Method for Preparing Aluminum Thin Film, Aluminum Thin Film, and Positive Electrode and Lithium Secondary Battery Which Include the Aluminum Thin Film

Abstract

A method for preparing an aluminum thin film includes; (A) slitting an aluminum thin film and winding the slit aluminum thin film in one direction, and (B) heat-treating a slit surface including a slit portion of the aluminum thin film in a roll of the wound aluminum thin film. The heat treatment may be performed to satisfy Equation 1 below: - 0.21 ⁢ t + 1 ⁢ 5 ⁢ 0 ≤ T ≤ - 0.21 ⁢ t + 2 ⁢ 1 ⁢ 0 , Equation ⁢ 1 where heat treatment temperature is indicated as T (unit: ° C.) and heat treatment time is indicated as t (unit: seconds). Also disclosed is an aluminum thin film having a thickness of 10 μm to 20 μm, having a tensile strength of 20.0 kgf/mm2 to 30.4 kgf/mm2 in the MD direction, and having an elongation of 1.8% to 2.6% in the MD direction. A positive electrode and a lithium secondary battery including the aluminum thin film are also disclosed.

Dependencies are inferred from the claim text.