A new technology has emerged that can solve the structural collapse problem in lithium-rich layered oxide cathodes, a next-generation battery material. By eliminating factors that reduce battery energy efficiency and shorten lifespan, the development of high-energy-density batteries using lithium-rich layered oxide cathodes is expected to accelerate.
On the 12th, Professor Lee Hyun-wook from the Department of Energy and Chemical Engineering at Ulsan National Institute of Science and Technology (UNIST), Dr. Jung Young-hwa from Pohang Accelerator Laboratory, and Professor Seo Dong-hwa's team at Korea Advanced Institute of Science and Technology (KAIST) announced they have developed a lithium-rich layered oxide cathode material that suppresses structural collapse and prevents energy efficiency loss by intentionally designing disordered atomic arrangements.
Unlike conventional batteries where only metals participate in reactions, lithium-rich layered oxides are next-generation materials that can significantly increase battery capacity by involving oxygen in reactions. However, the cascading structural collapse occurring during this process has been a persistent problem. Due to structural deformation, voltage differences and energy losses increase during initial charge-discharge cycles, and voltage gradually drops with repeated cycling until the battery reaches end of life.
The research team developed a lithium-rich layered oxide that suppresses structural collapse by irregularly mixing metal atomic arrangements. The irregular arrangement actually prevents entire layers from sliding at once during initial charging and distributes physical stress evenly, maintaining bonds between transition metals and oxygen that form the structural framework. This principle was cross-verified through density functional theory (DFT) calculations and advanced synchrotron analysis at Pohang Accelerator Laboratory.
Performance evaluation showed the voltage difference between first charge and discharge decreased to 0.31V—half that of conventional materials—with initial energy loss of only 0.6%. In contrast, conventional materials with regular atomic arrangements showed voltage differences twice as large and 25.8% energy loss. Larger voltage gaps between charge and discharge mean greater energy losses.
Additionally, the voltage decay rate during subsequent charge-discharge cycles dropped to one-tenth per cycle, maintaining 98% of initial energy even after 160 cycles.
Lead author Choi Myung-jun said, "This approach secures structural stability by reversely utilizing the disorder in atomic arrangement, which was previously dismissed as a defect," adding that "this is a universal approach applicable to various lithium-rich layered oxide cathode materials, not limited to specific compositions."
Professor Lee Hyun-wook said, "Lithium-rich layered oxides are promising cathode materials theoretically capable of very high energy density, but commercialization has been difficult due to structural collapse and voltage decay issues." He added, "This technology will help commercialize next-generation high-energy-density batteries that are smaller, lighter, and can store more electrical energy."
This research was supported by the Ministry of Science and ICT's National Research Foundation of Korea through the Nano and Future Materials Source Technology Development Program and the International Cooperation Development Program for Source Technology. The results were published online on February 3 in ACS Energy Letters, an international academic journal in the energy field.