Direct growth of carbon nanotubes forests on carbon fibers to replace microporous layers in proton exchange membrane fuel cells

A novel microporous layer structure for fuel cell application has been developed based on the direct growth of thin multiwall carbon nanotubes forests fiber support a commercial gas diffusion media free hydrophobic treatment. The process is hot filaments assisted chemical vapor deposition coupled with specific catalyst dedicated to support. so obtained nanotube are perpendicularly aligned all along fibers and cover surface media, providing unique new layer. composing about 10 ?m–20 ?m long, 6 walls an average diameter 7.5–8 nm. Fuel testing demonstrated performance improvement up 30% compared best state art even in presence liquid water cell, which main issue limiting performances.