Caterpillar Spinoff Uses Foam for EV Batteries

Highly porous carbon foam structures bonded with polymers such as polypropylene replace lead plates in typical vehicle batteries in a novel materials’ solution to problems with battery life and weight. The innovation comes from a company called Firefly Energy, using technology developed in the R&D Labs at Caterpillar, which was looking for a better battery for its vehicles. In the invention, carbon-graphite foam “grids” are loaded with lead oxides. The foam  structure, creates huge surface-area advantages over conventional lead acid grid structures. Active material utilization levels go from the historical 20-50 percent up into the range of 70-90 percent as well as enhanced fast-recharge capability and greater high-rate / low-temperature discharge times, according to Firefly.  Costs to produce energy will be higher than conventional lead acid batteries, but below other new technologies, such as lithium batteries.  Firefly hopes the approach will be competitive for electric vehicles under development. North Star Battery will produce prototypes for possible use by the US Army.