Published on April 3rd, 2013 | by James Ayre10
Longer-Lasting Lithium-Sulfur Batteries Developed For Use In EVs
April 3rd, 2013 by James Ayre
A new lithium-sulfur battery design has been created that improves the charge cycles of lithium-sulfur batteries by a factor of seven. This significant improvement in technology means that perhaps in the near future, lithium-sulfur batteries, which are considerably more cost-effective that lithium-ion batteries, will become a viable choice for use in electric vehicles. The new design was made by researchers at the Fraunhofer Institute for Material and Beam Technology IWS in Dresden.
“During previous tests, the batteries scarcely crossed the 200-cycle mark. By means of a special combination of anode and cathode material, we have now managed to extend the lifespan of lithium-sulfur button cells to 1,400 cycles,” says Dr. Holger Althues, head of the Chemical Surface Technology group at Fraunhofer IWS.
The primary issue with lithium-sulfur batteries that the new design addresses is that the sulfur cathode interacts too much with the liquid electrolyte, over time limiting performance and eventually causing the battery to stop working altogether. In the new design, this is addressed through the use of “porous carbons” that slow down the process.
“We have precisely altered the pores to allow the sulfur to lodge there, slowing down the rate at which it combines with the electrolyte,” states Althues. The researchers have also developed a method to manufacture these specialized cathodes.
Eventually, according to the researchers, lithium-sulfur batteries will reach energy densities much higher than those possible in lithium-ion batteries, up to more than two times higher. “In the medium term, figures around the 500 Wh/kg mark are more realistic. In practical terms, this means you can drive twice as far with the same battery weight,” says Althues. “This of course implies that significantly lighter battery models are possible — an interesting prospect not only for automakers but for smartphone manufacturers too. After all, the overall weight of smartphones would be greatly reduced if they had lighter batteries.”
That all sounds great, but here’s my favorite part: “Lithium-sulfur technology might even make electric flying a realistic possibility. Although such progress is still a long way off,” says Althues.