Microstructure, residual stress and corrosion resistance in electrodeposited copper foils

The current collector is a key component in rechargeable lithium ion batteries, which helps to carry electrode materials and collect the current. Copper foil, a thin sheet of Cu, is usually used as the current collector. To meet the requirement of lighter weight and higher energy density of lithium ion batteries, thinner copper foil with lower cost is demanded. In this paper, two commercial electrodeposited copper foils with thickness of 9 μm were studied by X-ray diffraction, scanning electron microscope and electron backscatter diffraction techniques. The corrosion resistance for the copper foils was also estimated by polarization curves. The crystal structure, microstructure, grain preferred orientation, residual stress, and corrosion resistance property were compared for the two foils.