Patent ID: 8741473

Claim:
A pouch-type lithium secondary battery, comprising: an electrode assembly having an anode, a cathode, and a separator interposed between the cathode and the anode for electrical insulation therebetween; a pouch-type case made of a sheet to provide a space in which the electrode assembly is housed; and a non-aqueous electrolyte injected into the electrode assembly, wherein the non-aqueous electrolyte is a non-linear carbonate-based non-aqueous electrolyte including a lithium salt, (a) a cyclic carbonate compound, and (b) a linear ester compound selected from the group consisting of propionate-based compound, methyl butyrate, propyl acetate, and mixtures thereof, and does not contain a linear carbonate compound, and wherein, during LiPF 6 1M dissolution, the non-aqueous electrolyte has an ionic conductivity of 9 mS/cm or above at about 23° C., wherein a volume ratio (a:b) of the (a) component and (b) component is about 2:8 to about 4:6.