Silicon/graphite composite anodes have drawn extensive attention in the field of power Li-ion batteries for application in electric vehicles because of their much higher capacity than that of traditional graphite anodes. In this work, ethylene sulfate (1,3,2-dioxathiolane-2,2-dioxide, DTD) is investigated as an electrolyte additive to improve the Li-storage performance of silicon/graphite composite anode. The electrochemical behavior of silicon/graphite anode including cyclic voltammogram, discharge/charge performance at various current density and during long-term cycling, and electrochemical impedance is systematically studied by adding different amounts of DTD into electrolyte. The effects of DTD on the solid/electrolyte interphase (SEI) film are analyzed through scanning electron microscopy, X-ray photoelectron and Fourier transform infrared spectroscopy. It is found that DTD participates into the film-formation process through its reductive decomposition reactions on electrode surface, producing a thin, uniform and stable SEI. The Li-storage performance of silicon/graphite anode is improved at an optimized addition amount of DTD.

中文翻译：

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硫酸乙烯酯作为电解质添加剂提高了硅/石墨负极的固体电解质界面和储锂性能

硅/石墨复合负极因其远高于传统石墨负极的容量而在电动汽车动力锂离子电池领域引起了广泛关注。在这项工作中，研究了硫酸乙烯酯 (1,3,2-dioxathiolane-2,2-dioxide, DTD) 作为电解质添加剂，以提高硅/石墨复合负极的储锂性能。通过在电解液中添加不同量的DTD，系统地研究了硅/石墨负极的电化学行为，包括循环伏安图、不同电流密度下和长期循环期间的放电/充电性能以及电化学阻抗。通过扫描电子显微镜分析DTD对固体/电解质界面（SEI）膜的影响，X射线光电子和傅里叶变换红外光谱。发现DTD通过其在电极表面的还原分解反应参与成膜过程，产生薄、均匀、稳定的SEI。在优化的DTD添加量下，硅/石墨负极的储锂性能得到改善。