Patent ID: 8163427

Claim:
A lithium secondary battery comprising a positive electrode, a negative electrode and a non-aqueous electrolytic solution, wherein the positive electrode comprises a positive electrode composition layer having a density in the range of 3.2 to 4.0 g/cm 3 provided on aluminum foil, said positive electrode composition layer comprising a complex metal oxide of lithium, wherein the negative electrode comprises a negative electrode composition layer having a density in the range of 1.3 to 2.0 g/cm 3 provided on copper foil, said negative electrode composition layer comprising a material capable of absorbing and releasing lithium, and wherein the non-aqueous electrolytic solution comprises an electrolyte salt and a non-aqueous solvent comprising a chain carbonate and a cyclic carbonate selected from the group consisting of ethylene carbonate and propylene carbonate, wherein the non-aqueous electrolytic solution contains a vinylene carbonate compound of formula (I) in an amount of 0.05 to 5 wt. % and an alkyne compound of formula (VI) in an amount of 0.1 to 3 wt. %: in which each of R 1 and R 2 independently is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms: in which each of R 25 to R 27 independently is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 12 carbon atoms, or R 26 and R 27 are combined with each other to form a cycloalkylene group having 3 to 6 carbon atoms; x is 1 or 2; W is sulfinyl or oxalyl; and Y 6 is an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkynyl group having 2 to 12 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 12 carbon atoms.