KAIST develops technology to solve ‘interfacial instability’ in lithium batteries, Extending Battery Lifespan and Enabling Ultra-fast Charging

The Korea Advanced Institute of Science and Technology (KAIST) announced on Feb. 24 that a research team led by Professor Choi Nam-soon of the Department of Chemical and Biomolecular Engineering and Professor Hong Seung-beom of the Department of Materials Science and Engineering has developed a technology to resolve ‘interfacial instability’—the most significant challenge facing lithium metal batteries—at the electronic structure level.

Interfacial instability is a phenomenon where the interface between the electrode and electrolyte fails to maintain uniformity during charging and discharging cycles. This leads to the formation of dendrites, where lithium grows in needle-like structures, resulting in reduced battery lifespan, internal short circuits, and fire hazards. This has been identified as the fundamental cause hindering the commercialization of lithium metal batteries.

The research team, in collaboration with Professor Kwak Sang-kyu’s team at Korea University, added ‘Thiophene’ to the battery electrolyte to create an ‘intelligent protective layer’ on the electrode surface that allows lithium ions to move stably.

This protective layer has the characteristic of its electronic structure rearranging itself. Much like a smart traffic system that adjusts lanes according to traffic volume, the charge distribution within the protective layer flexibly changes each time lithium ions move, creating optimal pathways.

As a result, the research team explained that they successfully suppressed dendrite growth effectively and significantly extended battery lifespan even in fast-charging environments.

The research team added that the significance lies in presenting a breakthrough that can fundamentally solve the ultra-fast charging problem—simultaneously achieving fast charging within 12 minutes and high-current operation of 8mA/cm² or more—which has been the biggest barrier to commercializing lithium metal batteries.

Professor Choi Nam-soon stated, “This will become the core foundational technology for next-generation electric vehicle batteries that achieve both fast charging and long lifespan,” adding, “It will be utilized in various future industrial sectors requiring high-performance batteries, including ultra-long-range electric vehicles, Urban Air Mobility (UAM), and next-generation high-density energy storage systems.”