A lithium secondary battery capable of preventing explosion or firing caused by the increase of inner pressure due to misusage is disclosed. The lithium secondary battery includes an electrode assembly having an anode plate, a cathode plate and a separator, a package having a receiving portion for receiving the electrode assembly and sealed and filled with electrolyte together with the electrode assembly, and an adhesive layer at least partially formed on an outer surface of the package. The lithium secondary battery functions as an explosion-proof safety device for preventing the package from exploding due to abrupt breakage of the package when the package is expanded due to the increase of inner pressure of the battery over a critical value.