Incorporating an industrial by-product into lithium-sulphur batteries could increase the driving range and cut the price of electric vehicle batteries, according to a new study by UBC researchers.
A by-product of the copper and lead-zinc smelting process, tellurium has 30 times the electrical conductivity of sulphur, which is itself emerging as a promising component of next-generation batteries due to its ability to support high energy density, despite its limitations as an electrical conductor.
A compound that combines sulphur and tellurium could overcome those limitations, said the lead researcher, assistant professor Jian Liu.
“People have been looking into sulphur batteries for many years, but it is challenging to commercialize because sulphur doesn’t transport electrons at all,” said Liu. “We are looking for a way to balance electronic conductivity with energy density as a way to make lithium-sulphur batteries viable.”
“Finding that compound is our next step,” he said.
The study – Materials Design and Fundamental Understanding of Tellurium-based Electrochemistry for Rechargeable Batteries – published in the journal Energy Storage Materials – notes tellurium’s high volumetric capacity, which could enable greater storage capacity and faster charging and discharging than existing rechargeable lithium-ion batteries.
Solid state tellurium-based batteries could be safer than conventional EV batteries, which employ flammable liquid electrolytes.
The researchers note that significant limitations must be overcome, including tellurium’s tendency to expand and contract leading it to pulverize other active materials where they are combined. The researchers believe that problem can be overcome by creating a stable compound combining sulphur, tellurium, and carbon.
While tellurium is relatively rare in the Earth’s crust it can be recovered during metals production and Liu is confident that tellurium can also be recovered from end-of-service tellurium batteries and used again. Canada is among the world’s leaders in tellurium production, with at least three firms engaged in tellurium production in British Columbia.
The study is the first stage in a three-year project aimed at creating next-generation solid state batteries that are smaller, safer and cheaper to manufacture than conventional lithium-ion batteries, with an eye to accelerating British Columbia’s ambitious plans to electrify the transportation sector and creating a made-in-B.C. battery production and recycling industry.
The UBC-led project is supported by the Pacific Institute for Climate Solutions, the Government of British Columbia, Nature Sciences and Engineering Research Council of Canada (NSERC), Canada Foundation for Innovation, BC Knowledge Development Fund, Mitacs Accelerate Program, and Fenix Advanced Materials.