Ultrasonic Spray Technology for PEM

Ultrasonic atomization and PEM (usually referring to proton exchange membrane) are core processes in hydrogen fuel cell manufacturing.

Ultrasonic: This refers to ultrasonic atomization technology. It uses the physical energy of high-frequency sound waves (typically > 20 kHz) to break liquids into extremely fine and uniform droplets.

PEM: Proton exchange membrane, a core component of hydrogen fuel cells, is a specialized solid electrolyte membrane that conducts protons (H⁺) and isolates hydrogen and oxygen.

Spraying: This refers to the process of precisely and evenly applying a catalyst slurry to a PEM or gas diffusion layer (GDL) as a coating.

Ultrasonic PEM spraying is an advanced manufacturing process that uses ultrasonic atomization technology to precisely apply the slurry required to form the fuel cell catalyst layer to a proton exchange membrane (PEM). This process is also known as CCM (Catalyst Coated Membrane). Membrane (catalyst-coated membrane).

Working Principle

Slurry Preparation: The catalyst (usually platinum or platinum alloy nanoparticles supported on carbon powder), ionomer (such as Nafion solution, which acts as a proton conductor and binder), and solvent (such as water or alcohol) are mixed according to a specific formula to form a uniform and stable slurry.

Ultrasonic Atomization: The slurry is delivered to the transducer head of the ultrasonic atomizer. The transducer converts the high-frequency electrical signal into mechanical vibrations of the same frequency.

Droplet Generation: The high-frequency vibrations are generated in the slurry. "Capillary waves" form on the liquid surface. When the vibration energy exceeds the surface tension of the liquid, droplets are "torn apart" and detached from the wave crests, forming small and uniform micron/submicron aerosol droplets.

Spray deposition: Aerosol droplets generated by atomization are carried by a carrier gas (usually an inert gas such as nitrogen) and sprayed onto the PEM substrate below.

Drying film formation: The droplets spread and fuse on the substrate surface, and the solvent rapidly evaporates, ultimately leaving behind a porous, dense, and uniform catalytic layer composed of catalyst and ionomer.

RPS-SONIC Ultrasonic spraying equipment videos: