Lithium-ion insertion kinetics of Na-doped Li2TiSiO5 as anode materials for lithium-ion batteries

作     者：Yueni Mei Yuyu Li Fuyun Li Yaqian Li Yingjun Jiang Xiwei Lan Songtao Guo Xianluo Hu Yueni Mei;Yuyu Li;Fuyun Li;Yaqian Li;Yingjun Jiang;Xiwei Lan;Songtao Guo;Xianluo Hu

作者机构：State Key Laboratory of Materials Processing and Die&Mould TechnologySchool of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China 

出 版 物：《Journal of Materials Science & Technology》 (材料科学技术（英文版）)

年 卷 期：2020年第54卷第22期

页      面：18-25页

核心收录：

学科分类：0808[工学-电气工程] 08[工学] 0806[工学-冶金工程] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：supported by the National Natural Science Foundation of China (Nos. 51772116 and 51972132) Program for HUST Academic Frontier Youth Team (2016QYTD04)。 

主　　题：Lithium-ion batteries Li2TiSiO5 Anode Lithium-ion diffusion Na doping 

摘      要：Li2TiSiO5 receives much interest recently in lithium-ion battery anodes because of its attractive Liinsertion/extraction potential at 0.28 V(vs. Li+/Li), which bridges the potential gap between graphite and Li4 Ti5 O12. However, Li2TiSiO5 suffers from the low intrinsic electronic conductivity and sluggish Liion transfer kinetics. In this work, we report lithium-ion insertion kinetics of Li2TiSiO5 by Na doping,achieving high-rate capability. Rietveld refinement of X-ray diffraction results reveals that Na doping can enlarge the space of Li slabs, thus reducing the Li-ion transfer barrier and enhancing the Li-ion diffusion kinetics. According to first-principles calculations, Na doping can tune the band structure of Li2TiSiO5 from indirect to direct band, leading to improved electronic conductivity and electrochemical performance. In particular, the Na-doped Li2TiSiO5(Li1.95 Na(0.05)TiSiO5) electrode exhibits outstanding rate capability with a high capacity of 101 m A h g^(-1) at 5 A g^(-1) and superior cyclability with a reversible capacity of 137 m A h g^(-1) under 0.5 A g^(-1) over 150 cycles.