The energy density of Li-S batteries is said to be five times higher than that of Li-ion batteries, which combined with low cost, put it at a significant advantage.
Li-S batteries are limited by rapid capacity fade, however, which means that the amount of charge these batteries can deliver at the rated voltage decreases significantly with use.
According to the Delaware team, this problem stems from a phenomenon known as the polysulphide shuttle effect, in which the spontaneous formation of polysulphides inhibits performance.
To solve this issue, the team demonstrated a polysulphide entrapping strategy that is said to improve the cycle stability of Li-S batteries.
The researchers claim the addition of ferroelectric nanoparticles into the battery cathode anchors the polysulphides, preventing them from dissolving and causing the loss of active materials at the cathode.
"While the mechanism underlying the trapping of polysulphides is unclear at this point, we're optimistic about the potential of this approach to high performance lithium-sulphur battery applications, as it not only solves the problem of the polysulphide shuttle effect but also can be coupled to current industrial battery manufacturing processes," said Delaware Professor Bingqing Wei.
