Researchers apply graphene to lithium-sulfur battery design

Dec. 18, 2014
2 min read

Lithium-sulfur batteries show promise for replacing lithium-ion ones. Li-S offers energy densities of about 500 Whr/kg, vs. 150 to 200 Whr/kg for Li-ion versions. Further, Li-S batteries have been demonstrated to withstand 1,500 charge/discharge cycles.

New research might bring the technology closer to commercialization. In the journal APL Materials, from AIP Publishing, a team of researchers led by Dr. Vasant Kumar at the University of Cambridge and Professor Renjie Chen at the Beijing Institute of Technology describe their design of a multifunctional sulfur cathode at the nanolevel to address performance-related issues such as low efficiency and capacity degradation.

The researchers essentially wrapped a sheet of graphene around a multifunctional sulfur electrode. They employed a metal-organic framework (MOF) as a template to form a conductive porous carbon cage.

“Our carbon scaffold acts as a physical barrier to confine the active materials within its porous structure,” explained Kai Xi, a research scientist at Cambridge, as quoted at Newswise. “This leads to improved cycling stability and high efficiency.” They also discovered that by further wrapping the sulfur-carbon energy storage unit within a thin sheet of flexible graphene speeds the transport of electrons and ions.

Xi said that in the future, “We’ll focus on fabricating hybrid free-standing sulfur cathode systems to achieve high-energy density batteries, which will involve tailoring novel electrolyte components and building lithium ‘protection layers’ to enhance the electrochemical performance of batteries.”

The article, “Graphene-wrapped sulfur/metal organic framework (MOF)-derived microporous carbon composite for lithium sulfur batteries,” is authored by Renjie Chen, Teng Zhao, Tian Tian, Shuai Cao, Paul R. Coxon, Kai Xi, David Fairen-Jimenez, R. Vasant Kumar, and Anthony K. Cheetham. It can be accessed here.

About the Author

Rick Nelson

Rick Nelson

Contributing Editor

Rick is currently Contributing Technical Editor. He was Executive Editor for EE in 2011-2018. Previously he served on several publications, including EDN and Vision Systems Design, and has received awards for signed editorials from the American Society of Business Publication Editors. He began as a design engineer at General Electric and Litton Industries and earned a BSEE degree from Penn State.

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