▎ 摘　　要

NOVELTY - Electrolytic copper foil comprises 99.9 wt.% copper, 210-260 μ g/g chlorine and 300-340 μ g/g rare earth element. USE - The electrolytic copper foil is used for lithium ion battery. ADVANTAGE - The electrolytic copper foil has high chlorine element content, good tensile property and folding resistance. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of the copper foil comprising adding additives to sulfuric acid-copper sulfate solution as electrolyte for electrolysis, washing obtained green foil, and drying electrolytic copper foil; where additives include graphene oxide, guar gum, soluble salts of rare earth elements, hydroxypropyl methyl cellulose, polyethylene glycol, polyethylene imine and chlorine-containing compounds.