添加剂氟代碳酸乙烯酯对锂离子电池性能的影响

在1 mol·L-1 LiPF6/碳酸乙烯酯(EC)+碳酸二甲酯(DMC)+碳酸甲乙酯(EMC)(EC、DMC、EMC体积比为1:1:1)电解液中加入体积比为2%的添加剂氟代碳酸乙烯酯(FEC), 用循环伏安法(CV)、扫描电镜(SEM)、能量散射光谱(EDS)、电化学阻抗谱(EIS)等方法, 研究了FEC 对锂离子电池性能及石墨化中间相碳微球(MCMB)电极/电解液界面性质的影响. 结果表明, 体积比2%FEC的添加可以抑制部分电解液溶剂的分解, 在MCMB电极表面形成一层性能优良的固体电解液相界面(SEI)膜, 降低了电池的阻抗, 明显提高了电池的比容量和循环稳定性.

Effect of Fluoroethylene Carbonate Additive on the Performance of Lithium Ion Battery

Fluoroethylene carbonate (FEC) with a volume ratio of 2%was added to the electrolyte containing 1 mol·L-1 LiPF6 in ethylene carbonate (EC), dimethyl carbonate (DMC), and methyl ethyl carbonate (EMC) (1:1:1 by volume). The effects of FEC on lithiumion battery performance and on the mesocarbon microbead (MCMB) electrode/electrolyte interphase were studied by cyclic voltammetry (CV), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and electrochemical impedance spectroscopy (EIS). The results indicated that the application of a 2% (volume ratio) of FEC suppressed electrolyte decomposition and caused the formation of an excellent solid electrolyte interphase (SEI) film on the MCMB electrode. The battery resistance decreased while the specific capacity and cyclic stability of the battery increased.