A nonaqueous electrolyte for improving overcharge safety of a lithium battery using the same includes an organic solvent, a lithium salt, and a hydride of a compound represented by the Formula 1: ##STR1##

R₁, R₂, R₃, R₄, R₅, R₆, R₇, R₈, R₉, R₁₀, R₁₁, R₁₂, R₁₃ and R₁₄ are the same or different, and are independently hydrogen, halogen, a substituted or unsubstituted C1-C20 alkyl, a substituted or unsubstituted C1-C20 alkoxy, nitro or amine group. The nonaqueous electrolyte forms a polymer due to its oxidative decomposition even if there is an increase in voltage due to overcharge of a battery by some uncontrollable conditions.