meeting report

Small Fuel Cells 10th Annual Conference

Atlanta, GA USA

April 30 - May 2, 2008

• by David Edlund
• Vice President, PEM & Reformer System Development
• Protonex Technology Corp.

David Edlund, vice president of PEM & Reform Systems Dev., Protonex Technology Corp., spoke at this year's conference.

The Knowledge Foundation sponsored the Small Fuel Cells 2008 Conference from May 1 through May 2 in Atlanta, Georgia. This was the 10th annual meeting and it was attended by about 190 persons representing governments, academia, and industry. A total of 24 oral papers were given by presenters from North America, Europe, and Asia. In keeping with past years, the conference was preceded on April 30 by a one-day seminar on fuel cell and battery hybrid technology.

The technical program for the conference covered the major aspects of small-scale fuel cell technology and applications. PEMFC, SOFC, and DMFC technology received the majority of attention. However, there was clearly an emphasis on commercial activities, and one paper in particular (given by Carl Kukkonen, Direct Methanol Fuel Cell Corp., a Viaspace company) addressed fuel cartridges and distribution.

Bill Eggers, president (middle) and John Stonewald (right) of Bio-Logic USA, LLC visit with Anja Bieberle-Hütter of ETH Zurich.

Terry Payne (U.S. Department of Energy) presented an overview of his agencies PEMFC programs. Motivated by the promise of better vehicle fuel efficiency, a significant reduction in emissions of carbon dioxide, and improvements in run time over conventional battery solutions, the U.S. Department of Energy remains very active in supporting fuel cell R&D as well as public awareness programs. However, while Dr. Payne conceded that the Department of Energy is primarily focused on fuel cells for automotive propulsion, this work has lead, indirectly, to developments that advance PEMFC systems for low-power applications: for instance, MEA development especially with respect to increased durability under adverse (as in dry) conditions.

Charles Wicker talks with visitors to MTI MicroFuel Cells Inc.'s booth.

Elizabeth Ferry (Research, Development & Engineering Command, U.S. Army) discussed how small fuel cell systems may be expected to mature from laboratory test articles to field-deployed hardware for the U.S. Army. Recognizing that technological maturity is still a challenge for small fuel cell systems, Ferry discussed many specific requirements that will have to be met by fuel cell systems in order to advance in degree of technical readiness prior to being fielded. In particular, reference was made to Mil-Std 810F requirements. Although military-specific, some of the 810F requirements dealing with safe operation are prudent for non-military applications as well; for instance, the maximum allowable external case temperature.

MyFC AB's Björn Westerholm (middle) and Anders Lundblad (right)

Developing work addressing the direct consumption of ethanol in a PEM-type fuel cell (DEFC) was presented by Dr. Carsten Cremers (Fraunhofer Institute for Chemical Technology). Although it is tempting to think that low-toxicity is a potential advantage of using ethanol as a fuel, Cremers pointed out that tax laws are such that denaturing agents are added to fuel-grade ethanol specifically for the purpose of rendering the fuel unsuitable for consumption. Understanding what these denaturing additives are, and how they interact with the electrocatalyst on the MEA, is subject of ongoing work. However, Cremers reported that a common commercial denaturing agent (denatonium benzoate, sold under the trade name Bitrex®) is completely unsuitable as it rapidly poisons the anode catalyst. The reported energy density for ethanol fuel is between that for methanol and sodium borohydride (methanol having the lowest gravimetric and volumetric energy density). In acidic solutions, platinum-tin anode catalysts were found to have higher catalytic activity than either platinum-ruthenium or pure platinum. Nevertheless, platinum loadings remain high at about 2mg/cm2 (anode) and 2-3mg/cm2 (cathode).

Will Lovell promotes Arbin Instruments.

Sony and Samsung presented back-to-back presentations on their respective small-scale DMFC programs. Sony's micro-DMFC system is reported to have a dry weight of about 50g and will delivery slightly more than 3W through hybridization with a lithium-ion battery. The fuel cell output is limited to just over 1W. Target applications include mobile phones, mobile game controllers, digital cameras, and Sony's Walkman. In contrast, Samsung is targeting PC applications and a correspondingly higher power output (12W). A large amount of durability test data was presented to emphasize stable performance (over a test period of 600 hours) and orientation independent operation.

Ron Zimm of AMREL American Reliance (middle).

With a focus on DMFC applications, Dr. Hanna Rajante (Johnson Matthey Fuel Cells) discussed the investigation of porous-carbon monoliths as a combined flow field and gas-diffusion layer. Expected advantages include increased volumetric density for a DMFC stack and improved manufacturability (the carbon monoliths are extruded through a die, with the flow fields formed by the enclosed channels of the monolith). A 2W demonstration device was made based on a simple "air-breathing" design.

A rather unusual PEMFC architecture for portable consumer electronics was presented by Allison Fischer (Motorola Labs). Dr. Fischer described a PEMFC system occupying only 8 cm3 and consisting primarily of a battery (2 cm3), a super capacitor (1 cm3), a fuel cell (1 cm3), and fuel (hydrogen; 4 cm3). The fuel cell appears to be planar, but when viewed under magnification it consists of a close-packed array of short cylinders. The cylinder wall is the electrolyte (Nafion). The internal cylinder surface becomes the anode and the external cylinder surface becomes the cathode. Current collection is via a gold-foam matrix that fills all internal and external voids around the array of cylinders. Fabrication of this three-dimensional fuel cell has been difficult, but the first report of fuel cell performance is expected soon.

Stephen Barlow, CCO of CMR Fuel Cells (middle).

An interesting paper from Europe demonstrated that not all effort aimed at fuel cell systems for portable consumer electronics is limited to direct alcohol systems and PEMFC systems. Dr. Anja Bieberle-Hütter (ETH Zürich) presented details of her group's development of a reformed-butane SOFC system (the "ONEBAT" project). Because the fuel cell stack and reformer are very small in size, a small amount of insulation is reported to be very effective at managing thermal losses. The fuel cell is planar, incorporating an LSCF electrolyte layer, and is fabricated on a Foturan glass-ceramic substrate using conventional photolithography and deposition techniques.

There were a collection of papers addressing commercialization of small-scale fuel cell systems and components including hydrocarbon membranes (PolyFuel Inc.); surveillance systems (EnerFuel Inc.); rechargeable hydrogen storage (Ovonic Hydrogen Systems LLC); and fuel cartridges (Direct Methanol Fuel Cell Corp.). However, perhaps the best example of commercial fuel-cell success was presented in the paper by Dr. Jens Müller (SFC Smart Fuel Cells). SFC has sold more than 8,000 commercial DMFC systems (almost 4,500 in 2007 alone) and currently product sales account for 75% of total revenue. Surprisingly, Dr. Müller reports that SFC does not make any of the components used in its DMFC products. To underscore SFC's focus on commercial sales, Dr. Müller pointed out that the company maintains over 1,000 points of sale for systems and fuel in Europe, and that the EFOY product carries a commercial warranty of three years/3,000 hours of operation.

This 10th anniversary of the Small Fuel Cell conference provided a good forum to meet colleagues and to learn of recent development work in the field.