Double-Sided Patterned Electrode for Fuel Cell Gas and Water Transport

The patent applies surface patterning to transform the two-dimensional smooth electrode surface into a three-dimensional patterned surface with increased surface area. The patterned structure includes protrusions and recesses that create additional active reaction sites without increasing the projected footprint area, thereby increasing the active area while maintaining the same electrode size and avoiding cost increase.

The patent creates localized patterned regions on the electrode surface with different properties from the bulk. The patterned surface has enhanced catalytic activity and improved mass transport characteristics in specific local areas, allowing the electrode to achieve higher overall performance without requiring a larger total size, thus avoiding additional costs.

The patterned electrode surface creates localized regions with different compression characteristics. The recessed areas allow for better fluid passage while the protruded areas maintain structural contact with the separator. This local differentiation enables the assembly to maintain structural integrity through pressure fastening while preserving fluid movement pathways in the recessed regions.

The electrode surface is segmented into multiple protrusion and recession regions, creating a distributed structure where different zones serve different functions. The protrusions provide structural support and contact points with the separator, while the recesses create channels for fluid flow, thereby resolving the conflict between structural integrity and fluid movement.

The patent applies the catalyst dispersion to a release film with a patterned structure before transferring it to the polymer electrolyte membrane. This preliminary patterning action creates a pre-formed patterned electrode layer that, when transferred, provides excellent interfacial contact with the membrane. The patterned structure on the release film ensures proper catalyst distribution and adhesion before the final transfer, reducing interfacial resistance while maintaining manufacturing simplicity.

The release film serves as an intermediary carrier that facilitates the transfer of the catalyst dispersion to the polymer electrolyte membrane. The patterned release film allows the catalyst layer to be formed with proper structure and adhesion properties before transfer, ensuring low interfacial resistance. This intermediary approach simplifies the overall process by enabling batch preparation and transfer of multiple electrodes while maintaining high interface quality.

Instead of dividing the cathode into separate sub-electrodes in the planar direction, the patent creates a patterned continuous electrode structure with three-dimensional protrusions and recesses. This vertical dimensionality provides oxygen transport pathways through the patterned structure while maintaining continuous catalytic activity across the entire electrode area, avoiding the active area loss associated with spaced sub-electrodes.

The patterned electrode structure creates a porous-like architecture with interconnected protrusions and recesses that facilitate oxygen transport throughout the electrode. This patterned porosity provides efficient gas diffusion pathways while maintaining continuous catalytic sites, achieving low oxygen transport resistance without the need for spaced sub-electrodes that would reduce active area.