An ultra-thin nanomaterial is at the heart of a major breakthrough by Waterloo scientists who are in a global race to invent a cheaper, lighter and more powerful rechargeable battery for electric vehicles.

Chemistry Professor Linda Nazar and her research team have discovered that a nanosheet of manganese dioxide can be used in a lithium-sulphur (Li-S) battery to dramatically boost its performance. The low-cost Li-S battery can theoretically power an electric car three times further than current lithium-ion batteries for the same weight.

Linda Nazar

Breakthrough published in Nature Communications

“This is a major step forward and brings the Li-S battery one step closer to reality,” said Nazar, who also holds the Canada Research Chair in Solid State Energy Materials and is a 2014 Thomson Reuters’ Highly Cited Researcher. Their research paper appeared recently in Nature Communications.

The surface of the manganese dioxide nanosheet essentially transforms the sulphur cathode of a Li-S battery into a high-performance cathode that can recharge more than 2,000 times.  Cathodes and anodes are the two electrodes on a battery, separated by an electrolyte solution.

Sulphur, which is an extremely abundant, relatively light and very cheap battery material, historically hasn’t worked as a cathode material because it dissolves into the electrolyte solution, as the battery discharges.

Metal oxides key to rechargeable battery

Earlier published research by Nazar found that metallic titanium oxide could work to stabilize the sulphur, but the research published this week shows that nanosheets of manganese dioxide work even better. The main goal of this paper is to explain the mechanism at work.

“You have to focus on the a fundamental understanding of the phenomenon before you can develop new, advanced materials,” said Nazar.

Link to golden age of German sulphur chemistry

The chemical reaction that stabilizes the sulphur is similar to a chemical process discovered in 1845 during the golden age of German sulphur chemistry. “Very few researchers study or even teach sulphur chemistry anymore,” said Nazar. “It’s ironic we had to look so far back in the literature to understand something that may so radically change our future.” 

Postdoctoral research associate Xiao Liang, the lead author, and graduate students Connor Hart and Quan Pang are currently investigating other oxides to find the best sulphur retaining material.

BASF International Scientific Network for Electrochemistry and Batteries funded the research. The paper’s co-authors include Arnd Garsuch and Thomas Weiss of BASF.