With increasing application demands of electronics and electric vehicles, the energy density of lithium-ion batteries (LIBs) is expected to be higher and higher. The silicon-based anode materials have triggered global research interest due to low operating voltage and high specific capacity. However, for the Si-based anode, the large volume change during cycling causes cracking and pulverization of Si particles, leading to the sluggish kinetics and poor cycle life. In this work, fluoroethylene carbonate (FEC) and lithium bis(fluorosulfonyl)imide (LiFSI) are used as synergistic functional additives to enhance the performance of silicon–carbon (Si–C) composite anode in pouch cell. The properties of solid electrolyte interphase (SEI) formed on the surface of Si–C composite anode have been systematically investigated. The images of different electrolytes infiltration and gas production after formation are analyzed with ultrasonic transmission scanning technique. DFT calculations are used to illustrate the mechanism. All date collection is at pouch cell level, which is more persuasive.

中文翻译：

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协同功能添加剂对软包电池中硅碳复合负极循环性能的影响


随着电子产品和电动汽车应用需求的增加，锂离子电池 （LIB） 的能量密度预计将越来越高。硅基负极材料因其低工作电压和高比容量而引发了全球研究的兴趣。然而，对于硅基负极，循环过程中较大的体积变化会导致硅颗粒开裂和粉碎，导致动力学缓慢和循环寿命差。在本工作中，氟碳酸乙烯酯 （FEC） 和双（氟磺酰基）酰亚胺锂 （LiFSI） 用作协同功能添加剂，以增强软包电池中硅-碳 （Si-C） 复合负极的性能。系统研究了在 Si-C 复合负极表面形成的固体电解质界面 （SEI） 的性质。使用超声透射扫描技术分析不同电解质浸润和形成后气体产生的图像。DFT 计算用于说明该机制。所有椰枣收集都在袋状细胞水平，这更有说服力。