Fuel cell catalyst slurry as well as preparation method and application thereof

Abstract

The invention discloses fuel cell catalyst slurry as well as a preparation method and application thereof, and belongs to the technical field of fuel cell stacks. The fuel cell catalyst slurry comprises a catalyst, a dispersing agent, an ionomer and water, and the mass ratio of the ionomer to the catalyst is (0.3-1.0): 1; the mass ratio of the dispersing agent to the water is (1-5): 1; the ionomer is one or more perfluorosulfonic acid ionomers with short-chain branch EW of less than or equal to 900. According to the fuel cell catalyst slurry disclosed by the invention, the catalyst slurry is regulated and controlled by adopting the short-branch-chain ionomers with the EW being less than or equal to 900, the pretreatment process and the dispersion process of the ionomers in the catalyst slurry are optimized by regulating and controlling the proportion of various short-branch-chain ionomers to each component of the catalyst, and meanwhile, the preparation parameters of a catalyst layer are regulated and controlled, so that the catalytic performance of the catalyst slurry is improved. Therefore, stable catalyst slurry and a high-performance catalyst layer are formed.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cell stacks, and particularly to a fuel cell catalyst slurry, a preparation method thereof, and an application thereof. Background Art

[0002] A fuel cell is an efficient energy conversion device that converts fuel (such as hydrogen, natural gas, etc.) and an oxidant (such as oxygen, etc.) into electrical energy through an electrochemical reaction. The catalyst plays a crucial role in a fuel cell. It can accelerate the rate of the electrochemical reaction and improve the efficiency of the fuel cell. The performance of the catalyst directly affects the performance and lifespan of the fuel cell. The preparation technology of the catalyst is an important part of the fuel cell technology field. During the preparation process of the catalyst, the dispersibility and stability of the catalyst slurry are key factors affecting the performance of the catalyst. The dispersibility and stability of the catalyst slurry directly affect the microstructure and morphology of the catalyst, and further affect the mass transfer performance and electrochemical performance of the catalyst. The polymer material field also plays an important role in the preparation of the catalyst. An ionomer is a polymer material with ion-conductive properties, and it is widely used in the catalyst of fuel cells. The proton conduction performance and water retention property of the ionomer are key factors affecting the performance of the catalyst.

[0003] The patent with the publication number CN112133928A discloses a stable and high-performance proton exchange membrane fuel cell catalyst slurry and a preparation method thereof. It specifically discloses that by virtue of the characteristic that the proton concentration of the Nafion solution after effective dispersion is large, the electrostatic repulsion of the slurry is increased, making the slurry more stable, thereby improving the performance of the fuel cell; the patent with the publication number CN115939420A discloses a preparation method of a highly stable proton exchange membrane fuel cell catalyst slurry. It specifically discloses that by first mixing and dispersing the catalyst only with water, the large particles of the catalyst can be dispersed smaller without an alcohol solution and a perfluorosulfonic acid polymer, ensuring the stability of the subsequent catalyst slurry; at the same time, during the mixing process of the catalyst and water, and during the mixing process of the alcohol solution and the perfluorosulfonic acid polymer solution, a method of first pre-dispersing and then performing high-speed shearing and re-dispersing is adopted, and the dispersion effect is better, and the catalyst slurry is more stable. Both of the above two patents regulate the feeding sequence and composition of components such as dispersants, binders, and catalysts in the slurry, but both use long-chain branched ionomers to prepare the catalyst slurry. However, long-chain branched ionomers are prone to form aggregates and crystalline states, resulting in a decrease in the dispersibility and stability of the catalyst slurry, thereby affecting the performance of the catalyst.

[0004] When preparing the catalyst slurry, the prior art often ignores the pretreatment of the ionomer and the influence of the ratio with the dispersant on the proton conduction performance and water retention of the ionomer. In addition, when optimizing the microscale structure of the catalyst layer, the prior art often ignores the influence of the coating process parameters on the dispersibility and stability of the catalyst slurry. Therefore, when preparing the catalyst slurry and optimizing the microscale structure of the catalyst layer, the prior art has problems of insufficient dispersibility and stability, which limits the performance and lifespan of the catalyst. Summary of the Invention

[0005] The object of the present invention is to provide a fuel cell catalyst slurry, its preparation method and application, to solve the technical problem of insufficient dispersibility and stability of the catalyst slurry in the prior art.

[0006] To achieve the above object, in one embodiment of the present invention, a fuel cell catalyst slurry is provided, which includes a catalyst, a dispersant, an ionomer and water. The mass ratio of the ionomer to the catalyst is 0.3 - 1.0:1; the mass ratio of the dispersant to water is 1 - 5:1; the ionomer is one or more perfluorosulfonic acid ionomers with short side chains and EW ≤ 900.

[0007] One of the preferred solutions of the present invention is that the catalyst is a platinum-carbon catalyst, and the mass percentage content of platinum in the platinum-carbon catalyst is 30% - 70%.

[0008] One of the preferred solutions of the present invention is that the dispersant is an alcohol dispersant.

[0009] One of the preferred solutions of the present invention is that the dispersant includes any one of n-propanol, isopropanol and ethylene glycol.

[0010] One of the preferred solutions of the present invention is that the carbon content of the fuel cell catalyst slurry is 2% - 5%.

[0011] The present invention also discloses a preparation method of a fuel cell catalyst slurry, which includes the following steps:

[0012] Mix the dispersant, ionomer and water, carry out aging pretreatment and cooling to obtain an ionomer system;

[0013] Carry out ball milling and vacuum treatment on the catalyst to obtain a treated catalyst;

[0014] Mix the ionomer system and the treated catalyst, and obtain the fuel cell catalyst slurry after ball milling.

[0015] One of the preferred solutions of the present invention is that mixing the dispersant, ionomer and water, carrying out aging pretreatment and cooling to obtain an ionomer system includes: mixing the dispersant, ionomer and water, and carrying out aging pretreatment under stirring and heating conditions. After the aging pretreatment is completed, cool to 20°C - 30°C to obtain the ionomer system.

[0016] One of the preferred embodiments of the present invention is that in the aging pretreatment, the heating temperature is 50°C - 100°C, and the stirring speed is 500 rpm - 1000 rpm.

[0017] One of the preferred embodiments of the present invention is that in the aging pretreatment, the aging time is 1 h - 3 h.

[0018] One of the preferred embodiments of the present invention is to ball mill and vacuum treat the catalyst to obtain a treated catalyst, including: mixing the catalyst with ball milling beads for vacuum treatment and displacing with an inert gas to obtain a treated catalyst.

[0019] One of the preferred embodiments of the present invention is that the mass ratio of the ball milling beads to the catalyst is 3 - 6:1, and the vacuum pressure in the vacuum treatment is 0.05 MPa - 0.1 MPa.

[0020] One of the preferred embodiments of the present invention is to mix the ionomer system and the treated catalyst and obtain a fuel cell catalyst slurry after ball milling, including that the ball milling time is 3 h - 10 h and the ball milling speed is 30 rpm - 120 rpm.

[0021] The present invention also discloses an application of a fuel cell catalyst slurry, using the fuel cell catalyst slurry to prepare a fuel cell catalytic layer.

[0022] One of the preferred embodiments of the present invention is to prepare a fuel cell catalytic layer, including: fixing a proton membrane on a spraying platform, and respectively preparing an anode catalytic layer and a cathode catalytic layer to obtain a fuel cell catalytic layer.

[0023] One of the preferred embodiments of the present invention is that the vacuum pressure for fixing the proton membrane is 0.05 MPa - 0.1 MPa.

[0024] One of the preferred embodiments of the present invention is that during the preparation of the anode catalytic layer, the preparation temperature is 50°C - 100°C, the preparation flow rate is 1 ml / min - 5 ml / min, the preparation speed is 150 mm / s - 250 mm / s, and the number of preparation passes is 1 - 10 times.

[0025] One of the preferred embodiments of the present invention is that during the preparation of the cathode catalytic layer, the preparation temperature is 50°C - 100°C, the preparation flow rate is 1 ml / min - 5 ml / min, the preparation speed is 100 mm / s - 300 mm / s, and the number of preparation passes is 1 - 10 times.

[0026] In summary, the beneficial effects of the present invention are as follows:

[0027] 1. The fuel cell catalyst slurry of the present invention uses an ionomer with short branched chains and an EW (ion exchange equivalent) ≤ 900 to regulate the catalyst slurry. By adjusting the ratios of various short branched chain ionomers to the components of the catalyst, optimizing the dispersion process of the catalyst slurry, and regulating the preparation parameters of the catalyst layer, a stable catalyst slurry and a high-performance catalyst layer are formed. The ionomer used in the present invention has better proton conduction performance and water retention, thereby improving the performance of the catalyst.

[0028] 2. The present invention forms a stable ionomer state by optimizing the aging short branched chain ionomer system, and uses the dispersion process of the catalyst slurry, combined with the particle size and viscosity slurry characterization process, to form a stable catalyst slurry. This method can effectively improve the dispersibility and stability of the catalyst slurry, thereby improving the performance of the catalyst.

[0029] 3. The present invention regulates the preparation process parameters of the catalyst layer such as temperature, flow rate, moving speed, and number of passes, optimizes the microscale structure of the catalyst layer, and combines the microscopic morphology of the catalyst layer, thereby improving the mass transfer performance of the catalyst layer and further improving the performance of the fuel cell. This method can effectively optimize the microscale structure of the catalyst layer, thereby improving the performance of the catalyst.

[0030] Other features and advantages of the present invention will be described in the subsequent specification, and part of them will become obvious from the specification or be understood by implementing the present invention. The objectives and other advantages of the present invention can be illustrated by the effects described in the specification and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic flow chart of the preparation method of the fuel cell catalyst slurry in the embodiment of the present invention;

[0032] Figure 2 It is a micrograph of the fuel cell catalyst layer in Embodiment 1 of the present invention;

[0033] Figure 3 It is a micrograph of the fuel cell catalyst layer in Embodiment 2 of the present invention;

[0034] Figure 4 It is a polarization performance curve graph of the fuel cell catalyst layers prepared in Embodiment 1 and Embodiment 2 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0036] In the present invention, the endpoints and any values disclosed in the ranges are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed in the present invention.

[0037] The present invention provides a fuel cell catalyst slurry, which includes a catalyst, a dispersant, an ionomer, and water. The mass ratio of the ionomer to the catalyst is 0.3 - 1.0:1. Preferably, the mass ratio of the ionomer to the catalyst is 0.5 or 0.7 or 0.9;

[0038] The mass ratio of the dispersant to water is 1 - 5:1; preferably, the mass ratio of the dispersant to water is 2:1 or 3:1;

[0039] The ionomer is one or more perfluorosulfonic acid ionomers with short branched chains and EW ≤ 900; preferably, the EW of the ionomer is 830 or 790 or 720;

[0040] The catalyst is a platinum-carbon catalyst, and the mass percentage content of platinum in the platinum-carbon catalyst is 30% - 70%. Preferably, the mass percentage content of platinum in the platinum-carbon catalyst is 40% or 50% or 60%;

[0041] The dispersant is an alcohol dispersant. Preferably, the dispersant is n-propanol or isopropanol or ethylene glycol;

[0042] The carbon content of the fuel cell catalyst slurry is 2% - 5%. Preferably, the carbon content of the fuel cell catalyst slurry is 3.5% or 4%.

[0043] The fuel cell catalyst slurry of the present invention regulates the catalyst slurry by using an ionomer with short branched chains and EW ≤ 900. By regulating the ratio of various short branched chain ionomers to each component of the catalyst, the dispersibility and stability of the catalyst slurry are improved.

[0044] The present invention also discloses a preparation method of a fuel cell catalyst slurry, as Figure 1 shown, which includes the following steps:

[0045] Step (1): Mix the dispersant, ionomer and water, conduct aging pretreatment and cooling to obtain an ionomer system; specifically, mix the dispersant, ionomer and water, and conduct aging pretreatment under stirring and heating conditions. After the aging pretreatment, the solution is stirred and cooled to 20°C - 30°C to obtain an ionomer system. Among them, the heating temperature during the aging pretreatment is 50°C - 100°C, preferably 70°C; the stirring method is magnetic stirring or overhead stirrer stirring, and the stirring speed is 500 rpm - 1000 rpm, preferably 800 rpm; the aging time during the aging pretreatment is 1 h - 3 h, preferably 2 h.

[0046] Step (2): Ball-mill and vacuum-treat the catalyst to obtain the treated catalyst; specifically, mix the catalyst with ball-milling beads and conduct vacuum treatment, and displace with an inert gas to obtain the treated catalyst. Among them, the vacuum pressure for the catalyst vacuum treatment is 0.05 MPa - 0.1 MPa, and the pressure after displacement is at atmospheric pressure; the inert gas is argon, the diameter of the ball-milling beads is 0.2 mm - 2 mm, preferably, the diameter of the ball-milling beads is 0.5 mm or 1 mm; the mass ratio of the ball-milling beads to the catalyst is 3 - 6:1.

[0047] Step (3): Mix the ionomer system and the treated catalyst, and obtain a fuel cell catalyst slurry after ball-milling; among them, the ball-milling speed is 30 rpm - 120 rpm, preferably 60 rpm or 80 rpm; the ball-milling time is 3 h - 10 h, preferably 5 h or 8 h.

[0048] After the fuel cell catalyst slurry is prepared, record the change curve of parameters such as the viscosity of the fuel cell catalyst slurry over time.

[0049] The preparation method of the fuel cell catalyst slurry of the present invention optimizes the formation of a stable ionomer state in the aged short-chain ionomer system, utilizes the dispersion process of the catalyst slurry, and combines the particle size and viscosity slurry characterization processes to form a stable catalyst slurry.

[0050] The present invention also discloses an application of the fuel cell catalyst slurry, and the fuel cell catalyst slurry is used to prepare a fuel cell catalyst layer.

[0051] To prepare a fuel cell catalyst layer, it includes: fixing the proton exchange membrane on the spraying platform, and respectively preparing the anode catalyst layer and the cathode catalyst layer to obtain a fuel cell catalyst layer; specifically, it includes:

[0052] 1) Fix the proton membrane on the spraying platform under vacuum, and prepare the anode catalyst layer by adjusting parameters such as temperature, flow rate, moving speed, and number of passes. Among them, the vacuum pressure for fixing the proton membrane is 0.05 MPa - 0.1 MPa, preferably 0.08 MPa. During the preparation of the anode catalyst layer, the preparation temperature is 50°C - 100°C, preferably 80°C, the preparation flow rate is 1 ml / min - 5 ml / min, preferably 2 ml / min, the preparation speed is 150 mm / s - 250 mm / s, preferably 200 mm / s, and the number of preparation passes is 1 - 10 times, preferably 3 times.

[0053] 2) Flip the proton membrane, fix the other side of the proton membrane without spraying the catalyst on the spraying platform under vacuum, and prepare the cathode catalyst layer by adjusting parameters such as temperature, flow rate, moving speed, and number of passes. Among them, the vacuum pressure for fixing the proton membrane is 0.05 MPa - 0.1 MPa, preferably 0.08 MPa. During the preparation of the cathode catalyst layer, the preparation temperature is 50°C - 100°C, preferably 70°C, the preparation flow rate is 1 ml / min - 5 ml / min, preferably 3 ml / min, the preparation speed is 100 mm / s - 300 mm / s, preferably 150 mm / s, and the number of preparation passes is 1 - 10 times, preferably 7 times.

[0054] 3) Place the proton membrane after the cathode catalyst layer and the anode catalyst layer are prepared into the drafting paper to obtain the fuel cell catalyst layer.

[0055] After the fuel cell catalyst layer is prepared, the microporous morphology and loading uniformity of the catalyst layer are characterized.

[0056] Example 1

[0057] A fuel cell catalyst slurry, its preparation method and application

[0058] 1. Fuel cell catalyst slurry: It includes a catalyst, a dispersant, an ionomer, and water. Among them, the catalyst is a platinum-carbon catalyst with a platinum content of 50%, the dispersant is n-propanol, and the ionomer is Solvay D79 - 25BS (EW = 790).

[0059] The mass ratio of the ionomer to the catalyst is 0.5, and the mass ratio of the dispersant to water is 2:1.

[0060] The carbon content of the fuel cell catalyst slurry is 3.5%.

[0061] A preparation method of a fuel cell catalyst slurry includes the following steps:

[0062] 1) Cure the ionomer system by mixing n-propanol, water, and Solvay D79-25BS, and perform a curing pretreatment under stirring and heating conditions. The heating and curing temperature is 50 °C, the stirring method is magnetic stirring, the stirring speed is 600 rpm, and the curing time is 2 h;

[0063] 2) Cool the ionomer system treated in step 1) to 25 °C under stirring at 600 rpm;

[0064] 3) Mix the platinum-carbon catalyst with 50% platinum content with 0.5 mm ball milling beads, perform a vacuum treatment under a vacuum pressure of 0.08 MPa, and displace it at atmospheric pressure with argon;

[0065] 4) Mix the ionomer system treated in step 2) with the catalyst treated in step 3) under argon conditions;

[0066] 5) Ball mill the solution after mixing in step 4) for 5 h at a rotation speed of 60 rpm to obtain a stable fuel cell catalyst slurry;

[0067] 6) After preparation, record the change curves of parameters such as the slurry viscosity over time.

[0068] An application of a fuel cell catalyst slurry, using the fuel cell catalyst slurry to prepare a fuel cell catalyst layer. The preparation of the fuel cell catalyst layer includes the following steps:

[0069] 1) Vacuum fix the proton exchange membrane on the spraying platform, with a vacuum pressure of 0.08 MPa;

[0070] 2) Control parameters such as a temperature of 80 °C, a flow rate of 2 ml / min, a moving speed of 200 mm / s, and 3 passes to prepare the anode catalyst layer;

[0071] 3) Flip the proton exchange membrane, and vacuum fix the other side of the proton exchange membrane without spraying the catalyst on the spraying platform, with a vacuum pressure of 0.08 MPa;

[0072] 4) Control parameters such as a temperature of 70 °C, a flow rate of 3 ml / min, a moving speed of 150 mm / s, and 7 passes to prepare the cathode catalyst layer;

[0073] 5) Place the proton exchange membrane after the preparation of the cathode catalyst layer and the anode catalyst layer in the drafting paper to complete the preparation of the fuel cell catalyst layer CCM;

[0074] 6) After preparation, characterize the microporous morphology and loading uniformity of the catalyst layer. The microscopic morphology is as Figure 2 shown. It can be seen from Figure 2 that the coating on the surface is evenly coated and there are no obvious large particle agglomerations.

[0075] Example 2

[0076] A fuel cell catalyst slurry, its preparation method and application

[0077] 1. Fuel cell catalyst slurry: It includes a catalyst, a dispersant, an ionomer and water. The catalyst is a platinum-carbon catalyst with 60% platinum content, the dispersant is n-propanol, and the ionomers are Solvay D72-25BS (EW = 720) and Solvay D83-24B (EW = 830). The ratio of Solvay D72-25BS to Solvay D83-24B is 1:1;

[0078] The mass ratio of the ionomer to the catalyst is 0.7, and the mass ratio of the dispersant to water is 3:1;

[0079] The carbon content of the fuel cell catalyst slurry is 3.5%.

[0080] A preparation method of a fuel cell catalyst slurry, including the following steps:

[0081] 1) Cure the ionomer system. Mix n-propanol, water, Solvay D72-25BS and Solvay D83-24B, and carry out a pre-curing treatment under stirring and heating conditions. The heating and curing temperature is 70°C, the stirring method is magnetic stirring, the stirring speed is 800 rpm, and the curing time is 2 h;

[0082] 2) Cool the ionomer system treated in step 1) to room temperature under stirring at 800 rpm;

[0083] 3) Mix the platinum-carbon catalyst with 60% platinum content with 1 mm ball milling beads, carry out vacuum treatment under a vacuum pressure of 0.08 MPa, and displace it at normal pressure with argon;

[0084] 4) Mix the ionomer system treated in step 2) with the catalyst treated in step 3) under argon conditions;

[0085] 5) Ball mill the solution mixed in step 4) for 5 h at a rotation speed of 80 rpm to obtain a stable fuel cell catalyst slurry;

[0086] 6) After preparation, record the change curve of parameters such as slurry viscosity over time.

[0087] An application of a fuel cell catalyst slurry. Use the fuel cell catalyst slurry to prepare a fuel cell catalyst layer. The preparation of the fuel cell catalyst layer includes the following steps:

[0088] 1) Vacuum-fix the proton membrane on the spraying platform, and the vacuum pressure is 0.08 MPa;

[0089] 2) Prepare the anode catalyst layer by adjusting parameters such as a temperature of 80 °C, a flow rate of 2 ml / min, a moving speed of 150 mm / s, and 3 passes.

[0090] 3) Flip the proton membrane, and vacuum-fix the other side of the proton membrane without sprayed catalyst on the spraying platform with a vacuum pressure of 0.08 MPa.

[0091] 4) Prepare the cathode catalyst layer by adjusting parameters such as a temperature of 70 °C, a flow rate of 3 ml / min, a moving speed of 200 mm / s, and 7 passes.

[0092] 5) Place the proton membrane after the preparation of the cathode catalyst layer and the anode catalyst layer in the drafting paper, and the preparation of the fuel cell catalyst layer CCM is completed.

[0093] 6) After the preparation, characterize the microporous morphology and the uniformity of the loading amount of the catalyst layer. The microscopic morphology is as Figure 3 shown. It can be seen from Figure 3 that the surface of the coating is relatively uniform and there are no obvious large particle agglomerations.

[0094] Experimental detection: Test the viscosity and the coating loading amount of the fuel cell catalyst slurries prepared in Example 1 and Example 2. Among them, the changes in the viscosity of the fuel cell catalyst slurries prepared in Example 1 and Example 2 with the standing time are shown in Table 1; the loading amount distributions of the fuel cell catalyst layers prepared in Example 1 and Example 2 are shown in Table 2;

[0095] Table 1: Changes in the viscosity of the fuel cell catalyst slurries prepared in Example 1 and Example 2 with the standing time

[0096]

[0097] It can be seen from Table 1 that the viscosities of the fuel cell catalyst slurries prepared in Example 1 and Example 2 of the present invention are relatively stable within 2 h of standing, and the viscosity stability is good.

[0098] Table 2: Loading amount distributions of the fuel cell catalyst layers prepared in Example 1 and Example 2

[0099] Coating serial number <![CDATA[Example 1 Coating loading mg / cm 2 > <![CDATA[Example 2 Coating loading mg / cm 2 > 1 0.33 0.32 2 0.34 0.32 3 0.33 0.33 4 0.35 0.34 5 0.34 0.32

[0100] It can be seen from Table 2 that the loading amount distributions of the fuel cell catalyst layers prepared in Example 1 and Example 2 of the present invention are uniform.

[0101] Detect the polarization performance of the fuel cell catalyst layers prepared in Example 1 and Example 2. The test results are as Figure 4 shown. According to Figure 4The polarization curve data shows that Example 1 reaches 2.4 A @ 0.651 V and Example 2 reaches 2.4 A @ 0.64 V, both reaching the first-class level of membrane electrode performance at home and abroad.

[0102] In summary, the fuel cell catalyst slurry prepared by the present invention has high dispersibility and stability, and the prepared catalytic layer has the advantages of high performance.

[0103] The above-described embodiments are only descriptions of the preferred embodiments of the present invention and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A fuel cell catalyst slurry, characterized in that: The invention comprises a catalyst, a dispersant, an ionomer and water, wherein the mass ratio of the ionomer to the catalyst is 0.3-1.0:1; the mass ratio of the dispersant to the water is 1-5:1; and the ionomer is one or more perfluorosulfonic acid ionomers with short-chain EW≤900.

2. A fuel cell catalyst slurry according to claim 1, characterized in that: The catalyst is a platinum-carbon catalyst, and the mass percentage of platinum in the platinum-carbon catalyst is 30%-70%.

3. A fuel cell catalyst slurry according to claim 1, characterized in that: The dispersant is an alcohol dispersant.

4. A fuel cell catalyst slurry as claimed in claim 3, characterized in that: The dispersant includes any one of n-propanol, isopropanol and ethylene glycol.

5. A fuel cell catalyst slurry according to claim 1, characterized in that: The fuel cell catalyst slurry has a carbon content of 2%-5%.

6. A method for preparing a fuel cell catalyst slurry according to any one of claims 1 to 5, characterized in that: The following steps are involved: The dispersant, ionomer and water are mixed for aging pretreatment and cooling to obtain an ionomer system; ball milling and vacuum treating the catalyst to obtain a treated catalyst; The ionomer system and the treated catalyst are mixed and ball-milled to obtain fuel cell catalyst slurry.

7. The method for preparing a fuel cell catalyst slurry according to claim 6, characterized in that: The method of mixing the dispersant, ionomer and water, performing aging pretreatment and cooling to obtain the ionomer system includes: mixing the dispersant, ionomer and water, performing aging pretreatment under stirring and heating conditions, and cooling to 20° C.-30° C. after the aging pretreatment to obtain the ionomer system.

8. The method for preparing a fuel cell catalyst slurry according to claim 7, characterized in that: The heating temperature in the aging pretreatment is 50°C-100°C, and the stirring speed is 500rpm-1000rpm.

9. The method for preparing a fuel cell catalyst slurry according to claim 7 or 8, characterized in that: The aging time in the aging pretreatment is 1h-3h.

10. The method for preparing a fuel cell catalyst slurry according to claim 6, characterized in that: The process of ball milling and vacuum treating the catalyst to obtain the treated catalyst includes: mixing the catalyst with ball milling beads, vacuum treating the mixture, and replacing the mixture with an inert gas to obtain the treated catalyst.

11. The method for preparing a fuel cell catalyst slurry according to claim 10, characterized in that: The mass ratio of the ball milling beads to the catalyst is 3-6:1, and the vacuum pressure in the vacuum treatment is 0.05MPa-0.1MPa.

12. The method for preparing a fuel cell catalyst slurry according to claim 6, characterized in that: The ionomer system and the treated catalyst are mixed and ball-milled to obtain fuel cell catalyst slurry, wherein the ball-milling time is 3h-10h and the ball-milling speed is 30rpm-120rpm.

13. An application of a fuel cell catalyst slurry according to any one of claims 1 to 5, characterized in that: The fuel cell catalyst slurry is used to prepare a fuel cell catalyst layer.

14. The use of a fuel cell catalyst slurry according to claim 13, characterized in that: The preparation of the fuel cell catalyst layer comprises: fixing the proton membrane on a spraying platform, and preparing the anode catalyst layer and the cathode catalyst layer respectively to obtain the fuel cell catalyst layer.

15. The use of a fuel cell catalyst slurry according to claim 14, characterized in that: The fixed vacuum pressure of the proton membrane is 0.05MPa-0.1MPa.

16. The use of a fuel cell catalyst slurry according to claim 14, characterized in that: During the preparation of the anode catalyst layer, the preparation temperature is 50° C.-100° C., the preparation flow rate is 1 ml / min-5 ml / min, the preparation speed is 150 mm / s-250 mm / s, and the preparation times are 1-10 times.

17. The use of a fuel cell catalyst slurry according to claim 14, characterized in that: During the preparation of the cathode catalyst layer, the preparation temperature is 50°C-100°C, the preparation flow rate is 1ml / min-5ml / min, the preparation speed is 100mm / s-300mm / s, and the number of preparation passes is 1-10 times.

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