Fabrication of copper foil using cuprous sulfide superionic conductor under electric field

In this study, the feasibility of preparing copper foil by treating cuprous sulfide superionic conductor with electric field was investigated. The original cuprous sulfide powder was first loaded into the mold, then sandwiched between two electrodes, and then subjected to electropulsing treatment, in which process copper foil grown on the spacer at the cathode. Copper foil with smooth, complete and uniform thickness (the thinnest one is 18 μm) was successfully prepared. The addition of alloying elements in the original powder affected the copper precipitation. The basic factors determining the thickness, flatness and integrity of copper foil is the copper concentration caused by electric field at the cathode end of the copper sulfide block and the energy barrier of copper precipitation in cuprous sulfide matrix and interface. The processing conditions that will affect these fundamental factors will affect the characteristics of the formed Cu foil. Electropulsing processing of superionic conductor provides a new option for the preparation of high-quality Cu foil, which is expected to be used in lithium batteries and printed circuit boards. This method is also applicable to the preparation of other kinds of metal foils.