标题：Effect of rich R-TiO2 on the rate and cycle properties of Li4Ti5O12 as anode for lithium ion batteries
作者：Qian, Delai ;Gu, Yijie ;Guo, Shuainan ;Liu, Hongquan ;Chen, Yunbo ;Wang, Juan ;Ma, Guoxuan ;Wu, Chuan
作者机构：[Qian, Delai ;Gu, Yijie ;Liu, Hongquan ;Wang, Juan ;Ma, Guoxuan ] College of Materials Science and Engineering, Shandong University of Science and Tec 更多
来源：Journal of Energy Chemistry
摘要：Li4Ti5O12 (LTO) with rich R-TiO2 (17.06, 23.69, and 34.42 wt%), namely, R-TiO2@Li4Ti5O12 composites, were synthesized using the hydrothermal method and tetrabutyl titanate (TBT) as the precursor. Rietveld refinement of X-ray diffraction (XRD) results show that the proportion of Li occupying 16d sites is extraordinary low and the lattice constants of LTO and R-TiO2 change with the titanium dioxide content. EIS measurements showed that with increasing R-TiO2 content, both its charge transfer impedance (Rct) and lithium ion diffusion coefficient (DLi) decreased. The changes of Rct and DLi caused by the increase of titanium dioxide content have synergic-antagonistic effects on the rate and cycle properties of Li4Ti5O12. The rate performance is positively related to DLi, while the cycle property is negatively correlated with Rct, indicating that the rate performance is mainly related to DLi, while Rct more significantly affects the cycle performance. LTO-RT-17.06% exhibited excellent rate properties, especially under a high current density (5.0 C, 132.5 mAh/g) and LTO-RT-34.42% showed superior long-term cycle performance (0.012% capacity loss per cycle) compared to that of LTO-RT-17.06% and LTO-RT-23.69%.
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