Lithium battery copper foil annealing process

The invention discloses a lithium battery copper foil annealing process which comprises the following steps: (1) carrying out anti-oxidation treatment on a copper foil, and adopting chromium liquid as anti-oxidation liquid; (2) first-stage annealing: performing first-stage annealing on the copper foil subjected to the anti-oxidation treatment, raising the temperature of the first-stage annealing from room temperature to 100 DEG C, and keeping the temperature for 0.5-30 hours; and (3) second-stage annealing: the copper foil subjected to the first-stage annealing is directly subjected to second-stage annealing in a vacuum environment or a nitrogen protection environment, the temperature of the second-stage annealing is increased to 200 DEG C from 100 DEG C, and heat preservation is conducted for 0.5-20 h. The method has the beneficial effects that after the annealing process is completed, the elongation of the copper foil is improved by 1-5%, and the surface and the end face of the annealed copper foil are free