POUCH-TYPE LITHIUM SECONDARY BATTERY

摘要

A pouch-type lithium secondary battery includes an electrode assembly having an anode made of carbon material capable of occluding or emitting lithium ions, a cathode made of lithium-containing oxide, and a separator interposed between the cathode and the anode for electrical insulation therebetween; a pouch-type case made of sheet to provide a space receiving the electrode assembly; and a non-aqueous electrolyte injected into the electrode assembly. 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 propionate-based compound, methyl butyrate, and propyl acetate, or their mixtures. During LiPF6 IM dissolution, the non-aqueous electrolyte has an ion conductivity of 9 mS/cm or above at about 23 °C. This pouch-type lithium secondary battery ensures excellent high-rate discharging characteristics and solves swelling problems associated with a pouch-type lithium secondary battery.