Abstract:Lithium electrolytic copper foil was prepared under different chloride ion mass concentration （0~60 mg/L） by self-made copper foil test device. The microstructure and properties of copper foil were analyzed by glossmeter， roughness meter， electronic universal testing machine， scanning electron microscope （SEM） and X-ray diffractometer （XRD）. The results showed that with the increase of chloride ion mass concentration， the luster of copped foil increased first and then decreased， and the tensile strength was reduced from 58 kg/mm2 to about 33 kg/mm2 and then remained basically unchanged. Adding appropriate amount of chloride ions could make the copper foil surface smoother， and excessive chloride ions could make the copper foil surface rough.