News | Energies
Lithium-sulfur batteries are ideal candidates for applications requiring high specific energy, but they do have limitations.Researchers at Liten, a CEA Tech institute, have successfully overcome the most serious of them.
At equivalent weight,
lithium-sulfur (Li-S) batteries last three times longer between charges than the
lithium-ion batteries powering most of our everyday items. This makes Li-S
batteries ideal for electric vehicles, aircraft, or anywhere else a large
amount of on-board energy is needed and where space is tight.
batteries have a limited lifetime. “During discharge, the sulfur from the
positive electrode dissolves in the liquid electrolyte used to transfer ions
from one electrode to another. With each cycle, the negative lithium
electrode corrodes and an insulating layer forms on the positive sulfur
electrode, increasing its electrical resistance and greatly reducing the amount
of energy supplied.” To overcome this problem, Liten researchers decided to take
advantage of lithium-sulfur’s solubility, placing it directly in the
electrolyte. The result is a liquid positive electrode, or “catholyte”. They
also increased the active surface of the positive electrode’s current collector
using carbon nanotube mats placed on a strip of aluminum.
tricks combined increased the amount of sulfur in the battery to achieve higher
specific energy while maintaining current cycling lifetimes at higher discharge
rates. The Li-ion battery now has a worthy successor.
CEA is a French government-funded technological research organisation in four main areas: low-carbon energies, defense and security, information technologies and health technologies. A prominent player in the European Research Area, it is involved in setting up collaborative projects with many partners around the world.