Method for testing influence of gas shortage and ion attack on membrane electrode
By coating the catalyst layer with a solution containing impurity ions and adhering conductive non-permeable materials, combined with hydrogen peroxide treatment, the undergassing and ion attack of the membrane electrode were simulated, thus solving the fuel cell durability problem and enabling quantitative research on membrane electrode performance and guidance for material development.
Patent Information
- Application Number
- CN202511035883.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-25
- Publication Date
- 2025-11-18
AI Technical Summary
The existing technology lacks an effective method to simulate and test the undergassing and impurity ion attack of the membrane electrode during the operation of the fuel cell stack, which leads to fuel cell durability problems and affects the overall stack performance and operating time.
By coating the surface of the fuel cell catalyst layer with a solution containing impurity ions and adhering a conductive, non-permeable material, undergassing and ion attack were simulated. Combined with hydrogen peroxide treatment, the changes in the electrochemical performance of the membrane electrode and the types and contents of ions in the discharged water were tested.
This study enables quantitative research on the impact of impurity ions and undergassing on membrane electrode performance, guiding membrane electrode research and development and material development, and improving the overall stack life of fuel cells.
Abstract
Description
Technical Field
[0001] This application belongs to the field of fuel cell technology, specifically relating to a test method for the effects of undergassing and ion attack on membrane electrodes. Background Technology
[0002] Proton exchange membrane fuel cells (PEMFCs) possess numerous advantages, including high power density and low operating temperature, and have been widely applied in hydrogen transportation, backup power, and stationary power sources. However, the durability (lifespan) of fuel cells still falls short of commercialization goals. Furthermore, durability issues are broad in scope and present significant challenges, becoming a major hurdle for the industrialization of fuel cell vehicles and constituting the final obstacle to the commercialization of automotive fuel cells in terms of vehicle technology. During stack operation, uneven gas flow distribution can lead to overall or localized undergassing of the membrane electrode assembly (MEA). This can cause localized high temperatures or reverse polarity within the stack, posing safety hazards. Additionally, wear and tear on auxiliary components such as pumps and fans can introduce impurity ions. The introduction of these impurity ions accelerates the decomposition of hydrogen peroxide, generating free radicals that attack the proton exchange membrane and the resin within the catalyst layer.
[0003] Therefore, undergassing of the membrane electrode assembly (MEA) and attack by impurity ions are key factors affecting overall stack performance and operating time. However, existing technologies lack solutions to address these issues, necessitating the exploration of a testing method to simulate the effects of undergassing and ion attack on the MEA, in order to guide the subsequent research and development and production of fuel cell MEAs. Summary of the Invention
[0004] This application provides a test method for the effects of insufficient gas supply and ion attack on membrane electrodes. The method aims to simulate the attack on membrane electrodes caused by insufficient gas supply and ion dissolution from metal plates during the operation of a metal stack, explore the corrosion mechanism of membrane electrodes, and propose solutions to improve the overall lifespan of the stack.
[0005] This application provides a test method for the effects of undergassing and ion attack on membrane electrodes, comprising the following steps:
[0006] (1) Test and record the electrochemical performance of the fuel cell under test;
[0007] (2) Simulate undergassing and simulate ion attack on the fuel cell to be tested, and then run:
[0008] A solution containing impurity ions was coated onto the surface of the fuel cell catalyst layer to form an impurity ion layer simulating ion attack treatment; a conductive, non-permeable material was then adhered to the surface of the impurity ion layer to simulate undergassing treatment; the battery after the simulation treatment was run, and the electrochemical performance of the fuel cell after the simulation treatment was tested and recorded.
[0009] (3) Collect the effluent from the cathode and anode of the fuel cell obtained in step (2) and analyze the types and contents of ions in the effluent.
[0010] According to some embodiments of the test method for the effect of under-gas and ion attack on membrane electrodes described in this application, in step (1), the electrochemical performance includes one or more of the following: battery polarization curve, cathode electrochemical active area, anode electrochemical active area, and hydrogen permeation current.
[0011] According to some embodiments of the test method for the effect of undergassing and ion attack on membrane electrodes described in this application, the solution containing impurity ions is a solution containing metal ions.
[0012] According to some embodiments of the test method for the effect of undergassing and ion attack on membrane electrodes described in this application, the impurity ions in the solution containing impurity ions include one or more of iron ions, copper ions, silver ions, titanium ions, and nickel ions.
[0013] According to some embodiments of the test method for the effect of undergassing and ion attack on membrane electrode as described in this application, the test method further includes applying a solution containing impurity ions to the surface of the fuel cell catalyst layer and then drying it.
[0014] According to some embodiments of the test method for the effect of under-gas and ion attack on membrane electrodes described in this application, the drying temperature is 20-80°C and the drying time is 10-12 hours.
[0015] According to some embodiments of the test method for the effect of undergassing and ion attack on membrane electrodes described in this application, the conductive non-permeable material includes conductive non-permeable tape.
[0016] According to some embodiments of the test method for the effect of under-gas and ion attack on membrane electrodes described in this application, the thickness of the conductive non-permeable material is 0.15-0.17 mm.
[0017] According to some embodiments of the test method for the effects of undergassing and ion attack on membrane electrodes described in this application, the simulated ion attack treatment further includes introducing hydrogen peroxide into the fuel cell.
[0018] According to some embodiments of the test method for the effect of under-gas and ion attack on membrane electrodes described in this application, the mass concentration of the hydrogen peroxide is 1%-3%.
[0019] According to some embodiments of the test method for the effect of undergassing and ion attack on membrane electrodes described in this application, the test method further includes allowing the simulated battery to stand and purge before running it.
[0020] According to some embodiments of the test method for the effects of undergassing and ion attack on membrane electrodes described in this application, the settling time is 10-24 hours.
[0021] The beneficial effects of this application include: the test method described in this application can quantitatively study the effects of different types of impurity ions, different corrosion concentrations, different deficient gas locations, and different deficient gas areas on the performance of membrane electrodes, filling the gap in detection methods in related fields; the test method described in this application, when applied to the research and development of membrane electrodes, can effectively guide the development of membrane electrodes and their key materials. Detailed Implementation
[0022] Embodiments of the present invention are described in detail below. These embodiments are exemplary and intended to explain the present invention, and should not be construed as limiting the invention.
[0023] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0024] This application provides a test method for the effects of undergassing and ion attack on membrane electrodes, comprising the following steps:
[0025] (1) Test and record the electrochemical performance of the fuel cell under test;
[0026] (2) Simulate undergassing and simulate ion attack on the fuel cell to be tested, and then run:
[0027] A solution containing impurity ions was coated onto the surface of the fuel cell catalyst layer to form an impurity ion layer simulating ion attack treatment; a conductive, non-permeable material was then adhered to the surface of the impurity ion layer to simulate undergassing treatment; the battery after the simulation treatment was run, and the electrochemical performance of the fuel cell after the simulation treatment was tested and recorded.
[0028] (3) Collect the effluent from the cathode and anode of the fuel cell obtained in step (2) and analyze the types and contents of ions in the effluent.
[0029] The testing method described in this application can quantitatively study the effects of different types of impurity ions, different corrosion concentrations, different deficient gas locations, and different deficient gas areas on the performance of membrane electrodes, filling the gap in detection methods in related fields. When applied to membrane electrode research and development, the testing method described in this application can effectively guide the development of membrane electrodes and their key materials.
[0030] In some embodiments of this application, in step (1), the electrochemical performance includes one or more of the following: battery polarization curve, cathode electrochemical active area, anode electrochemical active area, and hydrogen permeation current.
[0031] The battery polarization curve described in this application was tested according to GB / T 28817-2012 Test Method for Single Cell of Polymer Electrolyte Fuel Cell.
[0032] The cathode electrochemical active area described in this application was tested according to GB / T / 20042.5-2009 Proton Exchange Membrane Fuel Cell Part 5: Membrane Electrode Test Methods.
[0033] The anode electrochemical active area described in this application was tested according to GB / T / 20042.5-2009 Proton Exchange Membrane Fuel Cell Part 5: Membrane Electrode Test Methods.
[0034] The hydrogen permeation current described in this application is tested in accordance with GB / 20042.5-2009 Proton Exchange Membrane Fuel Cell Part 5: Membrane Electrode Test Methods.
[0035] In some embodiments of this application, the solution containing impurity ions is a solution containing metal ions.
[0036] In some embodiments of this application, the impurity ions in the solution containing impurity ions include one or more of iron ions, copper ions, silver ions, titanium ions, and nickel ions. As battery operating time increases, ions in the battery metal plates may corrode and dissolve, and auxiliary systems may also introduce certain metal impurities. The aforementioned ions are potential leaching ions from the plates or ions introduced by the auxiliary systems. The concentration and coating amount of the metal ion-containing solution can be selected according to reagent requirements. For example, in the following specific embodiment 1, based on actual measurement data from the entire stack operation, the Fe on the membrane electrode... 2+ The concentration is 500 ppm. If actual needs require simulating 500 ppm Fe... 2+ The effect on the membrane electrode was determined by coating the surface of the membrane electrode with 0.4 mg of ferrous perchlorate (calculated as Fe). 2+ The concentration was 500 ppm, meaning that in the example, 0.4 mg of ferrous perchlorate was dissolved in 1.5 mL of water, and the entire prepared solution was coated onto the surface of the catalyst layer.
[0037] In some embodiments of this application, the testing method further includes coating a solution containing impurity ions onto the surface of the fuel cell catalyst layer and then drying it. Under open-circuit and idling conditions, the fuel cell undergoes a two-electron reaction due to hydrogen-oxygen cross-permeation. The product of this two-electron reaction is H₂O₂. H₂O₂ in M... 2+ The decomposition of H2O is accelerated under the catalysis of metal ions. - HO -It directly attacks the resin in the membrane and catalyst layer, causing the membrane and catalyst layer to degrade and generate hydrofluoric acid. The main reaction formula is:
[0038] H2O2+M 2+ →HO·+OH - +M 3+
[0039] R f -CF2COOH+·OH→R f -CF2+CO2+H2O
[0040] R f -CF2·+·OH→R f -CF2OH+R f -COF+HF
[0041] R f -COF+H2O→R f -COOH+HF
[0042] In some embodiments of this application, the drying temperature is 20-80℃, such as 20℃, 25℃, 30℃, 35℃, 43℃, 46℃, 58℃, 65℃, 72℃, 80℃, etc., and the drying time is 10-12h, such as 10h, 11h, 12h, etc.
[0043] In some embodiments of this application, the conductive non-permeable material includes conductive non-permeable tape. The placement of the conductive non-permeable tape is equivalent to performing a low-gas treatment on the fuel cell. The area of the conductive non-permeable material can be selected according to actual needs. For example, in Embodiment 1, during the fault diagnosis of the entire stack, it was determined that approximately 40% of the area of a certain membrane electrode within the stack had a low-gas fault. Therefore, in simulating the low-gas condition, Embodiment 1 sets the low-gas area to 3*3cm (the active area of the membrane electrode is 25cm²). 2 ).
[0044] In some embodiments of this application, the thickness of the conductive non-permeable material is 0.15-0.17 mm, such as 0.15 mm, 0.16 mm, 0.17 mm, etc.
[0045] In some embodiments of this application, the simulated ion attack treatment further includes introducing hydrogen peroxide into the fuel cell. When introducing hydrogen peroxide, a syringe or pump is typically used to introduce it from the fuel cell's inlet, and the amount of hydrogen peroxide introduced is sufficient to fill the fuel cell by allowing it to flow out from the fuel cell's outlet.
[0046] In some embodiments of this application, the mass concentration of the hydrogen peroxide is 1%-3%, such as 1%, 2%, 3%, etc.
[0047] In some embodiments of this application, the testing method further includes allowing the simulated battery to stand and purge before running it. Purge can remove residual processing liquid from the fuel cell.
[0048] In some embodiments of this application, the settling time is 10-24 hours, such as 10 hours, 11 hours, 12 hours, 15 hours, 20 hours, 24 hours, etc.
[0049] The technical solution of this application will be further explained below with reference to specific implementation cases.
[0050] In the embodiments of this application, the battery polarization curves were tested according to GB / T 28817-2012 Test Method for Single Cells of Polymer Electrolyte Fuel Cells.
[0051] The cathode electrochemical active area described in this application was tested according to GB / T / 20042.5-2009 Proton Exchange Membrane Fuel Cell Part 5: Membrane Electrode Test Methods.
[0052] The anode electrochemical active area described in this application was tested according to GB / T / 20042.5-2009 Proton Exchange Membrane Fuel Cell Part 5: Membrane Electrode Test Methods.
[0053] The hydrogen permeation current described in this application is tested in accordance with GB / 20042.5-2009 Proton Exchange Membrane Fuel Cell Part 5: Membrane Electrode Test Methods.
[0054] Example 1
[0055] A test method for the effects of undergassing and ion attack on membrane electrodes includes the following steps:
[0056] (1) Install the single cell with a specification of 5cm*5cm to be tested using tooling fixtures, and test the polarization curve, cathode electrochemical active area, and hydrogen permeation current of the cell before degassing and ion attack.
[0057] Test results: Performance at critical current density of polarization curve: 0.653V@1.6A / cm 2 The cathode electrochemical active area is 54.14 m². 2 / g, hydrogen permeation current 3.14mA / cm 2 .
[0058] (2) Preparation of a solution containing impurity ions: A ferrous perchlorate solution with a concentration of 0.27 g / L (denoted as C1) was prepared as the solution containing impurity ions. This solution was coated onto the surface of the fuel cell catalyst layer and air-dried at 25°C for 12 hours to obtain the impurity ion layer. The mass of the coated ferrous perchlorate solution was 0.0004 g (denoted as m1), and the mass of the fuel cell catalyst layer was 0.18 g (denoted as m2). Therefore, the concentration of iron ions in the impurity ion layer was calculated to be 500 ppm (denoted as C2).
[0059] The calculation formula is: Where M Fe is the relative molecular mass of iron; M is the relative molecular mass of ferrous perchlorate.
[0060] (3) A conductive non-permeable tape with a size of 3cm*3cm and a thickness of 0.16mm was adhered to the surface of the impurity ion layer located at the anode outlet of the fuel cell (the anode outlet is easily flooded by water) as a low-gas treatment. Then, a hydrogen peroxide solution with a mass concentration of 3% was injected from the feed port of the single cell. The injection was considered complete when the hydrogen peroxide solution flowed out of the discharge port. The cell was left to stand for 24 hours, then purged for 30 minutes. The cell was then run, and the polarization curve, cathode electrochemical active area, anode electrochemical active area, and hydrogen permeation current of the cell were tested again.
[0061] Test results: Performance at the critical current density point of the polarization curve is 0.614V@1.6A / cm. 2 The cathode has an electrochemical active area of 27.9 m². 2 / g, hydrogen permeation current 2.87mA / cm 2 .
[0062] (4) Collect the effluent from the cathode and anode of the single cell, and test the Pt, Fe and SO4 in the effluent. 2- Content, in this example, Pt, F and SO4 in the cathode drainage 2- The content of these substances was higher than that of the anode, indicating that the corrosion of the resin layer on the cathode side was more severe.
[0063] Example 2
[0064] A test method for the effects of undergassing and ion attack on membrane electrodes includes the following steps:
[0065] (1) Install the single cell with a specification of 5cm*5cm to be tested using tooling fixtures, and test the polarization curve, cathode electrochemical active area, and hydrogen permeation current of the cell before degassing and ion attack.
[0066] Test results: Performance at critical current density of polarization curve: 0.667V@1.6A / cm 2 The cathode electrochemical active area is 57.29 m². 2 / g, hydrogen permeation current 2.39mA / cm 2 .
[0067] (2) Preparation of a solution containing impurity ions: A copper chloride solution with a concentration of 0.45 g / L (denoted as C1) was prepared as the solution containing impurity ions. This solution was coated onto the surface of the fuel cell catalyst layer and air-dried at 25°C for 12 hours to obtain the impurity ion layer. The mass of the coated copper chloride solution was 0.00001 g (denoted as m1), and the mass of the fuel cell catalyst layer was 0.18 g (denoted as m2). The concentration of copper ions in the impurity ion layer was calculated to be 26 ppm.
[0068] The calculation formula is: Where M Cu is the relative molecular mass of copper; M is the relative molecular mass of copper chloride.
[0069] (3) A conductive non-permeable tape with a size of 3cm*3cm and a thickness of 0.16mm was adhered to the surface of the impurity ion layer located at the anode outlet of the fuel cell (the anode outlet is easily flooded by water) as a low-gas treatment. Then, a hydrogen peroxide solution with a mass concentration of 3% was injected from the feed port of the single cell. The injection was considered complete when the hydrogen peroxide solution flowed out of the discharge port. The cell was left to stand for 24 hours, then purged for 30 minutes. The cell was then run, and the polarization curve, cathode electrochemical active area, anode electrochemical active area, and hydrogen permeation current of the cell were tested again.
[0070] Test results: Performance at the critical current density point of the polarization curve is 0.638V@1.6A / cm. 2 The cathode has an electrochemical active area of 31.7 m². 2 / g, hydrogen permeation current 3.84mA / cm 2 .
[0071] (4) Collect the effluent from the cathode and anode of the single cell, and test the Pt, Fe and SO4 in the wastewater. 2- Content, in this example, Pt, Fe, SO4 in the cathode drainage 2- The content of these substances was higher than that of the anode, indicating that the corrosion of the resin layer on the cathode side was more severe.
[0072] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.
Claims
1. A test method for the effects of under-gas and ion attack on membrane electrodes, characterized in that, Includes the following steps: (1) Test and record the electrochemical performance of the fuel cell under test; (2) Simulate undergassing and simulate ion attack on the fuel cell to be tested, and then run: A solution containing impurity ions was coated onto the surface of the fuel cell catalyst layer to form an impurity ion layer simulating ion attack treatment; a conductive, non-permeable material was then adhered to the surface of the impurity ion layer to simulate undergassing treatment; the battery after the simulation treatment was run, and the electrochemical performance of the fuel cell after the simulation treatment was tested and recorded. (3) Collect the effluent from the cathode and anode of the fuel cell obtained in step (2) and analyze the types and contents of ions in the effluent.
2. The test method for the effect of under-gas and ion attack on membrane electrodes according to claim 1, characterized in that, In step (1), the electrochemical performance includes one or more of the following: battery polarization curve, cathode electrochemical active area, anode electrochemical active area, and hydrogen permeation current.
3. The test method for the effects of under-gas and ion attack on membrane electrodes according to claim 1, characterized in that, The solution containing impurity ions is a solution containing metal ions; Preferably, the impurity ions in the solution containing impurity ions include one or more of iron ions, copper ions, silver ions, titanium ions, and nickel ions.
4. The test method for the effect of under-gas and ion attack on membrane electrodes according to claim 1, characterized in that, The test method also includes applying a solution containing impurity ions to the surface of the fuel cell catalyst layer and then drying it. Preferably, the drying temperature is 20-80℃ and the drying time is 10-12h.
5. The test method for the effects of under-gas and ion attack on membrane electrodes according to claim 1, characterized in that, The conductive non-breathable material includes conductive non-breathable tape.
6. The test method for the effect of under-gas and ion attack on membrane electrodes according to claim 1, characterized in that, The thickness of the conductive non-permeable material is 0.15-0.17 mm.
7. The test method for the effect of under-gas and ion attack on membrane electrodes according to claim 6, characterized in that, The simulated ion attack treatment method also includes introducing hydrogen peroxide into the fuel cell.
8. The test method for the effect of under-gas and ion attack on membrane electrodes according to claim 7, characterized in that, The hydrogen peroxide has a mass concentration of 1%-3%.
9. The test method for the effects of under-gas and ion attack on membrane electrodes according to claim 1, characterized in that, The testing method also includes allowing the simulated battery to stand and purge before running it.
10. The test method for the effect of under-gas and ion attack on membrane electrodes according to claim 9, characterized in that, The settling time is 10-24 hours.