Effect of polymer additives and chloride ions on electrodeposition behavior and morphology of electrolytic copper powder

To investigate the effect of polymer additives and chloride ions on the electrodeposition behavior and morphology of copper powder, the polarization curves were measured and constant current electrolysis of 300 A m-2 and 500 A m-2 was conducted in an electrolytic solution containing 0.079 mol dm-3 of Cu2+ and 0.5 mol dm-3 of free H2SO4 at 293K and 393K without stirring. Polyethylene glycol (PEG) and polyethyleneimine (PEI) were used as polymer additives. PEG and PEI had a suppressing effect on the electrodeposition of copper powder. The current efficiency for Cu deposition decreased with the addition of PEG and PEI. The addition of PEG decreased the average particle size of the copper powder, while PEI didn't change the average particle size. When Cl- coexisted with PEG, the suppressing effect on the electrodeposition of copper powder became even greater and the particle size of the copper powder became finer than when Cl- or PEG was added alone. © 2021 The Japan Institute of Metals and Materials.