Voronina, Natalia Yaqoob, Najma Kim, Hee Jae Lee, Kug-Seung Lim, Hee-Dae Jung, Hun-Gi Guillon, Olivier Kaghazchi, Payam Myung, Seung-Taek 2024-01-19T14:30:59Z 2024-01-19T14:30:59Z 2021-09-05 2021-07 1614-6832 https://pubs.kist.re.kr/handle/201004/116825 Herein, stable cationic and anionic redox in an O3-type layered Na[Ni2/3Ru1/3]O-2 cathode for sodium-ion batteries (SIBs) is revealed. Density functional theory (DFT) calculation shows that the electron density features change in density of state with mixing of delocalized valence states as well as localized deeper energy states of O(p), Ni(d), and Ru(d) for the highly desodiated Na-1-(x)[Ni2/3Ru1/3]O-2 electrode, revealing the covalent characteristic of the transition metal (TM)-O and TM-TM bonds in the charged system. These properties lead to cycling stability for 200 cycles, with approximate to 79% of the capacity retained at a rate of 1C (210 mA g(-1)). Operando X-ray diffraction, X-ray absorption spectroscopy, and DFT calculations reveal the reversible electrochemical activity of the Ni2+/Ni3+ and O2-/O1- redox reactions, which are sustainable throughout the cycles. In addition, no loss of oxygen from the crystal structure of Na[Ni2/3Ru1/3]O-2 occurs according to differential electrochemical mass spectrometry. The findings provide additional insight into the complex mechanism of the oxygen redox activity of high-capacity O3-type cathode materials for SIBs, encouraging further studies on their development. English WILEY-V C H VERLAG GMBH A New Approach to Stable Cationic and Anionic Redox Activity in O3-Layered Cathode for Sodium-Ion Batteries Article 10.1002/aenm.202100901 1 ADVANCED ENERGY MATERIALS, v.11, no.25 ADVANCED ENERGY MATERIALS 11 25 scie scopus 000652107800001 2-s2.0-85106265773 Chemistry, Physical Energy & Fuels Materials Science, Multidisciplinary Physics, Applied Physics, Condensed Matter Chemistry Energy & Fuels Materials Science Physics Article OXYGEN-REDOX STRUCTURAL STABILITY ELECTRODE MATERIAL OXIDE CAPACITY CHEMISTRY PERFORMANCE GENERATION EVOLUTION DENSITY anionic batteries cathodes cationic redox sodium