Electrochemical Performance and Reaction Mechanism of Li₃Fe₂(PO₄)₃/C Cathode Material

Authors

Yong XIE, College of Energy, Xiamen University, Xiamen 361005, Fujian, China;
Gui-ming ZHONG, State Key Lab of Physical Chemistry of Solid Surfaces, and College of Chemistry & Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China;
Zheng-liang GONG, College of Energy, Xiamen University, Xiamen 361005, Fujian, China;Follow
Yong YANG, College of Energy, Xiamen University, Xiamen 361005, Fujian, China;State Key Lab of Physical Chemistry of Solid Surfaces, and College of Chemistry & Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China;Follow

Corresponding Author

Zheng-liang GONG(zlgong@xmu.edu.cn);
Yong YANG(yyang@xmu.edu.cn)

Abstract

The cathode material of carbon coated Li₃Fe₂(PO₄)₃ (Li₃Fe₂(PO₄)₃/C) is successfully prepared by sol-gel method and ball-milling carbon coating technique. The cathode material is characterized by XRD, SEM, TEM, and in-situ XAFS techniques. XRD results indicate that the as prepared Li₃Fe₂(PO₄)₃ is of high purity and single phase, and has monoclinic structure with space group of P21/n. Electrochemical measurements show that the carbon-coated material is able to deliver a high initial discharge specific capacity of 128.6 mAh·g^-1 in the voltage range 2.0 ~ 4.0 V at 10 mA·g^-1. While in the voltage range 2.0 ~ 4.95 V, its initial discharge specific capacities can reach 165 mAh·g^-1, which is 1.3 times higher than the theoretical capacity. In-situ XAFS study show that no obvious evidence of Fe³⁺/Fe⁴⁺ redox couple is involved in the electrochemical reaction, indicating that the capacities which beyond the theoretical capacity may come from the high concentration of surface defects introduced by ball milling process.

Graphical Abstract

Keywords

lithium battery, Li3Fe2(PO4)3/C, electrochemical performance, in-situ XAFS technique

DOI Link

https://doi.org/10.13208/j.electrochem.141045

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Publication Date

2015-04-28

Online Available Date

2014-12-25

Revised Date

2014-12-19

Received Date

2014-11-03

Recommended Citation

Yong XIE, Gui-ming ZHONG, Zheng-liang GONG, Yong YANG. Electrochemical Performance and Reaction Mechanism of Li₃Fe₂(PO₄)₃/C Cathode Material[J]. Journal of Electrochemistry, 2015 , 21(2): 123-129.
DOI: 10.13208/j.electrochem.141045
Available at: https://jelectrochem.xmu.edu.cn/journal/vol21/iss2/3