Electrolyte, preparation method thereof and lithium ion battery

The invention provides an electrolyte, a preparation method thereof and a lithium ion battery, and relates to the technical field of lithium ion batteries. The electrolyte comprises a flame retardant and an additive; the flame retardant is pentafluorocyclotriphosphazene containing a functional group, and the functional group is an oxygen-containing functional group of alkyl and halogenated derivatives thereof; the additive is an anhydride compound. 本公开提供了一种电解液及其制备方法和锂离子电池，涉及锂离子电池技术领域；所述电解液包括：阻燃剂和添加剂；所述阻燃剂为含有官能团的五氟环三磷腈，所述官能团为烃基及其卤代衍生物的含氧官能团；所述添加剂为酸酐类化合物。