In a fuel cell for a fuel cell power plant having a PEM (9), a cathode
comprising at least a catalyst (10) and a support substrate (17),
possibly with a diffusion layer (16), on one side of the PEM, and an
anode comprising at least an anode support substrate (14) and an anode
catalyst (11) on the opposite side of the PEM, and a porous water
transport plate having reactant gas flow field channels (31, 32) (21, 28)
adjacent to each of said support substrates as well as water flow
channels (22) in at least one of said water transport plates, the thermal
conductance of the cathode is less than about one-half of the thermal
conductance of the anode, and preferably less than one-quarter of the
thermal conductance of the anode, to promote flow of water from the
cathode to the anode and to the adjacent water transport plate, obviating
the need, in some cases, for water or reactant pressure pumps.