In the core components of fuel cells, the dispersion quality of the catalyst slurry directly affects cell performance and lifespan. Traditional stirring or ball milling techniques often face problems such as uneven dispersion and particle agglomeration. Ultrasonic dispersion technology, with its unique physical effects, is becoming a key means to improve catalyst slurry performance.
The core principle of ultrasonic dispersion is to utilize the "cavitation effect" generated by high-frequency sound waves in a liquid. When sound waves propagate, countless tiny bubbles form inside the liquid. These bubbles rapidly expand and burst under pressure changes, releasing enormous energy that effectively breaks up catalyst particle agglomerates, achieving nanoscale uniform dispersion. Compared to traditional methods, ultrasonic dispersion requires no mechanical contact, avoiding contamination or abrasion of the catalyst's active components, while significantly shortening dispersion time and reducing energy consumption by approximately 30%.
In fuel cell catalyst slurries, the dispersion effect of platinum-based nanoparticles is particularly important. Agglomerated particles reduce the active surface area and decrease catalytic efficiency. Experimental data shows that in slurries treated with ultrasound, the dispersion of platinum particles can be increased to over 90%, resulting in a 15%-20% increase in fuel cell power density, significantly enhanced stability, and a lifespan extended to 1.5 times the original value. Furthermore, the vibration of ultrasound can improve the rheological properties of the slurry, making it easier to form a uniform film during coating and reducing the defect rate in membrane electrode preparation.
Currently, ultrasonic dispersion technology has been applied in the large-scale production of fuel cells. By controlling parameters such as ultrasonic power, processing time, and temperature, precise dispersion can be achieved for catalyst slurries of different systems (such as Pt/C slurry for proton exchange membrane fuel cells and composite oxide slurry for solid oxide fuel cells). Experiments show that when the ultrasonic power is controlled at 500-1000W and the processing time is 15-30 minutes, the optimal dispersion effect is achieved while avoiding particle structure damage caused by excessive ultrasound.
With the rapid development of the hydrogen energy industry and the increasing demands on fuel cell performance, ultrasonic dispersion technology is upgrading towards intelligent and continuous operation. In the future, as the ultrasonic dispersion equipment of the system can be controlled in real time, it will further promote the high-quality and low-cost preparation of fuel cell catalyst slurry, injecting new impetus into the widespread application of clean energy.
