Alkali ions pre-intercalated layered vanadium oxide nanowires for stable magnesium ions storage

• Published in: Nano energy 2019-04, Vol.58, p.347-354
• Main Authors: Tang, Han, Xiong, Fangyu, Jiang, Yalong, Pei, Cunyuan, Tan, Shuangshuang, Yang, Wei, Li, Maosheng, An, Qinyou, Mai, Liqiang
• Format: Article
• Language: English
• Subjects: Alkali ions pre-intercalated; Layered vanadium oxides; Magnesium ions storage; Nanowires
• ISSN: 2211-2855
• DOI: 10.1016/j.nanoen.2019.01.053

Owing to the high energy density, high security and low price, rechargeable magnesium batteries (RMBs) are promising candidate for the next generation of high-performance batteries. However, the development of cathode materials for RMBs is hindered by the intensive polarization of Mg2+, which tends to destroy the stability of crystal structure and results in the degradation of batteries. Pre-intercalating the different alkali ions in crystal structure is an effective strategy to improve the layered structure stability and electrochemical performance of materials. Herein, the alkali ions (Li+, Na+, K+) pre-intercalation is presented to improve the structure stability of layered vanadium oxide (A-V3O8) for Mg2+ storage. From the result, the cycling performance of cathode is promoted with the pre-intercalation radius increase. To explain the optimizing principle, we use density functional theory (DFT) calculation to simulate the interaction effect between pre-intercalated cation and layered structure. Among intercalation compounds A-V3O8 (A = Li, Na, K), the electrochemical performance of Na+ pre-intercalated materials (NaV3O8) is better than the most of cathode materials for RMBs. Besides, the reaction mechanism of NaV3O8 is demonstrated. This work confirms that the pre-intercalation of appropriate alkali cation is an efficient strategy to improve the electrochemical performance of layered cathode materials for RMBs. [Display omitted] •Among intercalation compounds A-V3O8 (A=Li, Na, K), NaV3O8 exhibits the best Mg2+ storage performance.•Interaction effect between pre-intercalated cations and layered structure was simulated by DFT calculation.•The structure evolution and reaction mechanism of NaV3O8 in Mg2+ storage have been revealed.