Cyclotriphosphazene compounds and their derivatives have the characteristics of high-efficiency flame retardancy and stable chemical and electrochemical properties. In recent years, they have received important attention in lithium-ion batteries' safety research as electrolyte flame retardant additives. Ethoxy pentafluoro cyclotriphosphazene (CAS: 33027-66-6) has excellent flame retardant properties; moreover, it has almost no effect on other battery performance aspects. It is an ideal and widely used lithium-ion electrolyte additive.

    Ethoxy pentafluoro phosphazene has two flame-retardant elements, P and F, which can reduce the required additives, improve the flame-retardant efficiency, significantly improve the safety performance of the electrolyte, and ultimately prevent fire and burning caused by battery abuse and overcharging; the hidden danger of explosion. Simultaneously, the presence of the F element helps to form an excellent SEI film on the electrode interface, improves the compatibility between the electrolyte and the active material, and then stabilizes the electrochemical performance of the electrode. It has good oxidation resistance and can significantly improve the high voltage—cycle performance of the battery.

    Shen Wang and others used ethoxy pentafluoro cyclotriphosphazene for lithium-sulfur batteries for the first time. The addition of 5% mass fraction of ethoxy pentafluoro cyclotriphosphazene made the highly flammable carbonate electrolyte completely incombustible and reduced Small polarization voltage, also significantly improve the rate performance of sulfur-based composites.

    In summary, ethoxy pentafluoro cyclotriphosphazene not only be used as an electrolyte additive for lithium-ion batteries but also can be used to prepare high-quality、flame-retardant materials.