设计并合成了一系列基于苯环和环状碳酸酯的有机分子双(2,3-环碳酸甘油酯)对苯二甲酸酯、 三(2,3-环碳酸甘油酯)均苯三甲酸酯和四(2,3-环碳酸甘油酯)均苯四甲酸酯,采用倍率测试、 恒流充放电测试、交流阻抗测试和扫描电子显微镜测试等手段研究了这些添加剂对锂离子电池性能的影响.通过对循环20周前后球化石墨电极形貌的对比,发现含均苯四甲酸酯和均苯三甲酸酯的电解液球化石墨电极表面相对于空白电解液可形成一层致密而稳定的固体电解质中间相膜(SEI),从而优化电极-电解液的界面性能,且电池电阻增加较小;在测试电池的倍率性能时发现,均苯四甲酸酯的加入可以改善电池的倍率性能,而对苯二甲酸酯的加入则未能改善电池的循环性能.%A series of organic molecules combined with benzene ring and cyclic carbonate as electrolyte additives, including terephthalicacidbis-( 2-oxo-[ 1, 3 ] dioxolan-4-ylmethyl ) ester ( TABE ) , benzene-1, 3, 5-tricarboxylic acid tris-( 2-oxo-[ 1, 3 ] dioxolan-4-ylmethyl ) ester ( BATE1 ) and benzene-1, 2, 4, 5-tetracarb-oxylic acid tetrakis-(2-oxo-[1,3]dioxolan-4-ylmethyl) ester(BATE2), was designed and synthesized. The effects of these additives on the electrochemical performance of lithium ion batteries were studied by rate capa-bility, constant current charge-discharge test, electrochemical impedance spectroscopy ( EIS ) and scanning electron microscopy ( SEM ) . The results showed that the amount of substituents on benzene ring greatly influenced the interface between electrolyte and graphite. Compared with the blank electrolyte, a dense and stable Solid electrolyte interface ( SEI ) film could be observed on the surface of the graphite electrode with BATE1 or BATE2 after 20 charge-discharge cycles, which could optimize the interface between the electrode and the electrolyte and led to the less increase of battery resistance. The test of the rate capability of the battery showed that the addition of BATE2 could improve the rate performance of the battery;meanwhile TABE could make the battery' s performance worse.
展开▼
