Novel technology aims to improve lithium metal battery life, safety

March 11, 2019, Pennsylvania State University
A reactive polymer composite, picturing the electrochemical interface between lithium metal anode and electrolyte is stabilized by the use of a reactive polymer composite, enabling high-performance rechargeable lithium metal batteries. Credit: Donghai Wang,Penn State

Rechargeable lithium metal batteries with increased energy density, performance, and safety may be possible with a newly-developed, solid-electrolyte interphase (SEI), according to Penn State researchers.

As the demand for higher-energy-density metal batteries increases—for , smartphones, and drones—stability of the SEI has been a critical issue halting their advancement because a salt layer on the surface of the battery's lithium electrode insulates it and conducts lithium ions.

"This layer is very important and is naturally formed by the reaction between the lithium and the electrolyte in the battery," said Donghai Wang, professor of mechanical and chemical engineering. "But it doesn't behave very well, which causes a lot of problems."

One of the least-understood components of lithium metal batteries, the degradation of the SEI contributes to the development of dendrites, which are needle-like formations that grow from the lithium electrode of the battery and negatively affect performance and safety. The researchers published their approach to this problem today (Mar. 11) in Nature Materials.

"This is why lithium metal batteries don't last longer—the interphase grows and it's not stable," Wang said. "In this project, we used a polymer composite to create a much better SEI."

Led by chemistry doctoral student Yue Gao, the enhanced SEI is a reactive consisting of polymeric lithium salt, lithium fluoride nanoparticles, and graphene oxide sheets. The novel construction of this battery component has thin layers of these materials, which is where Thomas E. Mallouk, Evan Pugh University Professor of Chemistry, lent his expertise.

"There is a lot of molecular-level control that is needed to achieve a stable lithium interface," Mallouk said. "The polymer that Yue and Donghai designed reacts to make a claw-like bond to the lithium metal surface. It gives the lithium surface what it wants in a passive way so that it doesn't react with the molecules in the electrolyte. The nanosheets in the composite act as a mechanical barrier to prevent dendrites from forming from the lithium metal."

Using both chemistry and , the collaboration between fields enabled the technology to control the lithium surface at the atomic scale.

"When we engineer batteries, we don't necessarily think like chemists, all the way down to the molecular level, but that's what we needed to do here," said Mallouk.

The reactive polymer also decreases the weight and manufacturing cost, further enhancing the future of lithium batteries.

"With a more stable SEI, it's possible to double the of current batteries, while making them last longer and be safer," Wang said.

Explore further: Organic/inorganic sulfur may be key for safe rechargeable lithium batteries

More information: Polymer–inorganic solid–electrolyte interphase for stable lithium metal batteries under lean electrolyte conditions, Nature Materials (2019). DOI: 10.1038/s41563-019-0305-8 , https://www.nature.com/articles/s41563-019-0305-8

Related Stories

A novel approach of improving battery performance

September 18, 2018

New technological developments by UNIST researchers promise to significantly boost the performance of lithium metal batteries in promising research for the next-generation of rechargeable batteries. The study also validates ...

Nanotubes may give the world better batteries

October 25, 2018

Rice University scientists are counting on films of carbon nanotubes to make high-powered, fast-charging lithium metal batteries a logical replacement for common lithium-ion batteries.

Recommended for you

Coffee-based colloids for direct solar absorption

March 22, 2019

Solar energy is one of the most promising resources to help reduce fossil fuel consumption and mitigate greenhouse gas emissions to power a sustainable future. Devices presently in use to convert solar energy into thermal ...

Paleontologists report world's biggest Tyrannosaurus rex

March 22, 2019

University of Alberta paleontologists have just reported the world's biggest Tyrannosaurus rex and the largest dinosaur skeleton ever found in Canada. The 13-metre-long T. rex, nicknamed "Scotty," lived in prehistoric Saskatchewan ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.