Year: 2025
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide Oxygen-redox layered oxides are promising electrode materials with the potential for superior energy density; however, their real-world employment is hindered by severe electrochemical irreversibility. The fundamental origin of this irreversibility has been difficult to pinpoint due to the complex evolution of both the structure and redox centers during cycling. Herein, we reveal that oxygen redox irreversibility is governed by the formation and persistence of oxygen dimer states and, for the first time, demonstrate the reversible recovery of the intrinsic high-voltage oxygen redox plateau (∼4.5 V vs Li/Li + ), which is typically lost after initial charge. Our in-depth tracking of oxygen dimer behavior establishes a direct correlation between the recoverability of the high-voltage plateau and the residual concentration of oxygen dimers in the electrode material. Furthermore, we identify sluggish dimer dissociation kinetics as the root cause of the irreversible loss of high-voltage oxygen redox activity. More importantly, we demonstrate that these kinetically trapped oxygen dimers can be eliminated by facilitating electron transfer from transition metal to oxygen dimers via redox reshuffling at a moderately elevated temperature, thereby fully restoring the high-voltage oxygen redox activity. These findings clarify the role of oxygen dimer kinetics in redox irreversibility and provide valuable insights toward achieving voltage-hysteresis-free anionic redox in oxygen redox electrodes.
DOI: 10.1021/jacs.5c11310
Authors: Youngsin Kim, Hyuk-Joon Kim, Dae Soo Jung, Okkyun Seo, Akhil Tayal, Hojoon Lim, Saki Imada, Jooha Park, Sung-Pyo Cho, Youngjun Jeon, Jihyeon Kim, Donggun Eum, Seongmin Kang, Byungwook Kang, Kyoungoh Kim, Hongjin Ahn, Jonghun Park, Ho-Young Jang, Sung-O Park, Joohyeon Noh, Chaelin Lee, Jong Deok Lee, Kun-hee Ko, Hyunsoung Jin, Kisuk Kang
Institutions: Seoul National University, Korea Institute of Ceramic Engineering and Technology, SPring-8, Japan Synchrotron Radiation Research Institute, Brookhaven National Laboratory, National Synchrotron Light Source II, Myongji University, Kyoto Institute of Technology, Stanford University, Institute for Basic Science, Institute of Engineering Research
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
Funders: National Research Foundation, Myongji University, Seoul National University, National Research Foundation of Korea, Institute for Basic Science, Ministry of Science and ICT, South Korea, Korea Institute of Ceramic Engineering and Technology, National Center for Inter-University Research Facilities, Seoul National University, Brookhaven National Laboratory
OpenAlex ID: W4415210204