TW201103183A - Multilayerd proton exchange membrane and method for manufacturing the same - Google Patents

Abstract

A multilayered proton exchange membrane and a method for manufacturing the same are provided. The multilayered proton exchange membrane includes a first proton exchange layer and a second proton exchange layer, wherein the water content of the first proton exchange layer is lower than that of the second proton exchange layer.

Description

201103183 VI. Description of the Invention: [Technical Field] The present invention relates to a proton exchange membrane, and more particularly to a proton exchange membrane for a direct methanol fuel cell. [Prior Art] A fuel cell is an electrochemical device that uses an electric fuel and an oxidant to perform an electrochemical reaction to generate electric energy. Due to the high theoretical power efficiency of the fuel cell, it is considered to be an alternative energy source that is expected to replace petrochemical energy. In general, fuel cells can be classified according to the type of electrolyte used in the fuel cell. Commonly used electrolyte types include polymer films, molten carbonates, phosphates, solid oxides, and the like. Among the above-mentioned types of electrolytes, polymer films have high power density and high energy conversion efficiency, and are therefore attracting attention. Further, a fuel cell using a polymer film has an operating temperature of from room temperature to about 100 ° C and is easy to be hermetically sealed and miniaturized. Therefore, the fuel cell is widely used. Further, a fuel cell using a polymer film as an electrolyte can be classified into a photon exchange membrane fuel cell (PEMFC) and a direct methanol fuel cell (DMFC) depending on the type of fuel used. Proton exchange membrane fuel cells use hydrogen as a fuel source, while direct methanol fuel cells use liquid methanol as a fuel source directly in the anode. The commonly used polymer film material is perfluorosulfonic acid (hereinafter referred to as PFSA) resin, for example Du 201103183

Perfluorosulfonated resins manufactured by Pont Co., whose commercial product names include NAFION®, FLEMION®, ACIPLEX®, etc. The properties of the PFSA resin film include mechanical strength, high chemical stability, high decomposition temperature (>280 °C), and high proton conductivity. However, when a PFSA resin film is used as an electrolyte material for a direct methanol fuel cell, an unreacted sterol liquid at the anode is highly permeable to the PFSA resin film to reach the cathode, a phenomenon known as methanol crossover. . Methanol breakthrough significantly reduces the energy conversion efficiency of direct methanol fuel φ cells and may also reduce the useful life of direct methanol fuel cells. A similar problem may occur when other organic polar compounds such as ethanol are used as the fuel source. Therefore, there is a need in the related art to propose a molecular film having low methanol permeability. [Invention] The present invention proposes a multi-layer proton exchange membrane which is disposed between an anode and a cathode of a fuel cell and has low methanol permeability and ideal proton conduction. rate. According to an embodiment of the present invention, the multi-layer proton exchange membrane comprises at least a first proton exchange layer and a second proton exchange layer, wherein the second proton exchange layer is coated on the first proton exchange layer, and the first proton exchange layer The content of = is lower than the water content of the second proton exchange layer. Another aspect of the invention provides a membrane electrode assembly that can be used in a direct methanol fuel cell. According to a specific embodiment of the present invention, the membrane electrode assembly comprises at least a root multi-layer proton exchange membrane, an anode and a cathode according to the above aspect of the invention. The anode is disposed adjacent to the first proton exchange layer; and the cathode is disposed adjacent to the second proton exchange layer. Still another aspect of the invention provides a fuel cell using a multilayer proton exchange membrane or membrane electrode assembly according to the above aspect of the invention. According to an embodiment of the present invention, the fuel cell comprises at least the multilayer proton exchange membrane, anode, cathode and current collector according to the above aspect of the invention. The anode is disposed adjacent to the first proton exchange layer; and the cathode is disposed adjacent to the second proton exchange layer. In addition, the current collector is in contact with the cathode and/or the anode. Another aspect of the invention provides a method of preparing a multilayer proton exchange membrane. According to a specific embodiment of the invention, the above method comprises at least the following steps. First, a first proton exchange layer is provided which is made of a first perfluorosulfonic acid resin solution, and the first perfluorosulfonic acid resin solution comprises a first perfluorosulfonic acid resin and a first solvent. Next, a second perfluorosulfonic acid resin solution is applied onto the first proton exchange layer to form a second proton exchange layer, and the second perfluorosulfonic acid resin solution comprises a concentration by weight of about 0.1% to about 50. % of the second perfluorosulfonic acid resin and the second solvent, and the first and second solvents are different solvents. Thereafter, the second solvent is removed to obtain a multi-layer proton exchange membrane; and the multilayer proton exchange membrane is annealed. [Embodiment] Factors which affect the penetration rate of an organic polar compound fuel such as decyl alcohol include gas diffusion layer material, film thickness, fuel liquid concentration, and operating temperature of a fuel cell. Traditionally, fuel infiltration has been mitigated by reducing the methanol concentration. However, when the fuel concentration is lowered, the fuel cell operating efficiency is also deteriorated. In addition, even if the fuel concentration is lowered, it is possible for the fuel liquid to permeate through the film. Another conventional technique is to reduce the penetration of sterol by increasing the thickness of the membrane; however, this tends to reduce the proton conductivity of the fuel cell. It has also been proposed in the literature to combine a polymer electrolyte membrane with an inorganic material to form a composite membrane to block the passage of methanol molecules; however, it also increases the internal impedance of the membrane, resulting in a decrease in fuel cell performance. In view of the fact that the prior art cannot effectively solve the problem of penetration of sterol (or other organic polar compound fuel), and often sacrifices the working efficiency of the fuel cell in order to reduce the methanol permeability, the present invention proposes a multilayer proton exchange membrane and its preparation. By this method, the multi-layer proton exchange membrane has a low sterol permeability and an ideal fuel cell operating efficiency. The characteristics, structure and preparation method of the multilayer proton exchange membrane of the present invention will be clarified below in a number of specific examples. Firstly, a variety of single-layer membranes were prepared and their water content, proton conductivity and methanol permeability were analyzed. Next, a multi-layer proton exchange membrane was prepared and analyzed for properties. Finally, the multilayer proton exchange membrane was fabricated into a membrane electrode assembly. With single cells, and perform single cell performance testing. 1.1 Preparation of a single layer film According to a specific embodiment of the present invention, the method for producing a single layer film comprises at least the steps of: dissolving a perfluorosulfonic acid resin in a suitable solvent to obtain a perfluorosulfonic acid resin solution; The acid resin solution is applied to a substrate, 201103183 to form a film; the solvent in the film is removed; and annealing is performed. The above steps will be further described in detail below. ° The above-mentioned full-flooded acid tree may be the perfluorinated acid and polytetrafluoroethylene. In the experimental example of the present invention, the perfluorosulfonic acid resin used was a NAFION® polymer dispersion from Pont Corporation. Since the U NAFION® polymer dispersion contains a variety of solvent compositions, it is necessary to remove the solvent to obtain a perfluorosulfonic acid resin solid. In general, the NAFI0N® polymer dispersion can be poured into a container and placed in aeration to evaporate at room temperature until the solvent is completely evaporated; then the resulting solid is placed in a wall vacuum oven at a temperature of 6 (TC). Vacuuming and timing weighing, when the solid weight is kept constant, means that the original solvent has been completely removed, and the desired perfluorosulfonic acid resin solid is obtained.

Thereafter, the obtained perfluorosulfonic acid resin solid was dissolved in various non-solvents to obtain a uniform perfluorosulfonic acid resin solution. In the experimental example of the present invention, the solvent used may be N, N-dimethyl, N, N-dimethylacetamide (DMAc), N, N-dioxin, T-amine.

(Ν, Ν-dimethylformamide, DMF N-N-methylformamide (NMF), alcohol, water or the above solvents. For example, 'the above alcohols may be decyl alcohol, ethanol, propanol Or a group of alcohols, and the alcohol/water mixture may be methanol/water (Me0H/H20), 7, internal) ethanol/water (EtOH/HzO) or isopropanol/water (IPA/H2〇), wherein the alcohols The weight ratio of eight is about 1: 1 to 4: 1. And, the water may be applied to a substrate by any suitable method to apply a perfluoroacid-reducing resin solution to form a uniform film. According to a specific embodiment of the present invention, a perfluorinated acid resin solution can be formed on the substrate by coating, spraying, 201103183 impregnation, screen printing, spin coating, blade coating or solution casting. Thin layer. Thereafter, the solvent in the thin layer of the above perfluorosulfonic acid resin solution may be removed by a heating method or other appropriate means to obtain a perfluorosulfonic acid resin film. The heating temperature and time required for drying depends primarily on the nature of the solvent itself; in general, a suitable heating temperature is about 50 to 80 ° C; in some embodiments, the heating temperature is about 50-70 °. C; while heating for about 20-30 hours, the solvent can be substantially removed. φ According to a specific embodiment of the present invention, the annealing treatment can be carried out in an oven that is purged with nitrogen. In general, the annealing temperature is about 110 to 150 ° C. In some embodiments, the annealing temperature is about 120-130 ° C; and the annealing time is about 10-300 minutes. In some embodiments, the above The annealing time is approximately 30-90 minutes. In addition, according to a specific embodiment of the present invention, the method for manufacturing a single-layer film further comprises: after the annealing treatment, placing the obtained single-layer film in distilled water and performing swelling treatment at room temperature to sufficiently absorb the moisture of the film. . In the experimental example of the present invention, the swelling treatment was carried out for about 24 hours. Further, according to a specific embodiment of the present invention, the above-mentioned swelled single-layer film can be further dried to facilitate storage of the film. For example, the drying step described above comprises vacuuming at a temperature of about 50-80 ° C for about 24 hours in a vacuum oven. The single layer of film can be stored in a glass desicator with an evacuated vacuum. 1.2 Single layer membrane property analysis In the following experimental examples, the perfluorosulfonic acid resin solid was dissolved in different solvents 201103183 'to form a solid solution of perfluorosulfonic acid resin with a weight concentration of about l〇wt〇 / 0' and Annealing was carried out at different annealing temperatures for about 90 minutes to form a single layer film. The heating conditions used when removing the solvent using DMAc, DMF or NMF as the solvent are heating temperature of about 7 (TC, heating time of about 30 hours; while using alcohol/water (such as Me〇H/H20, EtOH/H2〇) When the solvent is removed as a solvent, the heating conditions are as follows: the heating temperature is about 50 ° C, and the heating time is about 3 hours; further, in the relevant experimental example, the weight ratio of the alcohol to the water is about 4 : 1. • Analysis of the gold-containing proton conductivity and methanol penetration rate for a single-layer coffin prepared according to the above method. Tanning, 1.2.1 Moisture content of early film using thermogravimetric analysis The instrument (model: Q5〇; manufacturer: ta, usa) is used to measure the film = water rate. First, the film is swollen according to the above method to absorb moisture. Thereafter, a film of about 5 mg (w.) is taken. The weight loss of the membrane was measured at the rate of rise, the measurement bar = rolling enthalpy was 2 〇 ml / min; the heating rate was about 5 ° C / min; the range was 3 (rc to 6, c). 2〇〇.. Previous: The weight lost in this stage is the calculation of the moisture content of the water/knife in the membrane (Ww)° The formula is as follows: Moisture content % = 〇\^/1)*100% (Equation 1) In the experimental example, the moisture content of the monolayer film obtained under different solvent types and enthalpy conditions. Single layer coffin moisture content (%) 201103183 No. Solvent type Annealing temperature 125°C Annealing temperature 135°C Annealing temperature 150°C 1 DMAc 15.30 ------ 9.54 3.92 2 DMF 15.00 9.55 3.51 3 NMF 14.26 9.53 3.48 4 Me0H/H20 34.10 19.95 ----- 17.18 Et0H/H20 32.30 5 19.38 —--- 14.26 6 ipa/h2o 32.70 19.80 — 17 14 1 / · 1 *+ As can be seen from Table i, under the same annealing conditions, use The moisture content of the single layer gambling prepared by dmAc, MN or NMF solution is lower than the moisture content of the single layer film (four) prepared by using the alcohol/water series solvent. In addition, as the annealing temperature increases, the same _ dissolved (four) preparation The moisture content of the single layer (4) will gradually increase. 1.2.2 The proton conductivity of the single layer membrane can be determined by the film thickness (L, unit. cm), the membrane resistance value (five), unit: Ω) and the electrode lying _ (A , unit: em2) to calculate the proton conductivity (σ, unit: S / em) of the membrane, the calculated silk pattern is as follows:

L σ ---—Rbx A (Equation 2) This month uses the frequency response as the analyzer (FrequenCy

Response

Analyzer; Model: SA1255B; Manufacturer: s〇lanr〇n, this coffee (4) and the potentiostat (Potentiostat; model: SI 1287; manufacturer: s〇iartr〇n, England) to measure the impedance value of the membrane. During the test, the film was placed in 201103183 in a constant temperature and humidity chamber (temperature about 7 (TC; relative humidity about 95%); the test frequency ranged from about 1 MHz to 0.1 Hz; the AC amplitude was 1 (8) mv. The membrane resistance value and the known coffin thickness and contact area are substituted into Equation 2 above to obtain the proton conductivity of the membrane. Table 2 lists the relevant experimental examples, under different solvent types and annealing temperatures, The proton conductivity of the obtained single-layer film. Table 2 Single-layer film material sub-conductivity (S / cm) No. Solvent type annealing temperature 125 ° C Annealing temperature 135 ° C Annealing temperature 150 ° C 1 DMAc 1.22E- 02 3.89E-03 4.36E-03 2 DMF 5.64E-03 2.23E-03 1.81E-03 3 NMF 4.84E-03 1.90E-03 1.37E-03 4 Me0H/H20 5.81E-02 4.72E-02 1.76 E-02 5 Et0H/H20 2.79E-02 1.08E-02 8.11E-03 6 IPA/H20 1.76E-02 7.95E-03 7.01E-03

It can be seen from Table 2 that under the same annealing conditions, the monolayer film prepared by Me0H/H20 solvent has the best proton conductivity; in addition, the proton conduction of the single-layer film prepared by the same solvent increases with the annealing temperature. The rate will gradually decline. On average, the monolayer film prepared by using the alcohol/water series solvent has a higher proton conductivity than the monolayer film prepared by using DMAc, DMF and NMF. 1.2.3 Single layer membrane sterol permeability The method for measuring the methanol permeability of a single layer membrane is as follows. Place a single layer of 201103183 membrane between two connected glass tanks (A tank, B tank), pour 400 ml of methanol solution with a concentration of about 3 在 in tank A, and pour 400 ml into b tank. Water, test temperature is about 70 ° C. Then, every two hours, draw about 3 ml of the solution from the B tank, measure the density of the sample solution by density meter, and substitute the value into the calibration curve drawn by using the concentration and density of the alcohol to calculate the time. T of methanol rolls ^ CB (1). Finally, calculate the single layer of the film using Equation 3 below.

The permeability (ie, the methanol permeability coefficient p) and the methanol penetration of each single layer of tantalum are listed in Table 3: Thousand (Equation 3) where CA and CB are the weights of methanol in the A and B tanks, respectively. (wt%); w knife/length VB is the volume of the solution in the B tank (cm3); A is the cross-sectional area (cm2) of the single-layer coffin; L is the thickness (Cm) of the single-layer film; and P is Methanol penetration rate (cm2/s). No. Solvent type —---- DMAc

Annealing temperature 125 ° C Annealing temperature 135 ° C Annealing temperature 150 ° C 2.86E-06 2.13E-06 1.60E-06~^ __ 2.33E-06 2.08E-06 1.20E-06 ~ __2.28E-06 2.00E -06 9.23E-07~^ ----^ 12 [S] 201103183 4 Me〇H/H20 -^48E-〇6 _ 7.56E-〇6 5 Et0H/H20 _^69E-Q6 4.44E-06 6 Ipa/h2o 3.40E-06 --4.11E-06 As can be seen from Table 3, in the phase

Or under the fire condition prepared by NMF solvent, the methanol permeability of the division prepared by using DMAc and DMF water series solvent is lower than that of the alcohol/annealing temperature, and the same; -! = (4) methanol wear (4). In addition, as it gradually declines. The methanol permeability of the single-layer gambling prepared by the 胄 丨 丨 照 照 照 照 照 照 照 照 照 照 照 照 i i i i i i i i i i i i i i i i i i i i i i i i i i i The table is vice versa. When the moisture content of the other material is lowered, the quality of the single-layer film is =:: also: the single-layer film is low. That is to say, if only 4: = : = is lowered, the methanol permeability S and water rate of the single-layer membrane will be lowered, although the proton conductivity can be achieved. P may have to sacrifice a single layer of membrane material in an aspect of the invention to propose a multi-exchange membrane having a low methanol permeability to 2,1 to prepare a multilayer proton exchange membrane based on the results of the above experimental examples, a layer proton exchange membrane, Multilayer protons and proton conductivity are two properties. Fig. 1 is a schematic cross-sectional view showing a specific two-layer f-subject according to the present invention. The child exchange _ at least includes the :; sub-exchange layer 105 and the second proton exchange layer! H), wherein the water content of the first = parent exchange layer H) 5 is lower than the water content of the second f sub-exchange layer nG. 201103183 Therefore, when the multilayer proton exchange membrane 100 is to be used in a fuel cell, the first proton exchange layer 105 may be provided on the anode side of the fuel cell, and the second proton exchange layer 110 may be provided on the cathode side of the fuel cell. At this time, since the water content of the first proton exchange layer 105 is low, the methanol permeability is also low. Therefore, it is disposed on the anode side of the fuel cell, and the fuel sterol on the anode side can be effectively blocked by the osmosis. And the case of sterol penetration. On the other hand, the overall proton conductivity of the multilayer proton exchange membrane 1 可 can be improved by using a film having a higher water content as the second proton exchange layer 110'. According to a specific embodiment of the present invention, the first proton parent exchange layer and the second proton exchange layer of the multi-layer proton exchange membrane are prepared by using different perfluoro acid-reducing resin solutions (preparation methods will be described later), two of which The solute in the perfluorosulfonic acid resin solution may be the same or different perfluorosulfonic acid resin, but two different solvents must be used. Specifically, the ratio of the water content of the first proton exchange layer to the water content of the second proton exchange layer is about 0.15 to 0.8. In certain embodiments, the above ratio is between about 0.4 and 0.7. According to a specific embodiment of the present invention, the multilayer proton exchange membrane has a thickness of about 20 μηι to about 250 μηι, for example, the film thickness may be about 20, 25, 30, 40, 50, 60, 70, 80, 90, 100, 11, 、, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 245 or 250 μηι. In certain embodiments, the above thickness is from about 17 μm to about 190 μη. Another aspect of the invention provides a method of making the multilayer proton exchange membrane described above. According to an embodiment of the invention, the method comprises at least the following steps: 201103183

First, a first proton exchange layer is provided which is made of a first perfluoroacid resin solution. The first perfluorosulfonic acid resin solution comprises a first perfluoro acid resin and a first solvent. Receiving a first full gas sulphate solution onto the first proton exchange layer to obtain a second proton exchange layer, wherein the second perfluorosulfonic acid resin solution comprises a concentration by weight of about 0.1% to About 50% of the second perfluorosulfonic acid resin and the second solvent. φ thereafter 'removing the second solvent' to obtain a multilayer proton exchange membrane; and annealing the multilayer proton exchange membrane. According to the principle and spirit of the present invention, the first perfluoro acid-reducing resin solution and the second perfluorosulfonic acid resin solution are prepared by using different solvents; thus, the first and second proton exchange layers are prepared. The multi-layer proton exchange membrane of the present invention combines the characteristics of low methanol leakage rate and good proton conductivity. In fact, a commercially available proton exchange membrane can be used as the first mass φ subexchange layer, and then a second proton exchange layer is formed thereon. Alternatively, the first proton exchange layer may be formed on a substrate, and the solvent contained therein may be removed, and then a second proton exchange layer may be formed thereon. According to a specific embodiment of the present invention, the solvents used in the above two perfluoro acid-reducing resin solutions belong to two types, one of which is water, an alcohol or an alcohol/water mixture; and the other type of solvent is DMAc, DMF, NMF or a mixture thereof. More specifically, the above alcohol may be decyl alcohol, ethanol, propanol or isopropanol; and in the alcohol/water mixture, the weight ratio of alcohol to water may be from about 1:1 to 4:1. [s] 15 201103183 Specifically, when preparing the first and/or second perfluorosulfonic acid resin solution, a solid concentration of about 0.1% to about 50% by weight of the perfluorosulfonic acid resin solid may be dissolved in a suitable solvent. And the first perfluorosulfonic acid resin solution and the second perfluorosulfonic acid resin solution must use different types of solvents. For example, the weight percentage of the above-mentioned all-sulfonic acid resin solution may be about 0.1, 0.2, 〇3, 0.4, 0 5 x 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15 , 20, 25, 30, 35, 40, 45 or 50%. However, according to a specific embodiment of the present invention, when the above two proton exchange layers are sequentially formed on the substrate, since the boiling points of the solvents used in the two perfluorosulfonic acid resin solutions are largely different, in the preparation process, The first proton parent layer is prone to shrinkage and cracks, and the junction between the two membranes is uneven and the degree of bonding is poor; or the bubble on the upper surface of the second proton exchange membrane is not obtained. Flat membrane. On the other hand, when the second proton exchange layer is applied, the solvent in the second perfluoro acid recovery resin solution also penetrates into the first proton exchange layer, causing the first proton exchange layer to bulge. Therefore, it is necessary to adjust or control the proton exchange layer • the order of formation, the manner in which the proton exchange layer is applied, the conditions for removing the solvent, and the annealing conditions, etc., to obtain a flat multi-layer proton exchange membrane. In accordance with various embodiments of the present invention, in certain embodiments, a multilayer proton exchange membrane is prepared as follows. First, the first perfluorosulfonic acid resin solution is prepared by using a solvent having a relatively high boiling point (such as DMAc, DMF or NMF), and is directly applied to the substrate, and then the solvent contained therein is removed, thereby obtaining the first A proton exchange layer. Here, the above perfluoro% acid tree solution can be applied by the technique described in the above single layer film preparation method. The optimum temperature for removing such solvents is about 201103183 70-80 〇C. Thereafter, a lower boiling point falling agent (to prepare a solution, and the two are formed into a substrate) is used to form a second proton exchange layer thereon. In the case of Ming 2, this method can be divided into at least two times until it reaches the maximum:! The following: "The body embodiment" may partially volatilize (4) contained in the - total gas side fat solution to obtain a _ riding (four) whole __ lipid solution,

Then apply again. For example, a perfluoroproperate solution can be placed in an environment of about 50 C to volatize the solvent. In a specific embodiment, it may be volatilized first! The solvent volume of 〇 is to obtain a concentrated perfluorosulfonic acid resin solution. Thereafter, the solvent contained in the second perfluorosulfonic acid resin solution is removed, and the appropriate temperature for performing this step is about 50-6 (rc. Finally, the obtained multilayer proton exchange membrane is annealed, the conditions are the same as The manner is substantially similar to the annealing treatment step of the above single-layer film, and will not be described herein. It should be noted that in the multilayer proton exchange membrane prepared according to the above embodiment, the moisture content of the first proton exchange layer is lower than that of the second. The moisture content of the proton exchange layer. Therefore, when it is used in a fuel cell, the anode of the fuel cell should be placed adjacent to the first proton exchange layer, and the cathode should be placed adjacent to the second proton exchange layer. 2.2 Multilayer protons Analysis of the properties of the exchange membranes After the preparation of the multilayer proton exchange membrane was completed according to the above method, the methanol permeability and proton conductivity at 70 ° C were analyzed for these multilayer proton exchange membranes [S] 17 201103183. The equipment, conditions and methods used in the analysis are the same as those described above with reference to the single-layer membrane, and are not described here. The following is a list of the use of DMF and a weight ratio of about 4:1. Alcohol/water as a result of analysis of a multilayer proton exchange membrane prepared by preparing a solvent for the first proton exchange layer and the second proton exchange layer, and commercially available NAFION® 117 proton exchange membrane (purchased from DuPont Co.), and respectively The two monolayer proton exchange membranes prepared by using DMF solvent and isopropanol/water solvent in a weight ratio of about 4:1 are compared. In this experimental example, the thickness of the first proton exchange layer and the second proton exchange layer is about 1 : 1. The results of the above analysis are summarized in Table 4. Table 4 Methanol permeability and proton conductivity of various membrane materials Film material thickness (cm) Methanol permeability (cm2/sec) Proton conductivity (S /cm) NAFION®-117 1.78E-02 4.36E-06 4.50E-02 DMF Single Layer Film 1.73E-02 2.33E-06 5.64E-03 ΙΡΑ/Η20 Single Layer Film 1.78E-02 7.56E-06 4.36 E-02 DMF+IPA/H20 Multilayer Film 1.81E-02 4.24E-06 5.30E-02 From the data of Table 4, a multilayer proton exchange membrane and a single layer membrane or a commercially available membrane prepared according to an embodiment of the present invention can be found. Compared with the material, it has the characteristics of resistance to methanol penetration and high proton conductivity. 3.1 Preparation of membrane electrode group and single cell Another aspect of the invention is directed to a Membrane Electrode Assembly (MEA) made using a multilayer proton exchange membrane according to the above specific embodiment of the invention of 201103183. According to a specific embodiment of the invention, the membrane electrode assembly The invention comprises a multilayer proton exchange, an anode and a cathode, wherein the anode is disposed at a first proton exchange layer adjacent to the multilayer proton exchange membrane (a proton exchange layer having a relatively low water content); and the cathode is disposed at a second proton adjacent to the multilayer proton exchange membrane The exchange layer (a proton exchange layer with a relatively high water content). According to various embodiments of the present invention, the anode and the cathode respectively comprise at least one carbon cloth and a catalyst layer formed on the carbon cloth. For example, the material of the above catalyst layer contains at least platinum. In some embodiments, the catalyst layer material comprises carbon in addition to platinum. An experimental example of the present invention will be described here to explain the preparation method of the membrane electrode assembly. In the following experimental example, membrane electrode group 1 (experimental group) was prepared using the above-mentioned dmf+ipa/h2o multilayer proton exchange membrane, and membrane electrode group 2 (control group) was prepared using a commercially available Nafion 117 proton exchange membrane, and A single cell test was performed on each of the above membrane electrode groups. Proton exchange membranes used in membrane electrode sets are typically cleaned first. In general, the film may be sequentially placed in about 5 wt% of H202, distilled water, about 0.5 MH2S04, and distilled water, and heated at a temperature of 85 ° C for about 1 hour, 30 minutes, 10 minutes, and 10 minutes, respectively. On the other hand, it is necessary to prepare a catalyst slurry and an electrode group. According to an embodiment of the present invention, a catalyst slurry is separately coated on a carbon cloth to form an anode and a cathode. More specifically, in the preparation of the catalyst slurry, the catalyst material is added to water and ultrasonically shaken for about 5 minutes to uniformly disperse the catalyst in water. Next, isopropanol was added and ultrasonically shaken for about 5 minutes to evenly disperse the [s] 19 201103183 media solution system. Thereafter,

Nafion solution, and with ultrasonic _ I hundred = eight At · 细 η * - 丄 颂 以 ' to make Nafion mean = = use the water heating method to dissolve the catalyst to obtain a suitable viscosity The medium is made of Guanghou J!, and the completed anode and cathode catalyst slurry is evenly coated on the surface of the carbon 5 (purchased from MekCo., model GDL35BC), and the coating step can be divided into multiple times. When the catalyst on the carbon cloth is applied to a predetermined amount, the prepared anode and cathode can be obtained. In one embodiment, the catalyst slurry formulation and ratio used for the anode and cathode are as shown in Table 5 below. Catalyst slurry formulation anode cathode catalyst material 40 wt% Pt-Ru/C, where Pt:Ru=l:l —-—. 40 wt% Pt/C carbon cloth on catalyst material content 4.00 mg 2.00 mg Nafion content on carbon cloth 2.00 mg 1.00 mg H20 dosage 0.50 ml 0.25 ml Isopropanol dosage 0.10 ml —· — 0.05 ml The assembly of the membrane electrode assembly can be accomplished by any conventional technical method. The cathode and the anode are respectively placed in the center of the upper and lower sides of the cleaned membrane, and the hot press is used. About 135〇c, 20 .[s] 201103183 A pressure of about 50 kg/cm2 was contracted for 30 seconds, then pressurized to 100 kgf/m2 and pressed for 1 minute to obtain a membrane electrode set. 3.2 Single cell performance test Next, The cell tests of the membrane electrode group 1 and the membrane electrode group 2 described above were carried out separately. In the present embodiment, the membrane electrode group has an active area of about 5 x 5 cm2, and the single cell test system (model: Scribner 850C) was used for the single cell. Performance test, test parameters are shown in Table 6 below: Table 6 Single cell performance test parameters Battery temperature 70 °C Feed temperature 70 °C Feed humidity 100 % Anode sterol concentration 1 阴极 Cathode feed * Air * Methanol and air The amount of material is 3 times stoichiometric. Figure 2 illustrates the potential-to-current density curve (polarization curve) of membrane electrode group 1 (indicated by +) and membrane electrode group 2 (indicated by ◊) at 70 °C. It can be seen from Fig. 2 that the cell electrode performance of the membrane electrode assembly 1 obtained by using the multi-layer proton exchange membrane of the embodiment of the present invention is better. Specifically, compared with the membrane electrode group 2, the membrane electrode assembly The slope of the middle of the polarization curve of 1 is small (below It is known that the multilayered proton exchange membrane in the membrane electrode assembly 1 has a low ohmic impedance. [S] 21 201103183 From the above-described embodiments of the present invention, the most important advantage of applying the present invention is that the proposed multilayer proton exchange The membrane system is composed of proton exchange layers prepared by using different solvents, and these proton exchange layers have the characteristics of anti-sterol penetration and high proton conductivity, respectively, so that the multilayer proton exchange membrane can have both of the above characteristics. Although a two-layer membrane is utilized in the above description and drawings to illustrate the multilayer proton exchange membrane of the present invention, those of ordinary skill in the art to which the present invention pertains may wish to be based on the principles and spirit disclosed in the present specification. Various other appropriate changes. For example, the multilayer proton exchange membrane may be composed of three or more proton exchange layers as long as the proton exchange layers are configured in a manner consistent with the spirit of the present specification. While the invention has been described in terms of various specific embodiments thereof, it is not intended to limit the scope of the invention. And the scope of the present invention is defined by the scope of the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features, advantages and embodiments of the present invention will become more <RTIgt; A multilayer proton exchange membrane of a specific embodiment. Fig. 2 is a graph showing polarization curves of a membrane electrode assembly and a conventional membrane electrode assembly according to an embodiment of the present invention. [S] 22 201103183 [Description of main component symbols] 100 : Multilayer proton exchange membrane 105 : First proton exchange layer 110 : Second proton exchange layer

(S] 23

Claims (1)

201103183 VII. Patent application scope L multi-layer proton exchange membranes, comprising at least: a coating m layer 'where the first sub-cross == in the second proton exchange layer - containing the layer - the water content is low, 2 of which Multilayer proton exchange membrane, fluorinated acid resin. The material of the second proton exchange layer is a multi-layer proton exchange enthalpy as described in item 1 of the 4th Shishili range, and the ratio of the water content of the water layer to the water content of the fresh 1-2 exchange layer is About 0.15 to 〇.8. In the multi-layer proton exchange membrane of the fourth aspect of the invention, the ratio of the water content is about 〇.4Μ7. ^ The first-part proton exchange membrane has a thickness of about 2 〇 division to about 2 乂 5 = as described in the third paragraph of the patent application. A ruthenium electrode group comprising at least: a sub-intersection 3, as described in any one of claims 1 to 5, wherein the anode is provided adjacent to the first proton exchange layer. And a cathode disposed adjacent to the second proton exchange layer. 7. The membrane electrode assembly of claim 6, wherein the anode comprises at least a carbon cloth and a catalyst layer formed thereon; and the cathode comprises at least a carbon cloth and a catalyst layer formed thereon on. 8. The membrane electrode assembly of claim 7, wherein the material of the φ of the catalyst layers comprises at least platinum. 9. The membrane electrode assembly of claim 8, wherein the material of the catalyst layers further comprises at least carbon. 10. A fuel cell comprising: a multilayer proton exchange membrane as described in any one of claims 1 to 5; an anode disposed adjacent to the first proton exchange layer; a cathode And being disposed adjacent to the second proton exchange layer; and a current collector in contact with the cathode and/or the anode. 11. The fuel cell of claim 10, wherein the fuel cell is a direct sterol fuel cell. - 12. - A method for preparing a multilayer [S] 25 201103183 proton exchange crucible as described in claim 1 of the patent application, comprising at least: a solution of a proton exchange layer of a solution - a system of - a perfluoro Acid resin acid tree r blood knot, the first all-liquid acid resin solution comprises a first perfluorinated sulfonium tree and a first solvent; a second perfluorosulfonic acid resin solution is applied to the first a second proton exchange layer, wherein the second perfluoro acid recovery resin; the resin i—ϋ·ι% to about 1 1/2 perfluoro acid continued a first agent, and the first solvent is different from the second solvent; • removing the second solvent' to obtain the multilayer proton exchange membrane; and annealing the multilayer proton exchange membrane. ^ Preparation as described in claim 12:: the agent is hydrazine, hydrazine dimethyl acetamide, hydrazine, hydrazine dimethyl carbamide, amine amine or a mixture thereof; The second solvent is water, an alcohol or an alcohol/water mixture. The preparation method according to claim 12, wherein the continuous process is a water, an alcohol or an alcohol/water mixture, and the second solvent is ΝΝ-:: base ethyl amine, hydrazine, hydrazine-dimethyl ketone, hydrazine _ methyl methyl _ or its mixture as claimed in the scope of the 13th order, the alcohol is methanol, ethanol, propylene propylene: (four) borrow Method [26] [S3 201103183 16. The method for preparing a weight ratio of alcohol to water in the alcohol/water mixture is about H according to the scope of application of the invention, and the preparation method described in claim 12, 1 The step of applying the first king-acid resin solution is to divide the diester solution into at least two: under (four) lines of application. #酸树如巾Please take full-time (4) The preparation method described in item 12, before the application of the second perfluoro-lysate solution, the second solvent contained in the partially volatilized acid-reducing resin solution, '; 90%. ^ One of the first agent = as requested in the preparation method described in item 12, and the annealing treatment is annealed at about 110 to 150 dC / ^, ° 300 minutes. The method of preparing the method described in claim 12, wherein the first proton exchange layer is prepared by a method comprising the following steps: The first resin solution having a concentration by weight of about 0.1% to about 5G% is applied to a substrate; and M removes the first solvent. [S] 27 201103183 22. The preparation method according to claim 12 or 21, ^ ^ the step of applying the first perfluoro acid-reducing resin solution or %I of the second perfluoro acid-reducing resin solution Coating, spraying, dipping, screen printing, spin coating, knife coating or injection molding the first or second perfluorosulfonic acid resin solution on the substrate or the first proton exchange layer, A film is formed. The preparation method according to claim 12, wherein the first solvent or the first solvent is removed by a heating temperature of about 50 to 80 °C. [S3 28