Improved Decal Transfer Method to Reduce Membrane Damage from Foreign Particles in Membrane Electrode Assembly

Foreign particles unintentionally embedded in the membrane electrolyte assembly may be detrimental to polymer electrolyte fuel cell durability by dissolution of contaminants or puncture of the membrane. The presence of incidental particles may also affect the fuel cell production cost by imposing more stringent and costly quality control equipment and cleanroom facilities to the manufacturers. The present work aims to understand the impact of foreign particles deposited at the membrane-catalyst layer interface on the decal transfer process and the quality of the resulting catalyst coated membrane. Additionally, this work explores process related opportunities to mitigate material damage from said particles. Several samples are fabricated by specifically placing representative silica particles on the membrane surface subsequently laminated with catalyst layer using different decal transfer procedures. Non-destructive 3D X-ray computed tomography reveals that the model particles substantially penetrate the membrane during regular decal transfer conditions, leading to a vulnerable membrane state or even complete puncture. However, a tuned decal transfer method with modified pressure application rate and optimized supporting layers is shown to reduce membrane damage up to 69%. Additionally, finite element modeling shows that the tuned method can reduce membrane stress during fuel cell operation and thus benefit durability.