Japanese scientists set a record for solid electrolytes

Researchers from Nagoya University in Japan have significantly improved the properties of the LLNOF material, achieving an absolute record for lithium-ion conductivity among oxide-based solid electrolytes. According to ixbt.com, this scientific breakthrough could be a crucial step toward creating safer and more efficient solid-state batteries. This is reported by Ixbt.com news.

One of the main drawbacks of traditional lithium-ion batteries currently in widespread use is the flammable liquid electrolyte they contain. If a battery is damaged, such liquids can cause short circuits and fires. This is precisely why engineers around the world are actively working on developing safer solid-state batteries.

Barriers to increasing flow rate

However, the main factor that has hindered the development of solid-state systems until now has been the relatively low speed of lithium-ion movement within solid materials. Although sulfide and chloride electrolytes currently show the highest performance, they pose risks due to their extreme sensitivity to moisture and the potential release of toxic gases.

Oxide materials are considered chemically much more stable, but they have traditionally lagged behind their competitors in terms of lithium transport efficiency. Nevertheless, the LLNOF material has proven to be a unique exception in this regard and has attracted the attention of scientists.

The role of fluorine and the new record

According to reports, as recently as 2024, the conductivity of this material was at approximately 7 mS/cm (millisiemens per centimeter). Now, scientists have not only identified the cause of this phenomenon but have also managed to more than double the performance.

Studies have shown that as a lithium ion moves, a neighboring fluorine ion simultaneously shifts in the opposite direction. This lowers the energy barrier within the crystal lattice, ensuring that fluorine clears the path for lithium and significantly accelerates its migration.

By perfectly optimizing the ratio of lithium, lanthanum, and vacancies in the material structure, the researchers increased the conductivity level to 16.3 mS/cm. Experts note that this is the highest bulk conductivity ever recorded for this class of oxide solid electrolytes.

For now, this is a fundamental scientific study rather than a finished battery product. Nevertheless, the newly discovered physical mechanism is expected to serve as a solid foundation for creating a new generation of solid-state batteries that combine the high safety and high conductivity of oxide electrolytes.