ELECTROLYTE SOLUTION FOR LITHIUM SECONDARY BATTERY, LITHIUM SECONDARY BATTERY CONTAINING THE SOLUTION WITH GOOD COATING QUALITY AND PREPARATION METHOD THEREOF

摘要

PURPOSE: A nonaqueous electrolyte solution for a lithium secondary battery, a lithium secondary battery containing the electrolyte solution and its preparation method are provided, to improve the quality of coating by removing the impurities adhered to the surface of a negative electrode active material. CONSTITUTION: The nonaqueous electrolyte solution comprises 0.005-0.5 wt% of a radical generator; a nonaqueous organic solvent containing 30-95 vol% of a cyclic carbonate; and a solute. Preferably the radical generator is an azo compound; and/or comprises at least one peroxide selected from the group consisting of a diacyl peroxide, a peroxydicarbonate and a peroxyester. Preferably the nonaqueous organic solvent contains 5-70 vol% of a chain carbonate. The method comprises the steps of adding the nonaqueous electrolyte solution to a positive electrode and a negative electrode to form an electrode assembly; and heating the electrode assembly. Preferably the heating is carried out at a temperature of 40-90 deg.C for 30-600 min.