ElectroChem proposes a Phase II program to advance its very successful SBIR Phase I PEM fuel cell (PEMFC) program. In Phase I, the unique integrated-flow-field design (IFF) has been shown to provide highly superior passive water management that results in a H2/O2 PEMFC that is gravity independent, achieves higher voltage efficiencies than conventional PEMFC designs, can be operated safely at high pressure (with resulting higher efficiencies), will enable passive operation, and requires extremely low excess O2 to maintain stable operation. The Phase II Program will bring ElecroChem's IFF PEMFC concept to the threshold of commercialization. In Phase II, scale-up and IFF optimization will be carried out. For complete passive operation, stack systems will incorporate an ejector to produce the low reactant flows and for product water removal. High performance membrane electrode assemblies (MEAs) will be developed. These Ph II efforts will produce a 250W IFF stack deliverable that will be integrated directly into NASA's Exploration Energy Storage Plan. The use of the IFF innovation will significantly simplify PEMFC operation and will result in higher and safer performance. Specifically, for space applications, the higher voltage efficiencies produced and the lower excess O2 required by the IFF will result in significantly lower fuel cell power plant weight.