Carbon sheet as well as gas diffusion electrode substrate, membrane electrode assembly, and fuel cell using same

Abstract

This carbon sheet includes at least a carbon fiber structure formed from carbon fibers, a binding agent, and graphite particles, wherein in a pore diameter distribution of the carbon sheet, the ratio of the volume of a second peak present in a region having a pore diameter of 0.5 μm to 3 μm to the volume of a first peak present in a region having a pore diameter of 20 μm to 100 μm is 0.06 to 0.50. A carbon sheet which suppresses dry-up and achieves both conductivity and retention of moisture is provided in order to exhibit high power generation performance in a solid polymer fuel cell.

Dependencies are inferred from the claim text.