ELECTROLYTE SOLUTION ADDITIVE COMPOSITION, ELECTROLYTE SOLUTION AND LITHIUM SECONDARY BATTERY

The present invention relates to an electrolyte solution additive composition, an electrolyte solution and a lithium secondary battery. The electrolyte solution additive composition comprises a fluorine-containing pyridine compound having a structure as shown in formula (I) and a phosphite compound having a structure as shown in formula (II), wherein R1, R2, R3 and R4 are each independently selected from hydrogen, a halogen, a C1-C20 alkyl, a halogenated C1-C20 alkyl, a C6-C26 aryl, a halogenated C6-C26 aryl, an amino, an isocyano or an alkoxy; R5, R6 and R7 are each independently selected from a C1-C20 alkyl, a halogenated C1-C20 alkyl, a C6-C26 aryl, and a halogenated C6-C26 aryl; the mass ratio of the fluorine-containing pyridine compound to the phosphite compound is (3-10) : 1. The electrolyte solution additive composition can improve the high-temperature performance of the battery and suppress the increase of the acidity and chromaticity of the electrolyte solution. La présente invention concerne une com