锂离子电池用离子液体电解质的研究  

Research on ionic liquids electrolyte for lithium-ion battery

作　　者：孙珊珊[1] 安茂忠[1] 崔闻宇[1] 杨培霞[1] 

机构地区：[1]哈尔滨工业大学化工学院,黑龙江哈尔滨150001

出　　处：《电源技术》2010年第1期55-58,共4页Chinese Journal of Power Sources

摘　　要：合成了1-甲基-3-乙基咪唑二(三氟甲基磺酰)亚胺(EMI-TFSI)和1-丁基-3-乙基咪唑二(三氟甲基磺酰)亚胺(BMI-TFSI)两种离子液体,并分别研究了它们的各种电化学性质。结果表明,两种离子液体的电化学窗口分别为4.8V和4.6V,离子液体电解质的室温电导率分别为5.4mS/cm和1.6mS/cm。使用LiCoO2和LiFePO4作为锂离子电池正极材料,分别以EMI-TFSI+1.0mol/LLiTFSI、BMI-TFSI+1.0mol/LLiTFSI为电解质组装半电池,测试其循环性能,结果表明:LiCoO2与两种离子液体电解质的相容性较差,而采用LiFePO4正极,以EMI-TFSI+1.0mol/LLiTFSI为电解质组装的半电池具有较高的比容量,经过20次循环(0.1C)几乎无衰减,比容量仍保持在120mAh/g以上,表现出较好的循环能力。Room temperature ionic liquids （RTILs） of 1-ethyl-3-methylimidazolium -bis （trifluoromethylsulfonyl） imide （EMI-TFSI） and 1-butyl-3-methylimidazolium -bis （trifluoromethylsulfonyl）imide （BMI-TFSI） were synthesized and then 1 mol/L LiTFSI was respectively added to the two RIILs to make ionic electrolytes suitable for lithium batteries. The electrochemical properties of both of ionic liquids were investigated. The electrochemical windows are approximately 4.8 V and 4.6 V , and the ionic conductivities of the two electrolytes in room temperature are 5.4 mS/cm and 1.6 mS/cm, respectively. The cycle properties of Li/LiCoO2 and Li/LiFePO4 with the two ionic liquids as electrolyte were studied. The results show that the cell performances of Li/LiCoO2 with both of the electrolytes are not good enough, while LiFePO4 has a better compatibility with EMI-TFSI than that with BMI-TFSI. LiFePO4/Li cell using EMITFSI＋1.0 mol/L LiTFSI as the electrolyte still has the specific discharge capacity of 120 mAh/g after 20 cycles （0.1 C）,which shows quite a good cycle ability.

关 键 词：离子液体电解质 锂离子电池 循环性能 

分 类 号：TM911[电气工程—电力电子与电力传动]