A Size-Dependent Sodium Storage Mechanism in Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub> Investigated by a Novel Characterization
Technique Combining in Situ X‑ray Diffraction and Chemical
Sodiation
Xiqian Yu
Huilin Pan
Wang Wan
Chao Ma
Jianming Bai
Qingping Meng
Steven
N. Ehrlich
Yong-Sheng Hu
Xiao-Qing Yang
10.1021/nl402263g.s001
https://acs.figshare.com/articles/journal_contribution/A_Size_Dependent_Sodium_Storage_Mechanism_in_Li_sub_4_sub_Ti_sub_5_sub_O_sub_12_sub_Investigated_by_a_Novel_Characterization_Technique_Combining_in_Situ_X_ray_Diffraction_and_Chemical_Sodiation/2368255
A novel characterization technique
using the combination of chemical
sodiation and synchrotron based in situ X-ray diffraction (XRD) has
been detailed illustrated. The power of this novel technique was demonstrated
in elucidating the structure evolution of Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub> upon sodium insertion. The sodium insertion behavior
into Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub> is strongly size dependent.
A solid solution reaction behavior in a wide range has been revealed
during sodium insertion into the nanosized Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub> (∼44 nm), which is quite different from the
well-known two-phase reaction of Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub>/Li<sub>7</sub>Ti<sub>5</sub>O<sub>12</sub> system during
lithium insertion, and also has not been fully addressed in the literature
so far. On the basis of this in situ experiment, the apparent Na<sup>+</sup> ion diffusion coefficient (D<sub>Na+</sub>) of Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub> was estimated in the magnitude of 10<sup>–16</sup> cm<sup>2</sup> s<sup>–1</sup>, close to the
values estimated by electrochemical method, but 5 order of magnitudes
smaller than the Li<sup>+</sup> ion diffusion coefficient (D<sub>Li+</sub> ∼10<sup>–11</sup> cm<sup>2</sup> s<sup>–1</sup>), indicating a sluggish Na<sup>+</sup> ion diffusion kinetics in
Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub> comparing with that of
Li<sup>+</sup> ion. Nanosizing the Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub> will be critical to make it a suitable anode material for
sodium-ion batteries. The application of this novel in situ chemical
sodiation method reported in this work provides a facile way and a
new opportunity for in situ structure investigations of various sodium-ion
battery materials and other systems.
2013-10-09 00:00:00
Li 4Ti system
sodium insertion behavior
solution reaction behavior
chemical sodiation method
XRD
ion diffusion kinetics
Li 4Ti Investigated
ion diffusion coefficient
Novel Characterization Technique
sodium insertion
Chemical SodiationA novel characterization technique
Li 4Ti