Investigation on Coating Process Parameters Control of PET-Cu Composite Current Collector

The advantages of composite current collector (CCC), including high safety, high energy density, and low cost, have garnered significant attention in academia and industry. Currently, CCC is usually produced by vacuum winding coating, and its coating process parameters (CCP) are mainly determined by exploratory experiments and repeated sample performance tests, which are costly, with long debugging time and slow feedback iteration. Therefore, in this paper, the molecular dynamics method is employed to simulate the magnetron sputtering deposition process of copper (Cu) atoms on the polyethylene terephthalate (PET) substrate using the LAMMPS software to determine the appropriate CCP. The results show that the diffusion capability of the deposited Cu atoms is enhanced with increasing incident energy (1 – 10 eV) and decreasing incident angle (45 – 15°). This results in a gradual transition of the Cu film from amorphous to crystalline, the disappearance of island clusters and voids within the Cu film, and a continuous reduction in the surface roughness of the film. An elevation in the temperature of the PET substrate facilitates a decrease in the roughness of the Cu film. However, if the temperature of the PET substrate is excessively elevated, it can result in the disruption of the lattice structure of the Cu film, which subsequently leads to a deterioration in the quality of the Cu film.