Membrane Electrode Assembly and Its Verification Method, Proton Exchange Membrane Fuel Cell

Abstract

The present invention discloses a membrane electrode assembly, a verification method thereof, and a proton exchange membrane fuel cell. The verification method includes the following steps: when the operating conditions meet a predetermined temperature and a predetermined relative humidity, setting the impedance value standard and the airtightness value standard corresponding to the operating conditions as a first impedance standard and a first airtightness standard respectively; detecting the impedance value and the airtightness value of the membrane electrode assembly; comparing the impedance value with the first impedance standard and comparing the airtightness value with the first airtightness standard; according to the change of the operating conditions, selecting corresponding impedance correction coefficients to correct the first impedance standard to obtain corresponding impedance standards, and selecting corresponding airtightness correction coefficients to correct the first airtightness standard to obtain corresponding airtightness standards; repeating according to steps S2 and S3 to determine whether the membrane electrode assembly is qualified under the corresponding operating conditions. According to the verification method for the membrane electrode assembly in the embodiments of the present invention, the detection verification method is more flexible, and the interference of the environment on the detection result is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicles, and in particular, to a membrane electrode assembly, a verification method thereof, and a proton exchange membrane fuel cell. Background Art

[0002] As is well known, a membrane electrode assembly is a core component of a proton exchange membrane fuel cell. Before being installed inside the battery, it is necessary to detect the impedance value and airtightness of the membrane electrode assembly, and determine whether the corresponding membrane electrode meets the performance requirements by comparing the test values with the pre-given standard values. During the detection process of the membrane electrode assembly, the requirements for the environment are very strict. For example, there are high requirements for temperature, humidity, and cleanliness.

[0003] In the related art, a constant and verified standard value is given under specific working conditions (such as constant temperature and a specific relative humidity of 40%-50%). If the test values of the airtightness and impedance of the membrane electrode exceed the standard value, it is determined as unqualified. However, in actual tests, since the relative humidity cannot be maintained only within a specific relative humidity range and may change due to environmental factors, it is impossible to accurately determine whether the membrane electrode meets the performance standard only for this specific relative humidity working condition. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art.

[0005] To this end, the present invention provides a verification method for a membrane electrode assembly, which can correct the impedance standard value and airtightness standard value under a predetermined working condition according to the change of the working condition, and make the performance determination of the membrane electrode assembly more accurate.

[0006] The present invention also provides a membrane electrode assembly adopting the above verification method for the membrane electrode assembly.

[0007] The present invention also provides a proton exchange membrane fuel cell having the above membrane electrode assembly.

[0008] According to an embodiment of the first aspect of the present invention, the verification method for a membrane electrode assembly includes the following steps:

[0009] S1. When the working condition meets a predetermined temperature and a predetermined relative humidity, respectively set the impedance value standard and the airtightness value standard corresponding to the working condition as a first impedance standard and a first airtightness standard;

[0010] S2. Place the membrane electrode assembly under the working condition, and detect the impedance value and the airtightness value of the membrane electrode assembly;

[0011] S3. Compare the impedance value with the first impedance standard and the airtightness value with the first airtightness standard. If the impedance value is lower than the first impedance standard and the airtightness value is lower than the first airtightness standard, it is determined that the membrane electrode assembly is qualified;

[0012] S4. According to the change of the working condition, select the corresponding impedance correction coefficient to correct the first impedance standard to obtain the corresponding impedance standard, and select the corresponding airtightness correction coefficient to correct the first airtightness standard to obtain the corresponding airtightness standard;

[0013] S5. Repeat steps S2 and S3, compare the impedance value with the corresponding impedance standard and the airtightness value with the corresponding airtightness standard to determine whether the membrane electrode assembly is qualified under the corresponding working condition.

[0014] According to the verification method for the membrane electrode assembly of the embodiment of the present invention, the impedance standard value and the airtightness standard value under the predetermined working condition can be corrected according to the change of the working condition, that is, when the working condition changes, the impedance value and the airtightness value of the membrane electrode are compared with the corrected impedance standard and airtightness standard, the performance determination of the membrane electrode assembly is more accurate, the detection and verification method is more flexible, and the interference of the environment on the detection result is reduced.

[0015] According to an embodiment of the present invention, in the step S4, set the first impedance standard as a0, the first airtightness standard as b0, the impedance correction coefficient as k1, and the airtightness correction coefficient as k2. Then the corrected impedance standard a = a0*(1 + k1), and the corrected airtightness standard b = b0*(1 + k2), where -1 < k1 < 1 and k1 ≠ 0, -1 < k2 < 1 and k2 ≠ 0.

[0016] According to an optional example of the present invention, set the predetermined temperature as a constant value, the predetermined relative humidity as φ0. When the working condition changes and the relative humidity φ is greater than the predetermined relative humidity φ0, then 0 < k1 < 1, 0 < k2 < 1.

[0017] Further, in the step S1, the predetermined temperature is 20°C - 25°C, and the predetermined relative humidity is 40% - 50%.

[0018] Further, when the relative humidity φ is 50%-60%, the corresponding impedance correction coefficient k1 is k11, and the corresponding airtightness correction coefficient k2 is k21. Both k11 and k21 are less than 1 and greater than 0. When the relative humidity φ is 60%-70%, the corresponding impedance correction coefficient k1 is k12, and the corresponding airtightness correction coefficient k2 is k22. Both k12 and k22 are less than 1 and greater than 0. When the relative humidity φ is 70%-80%, the corresponding impedance correction coefficient k1 is k13, and the corresponding airtightness correction coefficient k2 is k23. Both k13 and k23 are less than 1 and greater than 0, and k13 > k12 > k11.

[0019] According to another optional example of the present invention, when the working condition changes and the relative humidity φ is less than the predetermined relative humidity φ0, then -1 < k1 < 0 and -1 < k2 < 0.

[0020] Further, when the relative humidity φ is 30%-40%, the corresponding impedance correction coefficient k1 is k14, and the corresponding airtightness correction coefficient k2 is k24. Both k14 and k24 are less than 1 and greater than 0.

[0021] According to an optional embodiment of the present invention, the working condition is satisfied, the temperature is a constant value, and the relative humidity 30% < φ < 80%.

[0022] For the membrane electrode assembly according to the embodiment of the second aspect of the present invention, the pass rate is determined by using the verification method for the membrane electrode assembly described in the above embodiment. The membrane electrode assembly includes a proton exchange membrane, an electrocatalyst layer, and a gas diffusion layer. The electrocatalyst layer is coated on both the left and right sides of the proton exchange membrane, and the gas diffusion layer is provided on the side of each electrocatalyst layer away from the proton exchange membrane. For the membrane electrode assemblies composed of different materials, the impedance correction coefficient, the airtightness correction coefficient, the first impedance standard, and the first airtightness standard need to be recalibrated.

[0023] For the membrane electrode assembly according to the embodiment of the present invention, the performance determination of the membrane electrode assembly is more accurate, the detection and verification method is more flexible, the interference of the environment on the detection result is reduced, and the service performance of the membrane electrode assembly is ensured.

[0024] The proton exchange membrane fuel cell according to the embodiment of the third aspect of the present invention is characterized by including the membrane electrode assembly described in the above embodiment, and has the advantages of more reliable and stable performance and long service life.

[0025] The additional aspects and advantages of the present invention will be partially given in the following description, partially become apparent from the following description, or be understood through the practice of the present invention. Description of the Drawings

[0026] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0027] Figure 1 is a schematic flowchart of a verification method for a membrane electrode assembly according to an embodiment of the present invention;

[0028] Figure 2 is a schematic structural diagram of a membrane electrode assembly according to an embodiment of the present invention.

[0029] Reference numerals:

[0030] membrane electrode assembly 100, proton exchange membrane 10, electrocatalyst layer 20, gas diffusion layer 30. Detailed implementation manners

[0031] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary only for explaining the present invention and should not be construed as limiting the present invention.

[0032] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.

[0033] Next, refer to Figure 1 Describe a verification method for a membrane electrode assembly 100 according to an embodiment of the first aspect of the present invention. This method is used to verify whether the performance of the membrane electrode assembly 100 is qualified, and mainly detects whether the impedance value and airtight value of the membrane electrode assembly 100 meet the standards.

[0034] The verification method for the membrane electrode assembly 100 according to the embodiment of the present invention includes the following steps:

[0035] S1. When the working conditions meet the predetermined temperature and predetermined relative humidity, set the impedance value standard and airtight value standard corresponding to the working conditions as the first impedance standard and the first airtight standard, respectively.

[0036] That is to say, the impedance value standard and the airtightness value standard corresponding to the working conditions of a predetermined temperature and a predetermined relative humidity are respectively used as the first impedance standard and the first airtightness standard, which can be used as the judgment basis for evaluating whether the membrane electrode assembly 100 is qualified under this working condition.

[0037] S2. Place the membrane electrode assembly 100 under the working conditions, and detect the impedance value and the airtightness value of the membrane electrode assembly 100. The impedance value and the airtightness value of the membrane electrode assembly 100 in this step are the test values under this working condition.

[0038] S3. Compare the impedance value with the first impedance standard, and compare the airtightness value with the first airtightness standard. If the impedance value is lower than the first impedance standard and the airtightness value is lower than the first airtightness standard, it is determined that the membrane electrode assembly 100 is qualified.

[0039] It should be noted that under this working condition, by comparing the test values of the membrane electrode assembly 100 detected with the corresponding standard values (the first impedance standard and the first airtightness standard), it can be verified whether the performance of the membrane electrode assembly 100 is qualified.

[0040] S4. According to the change of the working conditions, select the corresponding impedance correction coefficient to correct the first impedance standard to obtain the corresponding impedance standard, and select the corresponding airtightness correction coefficient to correct the first airtightness standard to obtain the corresponding airtightness standard.

[0041] It can be understood that different working conditions and impedance correction coefficients are in one-to-one correspondence, and different working conditions and airtightness correction coefficients are also in one-to-one correspondence. Under the corresponding working conditions, select the corresponding impedance correction coefficient to correct the first impedance standard, so as to obtain the impedance standard corresponding to this working condition. Under the corresponding working conditions, select the corresponding airtightness correction coefficient to correct the first airtightness standard, so as to obtain the airtightness standard corresponding to this working condition.

[0042] S5. Repeat steps S2 and S3, compare the impedance value with the corresponding impedance standard, and compare the airtightness value with the corresponding airtightness standard, and then determine whether the membrane electrode assembly 100 is qualified under the corresponding working conditions.

[0043] Under the changed working conditions, if the impedance value of the membrane electrode assembly 100 is lower than the corrected impedance standard and the airtightness value of the membrane electrode assembly 100 is lower than the corrected airtightness standard, it can be determined that the performance of the membrane electrode assembly 100 under the corresponding working conditions is qualified and meets the requirements.

[0044] The verification method for the membrane electrode assembly 100 according to an embodiment of the present invention can correct the impedance standard value and the airtightness standard value under a predetermined working condition according to the change of the working condition, that is, when the working condition changes, the impedance value and the airtightness value of the membrane electrode are compared with the corresponding corrected impedance standard and airtightness standard, so that the performance determination of the membrane electrode assembly 100 is more accurate, the detection and verification method is more flexible, and the interference of the environment on the detection result is reduced.

[0045] According to an embodiment of the present invention, in step S4, the first impedance standard is set as a0, the first airtightness standard is set as b0, the impedance correction coefficient is k1, and the airtightness correction coefficient is k2. Then the corrected impedance standard a = a0*(1 + k1), and the corrected airtightness standard b = b0*(1 + k2), where -1 < k1 < 1 and k1 ≠ 0, -1 < k2 < 1 and k2 ≠ 0. Specifically, k1 can take -0.5, 0.5, etc., and k2 can take -0.5, 0.5, etc. In this way, from the perspective of quantitative relationship, a method is provided to obtain the impedance standard and the airtightness standard under the changed working condition according to the first impedance standard and the first airtightness standard respectively, making the method of obtaining the standard value under the changed working condition simpler and facilitating a more accurate determination of whether the performance of the membrane electrode assembly 100 is qualified.

[0046] According to an optional example of the present invention, the predetermined temperature is set as a constant value, and the predetermined relative humidity is φ0. When the working condition changes and the relative humidity φ is greater than the predetermined relative humidity φ0, then 0 < k1 < 1 and 0 < k2 < 1.

[0047] It can be understood that taking the predetermined temperature and the predetermined relative humidity as the boundary, when the temperature remains unchanged at the predetermined temperature, when the relative humidity is greater than the predetermined relative humidity, the corresponding impedance correction coefficient is greater than 0 and the corresponding airtightness correction coefficient is greater than 0. This is because when the relative humidity increases, the impedance value of the membrane electrode assembly 100 becomes larger and the gas permeation rate becomes larger, and vice versa.

[0048] Furthermore, in step S1, the predetermined temperature is 20°C - 25°C, and the predetermined relative humidity is 40% - 50%. That is, the impedance standard and the airtightness standard corresponding to the working condition are used as the benchmark.

[0049] Further, when the relative humidity φ is 50%-60%, the corresponding impedance correction coefficient k1 is k11, and the corresponding airtightness correction coefficient k2 is k21. Both k11 and k21 are less than 1 and greater than 0. When the relative humidity φ is 60%-70%, the corresponding impedance correction coefficient k1 is k12, and the corresponding airtightness correction coefficient k2 is k22. Both k12 and k22 are less than 1 and greater than 0. When the relative humidity φ is 70%-80%, the corresponding impedance correction coefficient k1 is k13, and the corresponding airtightness correction coefficient k2 is k23. Both k13 and k23 are less than 1 and greater than 0, and k13 > k12 > k11.

[0050] According to another optional example of the present invention, when the working conditions change and the relative humidity φ is less than the predetermined relative humidity φ0, then -1 < k1 < 0 and -1 < k2 < 0.

[0051] Further, when the relative humidity φ is 30%-40%, the corresponding impedance correction coefficient k1 is k14, and the corresponding airtightness correction coefficient k2 is k24. Both k14 and k24 are less than 0 and greater than -1.

[0052] It can be understood that taking the predetermined temperature and the predetermined relative humidity as the boundary, when the temperature remains constant at the predetermined temperature and the relative humidity is less than the predetermined relative humidity, the corresponding impedance correction coefficient is less than 0 and the corresponding airtightness correction coefficient is less than 0.

[0053] According to an optional embodiment of the present invention, the working conditions are met, the temperature is a constant value, and the relative humidity 30% < φ < 80%. It should be noted that in the present invention, the temperature of the working conditions always remains constant, and the relative humidity is in the range of 30%-80%. When the relative humidity is 0%-30% or 80%-90%, the arrival inspection of the membrane electrode assembly 100 should be stopped, and the inspection and determination should be carried out after the environmental conditions are suitable.

[0054] As Figure 2 As shown, for the membrane electrode assembly 100 according to the embodiment of the second aspect of the present invention, the pass rate determination is carried out by using the verification method for the membrane electrode assembly 100 in the above embodiment. The membrane electrode assembly 100 includes a proton exchange membrane 10, an electrocatalyst layer 20, and a gas diffusion layer 30. The electrocatalyst layer 20 is coated on the left and right sides of the proton exchange membrane 10, and a gas diffusion layer 30 is provided on the side of each electrocatalyst layer 20 away from the proton exchange membrane 10. For the membrane electrode assemblies 100 composed of different materials, the impedance correction coefficient, the airtightness correction coefficient, the first impedance standard, and the first airtightness standard need to be recalibrated.

[0055] According to the membrane electrode assembly 100 of the embodiments of the present invention, the performance determination of the membrane electrode assembly 100 is more accurate, the detection and verification method is more flexible, the interference of the environment on the detection results is reduced, and the service performance of the membrane electrode assembly 100 is ensured.

[0056] According to the proton exchange membrane 10 fuel cell of the third aspect embodiment of the present invention, it is characterized in that it includes the membrane electrode assembly 100 in the above embodiments, and has the advantages of more reliable and stable performance and long service life.

[0057] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0058] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A verification method for a membrane electrode assembly, characterized in that, It includes the following steps: S1. When the working conditions meet the predetermined temperature and the predetermined relative humidity, set the impedance value standard and the airtightness value standard corresponding to the working conditions as the first impedance standard and the first airtightness standard respectively; S2. Place the membrane electrode assembly under the working conditions, and detect the impedance value and the airtightness value of the membrane electrode assembly; S3. Compare the impedance value with the first impedance standard, and compare the airtightness value with the first airtightness standard. If the impedance value is lower than the first impedance standard and the airtightness value is lower than the first airtightness standard, it is determined that the membrane electrode assembly is qualified; S4. According to the change of the working conditions, select the corresponding impedance correction coefficient to correct the first impedance standard to obtain the corresponding impedance standard, and select the corresponding airtightness correction coefficient to correct the first airtightness standard to obtain the corresponding airtightness standard; S5. Cycle according to steps S2 and S3, compare the impedance value with the corresponding impedance standard, and compare the airtightness value with the corresponding airtightness standard to determine whether the membrane electrode assembly is qualified under the corresponding working conditions.

2. The verification method for a membrane electrode assembly according to claim 1, wherein, In step S4, set the first impedance standard as a0, the first airtightness standard as b0, the impedance correction coefficient as k1, and the airtightness correction coefficient as k2. Then the corrected impedance standard a = a0 * (1 + k1), and the corrected airtightness standard b = b0 * (1 + k2), where -1 < k1 < 1 and k1 ≠ 0, -1 < k2 < 1 and k2 ≠ 0.

3. The verification method for a membrane electrode assembly according to claim 2, characterized in that, Set the predetermined temperature as a constant value, and the predetermined relative humidity as φ0. When the working conditions change and the relative humidity φ is greater than the predetermined relative humidity φ0, then 0 < k1 < 1, 0 < k2 < 1.

4. The verification method for a membrane electrode assembly according to claim 3, wherein In step S1, the predetermined temperature is 20°C - 25°C, and the predetermined relative humidity is 40% - 50%.

5. The verification method for a membrane electrode assembly according to claim 4, characterized in that, When the relative humidity φ is 50% - 60%, the corresponding impedance correction coefficient k1 is k11, and the corresponding airtightness correction coefficient k2 is k21. Both k11 and k21 are less than 1 and greater than 0; when the relative humidity φ is 60% - 70%, the corresponding impedance correction coefficient k1 is k12, and the corresponding airtightness correction coefficient k2 is k22. Both k12 and k22 are less than 1 and greater than 0; when the relative humidity φ is 70% - 80%, the corresponding impedance correction coefficient k1 is k13, and the corresponding airtightness correction coefficient k2 is k23. Both k13 and k23 are less than 1 and greater than 0, and k13 > k12 > k11.

6. The verification method for a membrane electrode assembly according to claim 4, characterized in that, When the working conditions change and the relative humidity φ is less than the predetermined relative humidity φ0, then -1 < k1 < 0, -1 < k2 < 0.

7. The verification method for a membrane electrode assembly according to claim 6, wherein, When the relative humidity φ is 30% - 40%, the corresponding impedance correction coefficient k1 is k14, and the corresponding airtightness correction coefficient k2 is k24. Both k14 and k24 are less than 0 and greater than -1.

8. The verification method for a membrane electrode assembly according to claim 1, wherein, The working conditions are met, the predetermined temperature is a constant value, and the predetermined relative humidity 30% < φ < 80%.

9. A membrane electrode assembly, characterized in that, The pass rate is determined by using the verification method for the membrane electrode assembly described in any one of claims 1-8 above. The membrane electrode assembly includes a proton exchange membrane, an electrocatalyst layer, and a gas diffusion layer. The electrocatalyst layer is coated on both the left and right sides of the proton exchange membrane, and the gas diffusion layer is provided on the side of each electrocatalyst layer away from the proton exchange membrane. For the membrane electrode assemblies composed of different materials, it is necessary to recalibrate the impedance correction coefficient, the airtightness correction coefficient, the first impedance standard, and the first airtightness standard.

10. A proton exchange membrane fuel cell, characterized in that, It includes the membrane electrode assembly according to claim 9.

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