CN118117098A - Transfer catalytic layer, preparation method thereof and transfer method - Google Patents
Transfer catalytic layer, preparation method thereof and transfer method Download PDFInfo
- Publication number
- CN118117098A CN118117098A CN202410517567.XA CN202410517567A CN118117098A CN 118117098 A CN118117098 A CN 118117098A CN 202410517567 A CN202410517567 A CN 202410517567A CN 118117098 A CN118117098 A CN 118117098A
- Authority
- CN
- China
- Prior art keywords
- transfer
- catalytic layer
- nafion
- treating agent
- catalyst slurry
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000003197 catalytic effect Effects 0.000 title claims abstract description 135
- 238000012546 transfer Methods 0.000 title claims abstract description 115
- 238000000034 method Methods 0.000 title claims abstract description 40
- 238000002360 preparation method Methods 0.000 title abstract description 18
- 239000003054 catalyst Substances 0.000 claims abstract description 95
- 239000012528 membrane Substances 0.000 claims abstract description 55
- 239000002002 slurry Substances 0.000 claims abstract description 53
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 43
- 238000010023 transfer printing Methods 0.000 claims abstract description 33
- 238000000576 coating method Methods 0.000 claims abstract description 27
- 239000011248 coating agent Substances 0.000 claims abstract description 23
- 238000001035 drying Methods 0.000 claims abstract description 22
- 230000008569 process Effects 0.000 claims abstract description 21
- 239000003960 organic solvent Substances 0.000 claims abstract description 4
- 125000003158 alcohol group Chemical group 0.000 claims abstract description 3
- 229920000557 Nafion® Polymers 0.000 claims description 45
- 239000011230 binding agent Substances 0.000 claims description 27
- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 claims description 22
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 claims description 16
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical group CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 9
- 229920000831 ionic polymer Polymers 0.000 claims description 8
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 claims description 6
- 239000000853 adhesive Substances 0.000 claims description 5
- 230000001070 adhesive effect Effects 0.000 claims description 5
- 238000004519 manufacturing process Methods 0.000 claims description 5
- 239000011347 resin Substances 0.000 claims description 3
- 229920005989 resin Polymers 0.000 claims description 3
- 238000007581 slurry coating method Methods 0.000 claims description 2
- 125000000542 sulfonic acid group Chemical group 0.000 claims 1
- 239000000446 fuel Substances 0.000 abstract description 9
- 238000007582 slurry-cast process Methods 0.000 abstract description 4
- 239000010410 layer Substances 0.000 description 124
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 22
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 10
- 239000000463 material Substances 0.000 description 8
- 230000010287 polarization Effects 0.000 description 8
- 238000012360 testing method Methods 0.000 description 8
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 7
- DSVGQVZAZSZEEX-UHFFFAOYSA-N [C].[Pt] Chemical compound [C].[Pt] DSVGQVZAZSZEEX-UHFFFAOYSA-N 0.000 description 7
- 230000000052 comparative effect Effects 0.000 description 7
- 229920000554 ionomer Polymers 0.000 description 7
- 229910052799 carbon Inorganic materials 0.000 description 6
- 229910052697 platinum Inorganic materials 0.000 description 6
- 239000007787 solid Substances 0.000 description 6
- 239000002904 solvent Substances 0.000 description 6
- 238000005507 spraying Methods 0.000 description 6
- 238000009792 diffusion process Methods 0.000 description 5
- 239000007789 gas Substances 0.000 description 5
- 238000007731 hot pressing Methods 0.000 description 5
- 230000000670 limiting effect Effects 0.000 description 5
- 239000007921 spray Substances 0.000 description 5
- 239000012790 adhesive layer Substances 0.000 description 4
- 230000007547 defect Effects 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 238000011068 loading method Methods 0.000 description 4
- 239000012071 phase Substances 0.000 description 4
- 229920000642 polymer Polymers 0.000 description 4
- 230000003746 surface roughness Effects 0.000 description 4
- 230000005540 biological transmission Effects 0.000 description 3
- 239000007767 bonding agent Substances 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000001804 emulsifying effect Effects 0.000 description 3
- 238000002474 experimental method Methods 0.000 description 3
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 3
- 239000004810 polytetrafluoroethylene Substances 0.000 description 3
- 239000010935 stainless steel Substances 0.000 description 3
- 229910001220 stainless steel Inorganic materials 0.000 description 3
- 239000000758 substrate Substances 0.000 description 3
- 150000003460 sulfonic acids Chemical class 0.000 description 3
- 229910002837 PtCo Inorganic materials 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- -1 for example Substances 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 230000003993 interaction Effects 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 238000006722 reduction reaction Methods 0.000 description 2
- 239000007790 solid phase Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 229910000838 Al alloy Inorganic materials 0.000 description 1
- LSNNMFCWUKXFEE-UHFFFAOYSA-M Bisulfite Chemical compound OS([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-M 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- QYKIQEUNHZKYBP-UHFFFAOYSA-N Vinyl ether Chemical class C=COC=C QYKIQEUNHZKYBP-UHFFFAOYSA-N 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 238000007605 air drying Methods 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 238000010923 batch production Methods 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000007334 copolymerization reaction Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000003487 electrochemical reaction Methods 0.000 description 1
- 238000000635 electron micrograph Methods 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 230000002209 hydrophobic effect Effects 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- 239000002861 polymer material Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000008961 swelling Effects 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Landscapes
- Inert Electrodes (AREA)
Abstract
The invention relates to a transfer catalytic layer, a preparation method thereof and a transfer method. The preparation method of the transfer catalytic layer comprises the following steps: coating the catalyst slurry on a transfer printing film pre-paved with a treating agent, and drying to form a catalytic layer on the transfer printing film to obtain a transfer printing catalytic layer; the surface tension of the treating agent is greater than the surface tension of the catalyst slurry; the treating agent is an alcohol organic solvent. The catalytic layer transfer method comprises the following steps: and transferring the catalytic layer on the transfer catalytic layer onto the proton exchange membrane. The method for transferring the catalytic layer by using the transfer catalytic layer can effectively solve the problems of slurry casting, burr generation, low efficiency, catalyst layer flatness damage and the like in the transfer process of the catalytic layer of the fuel cell, and ensure the transfer efficiency of the catalytic layer and the integrity of the catalytic layer after transfer.
Description
Technical Field
The invention relates to a transfer catalytic layer, a preparation method thereof and a transfer method.
Background
The Membrane Electrode (MEA) is composed of a Gas Diffusion Layer (GDL), a Catalytic Layer (CL) and a Proton Exchange Membrane (PEM). The catalytic layer is used as a place where electrochemical reaction in the fuel cell occurs, hydrogen oxidation and oxygen reduction reactions are all generated at the three-phase interface, and the source for forming the three-phase interface material is the formula of catalyst slurry and the matching property of the material, so that the electrochemical performance of the membrane electrode is determined. The catalyst slurry is coated, dried and the like to prepare the catalytic layer. In the solvent volatilizing process, the cluster particles are mutually extruded and bonded to promote the connection of a bonding network, and finally the catalytic layer is formed. Therefore, the interaction and matching of the ionic polymer (ionomer for short), the solvent and the catalyst particles in the slurry affect the formation of three-phase interfaces in the catalytic layer, and further affect the catalytic capability of the catalytic layer on oxidation and reduction reactions.
The preparation process of the catalytic layer affects the distribution of the ionic polymer (proton transport channels), the carbon-binding network (electron transport channels) and the formation of porous structures (gas diffusion and water discharge channels). Therefore, the process of coating and drying the catalyst slurry is one of the most critical processes for preparing the MEA, and the quality of coating and drying greatly influences the final performance of the MEA.
The gas diffusion electrode (Gas diffusion electrode, GDE) is a first generation catalytic layer coating process that is used more in the early stages of fuel cells. The catalytic layer is prepared by directly coating catalyst slurry on two sides of a proton exchange membrane (Catalyst coated membrane, CCM). And the coating method mainly comprises spraying, slit coating and transfer printing. Because the spraying is low in efficiency, the method is only suitable for preparing CCM in a laboratory, and large-scale batch production is difficult to realize. Slit coating is a common CCM preparation method, wherein the slit width and the gap between a die head and a substrate are used for controlling the coating thickness of a catalytic layer, and the temperature and the humidity of air duct drying are used for controlling the drying speed of a wet coating. With further development of the catalytic layer preparation process, more and more experiments and production use a transfer printing process (DECAL TRANSFER method, DTM) to prepare the catalytic layer. The method is to coat the catalyst slurry on an inert medium, generally using film materials such as PET, PTFE and the like as a transfer film, forming a solid phase structure of a catalytic layer after drying, hot-pressing the solid phase structure with a proton exchange film, and removing a transfer substrate to realize the transfer process of the catalytic layer from the substrate to the proton exchange film.
The biggest problem in the preparation of the catalytic layer by the DTM at present is that slurry casting easily occurs in the process of coating the catalytic layer on the transfer film due to the self-characteristics of the transfer medium, burrs are generated and the like, so that the waste of the catalyst is caused; on the other hand, in the hot-pressing transfer printing process, the transfer printing film needs to be torn off slowly in the transfer printing process due to the fact that the difference of binding force between the transfer printing film and the catalytic layer and the difference of binding force between the proton exchange film and the catalytic layer are not large enough, and the efficiency is low. Part of the catalytic layer is taken away by the transfer film, so that the three-phase reaction interface is reduced, the flatness of the surface of the catalytic layer is destroyed, and defects such as pits and the like appear. These conditions make it difficult to ensure the efficiency of catalytic layer transfer and the integrity of the catalytic layer after transfer, resulting in loss of catalytic layer during transfer and defects in the catalytic layer, affecting the economy of catalytic layer production and the performance of the fuel cell.
Disclosure of Invention
The invention provides a transfer catalytic layer, a preparation method thereof and a transfer method thereof, and aims to solve the defects of slurry casting, burr generation, low transfer efficiency, damage to the flatness of the catalytic layer and the like in the transfer process in the prior art. The method for transferring the catalytic layer by using the transfer catalytic layer can effectively solve the problems of slurry casting, burr generation, low efficiency, catalyst layer flatness damage and the like in the transfer process of the catalytic layer of the fuel cell, and ensure the transfer efficiency of the catalytic layer and the integrity of the catalytic layer after transfer.
In order to achieve the above purpose, the present invention adopts the following technical scheme:
In a first aspect, the present invention provides a method for preparing a transfer catalytic layer, comprising the steps of: coating the catalyst slurry on a transfer printing film pre-paved with a treating agent, and drying to form a catalytic layer on the transfer printing film to obtain a transfer printing catalytic layer; the surface tension of the treating agent is greater than the surface tension of the catalyst slurry; the treating agent is an alcohol organic solvent.
In the present invention, in the case where the surface tension of the treating agent is larger than that of the catalyst slurry, both "surface tension" are measured under the same test condition, the temperature of the test condition is the ambient temperature of the production process, preferably 15 to 30 ℃, for example 20 ℃.
In the present invention, the values of the "surface tension" are all values of the surface tension measured at 20 ℃.
Treating agent
In the present invention, the surface tension of the treating agent may be between 20 and 50 mN/m, for example between 20 and 35 mN/m.
In the present invention, the alcohol-based organic solvent is preferably ethanol (surface tension: 22.27 mN/m), n-propanol (surface tension: 23.8 mN/m), isopropanol (surface tension: 21.7 mN/m) or ethylene glycol (surface tension: 32.12 mN/m).
In the present invention, the pre-applied amount of the treating agent may be 0.2 to 1.0 mg/cm 2, for example 0.6 mg/cm 2.
In the present invention, the pre-laid area of the treating agent may be 10% to 100% of the area where the catalyst slurry is coated.
In the present invention, the pre-laid shape of the treating agent may be rectangular, circular or elliptical.
In a specific embodiment of the present invention, the pre-laid shape and area of the treating agent is the same as the shape and area of the catalyst slurry coating.
In the present invention, the treating agent may be pre-applied on the transfer film by a spray or brush coating process, preferably spray coating. The spraying allows precise control of the amount of treatment agent.
Transfer film
In the present invention, the material of the transfer film is selected conventionally in the art, and in order to avoid excessive swelling shrinkage of the transfer film during use and to improve dimensional accuracy and process stability of the membrane electrode and improve catalyst slurry utilization rate, the material is generally selected in the art according to properties such as heat resistance, shrinkage, surface hydrophilicity and roughness of the film, for example, PET and/or PTFE.
In the present invention, the thickness of the transfer film may be 0.1 to 0.2 mm.
In the present invention, the tensile strength of the transfer film may be 50 to 100 MPa.
In the present invention, the elongation of the transfer film may be 310% to 350%.
In the present invention, the maximum working temperature of the transfer film may be 250 ℃.
In the present invention, the surface roughness Ra of the transfer film may be not more than 0.17 μm, and the surface arithmetic average height of the transfer film is referred to as surface roughness Ra.
In the present invention, the surface roughness Rz of the transfer film may be not more than 1.6 μm, and the sum of the peak-to-valley height average values of ten points on the surface of the transfer film is referred to as the surface roughness Rz.
Limit domain frame
In the invention, a domain-limiting frame can be arranged on the transfer printing film, and the catalyst slurry and the treating agent are positioned in the domain-limiting frame.
The material of the domain-limited frame is based on the requirement of the transfer printing process, and one or more of heat-stable materials such as stainless steel, aluminum alloy, high-molecular polymer and carbon material can be selected. The inner side of the limiting frame should be processed with hydrophobic treatment as much as possible to prevent the adhesion of catalyst slurry.
Wherein the thickness of the confinement frame may be 1-3 times, for example 20-180 μm, the thickness of the catalytic layer.
The size and shape of the domain-limiting frame are independently customized according to the active area of the catalytic layer, and are matched with the size and the property of the catalytic layer, for example, a rectangle.
In a specific embodiment of the present invention, the size of the domain-limiting frame is 250 mm ×150 mm.
Catalyst slurry, catalytic layer
In the present invention, the surface tension of the catalyst slurry may be between 15 and 35 mN/m, for example 20.4 mN/m or 21.7 mN/m.
In the present invention, the catalyst slurry is of a composition conventional in the art and may include a catalyst, a binder and a solvent.
Wherein the catalyst may be a platinum carbon catalyst, such as Pt/C or PtCo/C. The platinum group metal content in the platinum carbon catalyst can be 40-60% by mass of the catalyst. The mass ratio (I/C) of carbon in the platinum carbon catalyst to the binder may be (0.3-1.5): 1, for example 0.9:1 or 1.0:1.
In a specific embodiment of the invention, the catalyst is Pt/C, and the platinum accounts for 40-60% of the mass of the catalyst.
In a specific embodiment of the invention, the catalyst is PtCo/C, the metal content accounts for 40-60% of the catalyst mass, and the mass ratio of Pt to Co is 1:1.
Wherein the binder may be an ionomer. The ionomer may be one or more of Nafion D2020, nafion D520, nafion D521, nafion D2021, nafion D79, nafion D1020, and Nafion D1021.
Wherein the solvent can be one or more of isopropanol, ethanol, n-propanol and water, preferably isopropanol and water with a mass ratio of (0.1-10) 1, such as isopropanol and water with a mass ratio of 1:1.
Wherein the solid content of the catalyst slurry may be 6 to 15wt%.
The preparation method of the catalyst slurry can comprise the following steps according to the conventional method in the field: mixing and dispersing the raw materials. The dispersing equipment can be a high shear dispersing emulsifying machine, a ball mill or an ultrasonic machine. The time of dispersion may be 1-12 h. The dispersed rotational speed may be 2000-16000 rpm. The temperature at which the dispersion occurs may be less than 50 ℃. Cooling circulation water control can be adopted.
In the present invention, the catalyst slurry is coated by a conventional process in the art, such as a slot coating method. The equipment used in the slot coating mode is conventional equipment in the art, such as slot coating equipment.
In the present invention, the shape of the coating of the catalyst slurry may be rectangular, circular or oval.
In the present invention, the temperature of the drying may be not more than 90 ℃. After drying, the pre-laid treating agent volatilizes, no specific substance exists between the catalytic layer and the transfer printing film, at least no solid substance exists, and in the drying process, as the surface tension of the catalyst slurry is smaller than that of the treating agent, the repulsive interaction can be formed between the catalytic layer and the transfer printing film in the drying and volatilizing process of the treating agent, so that the cohesive force between the final catalytic layer and the transfer printing film is reduced.
In a specific embodiment of the present invention, the drying temperature is 30-90 ℃.
In a specific embodiment of the present invention, the drying temperature is at room temperature, i.e., 15-25 ℃.
In the present invention, the drying time may be 10 to 30 s.
In a specific embodiment of the present invention, the drying time is 10-20 s.
In a specific embodiment of the present invention, the drying time is 20-30 s.
In the present invention, the means for drying are conventional in the art, such as natural air drying, coating stage heating, or hot air knife heating.
In the present invention, the catalytic layer may include the catalyst and the binder.
In the present invention, the thickness of the catalytic layer may be 10 to 100. Mu.m, preferably 15 to 60. Mu.m, for example 20. Mu.m.
In the present invention, the platinum loading in the catalytic layer may be in the range of 0.2 to 0.35 mg/cm 2.
In a specific embodiment of the invention, the catalyst slurry comprises catalyst Pt/C and Nafion D2020, wherein the mass ratio (I/C) of the dry weight of the Nafion D2020 to carbon in the catalyst Pt/C is 0.9, the solid content of the catalyst slurry is 8wt%, and the treating agent is n-propanol.
In a specific embodiment of the invention, the catalyst slurry comprises a catalyst Pt/C and Nafion D2020, wherein the mass ratio (I/C) of the dry weight of the Nafion D2020 to carbon in the catalyst Pt/C is 1.0, the solid content of the catalyst slurry is 10wt%, and the treating agent is n-propanol.
In a second aspect, the present invention provides a transfer catalytic layer prepared by the method for preparing a transfer catalytic layer as described above, comprising a transfer film and a catalytic layer on the transfer film.
In a third aspect, the present invention provides a catalytic layer transfer method comprising the steps of: the catalytic layer on the transfer catalytic layer as described above is transferred onto the proton exchange membrane.
Proton exchange membrane
In the present invention, the proton exchange membrane may have a thickness of 8 to 50 μm, for example, 8 μm, 10 μm, 12 μm or 15 μm.
In the present invention, the proton exchange membrane is of a type conventional in the art, such as a perfluorinated sulfonated polymer proton exchange membrane, a partially sulfonated polymer proton exchange membrane, or a composite proton exchange membrane.
Wherein, the perfluorinated sulfonic acid polymer proton exchange membrane can be formed by copolymerization of polytetrafluoroethylene and perfluorinated vinyl ether with sulfonic acid tail chain according to the routine in the field, such as Nafion series (such as NR211 or NR 212) or Gore-Select series (such as M735.18, M788.12 or M820) of DuPont in the United states.
Transfer printing
In the present invention, the transfer may employ a thermal press transfer process conventional in the art.
The hot-pressing transfer printing equipment can be a hot press.
Wherein the temperature of the hot press transfer printing can be 110-160 ℃.
Wherein the pressure of the thermal compression transfer may be 150-500 kPa, for example 300 kPa.
Wherein the time of the hot pressing transfer printing can be 2-3 min.
Adhesive, adhesive layer
In the present invention, a bonding agent may be pre-laid on the proton exchange membrane to form a bonding layer before the transfer.
Wherein, the interfacial bonding force between the bonding layer and the catalytic layer can be more than 280N/m.
The interfacial binding force between the bonding layer and the proton exchange membrane can be larger than that between the transfer membrane and the catalytic layer, the interfacial binding force between the bonding layer and the catalytic layer is measured under the same test condition, the test temperature and the humidity are the ambient temperature and the ambient relative humidity of the transfer method, the ambient temperature is preferably 15-30 ℃, and the ambient relative humidity is preferably 40-60%.
Wherein, the interfacial binding force between the bonding layer and the proton exchange membrane can be more than 280N/m.
Wherein the binder may be an ionomer. The ionomer may be a perfluorinated sulfonic acid resin such as one or more of Nafion D2020, nafion D520, nafion D521, nafion D2021, nafion D79, nafion D1020, and Nafion D1021.
In a specific embodiment of the invention, the binder is the same as the binder in the catalytic layer.
The pre-laying thickness of the binder is selected according to practical situations, and is preferably 5% -10% of the thickness of the catalytic layer in order to ensure complete transfer of the catalytic layer.
Wherein the pre-applied thickness of the binder is chosen according to the actual situation, preferably 1-5 μm, for example 2 μm, in order to be able to ensure a complete transfer of the catalytic layer.
Wherein the binder may be pre-applied to the proton exchange membrane by a spray or brush application process, such as spraying. The spraying allows precise control of the amount of binder.
In a specific embodiment of the present invention, the thickness of the transfer film is 100 μm, the thickness of the proton exchange film is 15 μm, the thickness of the catalytic layer is 20 μm, and the thickness of the adhesive layer is 2 μm.
In a fourth aspect, the present invention provides a catalyst coated membrane comprising: a proton exchange membrane and a catalytic layer positioned on at least one side of the proton exchange membrane; and a bonding layer is arranged between the proton exchange membrane and at least one catalytic layer, and the bonding agent in the bonding layer is the same as the bonding agent in the catalytic layer.
In the present invention, the binder may be an ionomer. The ionomer may be a perfluorinated sulfonic acid resin such as one or more of Nafion D2020, nafion D520, nafion D521, nafion D2021, nafion D79, nafion D1020, and Nafion D1021.
In a fifth aspect, the present invention provides a membrane electrode comprising a catalyst coated membrane as described above.
In a sixth aspect, the present invention provides a fuel cell comprising a membrane electrode as described above.
On the basis of conforming to the common knowledge in the field, the above preferred conditions can be arbitrarily combined to obtain the preferred examples of the invention.
The reagents and materials used in the present invention are commercially available.
The invention has the positive progress effects that:
(1) According to the invention, the transfer printing film is treated by selecting a proper treating agent, and the occurrence of deformation and cracking phenomena of the catalytic layer can be reduced in the drying process by utilizing the difference between the surface tension of the treating agent and the surface tension of the transfer printing film, so that the transfer printing efficiency of the catalytic layer is improved, the transfer printing integrity of the catalytic layer is ensured, and the loss and the occurrence of surface defects in the transfer printing process of the catalytic layer are reduced to the minimum extent; meanwhile, the surface tension of the catalyst slurry is smaller than that of the treating agent, so that the catalyst slurry is not easy to flow and cast when being coated;
(2) According to the invention, the limiting frame is arranged, the physical limiting effect of the limiting frame is utilized, the casting and loss of the catalyst slurry on the transfer printing film are effectively reduced, the operation is simple, the limiting frame can be reused, and the applicability is stronger;
(3) According to the invention, the proper binder is applied to the proton exchange membrane, so that the bonding strength between the catalytic layer and the proton exchange membrane can be increased, an ion transmission channel between the catalytic layer and the proton exchange membrane can be established, the proton transmission impedance is reduced, the ohmic impedance of the whole cell is reduced, the efficiency of the fuel cell is improved, and the problem that the catalytic layer falls off from the surface of the proton exchange membrane due to long-time operation can be avoided;
(4) In the invention, the treating agent and the adhesive can be combined to make the binding force between the catalytic layer and the proton exchange membrane larger than the binding force between the catalytic layer and the transfer membrane, thereby improving the transfer efficiency of the catalytic layer of the fuel cell and ensuring the transfer integrity of the catalytic layer.
Drawings
FIG. 1 is an electron micrograph (5000X) of an anode catalytic layer obtained in example 1;
FIG. 2 is a schematic illustration of the coating of catalyst slurry on a transfer film in example 1;
FIG. 3 is a schematic view of the catalytic layer on the transfer film in example 1;
FIG. 4 is a schematic diagram of hot-press transfer in example 1;
FIG. 5 is a schematic illustration of the coating of catalyst slurry on the transfer film in comparative example 1;
FIG. 6 is a schematic diagram of the hot-press transfer in comparative example 1;
FIG. 7 is a polarization curve of a cell prepared with the catalyst coated film of examples 1-2, comparative example 1
The reference numerals in the figures indicate: transfer film 1, confinement frame 2, anode catalytic layer 31, proton exchange membrane 5.
Detailed Description
The invention is further illustrated by means of the following examples, which are not intended to limit the scope of the invention. The experimental methods, in which specific conditions are not noted in the following examples, were selected according to conventional methods and conditions, or according to the commercial specifications.
Example 1: catalyst coated membrane treated with treatment agent and in the presence of tie layer
1. Preparation of catalyst slurry: preparing catalyst slurry according to the loading of the catalyst and the parameter requirements of a slit coating device, and reasonably dispersing by using a dispersing device to obtain the catalyst slurry with proper rheological property.
Wherein the preparation steps of the anode catalyst slurry are as follows: isopropyl alcohol and water with the mass ratio of 1:1 are used as solvents, and a proper amount of platinum-carbon catalyst (Pt/C, the platinum accounts for 40 percent of the mass of the catalyst) and Nafion D2020 solution are added, so that the mass ratio (I/C) of the dry weight of the ionic polymer in the Nafion solution to the carbon in the platinum-carbon catalyst is kept to be 0.9. The high shear dispersing emulsifying machine is used for fully dispersing the anode catalyst slurry, the dispersing time is 8 h, the rotating speed is 16000 rpm, the cooling circulating water is adopted to control the temperature to be less than 50 ℃ and the solid content is 8%, and the surface tension of the prepared anode catalyst slurry is 21.7 mN/m.
Wherein, the preparation steps of the cathode catalyst slurry are as follows: isopropyl alcohol and water with the mass ratio of 1:1 are used as solvents, and a proper amount of platinum-carbon catalyst (Pt/C, the platinum accounts for 40 percent of the mass of the catalyst) and Nafion D2020 solution are added, so that the mass ratio (I/C) of the dry weight of the ionic polymer in the Nafion solution to the carbon in the platinum-carbon catalyst is kept to be 1.0. And (3) fully dispersing the cathode catalyst slurry by using a high-shear dispersing emulsifying machine, wherein the dispersing time is 8h, the rotating speed is 16000 rpm, the temperature is controlled to be less than 50 ℃ by adopting cooling circulating water, the solid content is 10%, and the surface tension of the prepared cathode catalyst slurry is 20.4 mN/m.
2. Preparation of anode catalytic layer on transfer film: as shown in fig. 2, a stainless steel border 2 was placed on the transfer film 1, the thickness of the transfer film 1 was 100 μm, the thickness of the border 2 was 20 μm, and the dimensions were 250 mm ×150 mm rectangular.
Pre-laying a layer of n-propanol (the pre-laying amount is 0.6 mg/cm 2) on the transfer film by using a spray pen; the anode catalyst slurry is coated on the transfer film 1 by a slit coating mode, and the catalyst slurry is not easy to flow out and spread due to the combined action of the surface tension of the n-propanol and the domain-limiting frame.
The anode catalytic layer 31 was dried by heating at 70℃for 20 seconds on a coating stage to give a thickness of 20 μm and a platinum loading of 0.2 mg/cm 2 as shown in FIG. 1.
3. Preparation of cathode catalytic layer on transfer film: and placing a stainless steel limit frame on the other transfer printing film, wherein the thickness of the transfer printing film is 100 mu m, and the thickness of the limit frame is 20 mu m.
Pre-laying a layer of n-propanol (the pre-laying amount is 0.6 mg/cm 2) on the transfer film by using a spray pen; the cathode catalyst slurry is coated on the transfer film 1 by a slit coating mode, and the catalyst slurry is not easy to flow out and spread due to the combined action of the surface tension of the n-propanol and the domain-limiting frame.
The cathode catalytic layer was dried by heating at 70℃for 20 seconds on a coating stage to give a thickness of 20 μm and a platinum loading of 0.35 mg/cm 2.
4. Preparation of proton exchange membrane containing binder: and (3) respectively pre-paving a layer of ionic polymer Nafion D520 with the thickness of 2 mu m on the surfaces of the two sides of the proton exchange membrane 5 by using a spray pen, wherein the pre-paved areas are respectively matched with the coverage areas of the anode catalytic layer 31 and the cathode catalytic layer, and the thickness of the proton exchange membrane is 15 mu m. The proton exchange membrane is made of Gore Select cube M820.
5. And (3) hot pressing transfer printing: transferring the anode catalytic layer 31 and the cathode catalytic layer onto the proton exchange membrane 5 by using a transfer machine to obtain a catalyst coating film; the hot press transfer temperature was 150 ℃, time was 3 min, and pressure was 300 kPa.
Because the binding force between the anode catalytic layer 31 and the proton exchange membrane 5 is greater than the binding force between the anode catalytic layer 31 and the transfer membrane 1, the transfer membrane 1 is easy to separate from the catalytic layer at the moment, and the transfer efficiency of the anode catalytic layer 31 is improved.
As shown in fig. 3, the transfer integrity of the anode catalytic layer 31 may reach 100%, and similarly, the transfer integrity of the cathode catalytic layer may reach 100%. Transfer integrity is: the mass of the catalytic layer transferred onto the proton exchange membrane is a percentage of the mass of the catalytic layer prior to transfer.
Example 2: catalyst coated membrane treated with treatment agent and without tie layer
The only difference compared with example 1 is that the two side surfaces of the proton exchange membrane 5 are not pre-laid with adhesive. The transfer integrity of the anode and cathode catalytic layers was only 95%.
Comparative example 1: catalyst coated film without treatment agent treatment+presence of adhesive layer
In comparison with example 1, only the difference was that n-propanol was not pre-laid on the transfer film 1 at the time of preparation of the anode catalyst layer on the transfer film and the cathode catalyst layer on the transfer film, as shown in fig. 5. The transfer integrity of the anode and cathode catalytic layers was only around 85% with a significant portion of the catalytic layer lost, as shown in fig. 6.
Comparative example 2: catalyst coated film without treatment agent treatment and without adhesive layer
The difference compared to example 2 is only that n-propanol is not pre-applied to the transfer film 1 when the anode catalytic layer on the transfer film and the cathode catalytic layer on the transfer film are prepared. The transfer integrity of the anode catalytic layer and the cathode catalytic layer is far below 85%, and a great deal of catalytic layer loss exists.
Effect examples: electrochemical performance test
1. Test object:
The Catalyst Coated Membranes (CCMs) prepared in examples 1-2 and comparative example 1 were prepared as Membrane Electrodes (MEAs) by: the catalytic layer was transferred to both sides of a 25 cm 2 proton exchange membrane (15 μm, gore Select @ M820) at 150 ℃ using a heated press (TYC-3-S-PCD, eastern oil pressure industry ltd.) using graphite plates to fix the PEM position on both sides of the proton exchange membrane. The transferred CCM was sandwiched between gas diffusion layers (AVCarb-2240B, ballard) and the membrane electrode was pressed using a hot press set at a hot press temperature of 110 ℃ and a pressure of 0.3 MPaG for a press time of 3 min.
2. The testing method comprises the following steps:
The MEA was electrochemically tested using a fuel cell test platform (GREEN LIGHT, G20) and electrochemical workstation (GAMRY REFERENCE 3000). The bipolar plates used for assembling the single cells are all serpentine flow channels, the current collecting plates are gold-plated copper plates, and the compression force of the MEA is 0.8 MPaG. The anode and anode backpressure were 140 and 120 kPaG, respectively, the humidity was 50% RH, the cell operating temperature was 80℃and the stoichiometric ratio of air and hydrogen was 3 and 1.7, respectively, when tested.
3. Test results:
At low current densities (e.g., 200 mA/cm 2), the activation resistance dominates the polarization loss. In the middle current density (e.g., 1000 mA/cm 2) interval, ohmic resistance dominates the polarization loss. In the high current density region (e.g., 2000 mA/cm 2), mass transfer impedance dominates polarization losses. The results of specific experiments for examples 1-2 and comparative examples 1-2 can be seen in Table 1 below and FIG. 7.
TABLE 1
The above results fully show the variation in cell performance before and after the addition of the treatment agent or binder. Wherein the addition of a treatment agent or binder has less effect on the cell performance in the active polarization region. In the ohmic polarization region, the efficiency of proton transfer is improved due to the additionally added ionic polymer, and the ohmic polarization influence of the whole single cell is reduced and the performance of the single cell is obviously improved because the proton transfer impedance accounts for most of the ohmic impedance of the single cell. In the mass transfer polarization region, after the treating agent or the binding agent is added, the surface of the transferred catalytic layer is flat and has no concave or convex (as shown in figure 4), the influence on the water vapor transmission in the catalytic layer is obvious, and the performance of the single cell is obviously improved.
In addition, the addition of the treating agent or the binder greatly affects the efficiency and integrity of the transfer of the catalytic layer (as shown in fig. 4 and 6), and the incomplete transfer of the catalytic layer affects the number of active reaction sites participating in the reaction, thereby seriously affecting the performance of the single cell.
Claims (9)
1. A method for preparing a transfer catalytic layer, comprising the steps of: coating the catalyst slurry on a transfer printing film pre-paved with a treating agent, and drying to form a catalytic layer on the transfer printing film to obtain a transfer printing catalytic layer; the surface tension of the treating agent is greater than the surface tension of the catalyst slurry; the treating agent is an alcohol organic solvent.
2. The method for producing a transfer catalyst layer according to claim 1, wherein the treating agent satisfies at least one of the following conditions ①-⑥:
① The surface tension of the treating agent is between 20 and 50 mN/m;
② The treating agent is ethanol, isopropanol, n-propanol or ethylene glycol;
③ The pre-paving amount of the treating agent is 0.2-1.0 mg/cm 2;
④ The pre-laid area of the treating agent is 10% -100% of the area coated by the catalyst slurry;
⑤ The pre-laid shape of the treating agent is rectangular, circular or elliptical;
⑥ The pre-laid shape and area of the treating agent is the same as the shape and area of the catalyst slurry coating.
3. The method of preparing a transfer catalyst layer according to claim 1, wherein the catalyst slurry satisfies at least one of the following conditions ①-④:
① The surface tension of the catalyst slurry is between 15 and 35 mN/m;
② The binder in the catalyst slurry is an ionic polymer;
③ The binder in the catalyst slurry is perfluorinated sulfonic acid resin;
④ The binder in the catalyst slurry is one or more of Nafion D2020, nafion D520, nafion D521, nafion D2021, nafion D79, nafion D1020 and Nafion D1021.
4. The method of preparing a transfer catalyst layer according to claim 1, wherein the drying satisfies at least one of the following conditions ①-②:
① The temperature of the drying is not more than 90 ℃;
② The drying time is 10-30 s.
5. A transfer catalytic layer produced by the production method of the transfer catalytic layer according to any one of claims 1 to 4.
6. A catalytic layer transfer method, comprising the steps of: transferring the catalytic layer on the transfer catalytic layer as claimed in claim 5 onto a proton exchange membrane.
7. The catalytic layer transfer process of claim 6, wherein an adhesive is pre-applied to the proton exchange membrane prior to the transfer to form a tie layer.
8. The catalytic layer transfer process of claim 7, wherein the pre-applied binder satisfies at least one of the following conditions ①-⑤:
① The pre-laid binder is the same as the binder in the catalytic layer;
② The pre-laid binder is an ionic polymer;
③ The pre-laid binder is one or more of Nafion D2020, nafion D520, nafion D521, nafion D2021, nafion D79, nafion D1020 and Nafion D1021;
④ The thickness of the pre-laid binder is 5% -10% of the thickness of the catalytic layer;
⑤ The thickness of the pre-laid adhesive is 1-5 μm.
9. The catalytic layer transfer process of claim 7, wherein the bonding layer has a greater interfacial bonding force with the proton exchange membrane than the transfer membrane and the catalytic layer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410517567.XA CN118117098A (en) | 2024-04-28 | 2024-04-28 | Transfer catalytic layer, preparation method thereof and transfer method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410517567.XA CN118117098A (en) | 2024-04-28 | 2024-04-28 | Transfer catalytic layer, preparation method thereof and transfer method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN118117098A true CN118117098A (en) | 2024-05-31 |
Family
ID=91209026
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202410517567.XA Pending CN118117098A (en) | 2024-04-28 | 2024-04-28 | Transfer catalytic layer, preparation method thereof and transfer method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN118117098A (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1534814A (en) * | 2003-03-31 | 2004-10-06 | ������������ʽ���� | Functonal porous layer forming method, fuel cell mfg. method, electronic apparatus and automobile |
| JP2006100092A (en) * | 2004-09-29 | 2006-04-13 | Nissan Motor Co Ltd | Catalyst layer precursor, mount, and electrolyte membrane-catalyst layer joining method using them |
| JP2007265733A (en) * | 2006-03-28 | 2007-10-11 | Dainippon Printing Co Ltd | Transfer sheet, catalyst layer-electrolyte membrane laminate, and manufacturing method of them |
| CN105247722A (en) * | 2013-03-22 | 2016-01-13 | 凸版印刷株式会社 | Substrate film for catalyst transfer film and method for producing same, method for producing catalyst transfer film, and electrolyte membrane with catalyst layer |
| CN108075158A (en) * | 2016-11-18 | 2018-05-25 | 中国科学院大连化学物理研究所 | A kind of preparation method of fuel cell CCM membrane electrodes |
| CN111740120A (en) * | 2020-06-30 | 2020-10-02 | 武汉理工新能源有限公司 | Membrane electrode, preparation method thereof and fuel cell |
| CN117691124A (en) * | 2023-12-14 | 2024-03-12 | 同济大学 | Proton exchange membrane fuel cell low platinum membrane electrode and preparation method thereof |
-
2024
- 2024-04-28 CN CN202410517567.XA patent/CN118117098A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1534814A (en) * | 2003-03-31 | 2004-10-06 | ������������ʽ���� | Functonal porous layer forming method, fuel cell mfg. method, electronic apparatus and automobile |
| JP2006100092A (en) * | 2004-09-29 | 2006-04-13 | Nissan Motor Co Ltd | Catalyst layer precursor, mount, and electrolyte membrane-catalyst layer joining method using them |
| JP2007265733A (en) * | 2006-03-28 | 2007-10-11 | Dainippon Printing Co Ltd | Transfer sheet, catalyst layer-electrolyte membrane laminate, and manufacturing method of them |
| CN105247722A (en) * | 2013-03-22 | 2016-01-13 | 凸版印刷株式会社 | Substrate film for catalyst transfer film and method for producing same, method for producing catalyst transfer film, and electrolyte membrane with catalyst layer |
| CN108075158A (en) * | 2016-11-18 | 2018-05-25 | 中国科学院大连化学物理研究所 | A kind of preparation method of fuel cell CCM membrane electrodes |
| CN111740120A (en) * | 2020-06-30 | 2020-10-02 | 武汉理工新能源有限公司 | Membrane electrode, preparation method thereof and fuel cell |
| CN117691124A (en) * | 2023-12-14 | 2024-03-12 | 同济大学 | Proton exchange membrane fuel cell low platinum membrane electrode and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5716437A (en) | Materials for use in electrode manufacture | |
| US8338059B2 (en) | Hybrid membrane-electrode assembly with minimal interfacial resistance and preparation method thereof | |
| KR101201816B1 (en) | Membrane-electrode assembly, method for preparing the same, and fuel cell system comprising the same | |
| KR20020010544A (en) | A membrane electrode unit for polymer electrolyte fuel cells and a process for the production thereof | |
| US20190280307A1 (en) | Composite electrode layer for polymer electrolyte fuel cell | |
| CN113921831B (en) | Electrode catalyst slurry, method for producing the same, catalyst coated membrane, and fuel cell | |
| CN101000963A (en) | Manufacturing method of membrane electrode of fuel cell | |
| KR100614100B1 (en) | Method for preparing the membrane-electrode assembly for fuel cell using membrane on electrode method before the dry-out of nafion ionomer solution and membrane-electrode assembly for fuel cell prepared by the method | |
| CN114420955B (en) | Preparation method and application of membrane electrode for improving water management of cathode catalytic layer of proton exchange membrane fuel cell | |
| KR102602407B1 (en) | The composition for manufacturing electrode of membrane-electrode assembly for fuel cell and method for manufacturing electrode of membrane-electrode assembly for fuel cell using the same | |
| JP2005108770A (en) | Manufacturing method of electrolyte membrane electrode joint body | |
| CN116364947A (en) | Fuel cell membrane electrode with gradient structure and preparation method thereof | |
| CN114566653B (en) | Non-uniform catalyst layer, membrane electrode and preparation method thereof | |
| CN118117098A (en) | Transfer catalytic layer, preparation method thereof and transfer method | |
| CN113437338B (en) | Fuel cell membrane electrode and preparation method thereof | |
| JPH1116586A (en) | Manufacture of high polymer electrolyte film-gas diffusion electrode body | |
| Wuttikid et al. | Analysis of catalyst ink compositions for fabricating membrane electrode assemblies in PEM fuel cells | |
| CN112310421B (en) | Electrode for fuel cell, membrane electrode assembly, chip, catalyst layer, catalyst dispersion, and method for producing same | |
| KR20090082457A (en) | Electrocatalyst layers for fuel cells and methods of making electrocatalyst layers for fuel cells | |
| KR100705553B1 (en) | Process for forming catalyst layers on a proton exchange membrane within membrane electrode assembly for fuel cell | |
| JP7452480B2 (en) | Catalyst layer and its manufacturing method | |
| JP5609475B2 (en) | Electrode catalyst layer, method for producing electrode catalyst layer, and polymer electrolyte fuel cell using the electrode catalyst layer | |
| Sasiwimonrit et al. | High-temperature proton exchange membrane fuel cell–Approaches to better performances | |
| CN118281241A (en) | Preparation method of membrane electrode CCM of fuel cell | |
| CN115275225A (en) | Preparation method of membrane electrode catalyst coating |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |