Carbon fiber nonwoven fabric and gas diffusion electrode of polymer electrolyte fuel cell using the same, polymer electrolyte fuel cell, method for producing carbon fiber nonwoven fabric and composite sheet

摘要

Provided is a carbon fiber nonwoven fabric that has low resistance when passing gas or liquid and has low resistance in the thickness direction of heat and electricity, and particularly suitable for a gas diffusion electrode of a polymer electrolyte fuel cell. A carbon fiber nonwoven fabric having a gap of 20 μm or more in diameter, wherein at least some of the carbon fibers are continuous from one surface to the other surface, and an apparent density is 0.2 to 1.0 g / cm 3, or It has voids with a diameter of 20 μm or more, at least some of the carbon fibers are entangled with each other, and at least some of the carbon fibers are oriented in the thickness direction, and the apparent density is 0.2 to 1.0 g / cm 3. Of carbon fiber nonwoven fabric.