Patent ID: 7662504

Claim:
A direct oxidation fuel cell comprising one or more electricity generators, each electricity generator having a membrane-electrode assembly and an anode member and a cathode member in close contact with respective sides of the membrane-electrode assembly, the membrane-electrode assembly being between the anode member and the cathode member to generate electrical energy and water by a reaction of a fuel and oxygen, wherein the cathode member comprises a plurality of air vents through which air flows and is exposed to the atmosphere, and wherein each of the air vents comprises: a first portion extending in a direction for a length from an area of the cathode member contacting the membrane-electrode assembly, the first portion having a substantially constant diameter along the length, and a second portion extending from an end of the first portion distal to the membrane-electrode assembly and having a diameter gradually increasing in the direction toward an area of the cathode member exposed to the atmosphere.