Patent ID: 8043767

Claim:
An electrochemical fuel cell comprising: a membrane-electrode assembly (MEA) having a cathode face and an anode face, the MEA being between a cathode fluid flow field plate and an anode fluid flow field plate, the cathode fluid flow field plate having fluid distribution conduits in a first surface thereof facing the cathode face, the anode fluid flow field plate having fluid distribution conduits in a first surface thereof facing the anode face; and a diffusion structure between the MEA and a corresponding fluid flow field plate, the corresponding fluid flow field plate being the cathode fluid flow field plate or the anode fluid flow field plate, the diffusion structure having a first face in contact with the MEA and a second face in contact with the-corresponding fluid flow field plate, the diffusion structure comprising a hydrophilic layer, a structural layer, and a resistance layer, the hydrophilic layer being adjacent to the corresponding fluid flow field plate, the structural layer being adjacent to the hydrophilic layer, and the resistance layer being adjacent to the structural layer, the hydrophilic layer having a higher permeability than the structural layer, the structural layer being a support layer having a stiffness that is greater than a stiffness of the hydrophilic layer, and the resistance layer having a lower permeability than the structural layer, a lower pore volume than the structural layer, and a greater resistance to liquid water dispersal than the structural layer.