Atomistic Mechanisms of Phase Transition of Spinel Oxides during the Li Intercalation-to-Conversion Reaction by In Situ TEM
Publication Name
ACS Materials Letters
Abstract
Spinel oxides exhibit both intercalation and conversion reaction mechanisms during (de)lithiation, thus exhibiting great potential for Li-ion battery electrodes. Atomic-scale understandings of phase transitions upon Li-ion insertion are critical for optimizing oxide electrodes’ performance. Herein, we employed single-crystalline Co3O4 nanosheets as a model and captured the phase transition dynamics process via in-situ TEM. We identified each step of lattice change (e.g., distortion and restructuring) of the spinel structure upon Li insertion and the atomistic mechanism of the following two-phase conversion reaction through in-situ electron diffraction and imaging. We also visualized the spatial distribution of typical transient phases during lithiation. Corroborated by theoretical calculations, we elucidate a comprehensive picture of the phase transition from spinel Co3O4 to rocksalt LixCo3O4, followed by the formation of a Li2O lattice and metallic Co precipitation. These atomic-scale insights provide fundamental understandings of phase transitions during solid-state electrochemical reactions for Li storage devices.
Open Access Status
This publication is not available as open access
First Page
3335
Last Page
3342
Funding Number
21873069
Funding Sponsor
National Natural Science Foundation of China