Surface treatment of 7005 aluminum alloy with anodization technique for aluminum air battery application

The arrangement of the aluminum anode impacts the discharge performance of aluminum-air batteries due to its microstructure, thus necessitating surface treatment to alter its structure. One surface treatment is anodization. This research aims to determine the optimal conditions for the anodization process for battery applications and its characterization, as well as the elec- trochemical performance utilizing the NaCl electrolyte. The anodization process was carried out in an oxalic acid solution with a concentration of 0.3 M. The applied anodizing potentials range from 10 V to 30 V, providing a broader spectrum for examining their effects, and the process is conducted for time periods of 40, 50, and 60 min. After the anodization stage, the aluminum is washed and then dried in an oven at 105 °C. In this research, characterization tests include linear polarization, electrochemical impedance spectroscopy (EIS) and galvanostatic discharge tests for aluminum anodes using NaCl concentration variations of 1.5–5 %. The optimal condition is achieved at a voltage of 30 V for 40 min. With anodization, the electrode resistance is reduced, and the conductivity is increased. Under this process condition, the lowest resistance value is 0.156 Ω, the corrosion current is 159 A/cm 2 , the voltage transfer resistance (Rp) is 35.260 Ω, and the con- ductivity (Y0) is 33.672 Mho. The highest specific discharge capacity was achieved in samples with a discharge current of 0.05 mA/cm 2 , which was 134.1867 mAh/gram. The samples with a NaCl electrolyte concentration of 1.5 % exhibited the greatest specific discharge capacity, measuring 130.1204 mAh/gram. • Optimal conditions using 0.3 M oxalic acid at 30 V for 40 min, decrease the electrode resistance and enhance conductivity. • Lower NaCl electrolyte concentrations contributing to prolonged discharge times and enhanced discharge capacities. • Galvanostatic discharge testing indicates lower currents result in longer discharge times and higher discharge capacities.