| 摘要 |
Provided is a method of preparing a lithium secondary battery including performing a pretreatment, in which an SEI (solid electrolyte interphase) film is formed on an electrode by impregnating the electrode in a composition for forming an SEI film, which includes a lithium salt, a non-aqueous organic solvent, and an SEI film-forming agent capable of forming the SEI film by an electrochemical oxidation or reduction decomposition reaction, and applying a voltage to the electrode, and preparing an electrode assembly using the electrode having the SEI film formed thereon, putting the electrode assembly in a battery case, and performing a combination process of electrolyte injection and charging one or more times. According to the preparation method, output characteristics and lifetime characteristics of a lithium secondary battery may be further improved by forming an SEI film on an electrode in advance through the pretreatment of the electrode, putting the electrode having the SEI film formed thereon in a battery case, and stepwise injecting an electrolyte one or more times. |
