Foundational Patent Awarded to Caterpillar Spin-out

January 18, 2006

Firefly Energy has received a U.S. patent for a new lead acid battery technology that it believes has the potential to revolutionize the existing $16 billion worldwide lead acid battery market as well as serve applications like hybrid electric vehicles which historically aren’t suitable for lead acid batteries.

The Peoria, IL-based company, which was formed to create the next generation of lead acid battery technology based on a material sciences innovation discovered by Caterpillar Inc., said the U.S. Patent and Trademark Office has issued patent number 6,979,513, titled, “Battery Including Carbon Foam Current Collectors.” The patent was awarded on December 27, 2005.

The invention is a battery comprised of an electrical current collector constructed of carbon or lightweight graphite foam. This foam exhibits a sizeable increase in surface area for chemical reactions to take place and eliminates the need for heavy lead plates found in traditional batteries. The graphite material resists corrosion and sulfation build-up, thus contributing to longer battery life and is lighter in weight than today’s lead acid batteries.

Firefly Chief Scientist Kurtis C. Kelley developed the technology while serving as senior research scientist in the advanced materials division of Caterpillar’s R&D center.

“Since Kurt, an accomplished material scientist, had never designed a battery before, his problem-solving approach was unconstrained by the conventional battery wisdom held by lead acid battery technologists,” says Edward F. Williams, CEO and a co-founder of Firefly Energy.

Performance improvements in lead acid batteries are realized through better utilization of surface area, he adds. The overwhelming restriction to lead acid battery efficiency to this point has been the lack of interface area between the active chemistry and the electrodes. Today, the chemistry is capable of delivering approximately 170 Watt hours per kilogram (Whr/kg), yet lead acid batteries only average around 30 Whr/kg. Up to now, achieving a higher surface area within a given lead-acid battery box required the addition of more and thinner lead electrodes. However, lead electrodes corrode, so increasing surface area by putting thinner lead electrodes in the battery increases corrosion and decreases battery life.

“By removing the corrosive heavy lead grids and replacing them with a graphite foam, Kurt Kelley’s invention has helped unleash the innate power of lead acid chemistry,” adds Williams. “It introduces a material that doesn’t corrode and enables the weights and sizes of lead acid batteries to be reduced significantly.”

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Firefly Energy Inc.