Battery breakthrough could extend range of EVs

While lithium-sulphur batteries are significantly more powerful and less expensive than their lithium-ion counterparts, their short lifespan has made them unsuitable for use in electric vehicles until now. "During previous tests, the batteries scarcely crossed the 200 cycle mark," noted Dr Holger Althues, from the Fraunhofer Institute for Material and Beam Technology IWS in Dresden. "By means of a special combination material, we have now managed to extend the lifespan of lithium-sulphur button cells to 1,400 cycles." The prototype anode is made from a silicon-carbon compound, which changes less during each charging process than metallic lithium. This, according to Dr Althues, avoids the liquid electrolyte breaking down as quickly. In the long term, IWS expects lithium-sulphur batteries to reach an energy density of up to 600Wh/kg. "In practical terms, this means you can drive twice as far with the same battery weight," Althues concluded.