This invention relates to the field of secondary batteries, specifically, to providing an organic
electrolyte for
sodium-
ion batteries, a preparation method thereof, and its application in
sodium-
ion batteries. The
electrolyte for
sodium-
ion batteries comprises sodium salts, organic solvents, and additives, wherein the additives include
nitrile compounds, sulfonates, and organic sodium salts; this
electrolyte can generate a dense SEI layer rich in various inorganic elements, ensuring the sodium... + The rapid
diffusion of ions, combined with a suitable reduction in the
organic content of the SEI, improves the stability of the SEI during long-term
cycling. Compared to sodium-ion batteries assembled using
phosphate materials as the positive
electrode active material, the capacity
retention rate is greater than 80% after 1000 cycles at 1C rate.