Patent ID: 8034507

Claim:
A direct-methanol fuel cell comprising: an anode into which an aqueous methanol solution is introduced as fuel; a cathode into which an oxidizing gas is introduced; an electrolyte membrane interposed between the anode and the cathode; an anode separator which is disposed on the anode side and comprises a fuel passage formed on a surface facing the anode; and a cathode separator which is disposed in the cathode side and comprises an oxidizing gas passage formed on a surface facing the cathode, wherein at least the cathode separator is provided with a coating film including a block copolymer which is represented by the following formula (I) and having a water-repellent functional group and an ionic functional group, the coating film being formed on at least an inside surface of the oxidizing gas passage where R 1 represents an aliphatic fluorocarbon having 2 to 6 carbon atoms or an organic silicon compound having a silanol skeleton, R 2 represents N,N,N′,N′-bis(pentamethylene)uronium hexafluorophosphate represented by the following structural formula (A) or N,N,N′,N′-bis(tetramethylene)uronium hexafluorophosphate represented by the following structural formula (B), and m and n represent degrees of polymerization of the first and second monomers (1 and 2) and are in the range of 5 to 220 and 30 to 260, respectively: