CN112924496A - Proton exchange membrane drying/wetting rate evaluation method - Google Patents
Proton exchange membrane drying/wetting rate evaluation method Download PDFInfo
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- CN112924496A CN112924496A CN202110134184.0A CN202110134184A CN112924496A CN 112924496 A CN112924496 A CN 112924496A CN 202110134184 A CN202110134184 A CN 202110134184A CN 112924496 A CN112924496 A CN 112924496A
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- exchange membrane
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- purging
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- 239000012528 membrane Substances 0.000 title claims abstract description 98
- 238000009736 wetting Methods 0.000 title claims abstract description 24
- 238000001035 drying Methods 0.000 title claims abstract description 23
- 238000011156 evaluation Methods 0.000 title claims abstract description 13
- 238000010926 purge Methods 0.000 claims abstract description 54
- 238000000034 method Methods 0.000 claims abstract description 24
- 230000008859 change Effects 0.000 claims abstract description 21
- 238000007664 blowing Methods 0.000 claims abstract description 16
- 238000012544 monitoring process Methods 0.000 claims abstract description 15
- 239000007789 gas Substances 0.000 claims description 42
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 11
- 239000011261 inert gas Substances 0.000 claims description 5
- 229920006395 saturated elastomer Polymers 0.000 claims description 5
- 238000012360 testing method Methods 0.000 abstract description 7
- 230000009286 beneficial effect Effects 0.000 abstract description 2
- 239000000446 fuel Substances 0.000 description 8
- 230000008569 process Effects 0.000 description 8
- 229910006069 SO3H Inorganic materials 0.000 description 5
- 125000000020 sulfo group Chemical group O=S(=O)([*])O[H] 0.000 description 5
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 3
- 239000001257 hydrogen Substances 0.000 description 3
- 229910052739 hydrogen Inorganic materials 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 238000010998 test method Methods 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 1
- 238000013329 compounding Methods 0.000 description 1
- 239000008358 core component Substances 0.000 description 1
- 239000011162 core material Substances 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000003487 electrochemical reaction Methods 0.000 description 1
- 239000007772 electrode material Substances 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000012854 evaluation process Methods 0.000 description 1
- 238000007731 hot pressing Methods 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
- G01N27/041—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a solid body
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
- G01N27/048—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance for determining moisture content of the material
Abstract
The invention relates to a proton exchange membrane drying/wetting rate evaluation method, which comprises the following steps of; placing the proton exchange membrane in a wet state in dry gas for purging, monitoring the change condition of the internal resistance along with the purging time, and recording the moment when the break point of the wet equilibrium internal resistance is reached as t1The time to reach the dry internal resistance is denoted as t2And the drying rate is t2‑t1(ii) a The method for evaluating the wetting rate comprises the following steps: blowing the dry proton exchange membrane in the humidified gas, monitoring the change of the internal resistance along with the blowing time, and recording the time when the sudden decrease of the internal resistance is finished as t4The time when the wet equilibrium internal resistance value is reached is recorded as t5And the wetting rate is t5‑t4. Compared with the prior art, the method is beneficial to judging the humidity change conditions of different proton exchange membranes under different purging protocols, so that the purging protocol after the system is shut down can be adjusted, and the working condition of accelerated life test of the membranes can be designed.
Description
Technical Field
The invention belongs to the technical field of fuel cells, and relates to a proton exchange membrane drying/wetting rate evaluation method.
Background
Due to the current increasingly serious problem of energy shortage, many green renewable energy sources, such as wind energy, solar energy, geothermal energy, hydrogen energy and the like, are receiving wide attention, wherein the hydrogen energy is regarded as an important green energy source which can replace the existing fossil energy in the future. The fuel cell is a clean and efficient energy conversion device, can generate water and directly generate electric energy by the electrochemical reaction of hydrogen and air, and has the advantages of high energy conversion rate, environmental friendliness, low noise and the like. The core component of the fuel cell is a membrane electrode material, and is formed by compounding a proton exchange membrane, a catalyst and a gas diffusion layer through a hot pressing process. The proton exchange membrane is one of the core materials in the membrane electrode, the service life of the membrane directly determines the service life of the fuel cell, and in the actual use process, the dry and wet state of the proton exchange membrane directly influences the output performance and the service life of the proton exchange membrane.
Purging is needed after normal fuel cell operation is finished, and meanwhile, the dry and wet state of the proton exchange membrane needs to be controlled through purging in the prediction of the accelerated life of the electric pile, so that the actual operation process of the fuel cell is simulated. The drying/wetting rate of the proton exchange membrane is an important factor influencing the mechanical attenuation of the proton exchange membrane, so that the accurate determination of the drying/wetting rate of different proton exchange membranes is important for adjusting the shutdown and purging protocol of the fuel cell stack and designing the accelerated life test working condition of the proton exchange membrane. At present, methods and procedures for testing the drying/wetting rate of different proton exchange membranes under different purging conditions are lacking.
Disclosure of Invention
The invention aims to provide a method for evaluating the drying/wetting rate of a proton exchange membrane.
The purpose of the invention can be realized by the following technical scheme:
a proton exchange membrane drying rate evaluation method comprises the following steps: purging the proton exchange membrane in a wet state in dry gas, monitoring the change condition of the internal resistance of the proton exchange membrane along with the purging time, and recording the moment when the internal resistance changes suddenly from the wet equilibrium internal resistance as t1The time when the internal resistance value reaches the dry internal resistance value is recorded as t2Then the drying rate of the proton exchange membrane is t2-t1。
Further, the preparation method of the proton exchange membrane in the wet state comprises the following steps: and (3) blowing the proton exchange membrane to be tested by using humidified gas until the internal resistance value reaches the wet equilibrium internal resistance.
Furthermore, the humidified gas comprises saturated steam or supersaturated steam, the purging temperature is 60-90 ℃, and the purging flow is 1-50 nlpm.
Further, the dry gas comprises inert gas, the purging temperature is 60-90 ℃, and the purging flow is 1-100 nlpm.
Further, the dry internal resistance value is that the water content of the film is 1H2O/SO3The internal resistance corresponding to H is generally considered to be that the film is in a dry state. The dry internal resistance value test method comprises the following steps:
s1, according to the literature (Mittersteadt C K, Liu H. conductivity, permability, and ohmic shortings of ionic membranes [ J]Handbook of Fuel Cells,2010.) to determine a proton exchange membrane water content of 1H at the test temperature2O/SO3The humidity of the ambient gas corresponding to H;
s2, blowing the proton exchange membrane by using gas with the same humidity and AT a blowing flow of 5nlpm, and monitoring the internal resistance change of the proton exchange membrane by using an alternating current resistance tester (Anbo AT526) until balance is achieved, wherein the internal resistance value is the dry internal resistance value.
A proton exchange membrane wetting rate evaluation method comprises the following steps: blowing the dry proton exchange membrane in the humidified gas, monitoring the change of the internal resistance of the proton exchange membrane along with the blowing time, and marking the time when the sudden decrease of the internal resistance is finished as t4The time when the internal resistance value reaches the wet equilibrium internal resistance value is recorded as t5Then the wetting rate of the proton exchange membrane is t5-t4。
Wherein the sudden drop of internal resistance refers to the fact that at the initial moment of blowing the dry proton exchange membrane by using humidified gas, the internal resistance of the membrane has a sudden drop process within a short time, usually 1-3s, which is mainly caused by the fact that the membrane is in a very dry state (the water content is 1H)2O/SO3H) In the low water content region of the film (water content is 1H)2O/SO3H is increased to2H2O/SO3H) However, the internal resistances differ greatly, and therefore the influence of this process on the evaluation of the rate of wetting of the proton exchange membrane should be excluded.
Further, the preparation method of the proton exchange membrane in a dry state comprises the following steps: blowing the proton exchange membrane to be tested by dry gas until the internal resistance value is larger than the water content of the membrane and is 1H2O/SO3H corresponding to the internal resistance.
Further, the dry gas comprises inert gas, the purging temperature is 60-90 ℃, and the purging flow is 1-100 nlpm.
Furthermore, before the dry gas is adopted to purge the proton exchange membrane to be tested, the humidified gas is adopted to purge the proton exchange membrane until the temperature of the proton exchange membrane to be tested is raised to the set temperature. And (4) blowing by adopting humidified gas so as to achieve a quick temperature rise effect on the proton exchange membrane to be tested.
Furthermore, the humidified gas comprises saturated steam or supersaturated steam, the purging temperature is 60-90 ℃, and the purging flow is 1-50 nlpm.
Compared with the prior art, the invention provides the test method for evaluating the drying/wetting rates of different proton exchange membranes under different purging conditions, which is beneficial to evaluating the humidity change conditions of different proton exchange membranes under different purging protocols, so that the purging protocol after the system is shut down can be adjusted, and the test working condition of the accelerated life of the membranes can be designed.
Drawings
FIG. 1 is a graph showing the change of internal resistance of a proton exchange membrane in the evaluation of the drying rate in the example;
FIG. 2 is a graph showing the internal resistance change of a proton exchange membrane in the evaluation process of the wetting rate in the example.
Detailed Description
The invention is described in detail below with reference to the figures and specific embodiments.
A proton exchange membrane drying rate evaluation method comprises the following steps:
1) adopting humidified gas to purge a proton exchange membrane to be tested, and monitoring the change condition of the internal resistance of the proton exchange membrane along with the purging time until the internal resistance value reaches the wet state balance internal resistance, so as to obtain the proton exchange membrane in the wet state;
2) purging the wet proton exchange membrane in dry gas, monitoring the change of the internal resistance along with the purging time, and recording the time when the internal resistance changes suddenly from the wet equilibrium internal resistance as t1The time when the internal resistance value reaches the dry internal resistance value is recorded as t2Then the drying rate of the proton exchange membrane is t2-t1。
A proton exchange membrane wetting rate evaluation method comprises the following steps:
1) adopting humidified gas to sweep until the temperature of the proton exchange membrane to be tested is raised to a set temperature;
2) switching the purging gas into dry gas, and monitoring the change condition of the internal resistance of the proton exchange membrane along with the purging time until the internal resistance value reaches the upper limit of the internal resistance, so as to obtain the proton exchange membrane in a dry state;
3) blowing the dry proton exchange membrane in the humidified gas, monitoring the change of the internal resistance along with the blowing time, and recording the time when the sudden decrease of the internal resistance is finished as t4The time when the internal resistance value reaches the wet equilibrium internal resistance value is recorded as t5Then the wetting rate of the proton exchange membrane is t5-t4。
Wherein, the humidified gas comprises saturated steam or supersaturated steam, the purging temperature is 60-90 ℃, and the purging flow is 1-50 nlpm; the dry gas comprises inert gas, the purging temperature is 60-90 ℃, and the purging flow is 1-100 nlpm; the water content of the dry internal resistance film is 1H2O/SO3H corresponds to the internal resistance value.
The present embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the scope of the present invention is not limited to the following embodiments.
Example (b):
a proton exchange membrane drying rate evaluation method comprises the following steps:
1) adopting humidified gas to purge a proton exchange membrane to be tested, and monitoring the change condition of the internal resistance of the proton exchange membrane along with the purging time until the internal resistance value reaches the wet state balance internal resistance, so as to obtain the proton exchange membrane in the wet state;
2) switching the purging gas into dry gas, monitoring the change condition of the internal resistance along with the purging time, and recording the moment when the internal resistance changes suddenly from the wet equilibrium internal resistance as t1The water content in the film is 1H2O/SO3The time corresponding to H is recorded as t2Then the drying rate of the proton exchange membrane is t2-t1。
The specific process parameters are shown in Table 2, the internal resistance change curve is shown in FIG. 2, and it can be seen from the graph that t1＝38s，t244s, the drying rate of the proton exchange membrane is t2-t1＝6s。
TABLE 1 proton exchange membrane drying Rate test protocol
A proton exchange membrane wetting rate evaluation method comprises the following steps:
1) adopting humidified gas to sweep until the temperature of the proton exchange membrane to be tested is raised to a set temperature;
2) switching the purging gas into dry gas, monitoring the change of the internal resistance of the proton exchange membrane along with the purging time until the internal resistance reaches the upper limit of the internal resistance, obtaining the proton exchange membrane in a dry state, and recording the time as t3；
3) Switching the purging gas into humidifying gas, purging the dry proton exchange membrane, monitoring the internal resistance change along with the purging time, and switching the gas to generate 1s sudden drop of the internal resistance at the moment, namely, at the end time t of the sudden drop of the internal resistance3+1 denotes t4The time when the internal resistance value reaches the wet equilibrium internal resistance value is recorded as t5Then the wetting rate of the proton exchange membrane is t5-t4。
The specific process parameters are shown in Table 2, the internal resistance change curve is shown in FIG. 2, and it can be seen from the graph that t3＝35s，t4＝36s，t5The wetting rate of the proton exchange membrane is t 40s5-t4＝4s。
TABLE 2 proton exchange membrane drying rate test protocol
The embodiments described above are described to facilitate an understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention based on the disclosure of the present invention.
Claims (10)
1. A method for evaluating a drying rate of a proton exchange membrane, comprising: purging the proton exchange membrane in a wet state in dry gas, monitoring the change condition of the internal resistance of the proton exchange membrane along with the purging time, and recording the moment when the internal resistance changes suddenly from the wet equilibrium internal resistance as t1The time when the internal resistance value reaches the dry internal resistance value is recorded as t2Then the drying rate of the proton exchange membrane is t2-t1。
2. The method for evaluating the drying rate of a proton exchange membrane according to claim 1, wherein the method for preparing the proton exchange membrane in a wet state comprises the following steps: and (3) blowing the proton exchange membrane to be tested by using humidified gas until the internal resistance value reaches the wet equilibrium internal resistance.
3. The method of claim 2, wherein the humidified gas comprises saturated steam or supersaturated steam, the purging temperature is 60-90 ℃, and the purging flow rate is 1-50 nlpm.
4. The method of claim 1, wherein the dry gas comprises an inert gas, the purge temperature is 60-90 ℃, and the purge flow is 1-100 nlpm.
5. The method of claim 1, wherein the dry state internal resistance value is that the water content of the membrane is 1H2O/SO3The corresponding internal resistance value at H.
6. A proton exchange membrane wetting rate evaluation method is characterized by comprising the following steps: blowing the dry proton exchange membrane in the humidified gas, monitoring the change of the internal resistance of the proton exchange membrane along with the blowing time, and marking the time when the sudden decrease of the internal resistance is finished as t4The time when the internal resistance value reaches the wet equilibrium internal resistance value is recorded as t5Then the wetting rate of the proton exchange membrane is t5-t4。
7. The method for evaluating the wetting rate of a proton exchange membrane according to claim 6, wherein the method for preparing the proton exchange membrane in a dry state comprises the following steps: blowing the proton exchange membrane to be tested by dry gas until the internal resistance value is larger than the water content of the membrane and is 1H2O/SO3Internal resistance value at H.
8. The method of claim 7, wherein the dry gas comprises an inert gas, the purge temperature is 60-90 ℃, and the purge flow is 1-100 nlpm.
9. The method for evaluating the wetting rate of the proton exchange membrane according to claim 7, wherein before the dry gas is used for purging the proton exchange membrane to be tested, the humidified gas is used for purging until the proton exchange membrane to be tested is heated to the set temperature.
10. The method of claim 6 or 9, wherein the humidified gas comprises saturated steam or supersaturated steam, the purge temperature is 60-90 ℃, and the purge flow is 1-50 nlpm.
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Citations (7)
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|---|---|---|---|---|
| US6383671B1 (en) * | 1998-09-08 | 2002-05-07 | Lynntech, Inc. | Gas humidification device for operation testing and evaluation of fuel cells |
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2021
- 2021-01-29 CN CN202110134184.0A patent/CN112924496A/en active Pending
Patent Citations (7)
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|---|---|---|---|---|
| US6383671B1 (en) * | 1998-09-08 | 2002-05-07 | Lynntech, Inc. | Gas humidification device for operation testing and evaluation of fuel cells |
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| US20130260185A1 (en) * | 2012-03-27 | 2013-10-03 | GM Global Technology Operations LLC | Subzero ambient shutdown purge operating strategy for pem fuel cell system |
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Application publication date: 20210608 |