Tris(4-fluorophenyl) phosphine (TFPP) and tris(2,2,2trifluoroethyl) phosphite (TTFP) were used as flame-retarding additives in Li-ion battery electrolytes. The cell performance of the TFPP- and TTFP-containing electrolytes was examined by cyclic voltammetry, differential scanning calorimetry, electrochemical impedance spectroscopy and scanning electron microscopy. The flammability of the electrolytes was also examined by measuring the self-extinguishing time of the electrolytes. The results showed that the TTFP additive suppressed the flammability of the electrolyte, improved the thermal stability of the battery and its electrochemical cell performance. On the other hand, the TFPP additive only improved the thermal stability of the electrolyte at the expense of a slight decrease in electrochemical cell performance. The results show that TTFP is a better flameretarding additive in the electrolyte of Li-ion batteries than TFPP.

中文翻译：

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三（4-氟苯基）膦和三（2,2,2-三氟乙基）亚磷酸酯作为锂离子电池的阻燃添加剂

三（4-氟苯基）膦（TFPP）和三（2,2,2三氟乙基）亚磷酸酯（TTFP）被用作锂离子电池电解质中的阻燃添加剂。通过循环伏安法、差示扫描量热法、电化学阻抗谱和扫描电子显微镜检查了含有 TFPP 和 TTFP 的电解质的电池性能。还通过测量电解质的自熄时间来检查电解质的可燃性。结果表明，TTFP添加剂抑制了电解液的可燃性，提高了电池的热稳定性和电化学电池性能。另一方面，TFPP 添加剂仅提高了电解质的热稳定性，代价是电化学电池性能略有下降。