Facile dynamic current deposition of high tensile gradient Cu foil with (110) preferred orientation

The conductive copper (Cu) foil is an important raw material in the electronic industry. However, the traditional Cu foil with low tensile strength (∼350 MPa) and poor toughness is prone to breakage during production and usage, which is not conducive to its application in high-density printed circuit boards and high-energy-density batteries. In this work, we report a facile dynamic current deposition (DCD) method for preparing a gradient Cu foil with adjustable thickness (9–50 µm) and a highly preferred crystal orientation of Cu (110). The gradient Cu foil transitions gradually from micron-scale coarse grains to nano-scale fine grains, which promotes its tensile strength (∼840 MPa) while maintaining toughness (∼3.6%). Particularly, the gradient Cu foil shows a high conductivity of 3.3 × 107 S m−1, indicating its promising application in negative electrode current collectors of lithium-ion batteries and printed circuit boards. The facile DCD method can also provide guidance for the fabrication of other metallic materials.