New technique for Lithium-Sulfur batteries improvement
Lithium-ion rechargeable batteries nowadays are used in many devices especially portable ones such as laptops, mobile phones, fitness trackers, tablets and smart watches. Nevertheless, their energy density(1) needs improvement to be used on a larger scale such as in smart grid and the new applications in electric transport systems.
On the other hand, it is found that the energy density of the Lithium-sulfur batteries (Li-S) are greater than the Li-ion by five times. This advantage along with the fact that it is much cheaper than the Li-ion gives it the potential of having these batteries as an alternative for high-energy storage applications.
However, the use of Li-S batteries is held back by its rapid capacity fade(2).
Professor Binqing Wei, at the Department of Mechanical Engineering, University of Delaware (UD), USA, says that this problem originated from what is called Polysulfide Shuttle Effect, where the creation of polysulfides, spontaneously, impedes the performance.
To improve the cycle stability of the Lithium-sulfur batteries, Prof. Wei, and his colleagues, has demonstrated new strategies for polysulfide entrapping, in the article titled “Ferroelectric-Enhanced Polysulfide Trapping for Lithium-Sulfur Battery Improvement”, which is published, not long ago, in “Advanced Materials”.
The authors included researches from the Northwestern Polytechnic University in the USA, Shenzhen University in China and Hong Kong Polytechnic University.
As explained by Prof. Wei, ferroelectric nanoparticles addition to the battery cathode will hold the polysulfides and prevent them from being dissolved, that was to cause the loss of active materials.
Prof. Wei says that the outcomes are not clear at the moment, however, they are hopeful that this approach might create high-performance Li-S battery applications, and it will not only solve the problems of polysulfide shuttle effect but will also be an advancement in the battery manufacturing as well.
(1) The amount of energy stored in a physical mass or material.
(2) The amount of charge these batteries can deliver at the rated voltage decreases significantly with use.