| Title |
A Study on the Relation between Passivation Behavior and Casting Microstructure of Copper Anode |
| Authors |
안승천(Sung Chen Ahan); 박수상(Soo Sang Park); 김용환(Young Hwan Kim); 정원섭(Won Sub Chung) |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
Copper; Anode; Passivation; Critical current density; Dendrite arm spacing; Impurity concentration ratio |
| Abstract |
The passivation behavior of copper anode containing impurities in copper sulfate solution was studied as a function of cooling rate in casting process. The passivaton behavior was investigated by electrochemical technique (galvanostatic and potentiostatic tests) and surface analysis (optical microscopy, electron probe micro analysis, scanning electron microscopy). The results obtained were that a anode with larger dendrite arm spacing (DAS) exhibited superior passivation properties such as longer time to passivation and higher critical current density. The optimum range of DAS was 0.2 to 0.25 mm. The improved passivation characteristics could be explained by the increase in (grain boundary)/(grain interior) concentration ratio of impurities such as As, Sb, Bi and O due to slow cooling of anode during casting process. The SEM image revealed that the higher impurities concentration ratios are, the more porous passivation film on the copper anode is. |