Ku, Kyojin Kim, Byunghoon Jung, Sung-Kyun Gong, Yue Eum, Donggun Yoon, Gabin Park, Kyu-Young Hong, Jihyun Cho, Sung-Pyo Kim, Noon Kim, Hyungsub Jeong, Eunsuk Gu, Lin Kang, Kisuk 2024-01-19T17:34:46Z 2024-01-19T17:34:46Z 2021-09-04 2020-04-01 1754-5692 https://pubs.kist.re.kr/handle/201004/118748 Lithium-rich layered oxides (LLOs) are considered promising cathode materials for lithium-ion batteries because of their high reversible capacity, which is attributed to the exploitation of the novel anionic redox in addition to the conventional cationic redox process. Transition metal (TM) migration, which is known to be the main cause of the voltage decay in LLOs, is now understood to also be the critical factor triggering anionic redox, although this origin is still under debate. A better understanding of the specific TM migration behavior and its effect during charge/discharge would thus enable further development of this class of materials. Herein, we demonstrate that the unique TM migration during charge/discharge significantly alters the lithium diffusion mechanism/kinetics of LLO cathodes. We present clear evidence of the much more sluggish lithium diffusion occurring during discharge (lithiation) than during charge (de-lithiation), which contrasts with the traditional lithium diffusion model based on simple topotactic lithium intercalation/deintercalation in the layered framework. The reversible but asymmetric TM migration in the structure, which originates from the non-equivalent local environments around the TM during the charge and discharge processes, is shown to affect the lithium mobility. This correlation between TM migration and lithium mobility led us to propose a new lithium diffusion model for layered structures and suggests the importance of considering TM migration in designing new LLO cathode materials. English Royal Society of Chemistry HIGH-CAPACITY ANIONIC REDOX ION BATTERIES ELECTRODES CHEMISTRY CATHODES LI2MNO3 ORIGIN ANODE RAMAN A new lithium diffusion model in layered oxides based on asymmetric but reversible transition metal migration Article 10.1039/c9ee04123k 1 Energy & Environmental Science, v.13, no.4, pp.1269 - 1278 Energy & Environmental Science 13 4 1269 1278 scie scopus 000528728700011 2-s2.0-85083875048 Chemistry, Multidisciplinary Energy & Fuels Engineering, Chemical Environmental Sciences Chemistry Energy & Fuels Engineering Environmental Sciences & Ecology Article HIGH-CAPACITY ANIONIC REDOX ION BATTERIES ELECTRODES CHEMISTRY CATHODES LI2MNO3 ORIGIN ANODE RAMAN Li-ion battery