Stack and fuel cell system having the same

摘要

A fuel cell system includes a fuel supply unit for supplying fuel, an air supply unit for supplying air, and a stack for allowing hydrogen and oxygen supplied from the fuel supply unit and the air supply unit, respectively, to electrochemically react with each other and generating electrical energy. The stack has a membrane-electrode assembly and separators disposed at both sides of the membrane-electrode assembly. Each of the separators has a fuel passage and an air passage, and the total volume of the air passage is greater than the total volume of the fuel passage.