A method for preparing a new functional layer of a catalyst-coated membrane (CCM)
By spraying SiO2 and Nafion solution onto the cathode and anode surfaces of the proton exchange membrane to form an enhanced functional layer, the problem of insufficient proton transport in proton exchange membrane fuel cells under low humidity conditions is solved, achieving performance improvement and cost reduction.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANGHAI JIAOTONG UNIV
- Filing Date
- 2026-02-04
- Publication Date
- 2026-06-09
AI Technical Summary
Existing proton exchange membrane fuel cells have insufficient proton transport performance under low humidity conditions, leading to performance degradation and increased production costs.
A solution of SiO2 and Nafion was prepared and an enhanced functional layer was formed on the cathode and anode surfaces of the proton exchange membrane using ultrasonic spraying technology. Combined with catalyst slurry spraying, a layered structure was formed to improve the water retention capacity and proton transport performance of the membrane electrode.
Under low humidity conditions, proton transport performance is significantly improved, peak power density is increased, catalyst utilization is increased, total Pt loading is reduced, and production costs are reduced.
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Figure CN122177854A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of membrane electrode assembly (MEA) technology for proton exchange membrane fuel cells (PEMFC), and particularly to a novel method for preparing a catalyst coated membrane (CCM) functional layer. Background Technology
[0002] Fuel cells are an important application of hydrogen energy, with advantages such as high energy conversion efficiency, low pollution, low noise, high stability, low operating temperature, wide range of fuel options, and wide application range. They have good development prospects and potential for huge economic benefits.
[0003] The main structure of a proton exchange membrane fuel cell (PEMFC) consists of four parts: the membrane electrode assembly (MEA), the gas diffusion layer, the flow field, and the current collector. Among these, the MEA, as the most critical component of the PEMFC, plays a crucial role. It is not only the site of multiphase mass transfer and electrochemical reactions for energy conversion, but also directly affects the performance, lifespan, and cost of the entire PEMFC system.
[0004] Classified by fabrication process, catalyst-coated membrane electrodes (CCM) represent the mainstream commercial membrane electrode manufacturing method. In CCM, the catalyst layer and proton exchange membrane are directly composited to form a combined structure, effectively improving the interfacial resistance between the catalyst layer and the proton exchange membrane, reducing proton transport resistance at the interface, and exhibiting superior normal phase conductivity. This method can improve catalyst utilization efficiency, reduce catalyst usage, and effectively lower production costs.
[0005] CCM applications in low-humidity conditions are significant in preventing flooding, improving durability, and reducing reliance on external humidification equipment. However, they also place stringent demands on proton transport. Currently widely used bulk perfluorosulfonic acid (PFSA) proton exchange membranes and polytetrafluoroethylene (PTFE) reinforced PFSA proton exchange membranes suffer severe water loss under low humidity conditions, making it difficult to meet the proton conductivity requirements for normal operation. Based on traditional PFSA resin proton exchange membranes, a composite water-retaining CCM structure is constructed using inorganic oxide ceramic materials with mechanical properties, chemical stability, and water retention, providing a convenient and efficient performance improvement solution for CCM operation in low humidity.
[0006] In summary, current technology still has room for improvement at the CCM ionomer level, which has become the core bottleneck restricting the efficiency of PEM electrolyzers. Summary of the Invention
[0007] The present invention aims to provide a novel method for preparing a functional layer of a catalyst coating membrane (CCM) to solve the problems mentioned in the background art.
[0008] To achieve the above objectives, the present invention provides the following technical solution:
[0009] A novel method for preparing a catalyst coating membrane (CCM) functional layer includes:
[0010] S1, the nominal BET:150m 2 / g of SiO2 and 20 wt% Nafion solution were prepared into a solution. The solvent for preparing the solution was a mixture of isopropanol and water, wherein the mass ratio of Nafion to oxide was 1.
[0011] S2. The slurry was ball-milled for 14 hours and ultrasonically removed for 30 minutes to remove agglomerates.
[0012] S3. Use an ultrasonic sprayer to spray SiO2 / Nafion slurry onto the PEM cathode / anode surface;
[0013] S4. Using an ultrasonic sprayer, spray a catalyst slurry with an I / C ratio of 0.6 onto the PEM cathode / anode surfaces that have been reinforced with an enhanced functional layer.
[0014] S5 is press-fitted with conventional MPL, GDL, sealing rings, flow channels, bipolar plates, insulating plates, and fixtures, with no additional sealing requirements.
[0015] Preferably, in step S3, the SiO2 / Nafion slurry is sprayed onto the PEM cathode / anode surfaces, with a SiO2 loading of 0.1 mg / cm² on each side. 2 The corresponding thickness is 1 µm.
[0016] Preferably, in step S3, the SiO2 / Nafion slurry is sprayed onto the PEM cathode / anode surfaces, with a SiO2 loading of 0.2 mg / cm² on each side. 2 The corresponding thickness is 2 µm.
[0017] Preferably, the cathode loading in step S4 is 0.3 mg / cm³. 2 The anodic loading is 0.1 mg / cm³. 2
[0018] Compared with the prior art, the present invention has the following beneficial effects:
[0019] This invention improves the water retention of the proton exchange membrane (PEM) and enhances proton transport performance under low humidity conditions by specifically modifying the membrane electrode assembly (MEA). Under conditions of 80°C and 35% RH, the peak power retention of a single cell is significantly better than that of the original membrane, demonstrating that the MEA maintains good performance even in low humidity. Furthermore, the layered structure used in this invention enhances water management and proton transport, improving the Pt / C utilization rate within the catalyst layer. This allows for a reduction in the total Pt loading while maintaining equivalent performance, effectively reducing production costs. Attached Figure Description
[0020] Figure 1 A flowchart illustrating a novel method for preparing a catalyst coating membrane (CCM) functional layer;
[0021] Figure 2 Battery test results (80 °C, 100% RH): (a) Polarization curve; (b) Comparison of HFR-current density curves;
[0022] Figure 3 Battery test results (80 °C, 35% RH): (a) Polarization curve; (b) Comparison of HFR-current density curves. Detailed Implementation
[0023] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments:
[0024] like Figure 1 As shown, this invention provides a novel method for preparing a functional layer of a catalyst-coated membrane (CCM). By adding a functional layer, the water retention capacity of the membrane electrode is significantly improved, enabling it to maintain excellent proton conductivity and output high power even under low humidity conditions. To achieve the above objective, this invention adopts the following technical solution:
[0025] I. Example 1
[0026] This example provides a membrane electrode comprising an anode catalyst layer, a proton exchange membrane, and a cathode catalyst layer stacked sequentially. The anode catalyst layer comprises only TEC10E50E platinum-carbon catalyst and Nafion, and the cathode catalyst layer comprises only TEC10E50E platinum-carbon catalyst and Nafion. The proton exchange membrane is selected from Gore M765.08 (with a thickness of 8µm).
[0027] II. Example 2
[0028] This embodiment provides a membrane electrode, which includes an anode catalytic layer, a proton membrane and a cathode catalytic layer stacked sequentially. The anode catalytic layer includes only TEC10E50E platinum-carbon catalyst and Nafion, and the cathode catalytic layer includes only TEC10E50E platinum-carbon catalyst and Nafion.
[0029] (1) SiO2 (nominal BET: 150m) 2 The solution was prepared by mixing isopropanol and water, with the Nafion:oxide mass ratio being 1.
[0030] (2) The slurry was ball-milled for 14 h and ultrasonically removed for 30 min to remove agglomerates;
[0031] (3) Using an ultrasonic sprayer, the SiO2 / Nafion slurry is sprayed onto the PEM cathode / anode surfaces, preferably with a SiO2 loading of 0.1 mg / cm² on each side. 2 The corresponding thickness is 1 µm;
[0032] (4) Using an ultrasonic sprayer, a catalyst slurry with an I / C ratio of 0.6 is sprayed onto the PEM cathode / anode surfaces with added reinforcing functional layers. Preferably, the cathode loading is 0.3 mg / cm³. 2 The anodic loading is 0.1 mg / cm³. 2 ;
[0033] (5) Press-fitting with conventional MPL, GDL, sealing ring, flow channel, bipolar plate, insulating plate and fixture, with no additional sealing requirements.
[0034] III. Example 3
[0035] This embodiment provides a membrane electrode, which includes an anode catalytic layer, a proton membrane and a cathode catalytic layer stacked sequentially. The anode catalytic layer includes only TEC10E50E platinum-carbon catalyst and Nafion, and the cathode catalytic layer includes only TEC10E50E platinum-carbon catalyst and Nafion.
[0036] (1) SiO2 (nominal BET: 150m) 2 The solution was prepared by mixing isopropanol and water, with the Nafion:oxide mass ratio being 1.
[0037] (2) The slurry was ball-milled for 14 h and ultrasonically removed for 30 min to remove agglomerates;
[0038] (3) Using an ultrasonic sprayer, the SiO2 / Nafion slurry is sprayed onto the PEM cathode / anode surfaces, preferably with a SiO2 loading of 0.2 mg / cm² on each side. 2 The corresponding thickness is 2 µm;
[0039] (4) Using an ultrasonic sprayer, a catalyst slurry with an I / C ratio of 0.6 is sprayed onto the PEM cathode / anode surfaces with added reinforcing functional layers. Preferably, the cathode loading is 0.3 mg / cm³. 2 The anodic loading is 0.1 mg / cm³. 2 ;
[0040] (5) Press-fitting with conventional MPL, GDL, sealing ring, flow channel, bipolar plate, insulating plate and fixture, with no additional sealing requirements.
[0041] IV. Experimental Conclusions
[0042] The membrane electrode described in the above embodiments was subjected to polarization performance testing under two conditions: (1) 80℃, 100% RH; and (2) 80℃, 35% RH. The test results are as follows: Figure 2 and Figure 3 As shown;
[0043] The experimental results show that, under the conditions of 80℃ and 100% RH, the polarization curves of Example 1 and Example 3 tend to be consistent, while the polarization curve of Example 2 is slightly lower than that of Example 1 and Example 3.
[0044] Because the hydrophilic SiO2 / Nafion interlayer increases the thickness of the intermediate structure, and SiO2 itself is non-conductive, the HFR of Examples 2 and 3 is slightly higher than that of Example 1: the HFR of Examples 2 and 3 increased by an average of 11% and 22%, respectively. Under the condition of 80°C and 35% RH, the peak power density of Example 1 is 30.6% of that under the condition of 80°C and 100% RH, and the HFR increases to 3.5 times the original value.
[0045] The modified films in Examples 2 and 3 showed significant increases in peak power density, with maximum battery power increases of approximately 49.4% and 132.3% respectively compared to Example 1. Example 2 exhibited the best performance, retaining 85.95% of its peak power density under 80°C and 100% RH conditions. This indicates that a higher SiO2 loading improves the water retention of the ionomer, resulting in a smaller decrease in proton conductivity under low humidity conditions.
[0046] Furthermore, the HFR in Examples 2 and 3 increased by an average of 53.9% and 46.6% respectively compared to the 80°C 100% RH condition, indicating that 0.2 mg / cm³... 2 The SiO2-enhanced functional layer with a higher loading tends to retain more water in the ionomer, thus resulting in a smaller decrease in proton conductivity.
[0047] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.
Claims
1. A method for preparing a novel catalyst coating membrane (CCM) functional layer, characterized in that, The steps of the method include: S1, SiO2with a nominal BET: 150 m 2 g of SiO2and 20 wt% Nafion solution configured as a solution with isopropanol and water mixture as solvent, where the Nafion:oxide mass ratio is 1 ; S2. The slurry was ball-milled for 14 hours and ultrasonically removed for 30 minutes to remove agglomerates. S3. Use an ultrasonic sprayer to spray SiO2 / Nafion slurry onto the PEM cathode / anode surface; S4. Using an ultrasonic sprayer, spray a catalyst slurry with an I / C ratio of 0.6 onto the PEM cathode / anode surfaces that have been reinforced with an enhanced functional layer. S5 is press-fitted with conventional MPL, GDL, sealing rings, flow channels, bipolar plates, insulating plates, and fixtures, with no additional sealing requirements.
2. The method for preparing a novel catalyst coating film (CCM) functional layer according to claim 1, characterized in that: In step S3, the SiO2 / Nafion slurry is sprayed onto the PEM cathode / anode surfaces, with a SiO2 loading of 0.1 mg / cm² on each side. 2 The corresponding thickness is 1 µm.
3. The method for preparing a novel catalyst coating film (CCM) functional layer according to claim 1, characterized in that: In step S3, the SiO2 / Nafion slurry is sprayed onto the PEM cathode / anode surfaces, with a SiO2 loading of 0.2 mg / cm² on each side. 2 The corresponding thickness is 2 µm.
4. The method for preparing a novel catalyst coating film (CCM) functional layer according to claim 1, characterized in that: The cathode loading in step S4 is 0.3 mg / cm³. 2 The anodic loading is 0.1 mg / cm³. 2 .