Sodium-ion battery flame-retardant electrolyte and application thereof

The invention relates to the technical field of sodium-ion batteries, in particular to a flame-retardant electrolyte for a sodium-ion battery and application of the flame-retardant electrolyte. The invention provides a sodium ion battery flame-retardant electrolyte, the electrolyte comprises 60-90 wt% of an organic solvent, 5-20 wt% of a sodium salt, 0.1-10 wt% of a film-forming additive, and 3-20 wt% of a composite flame-retardant additive, the composite flame-retardant additive comprises a phenyl phosphate compound and a phosphazene compound, and the mass ratio of the phenyl phosphate compound to the phosphazene compound is 1: 9-9: 1. According to the invention, the phenyl phosphate compound and the phosphazene compound are added into the electrolyte as the composite flame-retardant additive, and the ratio of the phenyl phosphate compound to the phosphazene compound is regulated, so that the addition amount of the phosphorus flame retardant is greatly reduced; and the electrolyte which is high in compatibil