A catalyst slurry for a hydrogen fuel cell, a preparation method thereof, a catalyst layer, a membrane electrode, and a hydrogen fuel cell
By precisely controlling the proportion of catalyst slurry components, the problem of precious metal Pt waste was solved, low-cost and high-efficiency catalyst utilization was achieved, and the performance of proton exchange membrane fuel cells was improved.
Patent Information
- Application Number
- CN202510115380.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-24
- Publication Date
- 2025-12-09
- Estimated Expiration
- 2045-01-24
AI Technical Summary
In existing proton exchange membrane fuel cells, the high amount of precious metal Pt leads to catalyst waste, increases costs, and affects performance. Therefore, it is necessary to improve the catalyst loading to increase utilization and reduce costs.
By precisely controlling the proportion of solid components in the catalyst slurry, including the catalyst, carbon support, Nafion resin, and organic solvent, the stability and activity of the catalyst are ensured, and stacking and shedding are avoided. 50% Pt/C catalyst and Nafion resin are used as solid components to control their loading on the proton exchange membrane.
This approach achieves improved catalyst utilization and membrane electrode performance with low platinum loading, reduces costs, and maintains high electrochemical reaction performance.
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Figure CN120072958B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application relates to the technical field of membrane electrodes, in particular to a catalyst slurry for a hydrogen fuel cell and a preparation method thereof, a catalyst layer, a membrane electrode and a hydrogen fuel cell. BACKGROUND
[0002] It is known that a proton exchange membrane fuel cell (PEMFC) is a kind of fuel cell which is currently relatively mature, and has special advantages such as no pollution to the environment, high energy conversion efficiency and power density, low emission and heat radiation, and small noise pollution. Therefore, the market prospect of the proton exchange membrane fuel cell is broad, and its application range is continuously expanding from small portable power equipment and small fixed base stations to pure electric vehicles, aerospace and military fields.
[0003] A membrane electrode (MEA) is a core component of the proton exchange membrane fuel cell, and together with the bipolar plates on both sides forms a fuel cell single cell. The membrane electrode provides a microchannel for multiphase material transfer and an electrochemical reaction site for the PEMFC, and its performance directly determines the performance of the PEMFC, which is of great significance to the commercialization development of the PEMFC. Usually, in order to improve the performance of the membrane electrode, the amount of noble metal Pt is relatively high, but this will cause the Pt to be stacked on the surface of the proton exchange membrane, resulting in waste of part of the catalyst, which is not conducive to reducing the cost of the catalyst. Therefore, in view of the above problems, the platinum loading on the membrane electrode needs to be further improved and perfected to ensure that the membrane electrode has high performance while controlling the cost and improving the utilization rate of the catalyst. SUMMARY
[0004] In order to improve the problem of catalyst waste caused by high platinum loading for ensuring high performance of the fuel cell by the current membrane electrode, the application provides a catalyst slurry for a hydrogen fuel cell and a preparation method thereof, a catalyst layer, a membrane electrode and a hydrogen fuel cell, which improves the performance of the membrane electrode on the premise of ensuring that the catalyst on the membrane electrode is stable and does not fall off and reducing the platinum loading on the membrane electrode.
[0005] In a first aspect, the application provides a catalyst slurry for a hydrogen fuel cell membrane electrode, which adopts the following technical scheme:
[0006] The application relates to a catalyst slurry for a hydrogen fuel cell membrane electrode, which comprises a solid phase component and a liquid phase component, wherein the mass proportion of the solid phase component is 0.5%-3%, the solid phase component comprises a catalyst, a carbon carrier and a Nafion resin, the liquid phase component comprises an organic solvent and water, the mass ratio of the Nafion resin to the liquid phase component is 1:160-320, and the mass ratio of the organic solvent to the water is 3.65-8.63:1.
[0007] The application can ensure sufficient catalyst active sites and avoid excessive stacking of the catalyst, so that the balance between high performance and low cost of the hydrogen fuel cell is achieved.
[0008] The application adds the Nafion resin as the solid phase component in the catalyst slurry, and the Nafion resin can fix the catalyst and provide a proton transmission channel.
[0009] The organic solvent mainly plays a role in adjusting flowability and dispersibility in the catalyst slurry.
[0010] Optionally, the mass ratio of the catalyst, the carbon carrier and the Nafion resin is 1:0.03-0.06:0.23-0.28.
[0011] The application further optimizes the mass ratio of the catalyst, the carbon carrier and the Nafion resin to ensure the stability and activity of the catalyst.
[0012] Optionally, the organic solvent comprises any one of ethanol, isopropanol.
[0013] Optionally, the catalyst is Pt / C catalyst with platinum content of 50%.
[0014] The present application selects Pt / C catalyst with platinum content of 50%, which has high catalytic activity and stability, and can achieve high performance at a lower load. At the same time, the cost of this catalyst is relatively low, which is conducive to reducing the overall cost of PEMFC.
[0015] Optionally, the carbon carrier is XC-72 carbon carrier.
[0016] In a second aspect, the present application provides a preparation method of catalyst slurry for hydrogen fuel cell membrane electrode, which adopts the following technical scheme:
[0017] A preparation method of catalyst slurry for hydrogen fuel cell membrane electrode, comprising the following steps:
[0018] Step S1: mixing the catalyst, the carbon carrier and the water to obtain a dispersion solution one;
[0019] Step S2: mixing the Nafion resin and part of the organic solvent to obtain a dispersion solution two;
[0020] Step S3: mixing the dispersion solution one, the dispersion solution two and the remaining organic solvent, and then stirring, ultrasonic dispersion, shearing and crushing to obtain the catalyst slurry for hydrogen fuel cell membrane electrode.
[0021] Optionally, the mass ratio of the organic solvent added in the step S2 to the organic solvent used in the step S3 is 2-3:3.
[0022] The preparation method of the catalyst slurry of the present application is simple and easy to operate, and the prepared catalyst slurry has excellent fluidity and dispersibility, so that the performance and service life of PEMFC are significantly improved. At the same time, since the proportion and steps of each component in the preparation process are accurately controlled, the prepared catalyst slurry has high stability and consistency.
[0023] In a third aspect, the present application provides a catalyst layer for hydrogen fuel cell membrane electrode, which adopts the following technical scheme: a catalyst layer for hydrogen fuel cell membrane electrode is obtained by the following method: adsorbing a proton exchange membrane on a heating platform of a spraying device, controlling the temperature to be 70-85℃, and then spraying catalyst slurry on both sides of the anode and cathode of the proton exchange membrane, thereby obtaining the catalyst layer formed on both sides of the proton exchange membrane.
[0024] Optionally, the catalyst loading in the catalytic layer is 0.1-0.7 mg / cm 2 .
[0025] Optionally, the thickness of the proton exchange membrane is 8-18 μm.
[0026] Optionally, the spraying speed of the catalyst slurry is 100-300 mm / s.
[0027] The present application can uniformly distribute the catalyst with less loading in the catalytic layer, and the catalyst particles are not stacked, not fallen off and not coated by Nafion resin, and show high reaction activity by using the above precisely regulated catalyst slurry.
[0028] In a fourth aspect, the present application provides a membrane electrode for a hydrogen fuel cell, which adopts the following technical solution:
[0029] A membrane electrode for a hydrogen fuel cell, comprising a proton exchange membrane, catalytic layers formed on both sides of the proton exchange membrane, and diffusion layers outside the catalytic layers.
[0030] Optionally, the thickness of the diffusion layer is 215-250 μm.
[0031] The present application can maximize the utilization of the catalytic layer, reduce the waste of catalyst, and fully utilize the catalytic activity of the catalytic layer to improve the performance and efficiency of the hydrogen fuel cell by precisely controlling the catalyst loading and structure of the catalytic layer and reasonably designing the diffusion layer.
[0032] In a fifth aspect, the present application provides a hydrogen fuel cell, which adopts the following technical solution:
[0033] A hydrogen fuel cell, comprising a bipolar plate and the membrane electrode.
[0034] The hydrogen fuel cell provided by the present application can still maintain excellent working performance under low platinum loading.
[0035] In summary, the present application includes at least one of the following beneficial effects:
[0036] The present application can reduce the platinum loading in the membrane electrode, improve the utilization of platinum in the catalyst, and obtain a membrane electrode with good performance, and further prepare a hydrogen fuel cell with high performance by precisely regulating the ratio of each component in the catalyst slurry. BRIEF DESCRIPTION OF DRAWINGS
[0037] Figure 1 is the voltage-current density curve of the single cell prepared in Example 1 and Comparative Examples 1-3 of the present application;
[0038] Figure 2 is a comparison chart of polarization curve and power density curve performance of the single cell prepared in Example 1 and Comparative Example 1 of the present application;
[0039] Figure 3 shows a micrograph of the catalytic layer after testing of Example 1;
[0040] Figure 4 shows a micrograph of the catalytic layer after testing of Comparative Example 4. DETAILED DESCRIPTION
[0041] In order to make the objects, technical solutions and advantages of the present application clearer, further detailed description will be given to the present application in combination with the drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.
[0042] Example 1
[0043] (1) Preparation of catalyst slurry:
[0044] S1: In a dispersion container, 400 mg of catalyst particles (Pt / C catalyst with Pt mass content of 50%), 16 mg of carbon carrier (XC-72) and 3.9 g of deionized water were added to obtain dispersion solution one;
[0045] S2: In another dispersion container, 0.1 g of Nafion resin and 9.3 g of ethanol were added to obtain dispersion solution two;
[0046] S3: Finally, dispersion solution one, dispersion solution two and 13.95 g of ethanol were mixed, and after stirring, ultrasonic dispersion, shearing and crushing, a uniform slurry in the state of suspension was obtained, which was the catalyst slurry. In the catalyst slurry, the solid content was 1.87%.
[0047] (2) Preparation of membrane electrode:
[0048] S4: The catalyst slurry was sprayed onto the surfaces of the proton exchange membrane on both sides to obtain a catalyst layer attached to the surface of the proton exchange membrane. In the catalyst layer, the platinum load on the proton exchange membrane was 0.38 mg / cm 2 , and was distributed on the cathode and anode in a ratio of cathode:anode = 3:1;
[0049] S5: Two diffusion layers (carbon paper) with a thickness of 250 μm were hot-pressed on both sides of the proton exchange membrane containing the catalyst layer with an adhesive (pressure-sensitive adhesive) to obtain a membrane electrode.
[0050] (3) Assembly of single cell:
[0051] The membrane electrode prepared in (2) was assembled into a single cell for testing. The testing conditions were: cell temperature 85°C, humidity of anode and cathode 50%, and back pressure of anode and cathode 150 kPa. The testing results are shown in Table 1. Figure 1 .
[0052] Example 2
[0053] (1) Preparation of catalyst slurry:
[0054] S1: 400 mg of catalyst particles (Pt / C catalyst with Pt mass content of 50%), 24 mg of carbon carrier (XC-72), and 3.72 g of deionized water were added into a dispersion container to obtain dispersion solution one;
[0055] S2: 0.112 g of Nafion resin and 12.84 g of ethanol were added into another dispersion container to obtain dispersion solution two;
[0056] S3: Finally, dispersion solution one, dispersion solution two, and 19.26 g of ethanol were mixed, and after stirring, ultrasonic dispersion, shearing, and crushing, a slurry in a uniform suspension state was obtained, which was the catalyst slurry. In the catalyst slurry, the solid content was 1.47%.
[0057] (2) Preparation of membrane electrode: same as in Example 1. The loading of platinum in the catalyst layer on the proton exchange membrane was 0.29 mg / cm 2 .
[0058] (3) Assembly of single cell: same as in Example 1.
[0059] Example 3
[0060] (1) Preparation of catalyst slurry:
[0061] S1: 400 mg of catalyst particles (Pt / C catalyst with Pt mass content of 50%), 12 mg of carbon carrier (XC-72), and 3.48 g of deionized water were added into a dispersion container to obtain dispersion solution one;
[0062] S2: 0.092 g of Nafion resin and 5.08 g of isopropyl alcohol were added into another dispersion container to obtain dispersion solution two;
[0063] S3: Finally, dispersion solution one, dispersion solution two, and 7.62 g of isopropyl alcohol were mixed, and after stirring, ultrasonic dispersion, shearing, and crushing, a slurry in a uniform suspension state was obtained, which was the catalyst slurry A. In the catalyst slurry A, the solid content was 3.00%.
[0064] (2) Preparation of membrane electrode: same as in Example 1. The loading of platinum in the catalyst layer on the proton exchange membrane was 0.63 mg / cm 2 .
[0065] (3) Assembling single cell: same as Example 1.
[0066] Comparative Example 1
[0067] (1) Preparation of catalyst slurry:
[0068] S1 : In a dispersion vessel, 400 mg of catalyst particles (Pt / C catalyst with Pt mass content of 50%), 16 mg of carbon support (XC-72) and 3.1 g of deionized water were added to obtain dispersion solution one;
[0069] S2: In another dispersion vessel, 0.12 g of Nafion resin and 9.48 g of ethanol were added to obtain dispersion solution two;
[0070] S3: Finally, dispersion solution one, dispersion solution two and 14.22 g of ethanol were mixed, and after stirring, ultrasonic dispersion, shearing and crushing, a slurry in a uniform suspension state was obtained, which was catalyst slurry A. In the catalyst slurry A, the solid content was 2.92%.
[0071] (2) Preparation of membrane electrode: same as Example 1. The loading of platinum in the catalyst layer on the proton exchange membrane was 0.57 mg / cm 2 .
[0072] (3) Assembling single cell: same as Example 1.
[0073] Comparative Example 2
[0074] (1) Preparation of catalyst slurry:
[0075] S1 : In a dispersion vessel, 400 mg of catalyst particles (Pt / C catalyst with Pt mass content of 50%), 16 mg of carbon support (XC-72) and 3.4 g of deionized water were added to obtain dispersion solution one;
[0076] S2: In another dispersion vessel, 0.14 g of Nafion resin and 8.98 g of ethanol were added to obtain dispersion solution two;
[0077] S3: Finally, dispersion solution one, dispersion solution two and 13.48 g of ethanol were mixed, and after stirring, ultrasonic dispersion, shearing and crushing, a slurry in a uniform suspension state was obtained, which was catalyst slurry A. In the catalyst slurry A, the solid content was 2.10%.
[0078] (2) Preparation of membrane electrode: same as Example 1. The loading of platinum in the catalyst layer on the proton exchange membrane was 0.40 mg / cm 2 .
[0079] (3) Assembling single cell: same as Example 1.
[0080] Comparative Example 3
[0081] (1) Preparation of catalyst slurry:
[0082] S1 : In a dispersion vessel, 400 mg of catalyst particles (Pt / C catalyst with a Pt mass content of 50%), 16 mg of carbon support (XC-72), and 2.7 g of deionized water were added, and a dispersion solution one was obtained by dispersion;
[0083] S2: In another dispersion vessel, 0.1 g of Nafion resin and 9.78 g of ethanol were added, and a dispersion solution two was obtained by dispersion;
[0084] S3: Finally, the dispersion solution one, the dispersion solution two, and 14.67 g of ethanol were mixed, and after stirring, ultrasonic dispersion, shearing, and crushing, a slurry in a uniform suspension state was obtained, which was catalyst slurry A. In the catalyst slurry A, the solid content was 1.87%.
[0085] (2) Preparation of membrane electrode: same as Example 1. The loading of platinum in the catalyst layer on the proton exchange membrane was 0.38 mg / cm 2 .
[0086] (3) Assembly of single cell: same as Example 1.
[0087] Comparative Example 4
[0088] (1) Preparation of catalyst slurry:
[0089] S1 : In a dispersion vessel, 400 mg of catalyst particles (Pt / C catalyst with a Pt mass content of 50%), 16 mg of carbon support (XC-72), and 3.9 g of deionized water were added, and a dispersion solution one was obtained by dispersion;
[0090] S2: In another dispersion vessel, 0.08 g of Nafion resin and 9.3 g of ethanol were added, and a dispersion solution two was obtained by dispersion;
[0091] S3: Finally, the dispersion solution one, the dispersion solution two, and 13.95 g of ethanol were mixed, and after stirring, ultrasonic dispersion, shearing, and crushing, a slurry in a uniform suspension state was obtained, which was catalyst slurry A. In the catalyst slurry A, the solid content was 1.79%.
[0092] (2) Preparation of membrane electrode: same as Example 1. The loading of platinum in the catalyst layer on the proton exchange membrane was 0.38 mg / cm 2 .
[0093] (3) Assembly of single cell: same as Example 1.
[0094] It should be noted that in the above examples and comparative examples, the spraying amount of the catalyst slurry of the anode and the cathode is kept consistent when the membrane electrode is prepared in step (2). The amount of the components of the catalyst slurry in the examples and comparative examples is shown in Table 1.
[0095] Table 1 Amount of components of catalyst slurry in examples and comparative examples
[0096]
[0097]
[0098] Figure 1 is the voltage-current density curve of the single cell prepared in Example 1 and Comparative Example 1-3 of the present application. It can be seen from Figure 1 that as the current density increases, the voltage of the single cell prepared in Example 1 decreases to a much lesser extent than the voltage of the single cell prepared in Comparative Example 1-3, and when the current density is 2550 A / cm 2 , the voltage of the single cell prepared in Example 1 is 0.64 V, while the voltage of the single cell prepared in Comparative Example 3 has already decreased to 0.58 V. This shows that the working performance of the single cell prepared in Comparative Example 1-3 is not as good as that of the single cell prepared in Example 1.
[0099] Figure 2 is the polarization curve and power density curve performance comparison diagram of the single cell prepared in Example 1 and Comparative Example 1 of the present application. It can be seen from Figure 2 that at a voltage of 0.65 V, the current density of the single cell prepared in Example 1 can reach 2.3 A / cm 2 , while the working performance of the single cell prepared in Comparative Example 1 is not as good as that of the single cell prepared in Example 1. 2
[0100] Figure 3 shows the microstructure of the catalyst layer of Example 1 after testing, Figure 4 shows the microstructure of the catalyst layer of Comparative Example 4 after testing. It can be seen from Figure 3 and Figure 4 that due to the low content of Nafion resin in the catalyst layer of Comparative Example 4, cracks appear in the catalyst layer, indicating that the catalyst has fallen off, while Example 1 does not have the phenomenon of catalyst falling off at all.
[0101] The above are preferred embodiments of the present application, which do not limit the protection scope of the present application, therefore: any equivalent changes made on the basis of the structure, shape, principle of the present application should be covered within the protection scope of the present application.
Claims
1. A catalyst slurry for a hydrogen fuel cell membrane electrode, characterized by, Comprise: A solid phase component and a liquid phase component, wherein the mass ratio of the solid phase component is 0.5%-3%, the solid phase component comprises a catalyst, a carbon carrier and a Nafion resin, the liquid phase component comprises an organic solvent and water, the mass ratio of the Nafion resin to the liquid phase component is 1:160-320, the mass ratio of the organic solvent to the water is 3.65-8.63:1, The mass ratio of the catalyst, the carbon carrier and the Nafion resin is 1:0.03-0.06:0.23-0.
28.
2. The catalyst slurry for a hydrogen fuel cell membrane electrode according to claim 1, characterized by, The organic solvent comprises any one of ethanol and isopropanol.
3. The catalyst slurry for a hydrogen fuel cell membrane electrode according to claim 1, characterized by, The catalyst is a Pt / C catalyst with a platinum content of 50%.
4. The method for preparing a catalyst slurry for a hydrogen fuel cell membrane electrode according to any one of claims 1 to 3, characterized by, Comprise the following steps: Step S1: mixing the catalyst, the carbon carrier and the water to obtain a dispersion solution one; Step S2: mixing the Nafion resin and part of the organic solvent to obtain a dispersion solution two; Step S3: mixing the dispersion solution one, the dispersion solution two and the remaining organic solvent, and then stirring, ultrasonic dispersion, shearing and crushing to obtain the catalyst slurry for hydrogen fuel cell membrane electrode.
5. The method for preparing a catalyst slurry for a hydrogen fuel cell membrane electrode according to claim 4, characterized by, The mass ratio of the organic solvent added in the step S2 to the organic solvent used in the step S3 is 2-3:
3.
6. A catalytic layer for a hydrogen fuel cell membrane electrode, characterized by, The following method is adopted: adsorbing the proton exchange membrane on the heating platform of a spraying device, controlling the temperature to be 70-85℃, and then spraying the catalyst slurry of any one of claims 1-3 on both sides of the anode and cathode of the proton exchange membrane, thereby obtaining the catalyst layer formed on both sides of the proton exchange membrane.
7. The catalytic layer for a hydrogen fuel cell membrane electrode according to claim 6, characterized by The catalyst loading in the catalytic layer is 0.1-0.7 mg / cm 2 .
8. A membrane electrode for a hydrogen fuel cell, characterized by, Comprise a proton exchange membrane, the catalyst layer formed on both sides of the proton exchange membrane obtained by claim 7 and the diffusion layer outside the catalyst layer.
9. A hydrogen fuel cell, characterized by Comprise a bipolar plate and the membrane electrode of claim 8.
Citation Information
Patent Citations
Self-humidifying fuel cell membrane electrode and preparation method thereof
CN116387580A