Economic Hydrophilic Carbon Paper Sheet (T 0.2mm * L 100mm * W 100mm) for Electrolyzer and Fuel Cell, CEFCEHPICPS

Hydrophilic carbon paper acts as a dual-function Gas Diffusion Layer (GDL) and Porous Transport Layer (PTL) in electrolyzers—most notably on the cathode side of Proton Exchange Membrane (PEM) water electrolyzers, Anion Exchange Membrane (AEM) water electrolyzers, and CO2 reduction cells. Unlike fuel cells, which require hydrophobic carbon paper (PTFE-treated) to repel liquid water and purge gas channels, electrolyzers present the opposite transport challenge: they must rapidly pull liquid water in to reach the catalyst layer while releasing generated gases (H2, O2) out without bubble accumulation.

Untreated raw carbon paper is moderately hydrophobic due to residual carbonaceous binders (e.g., phenolic resin). Surface modifications that induce strong hydrophilicity (water contact angle < 30 degrees, often approaching 0 degree) yield key performance advantages: (1) Capillary-Driven Water Feeding: Hydrophilic pores draw liquid water directly toward the catalyst coated membrane (CCM) interface via strong capillary action. This prevents local "dry-out" at high operating current densities (> 2 - 3 A/cm2). (2) Enhanced Bubble Detachment (Gas Evacuation): A hydrophilic solid surface is inherently aerophobic (gas-repelling) under water. Gas bubbles (H2) detach at significantly smaller critical diameters, reducing pore blockages, mass-transport overpotential, and voltage fluctuations. (3) Lower Contact Resistance (Rcontact): Superior liquid wetting ensures intimate ionic and physical contact across the interface between the microporous carbon network and the ionomer/catalyst layer.