Effect of Surface Properties of Titanium Anode on Surface Brightness of Electrodeposited Copper Foil

Copper foil has been widely used for fabricating electronic products as conducting wires. Of course, it is also employed as the current collector of lithium ion battery (LIB). For the current collector of a LIB, the common copper foil is made by rolling approach. However, its cost is high although its performance is good. Alternatively, electrodeposited (ED) copper foil, which is cheaper than the rolled copper foil, is produced to replace the rolled copper foil. To meet the requirement of the current collector of a LIB, the surface brightness and crystalline structure of the ED copper foil has to be specifically made. In this work, how to obtain a glossy and smooth surface of the ED copper foil is our target. According to papers(1, 2) the surface condition of the Ti anode for copper foil electrodeposition is critical. Herein, we designed two approaches to reveal which factor is significant if someone would like to obtain a glossy and smooth ED copper foil. One approach is physical, that is polish condition of the Ti anode; the other approach is chemical, that is etching condition of the Ti anode. The brightness of the ED copper foil was measured by a tool. The surface morphologies of the Ti anode and the ED copper foils were imaged using a scanning electron spectroscopy (SEM). The surface element on the processed Ti anode was analyzed by EDS. The copper deposition and oxidation (i.e., stripping) was examined using cyclic voltammetry (CV). The results show that chemical approach is more effective than physical approach to obtain a glossy and smooth ED copper foil. The result is interesting because it indicates that the surface oxidation condition is a key factor to form a glossy and smooth ED copper foil rather than surface roughness of the Ti anode. Keywords: Copper foil, Lithium ion battery, Electrodeposition, Ti anode References: 1. H. Kurihara, K. Kondo and Y. Okamoto, Journal of chemical engineering of Japan, 43, 612 (2010). 2. H. K. Chang, B.-H. Choe and J. K. Lee, Materials Science and Engineering: A, 409, 317 (2005).