Influences of FEC-based Electrolyte on Electrochemical Performance of High Voltage Cathode Material Li₂CoPO₄F

Authors

Zhi-gang WANG, College of Energy，Xiamen University，Xiamen 361005，Fujian，China;
Wei-min ZHAO, College of Energy，Xiamen University，Xiamen 361005，Fujian，China;
Hong-chun WANG, College of Energy，Xiamen University，Xiamen 361005，Fujian，China;
Min LIN, College of Energy，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 effects of fluoroethylene carbonate (FEC) as co-solvent on the electrochemical performance of high voltage cathode material Li₂CoPO₄F are investigated. Compared with traditional carbonate based electrolyte (1 mol·L^-1 LiPF₆ EC/DMC (1:1, m:m)), the FEC/DMC based electrolyte can significantly improved the electrochemical performance of Li₂CoPO₄F. After 100 cycles between 3V and 5.4 V at 1 C rate, the capacity retention of Li₂CoPO₄F electrode in 1 mol·L^-1 LiPF₆ EC/DMC (1:1, m:m) was 52.6 % , while that in the EC/DMC based electrolyte was only 14.5 %. Possible functional mechanisms of FEC improving the electrochemical performance of Li₂CoPO₄F were studied by LSV, EIS, SEM and XPS measurements. It was shown that compared with the traditional EC/DMC based electrolyte, the FEC/DMC based electrolyte exhibited higher stability at high voltage, which suppressed the side reactions at electrode/electrolyte interface when charged to high voltage, and improved the structure stability of Li₂CoPO₄F during cycling, thus, significantly enhanced the electrochemical performance of Li₂CoPO₄F.

Graphical Abstract

Keywords

lithium ion battery, high voltage electrolytes; fluoroethylene carbonate; Li2CoPO4F

DOI Link

https://doi.org/10.13208/j.electrochem.170509

Publication Date

2018-06-28

Online Available Date

2017-06-09

Revised Date

2017-06-06

Received Date

2017-05-11

Recommended Citation

Zhi-gang WANG, Wei-min ZHAO, Hong-chun WANG, Min LIN, Zheng-liang GONG, Yong YANG. Influences of FEC-based Electrolyte on Electrochemical Performance of High Voltage Cathode Material Li₂CoPO₄F[J]. Journal of Electrochemistry, 2018 , 24(3): 216-226.
DOI: 10.13208/j.electrochem.170509
Available at: https://jelectrochem.xmu.edu.cn/journal/vol24/iss3/3