Kyungpook National University and ETRI Unveil Key Principle of 12-Minute Ultra-Fast Charging for Lithium Batteries, Paving the Way for Next-Generation Mobility Innovation

A research team has unveiled the principle behind enabling ultra-fast charging-approximately 12 minutes-for high-energy-density lithium batteries used in next-generation mobility devices such as electric vehicles, drones, and robots.

According to Kyungpook National University on January 7, Professor Oh Jimin’s team from the Department of Smart Mobility Engineering, in collaboration with Dr. Lee Myungju of the Electronics and Telecommunications Research Institute (ETRI), has identified an electrolyte design and electrode surface performance enhancement mechanism that enables ultra-fast charging of high-energy-density lithium batteries using high-nickel cathodes.

Professor Oh Jimin (Department of Smart Mobility Engineering, Kyungpook National University). Courtesy of Kyungpook National University

While high-nickel lithium batteries offer high energy density and longer usage time per charge, there have been limitations to ultra-fast charging due to issues such as dendrite formation, delayed lithium-ion migration, and electrode degradation during charging and discharging processes when charging speed is significantly increased.

To address these challenges, the research team focused on electrolyte design. They introduced FEC (fluoroethylene carbonate), an additive that protects the battery electrode and enables ultra-fast charging, into an ether-based electrolyte that allows for rapid lithium-ion migration.

As a result, they confirmed that stable charging and discharging performance could be achieved even under ultra-fast charging conditions (5C or higher), which takes about 12 minutes.

In particular, FEC was found to form a robust protective layer of lithium fluoride (LiF) not only on the electrode surface but also internally during charging and discharging, thereby facilitating stable lithium-ion migration at both the cathode and anode.

This effectively suppressed electrode degradation and internal resistance increases even under high-power conditions.

Additionally, the research team systematically analyzed and compared NCM (nickel-cobalt-manganese) cathode materials with different design capacities and nickel contents, revealing that interfacial conductivity and ion migration behavior vary depending on electrode design conditions.

The team explained that these results experimentally demonstrate the importance of mass migration characteristics, which are critical to ultra-fast charging performance.

Professor Oh Jimin stated, "This research demonstrates the necessity of an 'integrated design strategy' that considers both the electrolyte and electrode, and provides design directions and guidelines to overcome the ultra-fast charging limitations of high-energy-density lithium batteries."

He added, "By elucidating the role of the inorganic protective layer formed at the electrolyte interface and the fundamental mechanisms behind ultra-fast charging performance degradation, this work will contribute to performance improvements in various applications, including electric vehicles, energy storage systems (ESS), drones, and robots."

This research was supported by the Kyungpook National University Excellent New Faculty Research Fund, the National Research Foundation of Korea Global Research Laboratory Program, the Korea Institute for Advancement of Technology’s Core Industry IT Convergence Program, and the Korea Technology and Information Promotion Agency for SMEs’ SME Technology Innovation Development Program.

The corresponding author is Professor Oh Jimin, the first author is Dr. Lee Myungju, and the co-author is Researcher Kim Jinseo from Yeungnam University. The research findings were published online in the top-tier international journal in engineering and convergence, 'Results in Engineering,' on December 25 of last year.