Effect of Potassium Carbonate Additives on the Properties of Copper Foils Electroplated at High Current Density

Abstract

The amount and kind of additives in electrolytes play a very important role on the electroplating of Cu foil, which is used as a cathode materials for secondary batteries. As the use of Cu foil increased, various studies on the electroplated Cu foil are urgently needed. We studied surface characteristics and changes in structural properties due to the addition of inhibitors under electroplating conditions with high current density. The surface layer was observed, to analyze the effect of the amount of potassium carbonate as an inhibitor. When the potassium carbonate was added at 5~25 ppm without any other additives, the initial plating voltage was observed to decrease. To uniformly distribute crystals without agglomeration at the initial stage of electroplating, it is reasonable to add potassium carbonate within the range of 20~25 ppm. There was no significant difference in surface roughness and specific resistance due to the amount of potassium carbonate, when the additives were added complexly. There was an increase in the relative strength of the preferred growth orientation of (220) in a group with 20 ppm potassium carbonate, compared to the group with 10 ppm potassium carbonate. The grain size decreased with the amount of potassium carbonate added with other additives. However, there was no significant difference in tensile strength and elongation (p-value: 0.000). To ensure uniform properties with a combination of 4 kinds of additives it is reasonable to add potassium carbonate in the range of 10~20 ppm.