R&D for Fuel Cells: A Continuing Process

October 30, 2005 – Vol.10 No.32

R&D FOR FUEL CELLS: A CONTINUING PROCESS.

Though fuel cells are commercialized right now - with enough cash anyone can buy one - they are not quite ready for the mass market yet. Cost, durability and a readily available fuel supply are still problems.

Companies and laboratories far and wide are still trying to iron out bugs and improve the technology.

One of the many expensive materials that is used in fuel cells is the fluorocarbon membrane, a cousin of nonstick Teflon (R) material and Gore-tex (R) fabrics from DuPont that were developed in the 1960’s. The membrane material is known commercially as Nafion (R) is not unlike stiff cellophane wrap.

In a proton exchange membrane (PEM) fuel cell, or instance, the membrane supports the chemical reaction that generates electricity as well as separates fuel on one side and air on the other.

PolyFuel of Mountainview, California thinks that its hydrocarbon membrane material would be much cheaper than Nafion (R) and has been testing it for durability in a direct methanol fuel cell. (DMFC).

The company says that its membrane has been operating for more than 5000 hours without failure exceeding the industry benchmark of 2000-3000 hours of lifetime expected for energy systems needed for portable power products like laptops or cell phones.

Used as a source of power for small devices, PolyFuel says a DMFC fuel cell will outlive state-of-the-art lithium batteries now in use. Visit Polyfuel at http://www.polyfuel.com/ .

Solid Oxide Fuel Cells (SOFCs) may become the choice of fuel cell manufacturers building stationary distributed power generation products such as micro fuel cell combined heat and power systems for homes and small business. The high operating temperatures of SOFCs are a perfect fit where hot water or hot air can be put to work.

One company developing SOFC home/micro combined heat and power systems is Ceramic Fuel Cells Limited (CFCL) of Australia. SOFCs use ceramic electrolyte materials in their fuel cell structures.

ESL Electro- Science of King of Prussia, Pennsylvania has announced that its scandia stabilized zirconia (ScSz) material can more than double the power density achieved with conventional SOFC electrolyte material such as yttria stabilized zirconia.

The company is offering the new ScSz material in fired substrate and tape form. Visit ESL Electro-Science at http://www.electroscience.com/ , CFCL at http://www.cfcl.com.au/

INI Power Systems of Cary, North Carolina has been developing a proprietary Direct Methanol Laminar Flow Fuel Cell (R) (LFFC). The LFFC does not have a now-conventional membrane electrode assembly found in proton exchange membrane (PEM) fuel cells made by companies such as Ballard Power Systems. An LFFC may be much simpler.

With an LFFC each cell has a minimum of two flowing liquid electrolyte solutions that remain discrete even though they share the same micro-channel within each cell. The solutions electrochemically connect but don’t blend. The electrolytes flow over and around a cathode and anode to create an electric current. The electrolytes are recycled.

The LFFC uses ambient air through a gas diffusion electrode for internal gas exchange.

The company says the design is much like that of living organisms that utilize flowing liquids and air to create a fuel cell-like mobile power source adaptable to a wide range of environmental conditions. (Like humans.)

INI seems to be looking only at the 10 - 250 watt portable power market for now. Visit INI at http://www.inipower.com/

Nature may already be guiding the way for fuel cells of the future.

Researchers in England and Germany have determined that microbes such as Ralstonia eutropha soil bacteria produce hydrogen-processing enzymes that could someday replace metals such as platinum in fuel cells.

Apparently certain types of enzymes known as hydrogenases found in oxygen-depleted mud help the Ralstonia eutropha microbes split hydrogen molecules and grab their electrons in the process. Free electrons can mean a flowing current. Researchers used microbes to make a laboratory-only fuel cell that produced a small current.

Don’t get too excited however. Researchers don’t think the microbes will ever find their way into commercial fuel cells, but instead research of them will help scientists find other electrode materials that could be used instead of pricey platinum.