Manipulating local electronic and interfacial structure of O3-type layered oxides for high-rate sodium-ion battery cathodes

O3-type layered oxide serves as dominant components in sodium ion batteries; however, the unstable electronic structure between transition metal and oxygen inevitably induces framework instability and severe kinetic hindrance. In this study, a two-in-one approach to synergistically modulate the local electronic and interfacial structure of NaNi1/3Fe1/3Mn1/3O2 by Ce modification is proposed. We present an indepth study to reveal the strong-covalent Ce-O bonds, which make local charge around oxygen more negative, enhance O 2p-Mn 3d hybridization, and preserve the octahedral structural integrity. This modification tailors local electronic structure between the octahedral metal center and oxygen, thus enhancing reversibility of O3-P3-O3 phase transition and expanding Na+ octahedral-tetrahedral-octahedral transport channel. Additionally, the nanoscale perovskite layer induced by Ce element is in favor of minimizing interfacial side reaction as well as enhancing Na+ diffusivity. As a result, the designed O3NaNi0.305Fe0.33Mn0.33Ce0.025O2 material delivers an exceptionally low volume variation, an ultrahigh rate capacity of 76.9 mA h g-1 at 10 C, and remarkable cycling life over 250 cycles with capacity retention of 80% at 5 C. (c) 2025 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights are reserved, including those for text and data mining, AI training, and similar technologies.