M E E T I N G   R E P O R T

Small Fuel Cells 2004
Arlington, Virginia, USA
May 6-7, 2004

David Edlund
IdaTech, LLC
Bend, OR

This annual conference (in its sixth year) is organized and hosted by the Knowledge Foundation. This year the two-day main conference focused on small fuel cells for portable power applications while the one-day pre-conference seminar covered combinatorial methods and research for discovering new catalysts for fuel cell applications. The conference was held at the Doubletree Hotel Crystal City in Arlington, Virginia, conveniently located near Reagan National Airport and the Pentagon City metro station. Serge Pan, conference organizer, expects to keep this location for next year’s meeting.

Application of Combinatorial and High-Throughput Methods for Fuel Cell Development

The pre-conference seminar comprised eight papers from industry and academia describing approaches and results of catalyst discovery work using combinatorial methods. If you are not familiar with this field of study, think of it as a very sophisticated trial-and-error approach using tiny, sometimes minute, samples. Once initial samples that exhibit interesting catalytic properties are discovered, then the work begins of analyzing the material to determine exactly what the composition of interest is. This is easier said than done: it involves chemical as well as physical characterization since structure may be the unique attribute that gives rise to catalytic activity.

Eugene Smotkin (NuVant Systems and faculty positions at both Illinois Institute of Technology and University of Puerto Rico at Rio Piedras) explained the importance of sample preparation in the discovery of electrocatalysts, focusing on Pt-Ru compositions. Indeed, the catalytic activity of the sample may be strongly dependent on sample preparation methods. Smotkin also illustrated with several examples that one cannot simply assume a uniform alloy is derived from mixing metal precursors and then processing them to give the electrocatalyst. Phase separation does occur and often the final catalyst is a complex mixture of different alloy phases, including the pure metal starting materials.

Jay Witacre (Jet Propulsion Laboratory) described sputtering methods to achieve a compositional gradient of two or more different materials, and Levi Thompson (University of Michigan) described high-temperature synthetic routes to make metal carbides and nitrides. But one of the more unique approaches was presented by Paolina Atanassova (Cabot Superior MicroPowders) using a spray-pyrolysis technique. This is a simple process in which solutions containing metal salts and suspended metal-oxide or carbon powder (support) are sprayed into a heated reactor. The temperature, atmosphere, and residence time are varied to achieve different chemical reactions, resulting in a wide range of potential products. This technique is perhaps unique in that the process readily scales from a hundred milligrams to a thousand kilograms.

Once samples are prepared by any method, they must be screened for activity. Again, we heard reports on many different approaches. Symyx is perhaps the most advanced in this regard with their high-throughput screening technology and extensive library of compounds and activity. Peter Strasser described how Symyx conducts a first-phase screening by preparing literally hundreds or thousands of new materials by gradient-based physical vapor depositions. These samples are prepared as an array (8 by 8) on a wafer, each sample is connected to electrical leads and then activity for the relevant half reaction can be measured to give an indication of relative performance. The best samples are then advanced to the second phase wherein the material is synthesized by conventional techniques at a larger scale and again tested. This is often an iterative step as the fabrication method may not yield material with activity shown by the original sample (see above comments).

Eduardo Wolf (University of Notre Dame) described a clever and fast approach to identify relative activity of water-gas-shift (WGS) catalysts. Since the WGS reaction is exothermic, Wolf’s group places small samples of new materials on a wafer and then subjects them to a mixture of CO and water vapor. Using thermography, relative reactivity is displayed as hot spots, the more reactive materials presumably being hotter than those with less activity. Amit Nayar (Illinois Institute of Technology) uses a laser to heat specific samples on a wafer and then looks for reaction products by mass spectroscopy. In this way he can place many small catalyst samples in a common “reactor” at one time.

Small Fuel Cells for Portable Power Applications

The two-day main conference focused on small fuel cells for portable power applications and was attended by an estimated 160 persons from at least eight countries in Europe, Asia, and North America. Twenty-three oral presentations were given; there was also a poster session, company/organization exhibitions, and a panel session.

The technical papers were split between DMFC and PEMFC (using hydrogen). There were also a few papers discussing methods for making hydrogen to use in these PEMFCs (IdaTech, Motorola, Millennium Cell, and Mesofuel). Overall, there was a high degree of anticipation for new products to be coming soon, and Walter Nasdeo (Ardour Capital Partners, LLC) pointed out that there is growing optimism in the financial communities concerning energy-technology companies. Nasdeo said that funding (both private and public) is available to companies with products being sold at a positive margin.

Perhaps the best example of product commercialization in this space was reported by Manfred Stefener (SFC Smart Fuel Cell AG). Stefener reported that Smart Fuel Cell has sold “several hundred” fuel cell products to industrial and private customers. He also reported that on July 1 Smart Fuel Cell will launch the model 850 which is a 50W version of their current model 825 (25W DMFC). Methanol crossover and concentration management are “solved problems,” he said, and pure methanol is purchased by the customer in a range of canisters sized from 2.5 liters to 10 liters. Smart Fuel Cell is targeting remote monitoring (security) applications, portable highway traffic signs, and recreational (boat, RV, remote cabin) markets.

Jerry Hallmark (Motorola) presented their development work targeting a small (about 10W) reformed hydrogen fuel cell system. The Motorola approach is to use a micro-reformer, made from inexpensive ceramic tapes, coupled to a high-temperature PEMFC (acid-doped PBI). The primary fuel to be reformed is methanol mixed with water. Millennium Cell showed results from their small sodium borohydride reactors and plans to offer this as a small cartridge for consumer devices. IdaTech discussed a different approach to fuel reforming that is more versatile and yet still produces >99.95% pure hydrogen from any fuel. A new compact planar reactor incorporating patented hydrogen purification was shown (this targeting the 50W to 1kW space). A 200W prototype weighs in at about 0.5kg and exhibits cold startup times of a few minutes.

Paul Osenar (Protonex) showed a family of compact and lightweight PEMFC stacks sized from about 20W up to about 250W. Protonex has focused on part-count reduction and adaptation of high-volume manufacturing methods to PEMFC stack design and construction. Their goal is to drive cost reduction while maintaining acceptable performance over the range of 10W to 1kW.

At fuel cell conferences it is somewhat unusual to hear about the balance-of-plant (BoP) components. Fortunately, the organizers invited a paper from Mesoscopic Devices, one of the leading developers of small BoP components. Christine Martin described some of the work directed at reducing size, mass, and power consumption of BoP pumps (liquid and air). She also showed an example of total system integration that Mesoscopic Devices completed for a DMFC system. Air delivery is typically a large consumer of power, and these devices are often heavy. Martin showed an example where Mesoscopic Devices developed a small air blower that will deliver 2 liters/minute of air at 0.3 psi: it draws 0.6W, produces 45dB, and weighs 22 grams. In comparison, another supplier offering a blower with similar output specs has inferior performance specifications (1.5W, 48dB, and weighs 56 grams).

Shimshon Gottesfeld (MTI Microfuel Cells) presented an update on activities at MTI surrounding DMFC system development. It was clear that MTI has focused much effort on simplifying the over system and BoP, apparently successfully although details could not be revealed for reasons related to pending patent applications. Like Smart Fuel Cell, MTI also has learned to design a DMFC system so that the user may supply 100% neat methanol, rather than a dilute methanol-water mixture. Water is recovered from the fuel cell and mixed in the proper ratio with the neat methanol. This is done automatically and is transparent to the user. Gottesfeld reported that the first commercial product from MTI will be a “device-integrated DMFC/battery power system for Intermec’s RFID tag reader.”

Several interesting papers were presented by various groups regarding truly micro fuel cells including Art Homa (Neah Power Systems), Levi Thompson (University of Michigan), Didier Marsacq (National Atomic Agency of France), Christopher Hebling (Fraunhofer Institute for Solar Energy Systems), and Kevin Stanley (National Research Council of Canada – Institute for Fuel Cell Innovation). These devices are made on silicon wafers using microelectronics manufacturing methods. Power levels are <1W and scale-up is unclear. In general, these micro-fuel cells seem to be intended to replace batteries in portable electronics. This work is still developmental, and commercial products in the near term are not expected.

Overall, this was a very informative fuel cell conference, and it covered a wide range of topics (especially if the pre-conference seminar is considered). Those interested in more information, perhaps even purchasing the conference proceedings, should contact the Knowledge Foundation at (617) 232-7400 or www.knowledge press.com.