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Reversible Flat to Rippling Phase Transition in Fe Containing Layered Battery Electrode Materials



Xi Chen, Sooyeon Hwang, Robin Chisnell, Yichao Wang, Fan Wu, Sooran Kim, Jeffrey W. Lynn, Dong Su, Xin Li


The Jahn-Teller effect in solid-state chemistry relates the symmetry of electronic configuration to the atomic arrangement around the individual transition metal ion. The collective behavior of many such Jahn-Teller active entities is of great interest in modern solid-state chemistry and physics. Here we report a novel spontaneous layer rippling in the sodium ion battery cathode material, revealed by in-situ X-ray diffraction, Cs-corrected scanning transmission electron microscopy and denisty functional theory simulation, where the Jahn-Teller distortion of Fe ions drives the flat TM planes into rippled ones with inhomogeneous interlayer distance at high voltage. In such a rippling phase, charge and discharge of Na ions take different evolution pathways, resulting in an unusual reversible hysteresis voltage loop. The rippling phase shows superior electrochemical performance, suggesting that the utilization and engineering of the spontaneous rippling can be a new route toward designing the advanced electrode materials for rechargeable battery applications.
Advanced Functional Materials


Battery electrode materials, Jahn-Teller effect, Neutron diffraction, rippled structure


Chen, X. , Hwang, S. , Chisnell, R. , Wang, Y. , Wu, F. , Kim, S. , Lynn, J. , Su, D. and Li, X. (2018), Reversible Flat to Rippling Phase Transition in Fe Containing Layered Battery Electrode Materials, Advanced Functional Materials, [online], (Accessed April 12, 2024)
Created September 25, 2018, Updated October 12, 2021