Fluorine-Incorporated Electrolytes Extend Lifespan of Li Metal Batteries

Recent study unveils that fluorine-incorporated electrolytes can evenly form a protective film on the positive and negative electrodes of Li metal batteries, prolonging the lifespan and output of the entire battery. According to report, a joint research team led by Professor Nam-Soon Choi and Sang Kyu Kwak of the School of Energy and Chemical Engineering at Ulsan National Institute of Science and Technology (UNIST) in Korea has developed the ion-concentration electrolyte using a fluorine atom-containing solvent liquid to enhance cycling stability of batteries.

When lithium ions move between the positive and negative electrodes of the batteries, the charging and discharging of Li metal batteries or a lithium-ion battery occurs. At this time, the channel through which lithium ions move is the electrolyte, and the electrolyte itself reacts on the electrode (anode/cathode) surface to form a protective film. However, when the formed protective film is not uniform, problems may arise.

Lithium metal can rise sharply on the negative electrode (dendrification), causing a short circuit, or modifying the positive electrode to reduce battery performance. Therefore, an ideal type of protective film must be manufactured, and the composition of the electrolyte must be effectively controlled for this purpose.

Professor Nam's research team has developed new fluorine-incorporated electrolytes to protect both the positive and negative electrodes of a battery and increase the energy output. Fluorine reacted with lithium to form a protective film on the surface of the lithium electrode and also repaired when the protective film was partially damaged.

Professor Kwak's team used theoretical calculations to determine reaction trends and reaction mechanisms of fluorinated solvents. Researchers have found that the fluorinated ether solvent, which has a reduction reaction more easily than conventional fluorine, has a property of easily emitting fluorine, and can promote the formation of a protective film (fluorinated interface) on the cathode.

The discovery of the fluorine-incorporated electrolytes is expected to help improve the electrochemical performance of next-generation high-energy-density batteries, including lithium-ion batteries that use the same positive electrode as Li metal batteries.

• < Prev
• Next >