NOVELTY - An electrolyte (A) comprises: a lithium salt composition including a first lithium salt; a lithium bisfluorosulfonyl imide as second lithium salt, where mole ratio of the first lithium salt to second lithium salt is 1:0.05 to 1:1; and a non-aqueous organic solvent.    USE - As electrolyte for rechargeable lithium battery (claimed), which is useful for laptops, mobile phones, electric vehicles (EV), and hybrid electric vehicles (HEV).    ADVANTAGE - The electrolyte for rechargeable lithium battery has improved low temperature output, and high temperature characteristics. In the electrolyte, first lithium salt and the second lithium salt are present at mole ratio of (1:0.05 to 1:1, preferably 1:0.25 to 1:0.43). When mole ratio of first lithium salt and second lithium salt goes out of this range i.e. when mole ratio of second lithium salt exceeds this range, current collector of positive electrode may corrode. Also, since lithium bisfluorosulfonyl imide, which is second lithium salt, has low viscosity at low temperature e.g. 35 mPas at -20 degrees C, electrolyte including lithium bisfluorosulfonyl imide shows small increase in viscosity of organic solvent at low temperature, thus mobility of resultant lithium ions can be maintained, and low temperature output can be remarkably improved. However, when lithium bisfluorosulfonyl imide is alone used as lithium salt of electrolyte, current collector of positive electrode formed of aluminum, may corrode. Further, in electrolyte amount of second lithium salt is 0.05-0.5 M. When amount of second lithium salt falls in this range; ion conductivity at room temperature and low temperature is higher than ion conductivity, when first lithium salt is used alone. The first lithium salt is present at 0.5-1.3 M. When amount of first lithium salt falls in this range; excellent output characteristics are obtained. The first lithium salt improves low temperature output characteristics. Also, in electrolyte, entire lithium salt composition including first lithium salt and second lithium salt at low temperature (-20 degrees C) has ion conductivity of greater than or equal to 1.7 mS/cm and viscosity of less than or equal to 60 mPas, which improves low temperature output.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a rechargeable lithium battery (1) comprising: the electrolyte (A); a positive electrode (3) including a positive active material; and a negative electrode (2) including a negative active material.    DESCRIPTION OF DRAWING(S) - The figure shows schematic view of structure of rechargeable lithium battery.    Rechargeable lithium battery (1)    Negative electrode (2)    Positive electrode (3)    Separator (4)    Battery case (5)    Sealing member (6)