Of all the flashy new devices devoted to furthering the sustainable-energy effort that will doubtless hit the market this year, only a handful are likely to signal significant technological advances. One of these in particular is truly revolutionary: a hydrogen fuel cell made for commercial use that was devised in a lab here at Caltech. This particular fuel cell is the Solid Acid Fuel Cell (SAFC), the brainchild of Caltech chemical engineering and materials science professor Sossina Haile.

The new technology is being marketed by Superprotonic, a Pasadena-based company founded in November 2003 by two former Caltech graduate students, Calum Chisholm and Dane Boysen. Prior to their business venture, Chisholm and Boysen worked in Sossina Haile’s lab, where they worked toward improving the SAFC. They founded Superprotonic with hopes of bringing this technology to the marketplace.

Now, four years after its founding, the dreams of Superprotonic are nearing realization. With the aid of $16.2 million from investors in April 2007, they were able to perfect a commercial SAFC. The first prototype will soon be sent to energy systems makers, an intermediate step on the way to the marketplace. Though currently only powerful enough to light a 100-watt bulb, these fuel cells will hopefully give way to improved, more robust models. And according to Haile, there are currently no other fuel cells on the market, “none that you can actually go out and buy.”

Haile serves as a Science Advisor for Superprotonic and is not involved much in the company’s business dealings. She still performs fundamental research in her lab, but most of the development of the fuel cells is done at Superprotonic. “As long as I know it’s proceeding forward, that’s good enough for me,” says Haile.

Fuel cells, Haile explained, are merely “part of an energy solution.” They are not primary sources of power but a means of using energy efficiently. Essentially, energy can be stored as electricity in a battery or as chemical fuel. Chemical fuel can then perform mechanical work by means of a combustion engine or electrical work by means of a fuel cell. Fuel cells are “greener” than combustion engines because they are more efficient and do not emit acid rain contributors such as sulfur and nitrous oxides.

SAFCs have several advantages over other fuel cells. The “solid acids” are crystalline compounds with protons integrated in their structure. These protons are mobile, resulting in remarkably high conductivity. Because the protons can move about without being attached to water molecules, problems such as dissolution of catalysis particles are easily avoided. In addition, SAFCs operate at mid-range temperatures, making them flexible in their usages.

Progressing from having an idea to actually producing a commercially viable product was a tedious journey for Haile. Her idea of using a solid acid for a fuel cell’s electrolyte was not given a warm welcome among fuel cell manufacturers in the late 1990s. Her electrolyte of choice was “so different from every other type of electrolyte that…no one wanted to work with us.” So Haile decided to fabricate these SAFCs herself. “It’s actually a nontrivial thing to go from having the material to making a device out of it,” she says. “But we muddled our way through, and now we’re actually pretty good at it.”

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