Membrane Electrode Assembly Preparation Method

The following is a detailed introduction to the membrane electrode assembly preparation method:

1. CCM method (catalyst coated on membrane)

• Preparation process:
  First, the catalyst, proton conductor (such as perfluorosulfonic acid resin), solvent and other additives are mixed to prepare catalyst slurry.
  Then, the catalyst slurry is directly coated on both sides of the proton exchange membrane by spraying, scraping, transfer printing and other methods.
  Finally, after drying, hot pressing and other treatments, the catalyst layer is tightly combined with the proton exchange membrane to form a membrane electrode.
• Advantages:
  – High catalyst utilization rate: The catalyst is directly coated on the proton exchange membrane, which reduces the distance between the catalyst and the proton exchange membrane, is conducive to the transfer of protons, and thus improves the utilization rate of the catalyst.
  – Reducing proton transfer resistance: It can greatly reduce the proton transfer resistance between the membrane and the catalyst layer and improve the performance of the membrane electrode.
  – Easy to achieve large-scale continuous production: Automated equipment can be used for coating and processing to improve production efficiency and is suitable for large-scale production.
  – Application: At present, more than 95% of membrane electrode preparation processes use the CCM method, which is widely used in the field of fuel cells.

2. CCS method (catalyst coated on substrate)

• Preparation process:
  Mix the catalyst, conductive agent, binder, etc. to prepare catalyst slurry.
  The catalyst slurry is coated on the gas diffusion layer by spraying, scraping, etc.
  The gas diffusion layer coated with the catalyst is hot-pressed with the proton exchange membrane to form a membrane electrode.
• Advantages:
  – Good gas diffusion performance: The gas diffusion layer has good air permeability and conductivity, which can increase the diffusion rate and reaction rate of the gas.
  – High mechanical strength: The gas diffusion layer is usually made of materials such as carbon fiber, has high mechanical strength, and can withstand the pressure and stress during the operation of the fuel cell.
• Disadvantages:
  – Low catalyst utilization: The distance between the catalyst and the proton exchange membrane is far, and the proton transfer resistance is large, resulting in low catalyst utilization.
  – Large interface resistance: The interface contact between the catalyst layer and the proton exchange membrane is poor, which is easy to produce a large interface resistance, affecting the performance of the membrane electrode.
  – Application: It is rarely used in practice, mainly due to its disadvantages such as low catalyst utilization and large interface resistance.

3. Common purpose of the two methods
Whether it is the CCM method or the CCS method, the ultimate goal is to improve the performance of the membrane electrode and reduce the cost, which includes the following aspects:

• Improve catalyst utilization: By optimizing the distribution and structure of the catalyst, improve the activity and utilization of the catalyst and reduce the amount of precious metals.
• Improve micropore coverage: Increase the number and size of micropores in the catalyst layer, increase the diffusion rate and reaction rate of the gas.
• Improve the binding force of the membrane electrode: Enhance the binding force between the catalyst layer and the proton exchange membrane and the gas diffusion layer to prevent the membrane electrode from stratification and shedding during operation.
• Avoid membrane swelling: Prevent the proton exchange membrane from swelling during operation, which affects the performance and life of the membrane electrode.
• Reduce the amount of precious metals: Reduce the cost of the membrane electrode and improve the economy of the fuel cell.
• Reduce interface resistance: Reduce the interface resistance between the catalyst layer and the proton exchange membrane and the gas diffusion layer to improve the performance of the membrane electrode.
• Achieve large-scale continuous production: Use automated equipment and processes to improve production efficiency, reduce production costs, and meet the needs of large-scale production.

Hydrogen production by electrolysis of water is the most advantageous method for producing hydrogen. Utrasonic coating systems are ideal for spraying carbon-based catalyst inks onto electrolyte membranes used for hydrogen generation. This technology can improve the stability and conversion efficiency of the diaphragm in the electrolytic water hydrogen production device. Cheersonic has extensive expertise coating proton exchange membrane electrolyzers, creating uniform, effective coatings possible for electrolysis applications.

Cheersonic ultrasonic coating systems are used in a number of electrolysis coating applications. The high uniformity of catalyst layers and even dispersion of suspended particles results in very high efficiency electrolyzer coatings, either single or double sided.

About Cheersonic

Cheersonic is the leading developer and manufacturer of ultrasonic coating systems for applying precise, thin film coatings to protect, strengthen or smooth surfaces on parts and components for the microelectronics/electronics, alternative energy, medical and industrial markets, including specialized glass applications in construction and automotive.

Our coating solutions are environmentally-friendly, efficient and highly reliable, and enable dramatic reductions in overspray, savings in raw material, water and energy usage and provide improved process repeatability, transfer efficiency, high uniformity and reduced emissions.

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