One of the main knocks on battery-electric and hybrid cars is that the chemicals, heavy metals and production processes that go into making their lithium-ion batteries aren’t much better, environmentally speaking, than the pollution footprint of their hydrocarbon-spewing internal combustion brethren. To help change that, Honda, along with researchers at the California Institute of Technology and NASA’s Jet Propulsion Laboratory, is developing a new battery chemistry using fluoride instead of lithium.
The team authored a paper on the topic, now published online in the journal Science.
“Fluoride-ion batteries offer a promising new battery chemistry with up to 10 times more energy density than currently available lithium batteries,” said Dr. Christopher Brooks, chief scientist, Honda Research Institute, and a co-author of the paper. “Unlike Li-ion batteries, FIBs do not pose a safety risk due to overheating, and obtaining the source materials for FIBs creates considerably less environmental impact than the extraction process for lithium and cobalt.”
Lithium-ion and metal hydride batteries are limited by the properties of their electrodes. Fluorine, according to the study, could offer up to 10 times greater energy densities. Currently, fluoride batteries need to operate at temps above 150 degrees Celsius, about 300 F, but the team has figured out a way to create a fluoride-ion electrochemical cell capable of operating at room temperature. They did this creating a stable liquid fluoride electrolyte with a wide operating voltage.
“The scientists developed the electrolyte using dry tetraalkylammonium fluoride salts dissolved in an organic, fluorinated ether solvent. When paired with a composite cathode featuring a core-shell nanostructure of copper, lanthanum and fluorine, the researchers demonstrated reversible electrochemical cycling at room temperature.”
See? Simple. Better chemicals equal cleaner, longer-lasting batteries.
Honda says that these batteries could power electric vehicles in the future, as well as other power-hungry products.