²³Na MAS NMR Spectroscopic Study of Na₂MnPO₄F as Cathode Material for Sodium-Ion Battery

Authors

Xu HOU, State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China;
Gui-ming ZHONG, State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China;
Xiao-chen LIN, State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China;
Zi-geng LIU, State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China;
Xiao-biao WU, State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China;
Yong YANG, State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China;Follow

Corresponding Author

Yong YANG(yyang@xmu.edu.cn)

Abstract

The Na₂MnPO₄F is one of the promising cathode materials for the sodium ion batteries. In the paper, we employed the ex situ X-ray diffraction and solid state NMR techniques to study the charge and discharge processes of this material, including the crystal structure and sodium sites changes. The ex situ x-ray diffraction patterns showed that two new diffraction peaks could be observed at 31^o and 36^o indicating an intermediate phase formed with the extraction of Na+. From the ²³Na MAS NMR spectrum of the material, three peaks were seen at -209 ppm，-258 ppm and -295 ppm, which can be assigned to Na1 + Na2, Na3 and Na4 sites in the crystal structure, respectively. The ex situ solid state NMR study demonstrated that the Na+ in Na1 and Na2 sites deintercalated firstly compared to Na3 and Na4 sites. The signal peaks of intermediate phase appeared at -132 ppm and -330 ppm when charging to 4.2 V. The opposite phenomenon occurred during the discharge process.

Graphical Abstract

Keywords

sodium ion batteries, cathode material, Na2MnPO4F, 23Na MAS NMR

DOI Link

https://doi.org/10.13208/j.electrochem.140401

Publication Date

2014-06-28

Online Available Date

2014-04-21

Revised Date

2014-04-14

Received Date

2014-04-01

Recommended Citation

Xu HOU, Gui-ming ZHONG, Xiao-chen LIN, Zi-geng LIU, Xiao-biao WU, Yong YANG. ²³Na MAS NMR Spectroscopic Study of Na₂MnPO₄F as Cathode Material for Sodium-Ion Battery[J]. Journal of Electrochemistry, 2014 , 20(3): 201-205.
DOI: 10.13208/j.electrochem.140401
Available at: https://jelectrochem.xmu.edu.cn/journal/vol20/iss3/2