Patent ID: 7927747

Claim:
An electrolyte for batteries, comprising an electrolyte salt and an organic solvent, the electrolyte comprising: (a) a first compound having an oxidation initiation voltage (vs. Li/Li + ) higher than the operating voltage of a cathode; and (b) a second reversible compound having an oxidation initiation voltage higher than the operating voltage of the cathode, but lower than the oxidation initiation voltage of the first compound, wherein the first compound is selected from the group consisting of fluorotoluene, t-butyl benzene, di-t-butyl benzene, t-amyl benzene, cyclohexyl benzene, biphenyl, and fluorobiphenyl, the second reversible compound is selected from the group consisting of tetrafluoro dihydrobenzo dioxine, and lithium borates according to the formula Li 2 B 12 F x H 12−x , wherein 0≦x≦3, and the first compound and the second reversible compound are used in an amount of 0.1-10 parts by weight, based on 100 parts by weight of the electrolyte, respectively.