Scientists from Yale University have developed a new ultra-thin, gel-like coating material that can potentially boost the performance of lithium-sulfur batteries, extending its life and improving its efficiency.

The new material, described in a paper published in the Proceedings of the National Academy of Sciences, is a dendrimer-graphene oxide composite film that can be applied to any sulfur cathode.

"Our approach is general in that it can be integrated with virtually any kind of sulfur electrode to increase cycling stability," explained Hailiang Wang, assistant professor of chemistry at Yale and lead author of the study, in a press release. "The developed film is so thin and light it will not affect the overall size or weight of the battery, and thus it will function without compromising the energy and power density of the device."

To develop the new material, the scientists combined the distinct properties of graphene oxide and dendrimer molecule. Graphene oxide is known for its mechanical strength, while dendrimer molecule has the ability to confine lithium polysulfides.

The combination of the two material components resulted in a gel-like slurry that can be readily coated as a 100-nanometer-thin film onto sulfur electrodes.

The researchers claim that their new material could enhance lithium-sulfur battery's efficiency and number of cylces. A sulfur cathode coated with the dendrimer-graphene oxide composite film can be stably discharged and recharged for more than 1,000 cycles.

Lithium-sulfur is one of the potential alternatives for the commonly-used lithium-ion batteries. Sulfur is considered to be both lightweight and abundant, with a high theoretical capacity. However, the present lithium-sulfur battery technology suffers from loss of capacity during cycling.

Yale's new coating material solves the capacity loss problems experienced by existing lithium-sulfur batteries. Aside from sulfur, the researchers are trying to develop new types of electrodes. New types of electrodes is considered to be necessary for the development of a new generation of high energy-density batteries.