Nissan Leafs currently use conventional lithium-ion batteries with liquid electrolytes. If new research comes to fruition, they may someday be powered by safer, more effective batteries with solid electrolytes. Image: cliff1066/Flickr/CC BY
There are serious safety concerns with the current lithium-ion batteries that are used in electric and hybrid vehicles. However, a research firm says that it has found a way to make a safer battery that can produce a longer driving range by utilizing a solid electrolyte instead of a liquid one.
Improving electrolytes for lithium-ion batteries
The Oak Ridge National Laboratory (ORNL) says it has developed first high-performance nanostructured solid electrolyte. That is, a denser version of the liquid electrolyte currently in most batteries for EVs and hybrid vehicles. Electrolytes are used to conduct ions between the cathode and the lithium anode.
Liquid electrolytes are flammable, posing safety risks. Its new solid electrolyte, says ORNL, will not only make for a safer battery, but it will also yield a greater energy density. That could extend the range of travel for motorists on a single full charge of the battery.
Chengdu Liang, the leader of the research, said, “To make a safer, lightweight battery, we need the design at the beginning to have safety in mind.”
Solid vs. liquid
Liquid electrolyte lithium-ion batteries do not use an anode of pure lithium, because of the increased combustion hazard. If they did, says ORNL, they would be five to 10 times more powerful than those currently being used in commercial vehicles, like the Nissan Leaf.
Come see the new Leaf at Everett, WA Magic Nissan.
The solid electrolyte is created by manipulating lithium thiophosphate at the nanoscale, making it more dense and allowing it to conduct ions at up to 1,000 times the rate of batteries that use the liquid form.
“Think about it in terms of a big crystal of quartz vs. very fine beach sand,” said Adam Rondinone, who co-authored the report. “You can have the same total volume of material, but it’s broken up into very small particles that are packed together. It’s made of the same atoms in roughly the same proportions, but at the nanoscale the structure is different. And now this solid material conducts lithium ions at a much greater rate than the original large crystal.”
May improve batteries for electronics as well
The innovation can not only be applied to alternative power automobile batteries. It also has the potential to make safer, longer-lasting batteries for a variety of uses, including consumer electronics.
ORNL published an account of its research, “Anomalous High Ionic Conductivity of Nanoporous ß-Li3PS4,” in the Journal of the American Chemical Society.