In the present invention, a compound represented by Formula (1) is used as an additive of electrolytic solution for a lithium secondary battery, (where, in Formula (1), R1 to R3 respectively denote any of hydrogen, an alkyl group and a functional group containing halogen; R4 to R8 respectively denote any of hydrogen, a hydrocarbon group, a functional group containing halogen and BF3X; X denotes alkali metal or alkali earth metal; and at least any of R4 to R8 is BF3X).