Real surface area determination of dendritic porous copper films electrodeposited by pulsating overpotential regime using cyclic voltammetry method

Abstract

To increase the active surface area of copper collectors in Li-ion batteries, electrochemical deposition of porous copper films was carried out using a solution of 0.15 M CuSO₄·5H₂O in 0.5 M H₂SO₄. Square-wave pulsating overpotential deposition was performed at overpotential amplitudes of −1100, −1250 and −1400 mV vs. Ag/AgCl on copper foil, rated for Li batteries. Energy-dispersive method analysis and a scanning electron microscope were used to characterize film morphology. X-ray diffraction method was used to analyse structural properties of the deposits. Electroactive and real surfaces of the samples were measured using cyclic voltammetry (CV) in a 0.1 M KOH solution. The results showed that by increasing the applied negative overpotential, the electroactive and real surface area of the samples were increased. As a result, the sample values of 47.13, 58.50 and 62.63 cm² were obtained at the respective deposition overpotential amplitudes of −1100, −1250 and −1400 mV. For untreated film, however, the value was around 9.35 cm². Ultimately, it was discovered that CV is a highly effective technique for determining the real surface area of porous copper foils.