%0 Journal Article
%T FEC 基电解液对高压正极材料 Li<sub>2</sub>CoPO<sub>4</sub>F 电化学性能的影响<br>Influences of FEC-based Electrolyte on Electrochemical Performance of High Voltage Cathode Material？Li<sub>2</sub>CoPO<sub>4</sub>F
%A 王志刚
%A 赵卫民
%A 王红春
%A 林 敏
%A 龚正良
%A 杨 勇&lt
%A br&gt
%A WANG Zhi-gang
%A ZHAO Wei-min
%A WANG Hong-chun
%A LIN Min
%A GONG Zheng-liang
%A YANG Yong
%J 电化学
%D 2018
%R 10.13208/j.electrochem.170509
%X 摘要 本文研究了以氟代碳酸乙烯酯FEC（fluoroethylene carbonate）为共溶剂的电解液对高压正极材料 Li2CoPO4F 电化学性能的影响，与碳酸酯基电解液1 mol·L-1 LiPF6 EC/DMC=1:1（m:m）相比，1 mol·L-1 LiPF6 FEC/DMC=1:1（m:m）可显著提高Li2CoPO4F的循环稳定性. 通过线性扫描伏安法（LSV）、扫描电镜（SEM）、X射线光电子能谱（XPS）、X射线衍射（XRD）结合电化学阻抗（EIS）对 FEC 改善 Li2CoPO4F 材料循环稳定性的机理进行了探索，结果表明与传统碳酸酯基电解液相比，FEC 基电解液在高压下有着优异的抗氧化性，能够有效抑制电解液的氧化分解. 同时，FEC 基电解液中形成的表面膜具有更高的稳定性，能够抑制电极/电解液界面副反应的发生，提高循环过程中电极材料结构稳定性，从而有益于提高 Li2CoPO4F 材料的电化学性能.<br>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
%K 锂离子电池
%K 高压电解液
%K 氟代碳酸乙烯酯
%K 氟磷酸钴锂
%K &lt
%K br&gt
%K lithium ion battery
%K high voltage electrolytes
%K ？fluoroethylene carbonate
%K ？Li&lt
%K sub&gt
%K 2&lt
%K /sub&gt
%K CoPO&lt
%K sub&gt
%K 4&lt
%K /sub&gt
%K F
%U http://electrochem.xmu.edu.cn/CN/abstract/abstract10399.shtml