Method for manufacturing ultrathin electrolytic copper foil

The invention relates to a method for manufacturing a super-thin electrolytic copper foil. (1) An electrolyte contains 90-130g/L copper, 130-150g/L sulphuric acid. (2) The electrolyte is heated 55-66 DEG. C, 5-12 parts dithio-bis-propylene sulfonic acid sodium salt, 0.1-0.9 parts urinary sulfur, 0.9-2.2 parts 2-mercaptobenzothiazole and 20-50 parts polyethyleneglycol molecular weight 400 by weight ratio are added into the electrolyte in 1000 volume part per hour for entering an anode groove after being mixing well. (3) In an electric field, the current density is 65-75A/dm(2) for reacting and obtaining the super-thin electrolytic copper foil. The super-thin electrolytic copper foil crystal is tiny and uniform, difference of thickness uniform is less than 0.3 mum, Ra is less than 0.2 mum, Rz is not larger than 2.0 mum, tensile strength is in between 380-420 N/mm(2). A lithium battery with big capacity manufactured by the super-thin electrolytic copper foil has long cycle life of charge/discharge, and is not easy rupture during over charge.