Elucidating the Limit of Li Insertion into the Spinel Li 4Ti 5O 12

Elucidating the Limit of Li Insertion into the Spinel Li 4Ti 5O 12

TitleElucidating the Limit of Li Insertion into the Spinel Li 4Ti 5O 12
Publication TypeJournal Article
Year of Publication2019
AuthorsHaodong Liu, Zhuoying Zhu, Jason Huang, Xin He, Yan Chen, Rui Zhang, Ruoqian Lin, Yejing Li, Sicen Yu, Xing Xing, Qizhang Yan, Xiangguo Li, Matthew J Frost, Ke An, Jun Feng, Robert Kostecki, Huolin L Xin, Shyue Ping Ong, Ping Liu
JournalACS Materials Letters
Volume1
Issue1
Pagination96 - 102
Date Published05/2019
ISSN2639-4979
Abstract

In this work, we show that the well-known lithium-ion anode material, Li4Ti5O12, exhibits exceptionally high initial capacity of 310 mAh g–1 when it is discharged to 0.01 V. It maintains a reversible capacity of 230 mAh g–1, far exceeding the “theoretical” capacity of 175 mAh g–1 when this anode is lithiated to the composition Li7Ti5O12. Neutron diffraction analyses identify that additional Li reversibly enters into the Li7Ti5O12 to form Li8Ti5O12. density functional theory (DFT) calculations reveal the average potentials of the Li4Ti5O12 to Li7Ti5O12 step and the Li7Ti5O12 to Li8Ti5O12 step are 1.57 and 0.19 V, respectively, which are in excellent agreement with experimental results. Transmission electron microscopy (TEM) studies confirm that the irreversible capacity of Li4Ti5O12 during its first cycle originates from the formation of a solid electrolyte interface (SEI) layer. This work clarifies the fundamental lithiation mechanism of the Li4Ti5O12, when lithiated to 0.01 V vs Li.

DOI10.1021/acsmaterialslett.9b00099
Short TitleACS Materials Lett.
Refereed DesignationRefereed