High Rate and Stable Li-Ion Insertion in Oxygen-Deficient LiV3O8 Nanosheets as a Cathode Material for Lithium-Ion Battery

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• 作者：Huanqiao SongMingsheng Luo ; Aimei Wang
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2017
• 出版时间：January 25, 2017
• 年：2017
• 卷：9
• 期：3
• 页码：2875-2882
• 全文大小：582K
• ISSN：1944-8252

文摘

Low performance of cathode materials has become one of the major obstacles to the application of lithium-ion battery (LIB) in advanced portable electronic devices, hybrid electric vehicles, and electric vehicles. The present work reports a versatile oxygen-deficient LiV₃O₈ (D-LVO) nanosheet that was synthesized successfully via a facile oxygen-deficient hydrothermal reaction followed by thermal annealing in Ar. When used as a cathode material for LIB, the prepared D-LVO nanosheets display remarkable capacity properties at various current densities (a capacity of 335, 317, 278, 246, 209, 167, and 133 mA h g^–1 at 50, 100, 200, 500, 1000, 2000, and 4000 mA g^–1, respectively) and excellent lithium-ion storage stability, maintaining more than 88% of the initial reversible capacity after 200 cycles at 1000 mA g^–1. The outstanding electrochemical properties are believed to arise largely from the introduction of tetravalent V (∼15% V⁴⁺) and the attendant oxygen vacancies into LiV₃O₈ nanosheets, leading to intrinsic electrical conductivity more than 1 order of magnitude higher and lithium-ion diffusion coefficient nearly 2 orders of magnitude higher than those of LiV₃O₈ without detectable V⁴⁺ (N-LVO) and thus contributing to the easy lithium-ion diffusion, rapid phase transition, and the excellent electrochemical reversibility. Furthermore, the more uniform nanostructure, as well as the larger specific surface area of D-LVO than N-LVO nanosheets may also improve the electrolyte penetration and provide more reaction sites for fast lithium-ion diffusion during the discharge/charge processes.