| 摘要 |
PURPOSE: Provided is a lithium secondary battery which effectively prevents the swelling of the electrolyte, and makes no leakage, so that instability of the battery due to the leakage is prevented. CONSTITUTION: The battery comprises: a roll type electrode assembly consisting cathode, anode and a separator in between; the electrolyte including 3-30wt.% (based on total electrolyte) of the crosslinked product of polyethylene glycol dimethylacrylate of formula 1, lithium salts such as LiClo4, LiBF4, LiPF6, LiCF3SO3 and LiN(CF3SO2)2 and more than one organic solvent selected from propylene carbonate, ethylene carbonate, dimethyl carbonate, methylethyl carbonate, diethyl carbonate and vinylene carbonate; and a pouch type case containing the above materials. In the formula 1, n is an integer from 25 to 25000, R1 and R2 are independently hydrogen or C1-20 alkyl. The molecular weight of the above crosslinked product of polyethylene glycol dimethylacrylate is 5000-5,000,000 and the crosslinked product is obtained by heat polymerization after the whole electrolyte is introduced into the above battery case. |
