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Nano Research

Article Title

NaV6O15: A promising cathode material for insertion/extraction of Mg2+ with excellent cycling performance

Authors

Dongzheng Wu, Collaborative Innovation Center of Chemistry for Energy Materials, State Key Lab of Physical Chemistry of Solid Surfaces, State-Province Joint Engineering Laboratory of Power Source Technology for New Energy Vehicle, Engineering Research Center of Electrochemical Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
Jing Zeng, Collaborative Innovation Center of Chemistry for Energy Materials, State Key Lab of Physical Chemistry of Solid Surfaces, State-Province Joint Engineering Laboratory of Power Source Technology for New Energy Vehicle, Engineering Research Center of Electrochemical Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
Haiming Hua, Collaborative Innovation Center of Chemistry for Energy Materials, State Key Lab of Physical Chemistry of Solid Surfaces, State-Province Joint Engineering Laboratory of Power Source Technology for New Energy Vehicle, Engineering Research Center of Electrochemical Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
Junnan Wu, Collaborative Innovation Center of Chemistry for Energy Materials, State Key Lab of Physical Chemistry of Solid Surfaces, State-Province Joint Engineering Laboratory of Power Source Technology for New Energy Vehicle, Engineering Research Center of Electrochemical Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
Yang Yang, School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China
Jinbao Zhao, Collaborative Innovation Center of Chemistry for Energy Materials, State Key Lab of Physical Chemistry of Solid Surfaces, State-Province Joint Engineering Laboratory of Power Source Technology for New Energy Vehicle, Engineering Research Center of Electrochemical Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China

Keywords

NaV6O15, alkali metal pre-intercalation, rechargeable magnesium battery, cathode, electrochemical mechanism

Abstract

The rechargeable magnesium batteries (RMBs) are getting more and more attention because of their high-energy density, high-security and low-cost. Nevertheless, the high charge density of Mg2+ makes the diffusion of Mg2+ in the conventional cathodes very slow, resulting in a lack of appropriate electrode materials for RMBs. In this work, we enlarge the layer spacing of V2O5 by introducing Na+ in the crystal structure to promote the diffusion kinetics of Mg2+. The NaV6O15 (NVO) synthesized by a facile method is studied as a cathode material for RMBs with the anhydrous pure Mg2+ electrolyte. As a result, the NVO not only exhibits high discharge capacity (119.2 mAh·g−1 after 100 cycles at the current density of 20 mA·g−1) and working voltage (above 1.6 V vs. Mg2+/Mg), but also expresses good rate capability. Besides, the ex-situ characterizations results reveal that the Mg2+ storage mechanism in NVO is based on the intercalation and de-intercalation. The density functional theory (DFT) calculation results further indicate that Mg2+ tends to occupy the semi-occupied sites of Na+ in the NVO. Moreover, the galvanostatic intermittent titration technique (GITT) demonstrates that NVO electrode has the fast diffusion kinetics of Mg2+ during discharge process ranging from 7.55 × 10−13 to 2.41 × 10−11 cm2·s−1. Our work proves that the NVO is a potential cathode material for RMBs.

Graphical Abstract

Publisher

Tsinghua University Press

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