CN102593470A - Device and method for preparing diffusion layer slurry of proton exchange membrane fuel cell - Google Patents

Abstract

The invention relates to equipment and a method for preparing the slurry for the diffusion layer of a proton exchange membrane fuel cell. The device includes a power unit, a transmission device, a mixing tank, a low-speed agitator, a high-speed disperser and internal cooling components, etc. The transmission device includes a hollow low-speed transmission shaft and a high-speed transmission shaft placed in the hollow shaft, which are installed in rotation on the shaft. The low-speed agitator, high-speed disperser and internal cooling components are installed on the turret and rotate together with the turret, while the high-speed dispersing component rotates at high speed driven by the high-speed drive shaft connected to the transmission device; the circulating water pipeline is installed in the hollow high-speed The pipeline shaft in the transmission shaft is introduced to realize the internal cooling function. The equipment of the present invention has the internal cooling function of the pulping process for the first time, which solves the problem of demulsification caused by the internal temperature rise in the preparation of high-viscosity slurry, and integrates pre-mixing and high-speed dispersion into the same equipment, which has a large processing capacity and a wide range of applicable viscosity , high efficiency, low cost, easy operation and so on.

Description

A device and method for preparing diffusion layer slurry for proton exchange membrane fuel cells

technical field

The invention relates to a device and a method for preparing slurry for a diffusion layer of a proton exchange membrane fuel cell, belonging to the field of fuel cell preparation.

Background technique

Proton exchange membrane fuel cell (PEMFC) is a power generation device that converts chemical energy into electrical energy through electrochemical reactions. It has the advantages of high energy density, low operating temperature and good stability. It is used in mobile devices, electric vehicles (EV), distributed It has broad application prospects in power stations and other fields. Its core component, the three-in-one membrane electrode (MEA), is prepared by a hot-pressing process from a gas diffusion layer, a catalytic layer and a proton exchange membrane. Composed of conductive porous materials, the gas diffusion layer plays multiple roles such as supporting the catalytic layer, collecting current, conducting gas, and discharging water. It is one of the key components that affect the performance of the electrode and has received extensive attention in recent years. Factors such as the preparation process of the diffusion layer, the content of each component, and the dispersion degree of the diffusion layer slurry directly affect the performance of the diffusion layer, and then affect the overall performance of the electrode. Therefore, in order to improve the overall performance of the electrode, it is necessary to solve the problem of preparing a high-stability diffusion layer slurry.

The published patents and documents only mention the preparation process of the diffusion layer slurry, and there is no report on the corresponding large-scale production of special equipment. When preparing the diffusion layer slurry, the carbon powder is added to the water dispersion containing the PTFE emulsion, and the carbon powder is wetted and dispersed by high-intensity ultrasound or shear force or a combination of the two. This process not only disperses the two phases of incompatible water and PTFE emulsion into droplets and the diameter of the droplets is within a certain range, but also highly disperses the carbon powder into the emulsion. The mixing process must improve the dispersion of nano-carbon powder as much as possible under the condition of ensuring no demulsification. However, high-intensity ultrasound or shearing can easily cause the demulsification of PTFE emulsion, and the slurry will have obvious solid-liquid separation. However, if the shear strength is reduced, on the one hand, it may lead to prolonged dispersion time and reduced dispersion efficiency, causing slurry The internal temperature rises and demulsification occurs. On the other hand, the dispersion effect may not meet the product requirements. This requires that when choosing a reasonable shear strength or ultrasonic strength, the temperature of the dispersion system should be controlled to prevent the temperature from being too high.

Chinese patent CN102024961A, a gas diffusion layer of a proton exchange membrane fuel cell and its preparation method, mentions that the slurry is prepared by ultrasonic vibration, but this method is suitable for the configuration of a small amount of slurry, and is not suitable for large-scale production. Ultrasonic wave easily causes the demulsification of PTFE emulsion in the operation; Chinese patent CN101038970A a kind of preparation method of high-temperature proton exchange membrane fuel cell water-retaining diffusion layer points out that first carbon powder is mixed with PTFE, then adds water or anhydrous organic solvent, then in 1000 Stirring at a stirring speed of 5000 rpm for 10-24 hours to obtain a diffusion layer slurry. However, this method is only suitable for the configuration of a small amount of slurry, and the dispersion efficiency is low, the stirring time is long, and the slurry is prone to obvious temperature rise when the slurry is stirred at a high speed for a long time, and it is not suitable for the efficient mixing of a large amount (≥20L) of the diffusion layer slurry. ; The preparation method of Chinese patent CN101022164A fuel cell gas diffusion layer first mixes carbon black powder, distilled water, and dispersant Tween-60 in proportion, then PTFE emulsion is evenly added in the above-mentioned carbon black powder dispersion system, and continues to mix 0.5-3 Hours, the mixing method adopts ultrasonic and mechanical high-speed shearing. However, in the first step of this method to prepare the carbon black powder dispersion system, the carbon powder needs to be added in 10 times, and the pre-mixing of the carbon powder cannot be realized. The pre-mixing process needs to add a dispersant, which increases the cost and splits the entire dispersion process. It is carried out in two steps, and the dispersion efficiency is low. At the same time, the ultrasonic wave is easy to cause the PTFE emulsion to demulsify in actual operation.

One of the most important issues in the efficient mixing of the diffusion layer slurry is to disperse uniformly, have good stability, and ensure that it does not break the emulsion. Therefore, very high requirements are put forward for the design of the agitator, and at the same time, it is necessary to accurately control the temperature during the agitation process. Most of the existing mixing equipment adopts jacket cooling, but for the efficient mixing and dispersion of a large amount (≥20L) of diffusion layer slurry, due to the high viscosity of the slurry, it is easy to cause the slurry to be far away from the center of the jacket wall surface due to the high viscosity of the slurry. If the temperature is too high, it will seriously affect the homogenization effect, and even cause serious demulsification, resulting in the scrapping of the slurry. Therefore, for the efficient mixing of a large number of diffusion layer slurries, the current homogenization equipment cannot meet the requirements, and it is urgent to develop special homogenization equipment for high-efficiency dispersion and cooling.

Contents of the invention

The main technical problem to be solved by the present invention is to provide a high-viscosity proton exchange membrane fuel cell diffusion layer material with internal cooling function, adjustable installation position, integration of pre-mixing and high-speed dispersion, and large-scale preparation Apparatus and method for slurry. It has the advantages of high mixing efficiency, low cost, easy operation, anti-demulsification, etc. It can effectively prevent the deposition of solid-liquid separation during the use of materials, and solve the problems existing in the current production practice.

The present invention is achieved through the following technical solutions:

A device for preparing proton exchange membrane fuel cell diffusion layer slurry, comprising a power unit, a transmission device, a mixing tank 3, a low-speed agitator 4 driven by the power unit through a transmission device, and a high-speed disperser 5; it is characterized in that the The power unit comprises a low-speed dispersing motor 101, a high-speed dispersing motor 102 and an automatic lifting motor 103, and the transmission device includes a transmission wheel train 205, a transmission shaft and a turret 204, and the transmission shaft includes a hollow motor driven by the low-speed dispersing motor 101. The low-speed transmission main shaft 201, the high-speed transmission shaft 202 driven by the high-speed dispersion motor 102 placed in the hollow low-speed transmission main shaft 201, and the hollow pipeline shaft 203 placed in the high-speed transmission shaft 202, the interior of the above three shafts is fixed by bearing nesting , fixed on the frame 7 through the bearing seat; a hollow cylindrical turret 204 is installed on the main shaft 201 through a key connection, and rotates together with the main shaft 201;

The turret 204 is provided with two low-speed rotating shafts 4a, 4b, the lower ends of which pass through the turret and are perpendicular to the lower surface of the turret, and the two installation points are symmetrical to the center of the lower end surface, and the distance between the installation points and the center of the circle is 1/8d. -1/4d, preferably 1/6d, two low-speed agitators 4 are installed on the lower end of the rotating shaft 4a, 4b and extend into the mixing bucket 3; the upper end of the rotating shaft 4a, 4b passes through the upper end surface of the turret and passes through the pinion and The large gear 205 meshing fixed on the frame, the transmission ratio is 1: 1-1: 4, preferably 1: 2, and the rotating shafts 4a, 4b drive two low-speed agitators 4 to realize their own rotation when rotating with the turret 204. turn;

The turret 204 is also provided with two high-speed rotating shafts 5a, 5b perpendicular to the lower end surface of the turret 204. The two installation points are symmetrical to the center of the lower end surface, and the installation points are 1/6d-3/10d away from the center of the circle. Preferably 1/4d, the line connecting the installation points of the high-speed transmission shaft is perpendicular to the line connecting the installation points of the low-speed transmission shaft, and the tops of the high-speed rotating shafts 5a and 5b are equipped with driven pulleys 206, and the driven pulleys are connected to the high-speed transmission through the synchronous belt. The driving pulley 208 on the shaft 202 is connected;

The lower ends of the high-speed rotating shafts 5a, 5b are each equipped with a disperser 5 placed in the mixing tank 3, the high-speed disperser 5 rotates with the turret 204 driven by the high-speed rotating shafts 5a, 5b, and simultaneously driven by the high-speed transmission shaft 202 Realize its own rotation, the speed is between 0-7500rpm;

There is at least one internal cooling assembly 6 in the mixing bucket 3, and the internal cooling assembly 6 includes a coiled heat exchange tube and its connecting pipeline 8. The internal cooling assembly 6 is vertically installed on the lower end surface of the turret 204 through bolt connection and Rotate with the turret, the installation point is 3/10d-9/20d, preferably 2/5d, from the center of the lower end face, installed in the direction of 45°-75°, preferably 60°, of the line connecting the installation points of the two low-speed transmission shafts, coil type The flow rate of the heat exchange tube is 100-150L/h, preferably 120L/h; the connecting pipeline 8 is connected to the rotary adapter 9 through the hollow pipeline shaft 203, and then connected to the external circulating water bath;

The mixing bucket 3 is a jacketed structure with external cooling function, the mixing bucket 3 is automatically lifted by the worm wheel screw 10 driven by the automatic lifting motor 103, and the design capacity of the mixing bucket is 10-50L;

Wherein d is the diameter of the lower end surface of the turret 204 .

The high-speed disperser 5 can be installed at a suitable installation height according to the amount of slurry processed, and the high-speed disperser 5 is installed at different heights in the mixing tank 3, so as to achieve sufficient mixing of the slurry at different heights. The high-speed disperser type is preferably a wheel-disc structure; the low-speed agitator 4 can be a frame type, a blade type, or a twist frame type, preferably a twist frame type, to achieve sufficient mixing of the slurry;

The present invention also provides a method for preparing the diffusion layer slurry of a proton membrane fuel cell based on the above-mentioned device, the method comprising the steps of:

1) Water and polytetrafluoroethylene (PTFE) emulsion are added in the mixing tank according to the proportioning, the mass ratio of water and PTFE emulsion is 80: (1～5), preferably 80: 3; The solid content of PTFE emulsion is 60 ±2wt%, surfactant content is 3.6-7wt%, pH value is 8-10, viscosity is 20-35Mpa s, open low-speed dispersion motor 101 and high-speed dispersion motor 102, adjust the rotating speed of low-speed dispersion motor 101 to be 4-8rpm , preferably 5rpm, the rotating speed of high-speed dispersion motor 102 is 400-500rpm, preferably 500rpm, mixing 4-7min, preferably 5min, realizes the pre-mixing of water and PTFE emulsion;

2) carbon powder is added to the mixed solution of water and PTFE emulsion in step 1), the amount of carbon powder is 1-20%wt of the whole system, preferably 6wt%, open the vacuum pump, the temperature of the circulating water bath is set at 10-40 °C, preferably 20 °C, increase the speed of the low-speed dispersion motor 101 to 10-15 rpm, preferably 10 rpm, keep the speed of the high-speed dispersion motor 102 constant, mix for 15-20 minutes, preferably 15 minutes, to achieve wetting and pre-mixing of the carbon powder;

3) Adjust the rotating speed of the low-speed dispersing motor 101 to 20-30rpm, preferably 30rpm, and the rotating speed of the high-speed dispersing motor 102 to 2000-5000rpm, preferably 3500rpm, and mix for 1.5-2 hours to prepare the proton membrane fuel cell diffusion layer slurry.

Beneficial effect

The invention adopts low-speed agitator and high-speed dispersing agitator at the same time, supplemented by internal and external circulation cooling, so as to achieve the effects of shearing, dispersing and fully mixing.

The invention has the advantage of integrating high-speed dispersion and internal cooling for the first time, providing a device and method that integrates premixing and high dispersion in the same equipment, and can prepare high-viscosity proton exchange membrane fuel cell diffusion layer slurry on a large scale. Compared with the existing technology, first of all, no ultrasonic strengthening components are needed, which avoids the problem of demulsification caused by ultrasonic strengthening; secondly, a set of mixing and stirring components with high speed, medium speed and low speed are provided, and various mixing and stirring components can be used Rotating around its own axis and revolving around the central axis, the mixing efficiency is high. At the same time, by adjusting the installation positions of the two high-speed dispersion components, it can effectively prevent the problem of demulsification caused by excessive local shear rate; finally, compared with the existing technology , It has the functions of internal cooling of slurry and external circulation cooling, which solves the problem of temperature control when preparing a large amount of high-viscosity slurry, and has a wide application prospect.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Figure 1 Front sectional view of the slurry preparation device for the diffusion layer of the proton exchange membrane fuel cell

Among them: 101-low-speed dispersion motor, 102-high-speed dispersion motor, 103-automatic lifting motor, 201-low-speed transmission spindle, 202-high-speed transmission shaft, 203-pipeline shaft, 204-turret, 205-big gear, 207-drive Pulley, 3-stirring bucket, 4-low-speed agitator, 4a, 4b-low-speed rotating shaft, 7-frame, 9-rotary adapter, 10-worm gear screw.

Fig. 2 Right side sectional view of the slurry preparation device for diffusion layer of proton exchange membrane fuel cell

Among them: 201-low-speed transmission spindle, 202-high-speed transmission shaft, 203-pipeline shaft, 204-turret, 206-driven pulley, 208-driving pulley, 3-mixing barrel, 5-high-speed disperser, 5a, 5b-High-speed rotating shaft, 6-Internal cooling assembly, 8-Heat exchange tube connecting pipeline, 9-Rotary adapter.

Figure 3 Schematic diagram of the installation of each component of the diffusion layer slurry preparation device for proton exchange membrane fuel cells

Among them: 4-low-speed agitator, 5-high-speed disperser, 6-internal cooling assembly, 204-turret.

Figure 4 Schematic diagram of internal cooling components of the diffusion layer slurry preparation device for proton exchange membrane fuel cells

Among them: 6-internal cooling assembly, 6a-water inlet, 6b-water outlet.

Figure 5 embodiment one slurry solid content variation diagram

Figure 6 embodiment two slurry solid content variation diagram

Detailed ways

In order to make the purpose, features and advantages of the present invention more obvious and understandable, the content of the present invention will be further clarified below in conjunction with the examples, but the content of the present invention is not limited to the following examples.

Embodiment one

The two rotating shafts of the low-speed agitator are symmetrically installed on both sides of the 1/6d away from the center of the turret. The rotating shaft passes through the turret and meshes with the large gear fixed on the frame through the pinion gear. The transmission ratio is 1:2. The type of low-speed agitator is a twist frame, which can stir the slurry to the greatest extent. The two rotating shafts of the high-speed disperser are installed symmetrically on both sides 1/4d away from the center of the turret, perpendicular to the line connecting the center of the low-speed rotating shaft. 10cm. Two sets of internal cooling components are installed, which are symmetrically installed at 2/5d from the center of the turret, at a 60° angle to the low-speed rotation axis. The heat exchange tube is coil type, and the flow rate is 120L/h. The mixing tank is a jacketed structure with a volume of 30L and a slurry handling capacity of 20L.

Start the automatic lifting motor, lower the mixing tank, add 16.8kg of water and 630g of PTFE emulsion, raise the mixing tank, turn on the low-speed dispersion motor and high-speed dispersion motor with speeds of 5rpm and 500rpm respectively, and disperse for 5min to realize the separation of water and PTFE emulsion. premixed. Then add 1092g of carbon powder into the water dispersion of PTFE at one time, turn on the circulating water bath and internal cooling components, set the temperature of the circulating water bath to 20°C, increase the speed of the low-speed dispersion motor to 10rpm, and keep the speed of the high-speed dispersion motor unchanged. After powder wetting and pre-mixing for 15 minutes, increase the rotation speed of the low-speed dispersion motor to 30 rpm, and the rotation speed of the high-speed dispersion motor to 3500 rpm, and mix for 2 hours to prepare a diffusion layer slurry. Put the slurry in a graduated cylinder and let it stand for 24 hours. The graduated cylinder has 4 sampling ports evenly distributed on the side and a sampling port at the bottom. The solid content of the slurry at different sampling ports was measured, and it was found that the difference of the solid content was within ±3%, and the stability of the slurry was good. The results of the solid content of the slurry are shown in Figure 5. The slurry temperature was maintained at 25-26°C throughout the dispersion process.

As a modification of this embodiment, according to actual production needs, the mixing process can be carried out in a vacuum environment, that is, the mixing tank is under negative pressure.

Embodiment two

The two rotating shafts of the low-speed agitator are symmetrically installed on both sides of the 1/6d away from the center of the turret. The rotating shaft passes through the turret and meshes with the large gear fixed on the frame through the pinion gear. The transmission ratio is 1:2. The type of low-speed agitator is a twist frame, which can stir the slurry to the greatest extent. The two rotating shafts of the high-speed disperser are installed symmetrically on both sides 1/4d away from the center of the turret, perpendicular to the line connecting the center of the low-speed rotating shaft. 10cm. Two sets of internal cooling components are installed, which are symmetrically installed at 2/5d from the center of the turret, at a 60° angle to the low-speed rotation axis. The heat exchange tube is coil type, and the flow rate is 120L/h. The mixing tank is a jacketed structure with a volume of 40L and a slurry handling capacity of 30L.

Start the automatic lifting motor, lower the mixing bucket, add 25.2kg of water and 945g of PTFE emulsion, raise the mixing bucket, turn on the low-speed dispersion motor and high-speed dispersion motor with speeds of 5rpm and 500rpm respectively, and disperse for 5 minutes to realize the pre-preparation of water and PTFE emulsion. mix. Then add 1638g of carbon powder into the PTFE water dispersion at one time, turn on the circulating water bath and internal cooling components, set the temperature of the circulating water bath to 20°C, increase the speed of the low-speed dispersion motor to 10rpm, and keep the speed of the high-speed dispersion motor unchanged. After powder wetting and pre-mixing for 15 minutes, increase the rotation speed of the low-speed dispersion motor to 30 rpm, and the rotation speed of the high-speed dispersion motor to 3500 rpm, and mix for 2 hours to prepare a diffusion layer slurry. Put the slurry in a graduated cylinder and let it stand for 24 hours. The graduated cylinder has 4 sampling ports evenly distributed on the side and a sampling port at the bottom. The solid content of the slurry at different sampling ports was measured, and it was found that the difference of the solid content was within ±3%, and the stability of the slurry was good. The results of the solid content of the slurry are shown in Figure 6. The slurry temperature was maintained at 25-26°C throughout the dispersion process.

As a modification of this embodiment, according to actual production needs, the mixing process can be carried out in a vacuum environment, that is, the mixing tank is under negative pressure.

Claims (7)

1. A device for preparing proton exchange membrane fuel cell diffusion layer slurry, comprising a power unit, a transmission device, a mixing tank 3, a low-speed agitator 4, a high-speed disperser 5 driven by a power unit through a transmission device; it is characterized in that, Described power unit comprises low-speed dispersing motor 101, high-speed dispersing motor 102 and automatic lifting motor 103, and described transmission device comprises transmission wheel train 205, transmission shaft and turret 204, and transmission shaft comprises hollow, is driven by low-speed dispersing motor 101. The driven low-speed transmission main shaft 201, the high-speed transmission shaft 202 driven by the high-speed dispersion motor 102 placed in the hollow low-speed transmission main shaft 201, and the hollow pipeline shaft 203 placed in the high-speed transmission shaft 202, the interior of the above-mentioned three shafts is embedded through bearings. The sleeve is fixed and fixed on the frame 7 through the bearing seat; a hollow cylindrical turret 204 is installed on the main shaft 201 through a key connection, and rotates together with the main shaft 201; The turret 204 is provided with two low-speed rotating shafts 4a, 4b, the lower ends of which pass through the turret and are perpendicular to the lower end surface of the turret. The two installation points are symmetrical to the center of the lower end surface, and the distance between the installation points and the center of the circle is 1/8d- 1/4d, two low-speed agitators 4 are installed on the lower ends of the rotating shafts 4a, 4b and extend into the mixing bucket 3; The large gear 205 meshes, the transmission ratio is 1:1-1:4, preferably 1:2, and the rotating shafts 4a, 4b drive the two low-speed agitators 4 to realize their own rotation when rotating together with the turret 204; The turret 204 is also provided with two high-speed rotating shafts 5a, 5b perpendicular to the lower end surface of the turret 204. The two installation points are symmetrical to the center of the lower end surface, and the installation points are 1/6d-3/10d away from the center of the circle. The line connecting the installation points of the high-speed transmission shaft is perpendicular to the connection line of the installation points of the low-speed transmission shaft. The tops of the high-speed rotating shafts 5a and 5b are equipped with driven pulleys 206. The pulley 208 is connected; the lower ends of the high-speed rotating shafts 5a, 5b are respectively equipped with a disperser 5 placed in the mixing tank 3, and the high-speed dispersing device 5 rotates with the turret 204 under the drive of the high-speed rotating shafts 5a, 5b, and at the same time Driven by the transmission shaft 202, it realizes its own rotation, and the rotation speed is between 0-7500rpm; There is at least one internal cooling assembly 6 in the mixing bucket 3, and the internal cooling assembly 6 includes a coiled heat exchange tube and its connecting pipeline 8. The internal cooling assembly 6 is vertically installed on the lower end surface of the turret 204 through bolt connection and Rotating with the turret, the installation point is 3/10d-9/20d away from the center of the lower end face, installed in the 45°-75° direction of the line connecting the installation points of the two low-speed transmission shafts, and the flow rate of the coiled heat exchange tube is 100-150L /h; the connecting pipeline 8 is connected to the rotary adapter 9 through the hollow pipeline shaft 203, and then connected to the external circulating water bath; The mixing bucket 3 is a jacketed structure with external cooling function, the mixing bucket 3 is automatically lifted by the worm wheel screw 10 driven by the automatic lifting motor 103, and the design capacity of the mixing bucket is 10-50L; wherein d is a turret 204 lower end face diameter. 2. A device for preparing proton exchange membrane fuel cell diffusion layer slurry, characterized in that, the two high-speed dispersers 5 are installed in the mixing tank 3 at different vertical heights. 3. A device for preparing proton exchange membrane fuel cell diffusion layer slurry, characterized in that, the high-speed disperser is a wheel-disk structure; the low-speed agitator 4 is one of frame type, blade type, and twist frame type kind. 4. A device for preparing proton exchange membrane fuel cell diffusion layer slurry is characterized in that the installation point of the low-speed rotating shaft 4a, 4b is 1/6d away from the center of circle of the lower end face of the turret; the high-speed rotating shaft 5a, 5b The installation point is 1/4d away from the center of the lower end surface of the turret; the installation point of the internal cooling assembly 6 is 2/5d from the center of the lower end surface of the turret, and is installed in the 60° direction of the line connecting the installation points of the two low-speed transmission shafts. 5. A device for preparing the diffusion layer slurry of a proton exchange membrane fuel cell, characterized in that the flow rate of the coiled heat exchange tube is 120L/h. 6. a method for preparing proton membrane fuel cell diffusion layer slurry based on the device of claim 1, said method may further comprise the steps: 1) Add water and polytetrafluoroethylene (PTFE) emulsion into the mixing tank according to the proportion, the mass ratio of water and PTFE emulsion is 80: (1～5); the solid content of PTFE emulsion is 60 ± 2wt%, the surface The active agent content is 3.6-7wt%, the pH value is 8-10, and the viscosity is 20-35Mpa·s. Turn on the low-speed dispersing motor 101 and the high-speed dispersing motor 102, adjust the speed of the low-speed dispersing motor 101 to 4-8rpm, and the high-speed dispersing motor 102 The rotation speed is 400-500rpm, and the mixing time is 4-7min to realize the pre-mixing of water and PTFE emulsion; 2) carbon powder is added to the mixed solution of water and PTFE emulsion in step 1), the amount of carbon powder is 1-20%wt of the whole system, preferably 6wt%, open the vacuum pump, the temperature of the circulating water bath is set at 10-40 °C, preferably 20 °C, increase the speed of the low-speed dispersion motor 101 to 10-15 rpm, keep the speed of the high-speed dispersion motor 102 constant, and mix for 15-20 minutes to realize the wetting and pre-mixing of the carbon powder; 3) Adjust the rotation speed of the low-speed dispersion motor 101 to 20-30 rpm, the rotation speed of the high-speed dispersion motor 102 to 2000-5000 rpm, and mix for 1.5-2 hours to prepare the diffusion layer slurry of the proton membrane fuel cell. 7. a method for preparing proton membrane fuel cell diffusion layer slurry based on the device of claim 1, described method step 1) in: the rotating speed of low-speed dispersion motor 101 is 5rpm, the rotating speed of high-speed dispersion motor 102 is 500rpm, water Mix 5min with PTFE emulsion with the mass ratio of 80: 3; Step 2) the rotating speed of low-speed dispersion motor 101 is 10rpm, and mixing time is 15min; Step 3) the rotating speed of middle-low speed dispersion motor 101 is 30rpm, and high-speed dispersion motor 102 rotating speed is 3500rpm. the

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