The problem with existing lithium ion batteries is that they are utilizing volatile organic solvents with a rather low combustion point. Under high load, all batteries can heat up – and lithium-ion batteries sometimes catch fire as a consequence of this specific solvent. A group of researchers from Italy and Germany now succeeded in replacing the organic solvents. Instead of the organic material they used inorganic salt that had been liquefied at room temperature. With this so-called ionic liquid, they could significantly improve the batteries’ resistance to fire.
Ionic liquids have been discussed for a long time as electrolyte components of low flammability. For batteries however the long-term usability of batteries that make use of such liquids has been proved only recently. The lithium-ion cell developed by the University of Ferrara and the KIT withstands thousands of charging cycles without deteriorating, the researchers report in the Journal of Energy and Environmental Science, published by the Royal Society of Chemistry.