Propagation topography of redox phase transformations in heterogeneous layered oxide cathode materials

Propagation topography of redox phase transformations in heterogeneous layered oxide cathode materials

TitlePropagation topography of redox phase transformations in heterogeneous layered oxide cathode materials
Publication TypeJournal Article
Year of Publication2018
AuthorsLinqin Mu, Qingxi Yuan, Chixia Tian, Chenxi Wei, Kai Zhang, Jin Liu, Piero Pianetta, Marca M Doeff, Yijin Liu, Feng Lin
JournalNature Communications
Volume9
Issue1
Date Published07/2018
Abstract

Redox phase transformations are relevant to a number of metrics pertaining to the electrochemical performance of batteries. These phase transformations deviate from and are more complicated than the conventional theory of phase nucleation and propagation, owing to simultaneous changes of cationic and anionic valence states as well as the polycrystalline nature of battery materials. Herein, we propose an integrative approach of mapping valence states and constructing chemical topographies to investigate the redox phase transformation in polycrystalline layered oxide cathode materials under thermal abuse conditions. We discover that, in addition to the three-dimensional heterogeneous phase transformation, there is a mesoscale evolution of local valence curvatures in valence state topographies. The relative probability of negative and positive local valence curvatures alternates during the layered-to-spinel/rocksalt phase transformation. The implementation of our method can potentially provide a universal approach to study phase transformation behaviors in battery materials and beyond.

DOI10.1038/s41467-018-05172-x
Short TitleNat Commun
Refereed DesignationRefereed