Abstract:In order to meet the growing demand of power battery for high specific energy density, it is imperative to develop and apply ultra-thin lithium battery copper foil (≤ 6 μm). Since the low tensile strength of ultra-thin copper foil, the copper foil will break and reduce the qualified rate of products during the coating and winding processes. To solve the above problems, a new additive of ethylene thiourea is used to obtain 6 μm copper foil with tensile strength ≥ 45kg/mm2. The influences of ethylene thiourea on the surface microstructure and grain orientation of copper foil are studied by scanning electron microscope and X-ray diffraction. This work not only provides a new additive for the preparation of ultra-thin and high tensile lithium copper foil, but also provides a research direction for the development of extreme-thin lithium copper foil (≤4.5 μm).