table 1-1 and table 1-2, changes fuel cell and embodiment 1 similarly make MEA, estimate durability.Formation and result are shown in table 1-1 and table 1-2.In addition, the heat treatment temperature of the graphitization processing of employed conductivity raw material of wood-charcoal material, BET specific area, real density, interplanar distance d in the cathode electrode catalyst ₀₀₂, conductance gathers and is shown in table 4.

Embodiment 26

1. the preparation of cathode electrode catalyst

Make cathode electrode catalyst similarly to Example 1, used as cathode electrode catalyst (C).

Then, by under 2700 ℃, carbon black (Cabot company make VulcanXC-72) being carried out 10 hours graphitization processing, obtain carbon black (VulcanXC-72 of graphitization processing, the BET surface area=113m of graphitization processing ²/ g, real density 2.01g/cm ³, interplanar distance d ₀₀₂3.46 , conductance 300S/cm).In the carbon black of 4.0g graphitization processing, the adding 400g dinitro two ammino platinum aqueous solution (Pt concentration 1.0%) also stirred 1 hour.And then mix 50g formic acid as reducing agent, stirred 1 hour.Then, in 30 minutes, be heated to 40 ℃ and stirred 6 hours down at 40 ℃.In 30 minutes, be heated to 60 ℃, stirred 6 hours down at 60 ℃ again, in 1 hour, be cooled to room temperature then.Filtering precipitate, then under reduced pressure under 85 ℃ with dry 12 hours of resulting solids, use mortar to pulverize, obtain cathode electrode catalyst (D) (average grain diameter of Pt particle is 4.8nm, and Pt load concentration is 50 quality %).

2. the manufacturing of cathode catalyst layer

The electrode catalyst (C) and the electrode catalyst (D) of above-mentioned manufacturing are mixed according to mass ratio (C)/(D)=2/1,, add the Purified Water of 5 times of amounts, carry out 5 minutes decompression degassing operation with respect to the quality of resulting mixture.To the normal propyl alcohol that wherein adds 0.5 times of amount, further add the solution that comprises the proton-conducting polyelectrolyte and (comprise the 20wt% Nafion that DuPont company makes ^TM).The content of the polyelectrolyte in the solution is: the solid constituent mass ratio with respect to the carbonaceous amount of mixture (electrode catalyst (C) and (D)) is carbon/ionomer=1.0/0.9.By Soniprep resulting mixed slurry is fully disperseed, catalyst pulp is made in degassing operation by reducing pressure.

Except that using above-mentioned catalyst pulp and embodiment 1 similarly on a face of ptfe sheet, make cathode catalyst layer, use it to make MEA, carry out its evaluation.Formation and result are as shown in table 2.In addition, the heat treatment temperature of the graphitization processing of employed conductivity raw material of wood-charcoal material, BET specific area, real density, interplanar distance d in the cathode electrode catalyst ₀₀₂, conductance gathers and is shown in table 5.

Embodiment 27～33

Except the formation of change fuel cell as shown in table 2 and embodiment 26 similarly make MEA, estimate durability.Formation and result are as shown in table 2.In addition, the heat treatment temperature of the graphitization processing of employed conductivity raw material of wood-charcoal material, BET specific area, real density, interplanar distance d in the cathode electrode catalyst ₀₀₂, conductance gathers and is shown in table 5.

Embodiment 34

1. the manufacturing of cathode catalyst layer

The electrode catalyst (D) of manufacturing among the electrode catalyst (C) made among the embodiment 1 and the embodiment 26 is mixed according to mass ratio (C)/(D)=9/1, use resulting mixture and embodiment 26 similarly to prepare gas upstream side catalyst pulp.

The electrode catalyst (D) of manufacturing among the electrode catalyst (C) made among the embodiment 1 and the embodiment 26 is mixed according to mass ratio (C)/(D)=8/2, use resulting mixture and embodiment 26 similarly to prepare gas downstream side catalyst pulp.

Except using above-mentioned catalyst pulp, with embodiment 1 (the coating gas upstream side catalyst pulp of big or small 5.0cm * 2.5cm) on half of the single face of ptfe sheet similarly, by under 60 ℃, making its dry 24 hours, make the upstream side cathode catalyst layer.

Then, (the coating gas downstream catalyst pulp of big or small 5.0cm * 2.5cm) is by making its dry 24 hours, making downstream cathode catalyst layer under 60 ℃ on remaining second half of the single face of above-mentioned ptfe sheet.

Use it to make MEA, carry out its evaluation.Formation and result are as shown in table 3.In addition, cathode electrode catalyst (C) and (D) heat treatment temperature, BET specific area, real density, the interplanar distance d of the graphitization processing of employed conductivity raw material of wood-charcoal material ₀₀₂, conductance gathers and is shown in table 6.

In this cathode catalyst layer, be respectively 12.5cm with catalyst pulp and gas downstream with the formed electrode area of catalyst pulp by the coating gas upstream side ², thickness is respectively 12 μ m, the Pt load capacity is respectively every 1cm ²Apparent electrode area is 0.35mg.

In addition, when estimating the durability evaluation of using monocell, in the cathode catalyst layer, be coated with the gas upstream side and be arranged on the gas introduction port side, be arranged on the gas vent side with the part of catalyst pulp and be coated with the gas downstream side with the part of catalyst pulp.

Embodiment 35～41

Except the formation of change fuel cell as shown in table 3 and embodiment 34 similarly make MEA, estimate durability.Formation and result are as shown in table 3.In addition, cathode electrode catalyst (C) and (D) in heat treatment temperature, BET specific area, real density, the interplanar distance d of graphitization processing of employed conductivity raw material of wood-charcoal material ₀₀₂, conductance gathers and is shown in table 6.

Table 1-1

	Anode electrode catalyst agent kind	The cathode electrode catalyst kind	Catalyst loadings (mg/cm 2)		Anode catalyst layer average thickness Ya (μ m)	Cathode catalyst layer average thickness Yc (μ m)	Ya/Yc (-)	GDL thickness (μ m)	Starting stops number of times (inferior)
										Catalyst conductivity raw material of wood-charcoal material	Catalyst conductivity raw material of wood-charcoal material	Anode	Negative electrode
	Embodiment 1	Pt 50wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Ketjen BlackEC	0.05										0.35	1.5	12.0	0.13	320	2,450
Embodiment 2					Pt 50wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Ketjen BlackEC	0.10	0.35	3.2	12.0	0.27	320	2,670
	Embodiment 3	Pt 50wt％ Ketjan BlackEC	Pt 50wt% graphitization processing Ketjen BlackEC	0.15										0.35	5.0	12.0	0.42	320	2,760
Embodiment 4					Pt 40wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Ketjen BlackEC	0.05	0.35	1.9	12.0	0.16	320	2,570
	Embodiment 5	Pt 30wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Ketjen BlackEC	0.05										0.35	2.6	12.0	0.22	320	2,650
Embodiment 6					Pt 20wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Ketjen BlackEC	0.05	0.35	3.8	12.0	0.32	320	2,710
	Embodiment 7	Pt 10wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Ketjen BlackEC	0.05										0.35	7.5	12.0	0.63	320	2,605
Embodiment 8					Pt 40wt％ Ketjen BlackEC	Pt 30wt% graphitization processing Ketjen BlackEC	0.05	0.35	1.9	20.0	0.09	320	2,745
	Embodiment 9	Pt 50wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Ketjen BlackEC+PTFE handles Vulcan XC-72 (10wt%)	0.05										0.35	2.0	14.4	0.14	320	3,450
Embodiment 10					Pt 50wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Ketjen BlackEC+carbon nano-fiber (10wt%)	0.05	0.35	2.0	14.4	0.14	320	3,630
	Embodiment 11	Pt 50wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Ketjen BlackEC+carbon nano-tube (10wt%)	0.05										0.35	2.0	14.4	0.14	320	3,550
Embodiment 12					Pt 50wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Ketjen BlackEC+Carbon Nanohorn (10wt%)	0.05	0.35	2.0	14.4	0.14	320	3,870
	Embodiment 13	Pt 50wt％ Vulcan XC-72	Pt 50wt% graphitization processing Ketjen BlackEC	0.05										0.35	2.0	12.0	0.17	320	3,550
Embodiment 14					Pt 50wt% acetylene black	Pt 50wt% graphitization processing Ketjen BlackEC	0.05	0.35	2.0	12.0	0.17	320	3,370

Table 1-2

	Anode electrode catalyst agent kind	The cathode electrode catalyst kind	Catalyst loadings (mg/cm 2)		Anode catalyst layer average thickness Ya (μ m)	Cathode catalyst layer average thickness Yc (μ m)	Ya/Yc (-)	GDL thickness (μ m)	Starting stops number of times (inferior)
										Catalyst conductivity raw material of wood-charcoal material	Catalyst conductivity raw material of wood-charcoal material	Anode	Negative electrode
	Embodiment 15	Pt 50wt% graphitization processing Ketjen BlackEC	Pt 50wt% graphitization processing Ketjen BlackEC	0.05										0.35	2.5	12.0	0.21	320	3,740
Embodiment 16					Pt 50wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Ketjen BlackEC	0.05	0.35	2.5	12.0	0.21	320	2,830
	Embodiment 17	Pt 50wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Black Pearl	0.05										0.35	2.0	12.0	0.17	180	2,770
Embodiment 18					Pt 50wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Ketjen BlackEC600JD	0.15	0.35	6.0	12.0	0.50	180	1,950
	Embodiment 19	Pt 50wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Ketjen BlackEC	0.10										0.35	2.0	12.0	0.17	320	2,230
Embodiment 20					Pt 50wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Ketjen BlackEC	0.10	0.35	2.0	12.0	0.17	320	2,480
	Embodiment 21	Pt 50wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Ketjen BlackEC	0.10										0.35	2.0	12.0	0.17	320	2,550
Embodiment 22					Pt 50wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Ketjen BlackEC	0.10	0.35	2.0	12.0	0.17	320	2,980
	Embodiment 23	Pt 50wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Ketjen BlackEC	0.10										0.35	2.0	12.0	0.17	320	3,130
Embodiment 24					Pt 50wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Ketjen BlackEC600JD	0.10	0.35	2.0	12.0	0.17	320	2,540
	Embodiment 25	Pt 50wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Black Pearl	0.10										0.35	2.0	12.0	0.17	320	2,610
Reference example 1					Pt 50wt％ Ketjen BlackEC	Pt 50wt％ Ketjen BlackEC	0.4	0.4	13.7	13.7	1.0	320	450
	Reference example 2	Pt 50wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Ketjen BlackEC	0.4										0.4	14	14	1.0	320	750
Reference example 3					Pt 50wt％ Vulcan XC-72	Pt 50wt% graphitization processing Ketjen BlackEC	0.4	0.4	14	14	1.0	320	730
	Reference example 4	Pt 50wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Ketjen BlackEC	0.4										0.2	14	7.0	2.0	320	680
Reference example 5					Pt 50wt% graphitization processing Ketjen BlackEC	Pt 50wt％ Ketjen BlackEC	0.4	0.4	14	14	1.0	320	530

Table 2

	Anode electrode catalyst agent kind	The cathode electrode catalyst kind			Catalyst loadings (mg/cm 2)		Anode catalyst layer average thickness Ya (μ m)	Cathode catalyst layer average thickness Yc (μ m)	Ya/Yc (-)	GDL thickness (μ m)	Starting stops number of times (inferior)
												Catalyst conductivity raw material of wood-charcoal material	Electrode catalyst C catalyst conductivity raw material of wood-charcoal material	Electrode catalyst D catalyst conductivity raw material of wood-charcoal material	C/D (mass ratio)	Anode	Negative electrode
	Embodiment 26	Pt 50wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Ketjen BlackEC	Pt 50wt% graphitization processing Vulcan XC-72	2/1	0.10												0.35	2.0	12.0	0.17	320	3,450
Embodiment 27							Pt 50wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Ketjen BlackEC600JD	Pt 50wt% graphitization processing Vulcan XC-72	2/1	0.10	0.35	2.0	12.0	0.17	320	3,680
	Embodiment 28	Pt 50wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Black Pearl	Pt 50wt% graphitization processing Vulcan XC-72	2/1	0.10												0.35	2.0	12.0	0.17	320	3,120
Embodiment 29							Pt 50wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Ketjen BlackEC	Pt 50wt% graphitization processing acetylene black	2/1	0.10	0.35	2.0	12.0	0.17	320	3,680
	Embodiment 30	Pt 50wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Ketjen BlackEC	Pt 50wt% graphitization processing furnace black	2/1	0.10												0.35	2.0	12.0	0.17	320	3,650
Embodiment 31							Pt 50wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Ketjen BlackEC	Pt 50wt% graphitization processing Vulcan XC-72	4/1	0.10	0.35	2.0	12.0	0.17	320	3,020
	Embodiment 32	Pt 50wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Ketjen BlackEC	Pt 50wt% graphitization processing Vulcan XC-72	1/1	0.10												0.35	2.0	12.0	0.17	320	3,860
Embodiment 33							Pt 50wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Ketjen BlackEC	Pt 50wt% graphitization processing Vulcan XC-72	1/2	0.10	0.35	2.0	12.0	0.17	320	3,930

Table 3

	Anode electrode catalyst agent kind	The cathode electrode catalyst kind		Cathode catalyst layer C/D (mass ratio)		R up/ R down (-)	Catalyst loadings (mg/cm 2)		Anode catalyst layer average thickness Ya (μ m)	Cathode catalyst layer average thickness Yc (μ m)	Ya/Yc (-)	GDL thickness (μ m)	Starting stops number of times (inferior)
														Catalyst conductivity raw material of wood-charcoal material	Electrode catalyst C catalyst conductivity raw material of wood-charcoal material	Electrode catalyst D catalyst conductivity raw material of wood-charcoal material	Upstream side	The downstream	Anode	Negative electrode
	Embodiment 34	Pt 50wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Ketjen BlackEC	Pt 50wt% graphitization processing Vulcan XC-72	9/1		8/2	2.25/1													0.10	0.35	2.0	12.0	0.17	320	3,280
Embodiment 35						Pt 50wt％ Ketjen BlackEC			Pt 50wt% graphitization processing Ketjen BlackEC	Pt 50wt% graphitization processing Vulcan XC-72	9/1	7/3	3.86/1	0.10	0.35	2.0	12.0	0.17	320	3,550
	Embodiment 36	Pt 50wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Ketjen BlackEC	Pt 50wt% graphitization processing Vulcan XC-72	99/1		9/1	11/1													0.10	0.35	2.0	12.0	0.17	320	2,750
Embodiment 37						Pt 50wt％ Ketjen BlackEC			Pt 50wt% graphitization processing Ketjen BlackEC	Pt 50wt% graphitization processing acetylene black	9/1	9/l	1/1	0.10	0.35	2.0	12.0	0.17	320	2,890
	Embodiment 38	Pt 50wt％ Ketjen BlackEC	Pt 50wt% graphitization processing Ketjen BlackEC (2500 ℃)	Pt 50wt% graphitization processing Ketjen BlackEC (2700 ℃)	9/1		9/1	1/1													0.10	0.35	2.0	12.0	0.17	320	3,550
Embodiment 39						Pt 50wt％ Ketjen BlackEC			Pt 50wt% graphitization processing Ketjen BlackEC (2700 ℃)	Pt 50wt% graphitization processing Ketjen BlackEC (2900 ℃)	9/1	9/1	1/1	0.10	0.35	2.0	12.0	0.17	320	2,940
	Embodiment 40	Pt 50wt％ Ketjen BlackEC	Pt-Co 50wt% (Pt/Co=3/1) graphitization processing Ketjen BlackEC (2500 ℃)	Pt-Co 50wt% (Pt/Co=3/1) graphitization processing Ketjen BlackEC (2700 ℃)	9/1		9/1	1/1													0.10	0.35	2.0	12.0	0.17	320	2,950
Embodiment 41						Pt 50wt％ Ketjen BlackEC			Pt-Co 50wt% (Pt/Co=3/1) graphitization processing Ketjen BlackEC (2500 ℃)	Pt-Co 50wt% (Pt/Co=3/1) graphitization processing Ketjen BlackEC (2700 ℃)	9/1	8/2	2.25/1	0.10	0.35	2.0	12.0	0.17	320	3,130

Table 4

	The conductivity raw material of wood-charcoal material (heat treatment temperature) of cathode electrode catalyst	BET surface area (m 2/g)	Real density (g/cm 3)	d 002 ()	Conductance (S/cm)
						Embodiment 1～16 reference example 2～4	Graphitization processing Ketjen BlackEC (2700 ℃)	130	1.93	3.51	200
Embodiment 17	Graphitization processing Black Pearl (2700 ℃)	320	1.91	3.49	250
						Embodiment 18	Graphitization processing Ketjen BlackEC600JD (2700 ℃)	285	1.85	3.50	250
Embodiment 19	Graphitization processing Ketjen BlackEC (2400 ℃)	190	1.80	3.55	100
						Embodiment 20	Graphitization processing Ketjen BlackEC (2500 ℃)	160	1.85	3.53	130
Embodiment 21	Graphitization processing Ketjen BlackEC (2600 ℃)	145	1.90	3.52	160
						Embodiment 22	Graphitization processing Ketjen BlackEC (2800 ℃)	115	1.96	3.50	300
Embodiment 23	Graphitization processing Ketjen BlackEC (2900 ℃)	105	1.99	3.48	400
						Embodiment 24	Graphitization processing Ketjen BlackEC600JD (2500 ℃)	270	1.81	3.53	180
Embodiment 25	Graphitization processing Black Pearl (2500 ℃)	295	1.83	3.54	190
						Reference example 1,5	Ketjen BlackEC	800	1.80	-	20

Table 5

	The conductivity raw material of wood-charcoal material (heat treatment temperature) of cathode electrode catalyst		BET surface area (m 2/g)	Real density (g/cm 3)	d 002 ()	Conductance (S/cm)
							Embodiment 26	C	Graphitization processing Ketjen BlackEC (2700 ℃)	160	1.81	3.53	130
D	Graphitization processing Vulcan XC-72 (2700 ℃)	113	2.01	3.46	300
						Embodiment 27		C	Graphitization processing Ketjen BlackEC600JD (2700 ℃)	285	1.85	3.50	250
D	Graphitization processing Vulcan XC-72 (2700 ℃)	113	2.01	3.46	300
							Embodiment 28	C	Graphitization processing Black Pearl (2700 ℃)	320	1.91	3.49	250
D	Graphitization processing Vulcan XC-72 (2700 ℃)	113	2.01	3.46	300
						Embodiment 29		C	Graphitization processing Ketjen BlackEC (2700 ℃)	130	1.93	3.51	200
D	Graphitization processing acetylene black (2700 ℃)	113	2.1	3.44	400
							Embodiment 30	C	Graphitization processing Ketjen BlackEC (2500 ℃)	160	1.85	3.53	130
D	Graphitization processing furnace black (2700 ℃)	118	2.07	3.47	450
						Embodiment 31		C	Graphitization processing Ketjen BlackEC (2700 ℃)	130	1.93	3.51	200
D	Graphitization processing Vulcan XC-72 (2900 ℃)	102	2.04	3.44	500
							Embodiment 32	C	Graphitization processing Ketjen BlackEC (2500 ℃)	160	1.85	3.53	130
D	Graphitization processing Vulcan XC-72 (2700 ℃)	113	2.01	3.46	300
						Embodiment 33		C	Graphitization processing Ketjen BlackEC (2500 ℃)	160	1.85	3.53	130
D	Graphitization processing Vulcan XC-72 (2700 ℃)	113	2.01	3.46	300

Table 6

	The conductivity raw material of wood-charcoal material (heat treatment temperature) of cathode electrode catalyst		BET surface area (m 2/g)	Real density (g/cm 3)	d 002 ()	Conductance (S/cm)
							Embodiment 34	C	Graphitization processing Ketjen BlackEC (2700 ℃)	160	1.81	3.53	130
D	Graphitization processing Vulcan XC-72 (2700 ℃)	113	2.01	3.46	300
						Embodiment 35		C	Graphitization processing Ketjen BlackEC (2700 ℃)	130	1.93	3.50	200
D	Graphitization processing Vulcan XC-72 (2700 ℃)	113	2.01	3.46	300
							Embodiment 36	C	Graphitization processing Ketjen BlackEC (2700 ℃)	130	1.93	3.51	200
D	Graphitization processing Vulcan XC-72 (2700 ℃)	113	2.01	3.46	300
						Embodiment 37		C	Graphitization processing Ketjen BlackEC (2700 ℃)	130	1.93	3.51	200
D	Graphitization processing acetylene black (2700 ℃)	113	2.1	3.44	400
							Embodiment 38	C	Graphitization processing Ketjen BlackEC (2500 ℃)	160	1.85	3.53	130
D	Graphitization processing Ketjen BlackEC (2700 ℃)	130	1.93	3.51	200
						Embodiment 39		C	Graphitization processing Ketjen BlackEC (2700 ℃)	130	1.93	3.51	200
D	Graphitization processing Ketjen BlackEC (2900 ℃)	105	1.99	3.46	400
							Embodiment 40	C	Graphitization processing Ketjen BlackEC (2500 ℃)	160	1.85	3.53	130
D	Graphitization processing Ketjen BlackEC (2700 ℃)	130	1.93	3.51	200
						Embodiment 41		C	Graphitization processing Ketjen BlackEC (2500 ℃)	160	1.85	3.53	130
D	Graphitization processing Ketjen BlackEC (2700 ℃)	130	1.93	3.51	200

Shown in table 1～3, PEFC of the present invention stops to have very favorable durability for starting repeatedly.

The foregoing description is used to more specifically describe the present invention, but the present invention is not limited to the foregoing description.

In addition, the application is that its content mode by reference comprises in this application in full based on the Japanese patent application applied in Japanese patent application 2004-134401 number of on April 28th, 2004 application and on February 21st, 2005 2004-134401 number.

Claims (26)

1. fuel cell film-electrode bond, it comprises:

Cathode catalyst layer, it contains the conductivity raw material of wood-charcoal material and the proton-conducting polyelectrolyte of platinum or the formed cathod catalyst of platinum alloy, the described cathod catalyst of load;

Solid polyelectrolyte membrane;

Anode catalyst layer, it contains the conductivity raw material of wood-charcoal material and the proton-conducting polyelectrolyte of anode catalyst, the described anode catalyst of load,

Wherein,

The average thickness of described anode catalyst layer (Ya) is littler than the average thickness (Yc) of described cathode catalyst layer.

2. fuel cell film-electrode bond according to claim 1, wherein, described Ya and described Yc satisfy the relation of Ya/Yc=0.01～0.9.

3. fuel cell film-electrode bond according to claim 1 and 2, wherein, described Ya is 0.3 μ m～10 μ m, described Yc is 7 μ m～20 μ m.

4. according to any described fuel cell film-electrode bond of claim 1～3, wherein,, comprise the carbon black of graphitization processing as the conductivity raw material of wood-charcoal material of described cathode catalyst layer.

5. fuel cell film-electrode bond according to claim 4 is characterized in that, the real density of the carbon black of described graphitization processing is 1.80～2.11g/cm ³, interplanar distance d ₀₀₂Be 3.36～3.55 , conductance is 50～1000S/cm.

6. according to claim 4 or 5 described fuel cell film-electrode bonds, wherein, it is 100m that the carbon black of described graphitization processing comprises the BET surface area ²The carbon black (A) of the described graphitization processing that/g is above.

7. fuel cell film-electrode bond according to claim 6, wherein, the BET surface area of described carbon black (A) is 100～300m ²/ g.

8. according to claim 6 or 7 described fuel cell film-electrode bonds, wherein, the BET surface area of described carbon black (A) is 120～250m ²More than/the g.

9. according to any described fuel cell film-electrode bond of claim 6～8, wherein, described cathod catalyst loads on the last and formation cathode electrode catalyst (C) of described carbon black (A), and the load capacity of the described cathod catalyst in the described cathode electrode catalyst (C) is 20～80 quality %.

10. according to any described fuel cell film-electrode bond of claim 4～9, wherein, the carbon black of described graphitization processing also comprises the BET surface area less than 100m ²The carbon black of the graphitization processing of/g (B).

11. fuel cell film-electrode bond according to claim 10, wherein, the BET surface area of described carbon black (B) is 80～100m ²/ g.

12. according to claim 10 or 11 described fuel cell film-electrode bonds, wherein, described cathod catalyst loads on the last and formation cathode electrode catalyst (D) of described carbon black (B), and the load capacity of the described cathod catalyst in the described cathode electrode catalyst (D) is 10～50 quality %.

13. according to any described fuel cell film-electrode bond of claim 10～12, wherein, described cathode electrode catalyst (C) is counted more than 60/40 with mass ratio ((C)/(D)) with the mixing ratio of described cathode electrode catalyst (D).

14. fuel cell film-electrode bond according to claim 13, wherein, described cathode electrode catalyst (C) counts 60/40～99/1 with the mixing ratio of described cathode electrode catalyst (D) with mass ratio ((C)/(D)).

15. according to claim 13 or 14 described fuel cell film-electrode bonds, wherein, the described cathode electrode catalyst (C) of the upstream side of the gas flow path of described cathode catalyst layer and the mixing ratio (R of described cathode electrode catalyst (D) _Up), with the mixing ratio (R of described cathode electrode catalyst (C) with the described cathode electrode catalyst (D) in the downstream of the gas flow path of described cathode catalyst layer _Down) ratio be R _Up/ R _DownMore than=1/1.

16. according to any described fuel cell film-electrode bond of claim 1～15, wherein, as the conductivity raw material of wood-charcoal material of described cathode catalyst layer, the use fluorine compounds that also comprise gross mass with respect to the conductivity raw material of wood-charcoal material of described cathode catalyst layer and be 1～20 quality % carry out the carbon black that hydrophobization is handled.

17. according to any described fuel cell film-electrode bond of claim 1～16, wherein, as the conductivity raw material of wood-charcoal material of described cathode catalyst layer, the gross mass that also comprises the conductivity raw material of wood-charcoal material of described relatively cathode catalyst layer is carbon nano-tube, carbon nano-fiber or the Carbon Nanohorn of 1～20 quality %.

18. according to any described fuel cell film-electrode bond of claim 1～17, wherein, described platinum alloy is to be selected from the base metal more than at least a kind in chromium, manganese, iron, cobalt and the nickel and the alloy of platinum.

19. fuel cell film-electrode bond according to claim 18, wherein, the described platinum in described platinum alloy and the mixing ratio of described base metal count 1/1～5/1 with mass ratio (platinum/base metal).

20. according to any described fuel cell film-electrode bond of claim 1～19, wherein, the conductivity raw material of wood-charcoal material as described anode catalyst layer comprises carbon black.

21. fuel cell film-electrode bond according to claim 20 wherein, as the conductivity raw material of wood-charcoal material of described anode catalyst layer, comprises the carbon black of graphitization processing.

22. according to any described fuel cell film-electrode bond of claim 1～21, wherein, described anode catalyst loads on the described conductivity raw material of wood-charcoal material and forms the anode electrode catalyst agent, and the load capacity of the described anode catalyst in the described anode electrode catalyst agent is 30～70 quality %.

23. according to any described fuel cell film-electrode bond of claim 1～22, wherein, in the outside of described cathode catalyst layer and described anode catalyst layer, being provided with through the formed thickness of the carbon paper of water-proofing treatment is gas diffusion layers below the 200 μ m.

24. fuel cell film-electrode bond according to claim 23 wherein, is provided with mil layer between described gas diffusion layers and described cathode catalyst layer and described anode catalyst layer.

25. use the polymer electrolyte fuel cell of any described fuel cell of claim 1～24 with film-electrode bond.

26. carry the vehicle of the described polymer electrolyte fuel cell of claim 25.