The investigation of novel fluorinated electrolyte additives for lithium metal anodes has been conducted. Two acetic anhydride derivatives, difluoroacetic anhydride (DFAA) and trifluoroacetic anhydride (TFAA), were investigated in electrolytes composed of LiPF 6 in ethylene carbonate (EC) and ethyl methyl carbonate (EMC). The addition of either DFAA or TFAA results in a significant improvement in capacity retention and reversibility of lithium plating. Ex situ surface analysis (XPS, IR-ATR) suggests that incorporation of either TFAA or DFAA results in a lithium carboxylate rich SEI which in turn inhibits SEI degradation resulting in superior cycling performance.

中文翻译：

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氟化乙酸酐作为电解质添加剂可改善锂金属阳极的循环性能

已经进行了用于锂金属阳极的新型氟化电解质添加剂的研究。在碳酸亚乙酯（EC）和碳酸乙基甲酯（EMC）中由LiPF 6组成的电解质中研究了两种乙酸酐衍生物，二氟乙酸酐（DFAA）和三氟乙酸酐（TFAA）。DFAA或TFAA的添加都会显着改善容量保持性和锂电镀的可逆性。异位表面分析（XPS，IR-ATR）表明，掺入TFAA或DFAA都会产生富含羧酸锂的SEI，这反过来会抑制SEI降解，从而带来出色的循环性能。