The authors describe here results of recent efforts at Los Alamos National Laboratory (LANL), devoted to potential application of Direct Methanol Fuel Cells (DMFCs) as (1) portable power sources at the 50 W level, and (2) primary power sources for electric vehicles. In general, DMFC R and D efforts focus on further improvements in anode catalytic activity, fuel utilization (as related to methanol crossover) and air cathode performance in the presence of the presence of the significant flux of aqueous methanol from anode to cathode. There are significant differences between technical parameters and targets for the two different DMFC applications, which the authors have addressed. They include the lower cell temperature (about 60 C) preferred in portable power vs. operation around 100 C as target temperature for transportation applications, and the much stronger concern for cost of catalyst and any other stack materials in DMFCs developed for potential transportation applications. Most, if not all, recent DMFC work for either portable power or potential transportation applications has strongly focused on cells with polymeric (primarily PFSA) membrane electrolytes. In work at LANL, thin film catalysts bonded to the membrane, e.g., by the decal method, provided best results in terms of catalyst utilization and overall cell performance. In most tests, the single DMFC hardware consisted of uncatalyzed carbon-cloth gas-diffusion backings and graphite blocks with machined serpentine flow channels--quite similar to hardware employed in work with hydrogen/air PEFCs. However, the machined graphite hardware has recently been replaced by alternative, non-machined flow-field/bipolar plates, which enables effective air and aqueous methanol solution distribution along an active area of 50 cm{sup 2}, at a pitch per cell of 2 mm
