Authors
Weixin Song, Miguel A Pérez-Osorio, John-Joseph Marie, Emanuela Liberti, Xiaonan Luo, Colum O’Leary, Robert A House, Peter G Bruce, Peter D Nellist
Publication date
2022/5/18
Journal
Joule
Volume
6
Issue
5
Pages
1049-1065
Publisher
Elsevier
Description
Li-rich metal oxides, such as Li1.2Ni0.13Mn0.54Co0.13O2, can deliver high specific capacities because of the redox of lattice O2− in addition to the cations. Observing oxygen distortions is key to understand the redox process. Electron ptychography is a phase-reconstruction method in 4D scanning transmission electron microscopy, providing atomic-resolution phase images with high signal-to-noise ratio and dose efficiency. Herein, we use electron ptychography to image the oxygen shift in Li1.2Ni0.13Mn0.54Co0.13O2 during the first cycle. The picometer-scale precision measurement shows distinct oxygen shifts in the bulk and surface after charging and compares with various theoretical anionic redox models. The shift after discharging is not seen to recover in the bulk accounting for voltage hysteresis; however, it recovers close to the surface, although with a phase change. We suggest that Li1.2Ni0.13Mn0.54Co …
Total citations
202220232024198
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