(498a) Reformed Methanol Micro Fuel Cell Systems for Portable Power Applications

Fuel cells have gained renewed interest for applications in portable power since the energy is stored as fuel rather than as an integral part of the power source, as is the case with batteries. While miniaturized fuel cells have been demonstrated for the low power regime (1-20 Watts), numerous issues still must be resolved prior to deployment for applications as a replacement for batteries. As traditional fuel cell designs are scaled down in both power output and physical footprint, several issues impact the operation, efficiency, and overall performance of the fuel cell system. These issues include fuel storage, delivery, and distribution, system control, balance of plant, peak power requirements, packaging, and thermal management. A reformed methanol fuel cell system will be described. The fuel cell exploits MEMS technologies for stack, fuel processor, and balance of plant components. MEMS and microfluidic techniques offer inherent advantages resulting from the large surface-to-volume ratios and high level of integration possible. The combination of microfabrication, thin-film deposition, and micromachining approaches offers potential advantages with respect to fuel cell stack size and weight, flow field structure and manifolding, fuel storage and delivery, packaging, and thermal management. Furthermore, these technologies enable material and fuel flexibility,while providing a manufacturable, modular fuel cell approach. These approaches will be discussed, along with experimental results from proton exchange membrane thin-film fuel cells and catalytic fuel processor.