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
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
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