Researchers have developed a conductor material that could
lead to all-solid-state batteries with the highest energy density achieved to
date. Current batteries employ organic liquid electrolytes that are prone to
leakage, flammability, and limited energy density, issues which could be
eliminated with all-solid-state batteries.
The researchers developed a complex lithium superionic
conductor that showed high stability against a lithium metal anode and a high
conductivity of 6.7 mS/cm. The material enables all-solid-state lithium-sulfur
batteries with an energy density in excess of 2500 Wh/kg.
“Complex hydrides have received a lot of attention in
addressing the problems associated with the lithium metal anode because of
their outstanding chemical and electrochemical stability against the lithium
metal anode. But because of their low ionic conductivity, using complex
hydrides with the lithium metal anode have never been attempted in practical
batteries. So we were very motivated to see if developing complex hydride that
exhibit lithium superionic conductivity at room temperature can enable the use
of lithium metal anode. And it worked,” said lead researcher Sangryun Kim.
The researchers were based at Tohoku University and the High Energy Accelerator Research Organization. They published their results in Nature: A complex hydride lithium superionic conductor for high−energy−density all−solid−state lithium metal batteries.