TY - DATA T1 - A Size-Dependent Sodium Storage Mechanism in Li4Ti5O12 Investigated by a Novel Characterization Technique Combining in Situ X‑ray Diffraction and Chemical Sodiation PY - 2013/10/09 AU - Xiqian Yu AU - Huilin Pan AU - Wang Wan AU - Chao Ma AU - Jianming Bai AU - Qingping Meng AU - Steven N. Ehrlich AU - Yong-Sheng Hu AU - Xiao-Qing Yang UR - 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 DO - 10.1021/nl402263g.s001 L4 - https://ndownloader.figshare.com/files/4007707 KW - Li 4Ti system KW - sodium insertion behavior KW - solution reaction behavior KW - chemical sodiation method KW - XRD KW - ion diffusion kinetics KW - Li 4Ti Investigated KW - ion diffusion coefficient KW - Novel Characterization Technique KW - sodium insertion KW - Chemical SodiationA novel characterization technique KW - Li 4Ti N2 - 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 Li4Ti5O12 upon sodium insertion. The sodium insertion behavior into Li4Ti5O12 is strongly size dependent. A solid solution reaction behavior in a wide range has been revealed during sodium insertion into the nanosized Li4Ti5O12 (∼44 nm), which is quite different from the well-known two-phase reaction of Li4Ti5O12/Li7Ti5O12 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+ ion diffusion coefficient (DNa+) of Li4Ti5O12 was estimated in the magnitude of 10–16 cm2 s–1, close to the values estimated by electrochemical method, but 5 order of magnitudes smaller than the Li+ ion diffusion coefficient (DLi+ ∼10–11 cm2 s–1), indicating a sluggish Na+ ion diffusion kinetics in Li4Ti5O12 comparing with that of Li+ ion. Nanosizing the Li4Ti5O12 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. ER -