The Small Fuel Cell Conference
New Orleans, Louisiana


by Dennis Sieminski
Portable Energy Think Tank
Smyrna, GA

The Small Fuel Cell Conference sponsored by The Knowledge Foundation (www.knowledgefoundation.com, Brookline, MA, phone: 617-232-7400) was held in New Orleans on May 7-9. This conference has been an annual event since 1999. The attendees are representatives of companies, universities and government agencies from a number of countries whose focus is commercializing small fuel cells for portable electronic devices. This year’s attendance was about 200. A worthwhile opportunity in the exhibit area is to see, first hand, several operational prototype small fuel cells. This synopsis of the conference is arranged into five sections: the Nanomaterial Workshop, discussions on the small fuel cell market, companies commercializing fuel cell products, R&D at universities, and government agency work.

Nanomaterial Workshop

A pre-conference workshop occupied the first half-day of the conference and four presentations dealt with the subject of carbon nanostucture materials. Carbon nanomaterials are a class of polymers of pure carbon in new spatial configurations. The configuration that occupied much of the workshop was the Single Wall Nanotube (SWNT). This material can be produced as an extremely high aspect ratio tube (e.g., diameter of ~1nm, length of 1k to 10k nm) where the wall thickness can be one carbon atom with the surface of the tube a tile structure of hexagonal ring carbon molecules.

Carbon nanomaterials are an exciting development in material science because the properties they offer are extraordinary – strength 100x steel, conductivity similar to copper, surface area >2000m2/g, and thermal stability 500EC in air, 1400EC anaerobic. Applications for carbon nanomaterials include conductive inks and adhesives, high performance composites, flat panel displays and fuel cells.

Within the fuel cell category, there are multiple applications for carbon nanomaterials – anode and cathode structures with high conductivity and very finely dispersed Pt; high weight percent (4-6%) hydrogen storage medium; bipolar plates that are light, tough, highly conductive, easy to fabricate; and corrosion-resistant interconnects. The presentations dealt primarily with SWNTs as a catalyst support structure for fuel cell anodes and cathodes.

Carbon Nanotechnolgies Inc. of Houston, Texas, has a depth of intellectual property in the area of dispersion of catalysts in nanomaterials. David Karohl, director of business development, offered some very encouraging test results on PEM fuel cell anodes made with C nanomaterial that suggested excellent performance could be achieved with Pt loading levels about 1/100th of current anode materials. More work needs to be done to validate these initial results, and more compelling testing of the material in cathodes is planned.

Dr. Thomas Gennett, professor of chemistry, reviewed the Rochester Institute of Technology’s (RIT) capabilities for making SWNTs. A large variety are possible (e.g., diameter, length, level of impurities, chirality are some defining characteristics). Central to the successful development of nanomaterials is working through the maze of variables in the raw materials, processing methods and settings to arrive at material with the desired set of properties for the intended application. RIT is establishing methodologies for making and characterizing nanomaterials. One easy to communicate example of this is the SEM and TEM pictures, which reveal SWNT shapes and catalyst particle dispersion. RIT closes the development loop by working with commercial partners and government agencies that test the materials in different fuel cell applications. Here some performance gains for nanomaterials versus conventional materials are starting to be seen.

Dr. John Erkey, associate professor of chemistry at the University of Connecticut, is investigating carbon aerogels as a cathode material for PEMFC. These materials are mesoporous, with high surface area, good electrical conductivity and can be produced in a variety of shapes. Initial results with cathodes were promising: 0.5mg Pt/cm2 delivered 0.4V@1000mA/cm2.

Dr. John R. Regalbuto, associate professor of chemical engineering at the University of Illinois at Chicago, spoke on the fundamentals of Pt catalyst impregnation for carbon materials, introducing the revised physical adsorption (RPA) model which is an electrostatic mechanism and model where surface charge, point of zero charge (PZC) and proton balance are key factors in describing the absorbing anionic and cationic forms of Pt. Pt anions have high uptakes at low pH and Pt cation uptake is high at high pH. To control metal adsorption properties by altering the PZC of a substrate, they first tried ion doping of silica and alumina, but redissolution of the dopant foils this method. So, the next attempt will look at different oxidations of C surfaces.