四氟硼酸四乙基铵对超级电容电池性能的影响

研究了四氟硼酸四乙基铵(Et4,NBF4)添加到LiPF6基电解液(碳酸乙烯酯(EC)+碳酸二甲酯(DMC)+碳酸甲乙酯(EMC)(质量比为1∶1∶1)对(LiMn2O4+活性炭(AC))/Li4Ti5O12超级电容电池电化学性能的影响.线性扫描(LSV)、循环伏安(CV)及电池充放电等测试结果表明:Et4NBF4盐改变了复合电解液中离子对的结构,提高了复合电解液的高电压稳定性和电导率.在实验条件下,随着复合盐电解液中Et4NBF4含量的增加,电池放电容量也增加,含有Et4NBF4与LiPF6物质的量的比为4∶1的电解液的电池电化学性能最好,在4C倍率下循环5,000周后,容量还有86.8,mA·h,保持率为95.8%.

Effect of Tetraethylammonium Tetrafluoroborate on the Performance of Super-Capacitor Battery

The effect of blended salts（Et4NBF4 and LiPF6）added to the ethylene carbonate＋dimethyl carbonate＋ethyl（methyl）carbonate（mass ratio of EC,DMC and EMC is 1∶1∶1）on super-capacitor battery system consisting of LiMn2O4/activated carbon（AC）as the cathode,and Li4Ti5O12 as the anode was investigated. The electrochemical performance of the batteries was tested by linear sweep voltammetry（LSV）,cyclic voltammetry（CV） and charge-discharge tests. The results indicate that Et4NBF4 salt charges the structure of ion-pairs,and improves the high-voltage stability and conductivity of composite salts electrolyte. With the addition of Et4NBF4,more free ions are provided,and the capacity of the super capacitor battery increases. It is also found that the battery shows best electro-chemical performance with the mole ratio of Et4NBF4 and LiPF6 being 4∶1,the discharge capacity is 86.8,mA＆#183;h and the capacity retention is 95.8%after 5,000 cycles at 4C rate.