ETH researchers make lithium-metal batteries more environmentally friendly

Zurich – Lithium-metal batteries are characterized by their high storage capacity. However, they require large quantities of environmentally harmful fluorine. Researchers at the Swiss Federal Institute of Technology in Zurich (ETH) are working on a more environmentally friendly version.

Lithium-metal batteries are among the most promising high-performance batteries of the next generation, explains the ETH in a press release. The reason for this is their high storage capacity, which is at least double that of conventional lithium-ion batteries. At the same time, however, lithium metal batteries have the disadvantage that large quantities of fluorine-containing solvents and salts are added to them to keep the batteries stable and protect them from short circuits and overheating.

Researchers at ETH, led by Maria Lukatskaya, Professor of Electrochemical Systems, are working on drastically reducing the ecological footprint of high-performance batteries. They have developed a new method with which the amount of fluorine in the electrolyte can be reduced to one twentieth. Electrically charged fluorine-containing molecules bind the fluorine to the protective layer around the lithium metal at the negative terminal of the battery. "It protects the lithium metal from the constant reaction with the electrolyte components," explains Lukatskaya. The press release cites the search for the right metal that decomposes before reaching the positive pole as a major challenge.

The first batteries produced in the laboratory are the size of a coin. In the next step, the researchers now want to tackle pouch cells such as those used in smartphones. They have already applied for a patent for their development. Their method can be integrated into the existing battery production process without any adjustments to the production equipment. ce/hs

View full article