Effects of the synergistic interaction of Cl^- and organic additives on the organization and properties of copper foil

With the development of the lithium-ion battery industry, copper foil for negative current collectors is moving toward higher tensile strength, higher elongation, and extremely thin dimensions. By exploring the synergistic interaction laws of Cl^-, SPS, and collagen additives in the plating solution on the microscopic morphology and mechanical properties of copper foil, high-performance copper foils with a tensile strength of 502 MPa and elongation of 5.1% were prepared in this experiment. The surface morphology and texture of the copper foil were characterized by SEM, TEM, XRD and laser confocal microscopy. Its mechanical strength, electrochemical properties, and surface wettability of copper foil were evaluated by the universal testing machine, electrochemical workstation and contact angle tester. The results showed that the synergistic effect of Cl^- and SPS favored the grain refinement of copper foil, increased the Cu(220) crystal plane orientation, and improved the mechanical properties of copper foil. The synergistic effect of Cl^-, SPS and collagen further improved the copper foil (220) crystal orientation and the texture coefficient reached Tc 52%, which significantly improved tensile strength, elongation and surface wetting properties.