Patent ID: 6423437
Filing Date: 2002-07-23
Classification: H01M,Y02E

Abstract:
A polymer electrolyte fuel cell comprising:(a) a plurality of fuel cell units defining an outer periphery and arranged along a common central axis in a stack, the fuel cell units including a polymer electrolyte membrane, wherein the stacked fuel cell units have an inner periphery defining a fuel flow channel through which fuel can flow in an axial direction; (b) an electrically conductive current collector electrically connected to a fuel cell unit at one end of the stack of fuel cell units and an electrically conductive current collector electrically connected to a fuel cell unit at another end of the stack of fuel cell units; (c) a fuel supply inlet at one end of the stack to direct fuel therethrough to the fuel flow channel; and (d) at least one diffusion cell unit mounted at the end of the stack of fuel cell units opposite to that at which the fuel inlet is located and at a position below the current collector at that end of the stack, the diffusion cell unit comprising at least a layer of diffuser material, the diffusion cell unit having an outer periphery and an inner periphery that defines a continuation of the fuel flow channel, the diffuser material formed to diffuse water vapor from the fuel flow channel outwardly therethrough from the inner periphery to the outer periphery of the diffusion cell unit, the fuel flow channel being closed at an end thereof adjacent to the diffusion cell unit.