Impact of Mg-Doping Site Control in the Performance of Li4Ti5O12 Li-Ion Battery Anode: First-Principles Predictions and Experimental Verifications

Authors
Cho, HaneolSon, HyunsuKim, DonghunLee, MinhoBoateng, SamuelHan, HyukSuKim, Kang MinKim, SeungchulChoi, HeechaeSong, TaeseupLee, Kyu Hwan
Issue Date
2017-07-20
Publisher
American Chemical Society
Citation
The Journal of Physical Chemistry C, v.121, no.28, pp.14994 - 15001
Abstract
Li4Ti5O12 (LTO) has attracted tremendous attention as a stationary Li-ion battery anode material due to its excellent stability. However, the poor rate capability caused by the low electrical conductivity limits its practical use. Previously, Mg-doping in LTO has been used to improve the electrical conductivity and electrochemical properties, but the Mg-doped LTO system generally exhibits large anomalies in the electrical properties and capacities, which limits the reliable mass-production of engineered LTO. In this study, on the basis of first-principles calculations and related experiments, we systematically study the effects of charge-compensating point defects of the Mg-doped LTO on the electrical properties. A combination of first-principles calculations with thermodynamic modeling shows that high-temperature annealing under reducing conditions could effectively alter the Mg-doping site from a Ti4+ to Li+ site and increase the electrical conductivity significantly due to reduced electron effective mass and increased carrier concentration. Mg-doped LTO annealed under reducing condition exhibits a significantly improved rate compared capability with that of LTO annealed under air condition. The theoretical-analysis-associated experimental results provide more general design guidelines for the preparation of doped LTO with the promise of further improvements in performance.
Keywords
DOPED LI4TI5O12; ELECTROCHEMICAL PERFORMANCE; COMPUTATIONAL PREDICTIONS; LITHIUM BATTERIES; DIFFUSION; INSERTION; DEFECTS; STORAGE; CARBON; DOPED LI4TI5O12; ELECTROCHEMICAL PERFORMANCE; COMPUTATIONAL PREDICTIONS; LITHIUM BATTERIES; DIFFUSION; INSERTION; DEFECTS; STORAGE; CARBON
ISSN
1932-7447
URI
https://pubs.kist.re.kr/handle/201004/122514
DOI
10.1021/acs.jpcc.7b01475
Appears in Collections:
KIST Article > 2017
Files in This Item:
There are no files associated with this item.
Export
RIS (EndNote)
XLS (Excel)
XML

qrcode

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

BROWSE