Understanding the roles of Ti on the structure and electrochemical performances of Li2Ru1-xTixO3 cathode materials for Li-ion batteries

• 作者: Hu Zhao Li Xue Xiangfeng Liu Yanchao Shi Yingzhi Cheng Zhongbo Hu
• 来源期刊: 能源化学
• 年，卷（期）: 2019,（6）
• 页码范围: 9-16
• 页数: 8页
• 语种: 英文

摘要

The lattice doping has been widely used to improve the electrochemical performances of Li-rich cath-ode materials but the roles of the introduced foreign atoms are still not very clear. Herein, a series of Li 2 Ru 1- x Ti x O3 solid solutions have been synthesized and the roles of Ti doping on the structural and electrochemical properties of Li 2 RuO3 have been comprehensively investigated. The Rietveld refinement exhibits that the interlayer spacing gradually shortens with increasing Ti content. This shrinkage is fa-vorable to the layered structure stability but increases the lithium diffusion barrier. Galvanostatic mea-surements show that Li 2 Ru 0.8 Ti 0.2 O3 possesses the best cyclability with 196.9 and 196.1 mAh g 1 for charge and discharge capacity retaining after 90 cycles, respectively. Cyclic voltammetry scanning indi-cates that Ti dopant promotes the formation of more peroxo- or superoxo-like species but reduces the initial coulumbic efficiency. Results of electrochemical impedance spectroscopy display that Ti doping reduces the charge transfer impedance, which facilitates the lithium-ion diffusion across the electrolyte-electrode interface and improves the electronic conductivity. Li 2 Ru 0.8 Ti 0.2 O3 exhibits the best electrochem-ical performance owing to the balance among all the factors discussed above. This study also offers some new insights into optimizing the electrochemical performances of Li-rich cathode materials through the lattice doping.

作者信息

序号	姓名	单位	发文数	被引次数	H指数	G指数
1	Hu Zhao	中国科学院大学	1	0	0.0	0.0
2	Yanchao Shi	中国科学院大学	1	0	0.0	0.0
3	Li Xue	中国科学院大学	1	0	0.0	0.0
4	Yingzhi Cheng	中国科学院大学	1	0	0.0	0.0
5	Zhongbo Hu	中国科学院大学	1	0	0.0	0.0
6	Xiangfeng Liu	中国科学院大学	1	0	0.0	0.0