EFFECTS OF COPPER FOIL AS CATHODE CURRENT COLLECTOR ON PERFORMANCE OF LI-ION BATTERIES

The effects of copper foils with different surface profile as current collector on performance of Li-ion battery are investigated by cyclic voltammetry measurements,scanning electronic microscopy observations as well as measurement of of cyclic performance of batteries.The results indicate that the reducing reaction of electrolyte on the foil with rough surface is much visible than on that with shiny surface,the dissolution potential of matte copper foil is 0.8 V lower than that of the shiny copper foil which implies that the reduction reaction on the rough foil needs much less energy.In other wards,the rough foil is less corrosion resistant.The capacity decrease of battery with shiny copper foil as cathode current collector for Li-ion batteries is much smaller than that with matte copper foil,and the capacity decrease for the latter becomes much obviously speedy by cycling.