PARIS — Researchers from the French National Center for Scientific Research (CNRS) and the CEA-Liten, the Laboratory for Innovation in New Energy Technologies and Nanomaterials, said they can explain why lithium iron phosphate, to be used in future lithium batteries, conducts electricity despite being an insulating material. Their conclusions bring fresh perspectives in the search for improved battery electrode materials and a better understanding of how future hybrid and electric car batteries will work.

Lithium iron phosphate is the best candidate to be used in lithium batteries for future electric and hybrid cars. Environmentally friendly, this material combines low cost and good thermal stability. However, it does not present the ionic and electrical conduction properties to make the electrode work.

CNRS chemists from the Institute of Condensed Matter Chemistry of Bordeaux claimed they have solved this paradox.

As they were studying the lithium iron phosphate, in collaboration with a team from CEA-Liten, researchers said they observed that the battery's charge-discharge cycles were made possible via a "domino cascade process".

This phenomenon, they continued, occurs as soon as stresses are present at the interface between the discharging material and the material in the discharged state. Electrical and ionic conduction is then "extremely rapid" in the interfacial zone, propagating from one spot to the next like dominos as the interface moves, researchers concluded.