Lithium-ion insertion kinetics of Na-doped Li2TiSiO5 as anode materials for lithium-ion batteries
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2020年第22期
论文作者：Yueni Mei Yuyu Li Fuyun Li Yaqian Li Yingjun Jiang Xiwei Lan Songtao Guo Xianluo Hu
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 Na0.05TiSiO5) 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.
Yueni Mei，Yuyu Li，Fuyun Li，Yaqian Li，Yingjun Jiang，Xiwei Lan，Songtao Guo，Xianluo Hu
State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology
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 Na0.05TiSiO5) 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.
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