DIRECT METHANOL FUEL CELL

摘要

PROBLEM TO BE SOLVED: To provide a direct methanol fuel cell having a high output and high utilization rate of the fuel by controlling a crossover of methanol at the first half of a fuel flow path and a short supply of the methanol at the latter half of the fuel flow path so as to optimize a fuel supply to a fuel electrode. SOLUTION: In a direct methanol fuel cell 10 having a membrane electrode joint body 18, wherein a fuel electrode 14 and an air electrode 16 is bonded on the both sides of a solid polymer electrolytic membrane 12, a methanol permeability coefficient of a diffusion layer 14b of the fuel electrode 14 side increases as it goes to the downstream side of fuel. Specifically, when the diffusion layer of the fuel electrode is formed by applying a compound of carbon black and polytetrafluoroethylene to the surface of a base material comprising a carbon paper, the weight ratio of the polytetrafluoroethylene in the compound and/or the applying amount of the compound are changed in accordance with the flow of the fuel.