以丙酸乙酯（EP）作为碳酸乙烯酯（EC）、碳酸甲乙酯（EMC）和碳酸二甲酯（DMC）的共溶剂，研究其对LiFePO4锂离子电池低温电化学性能的影响. 利用循环伏安曲线、交流阻抗图谱和恒电流充放电曲线等方法测试电池电化学性能. 结果表明，添加一定量EP，可提高碳酸酯电解液的离子电导率，改善电解液与正极LiFePO4材料和负极石墨材料的相容性，从而提高了LiFePO4锂离子电池的低温性能. 使用1 mol·L-1 LiPF6/(EC:EMC:DMC:EP=1:1:1:3, by mass)电解液的石墨/LiFePO4锂离子电池在10 ºC（1C）、-10 ºC（0.2C）、-20 ºC（0.2C）、-30 ºC（0.2C）和-40 ºC（0.2C）下的相对放电容量（以25 ºC时的放电容量为基准）分别为82.9%、75.6%、59.0%、46.4%和37.6%.
李小平
,
郝连升
,
李伟善
,
许梦清
,
邢丽丹
. 丙酸乙酯对LiFePO4锂离子电池低温性能的影响[J]. 电化学, 2013
, 19(3)
: 237
-245
.
DOI: 10.61558/2993-074X.2955
A linear carboxylic, ester ethyl propionate (EP), was used as the co-solvent of carbonates, ethylene carbonate (EC), ethyl-methyl carbonate (EMC) and dimethyl carbonate (DMC), and its effect on low-temperature performance of LiFePO4-based Li-ion battery was studied by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge-discharge test. The application of EP enhances the ionic conductivity of the electrolyte, improves the compatibility of the electrolyte with both LiFePO4 and graphite materials, and thus improves the low-temperature performance of LiFePO4-based Li-ion battery. The Li-ion battery using the optimized electrolyte of 1 mol·L-1 LiPF6/EC:EMC:DMC:EP (1:1:1:3) shows the capacity retention of 82.9%, 75.6%, 59.0%, 46.4%, and 37.6% of discharge capacity at room temperature when discharged at 10 oC (1C), -10 oC (0.2C), -20 oC (0.2C), -30 oC (0.2C), and -40 oC (0.2C), respectively.
