An investigation on the performance assessment of copper-coated aluminium air battery using electro deposition method

In the present work, copper coatings deposited electrochemically on AA5083 alloy anodes for aluminium-air batteries (AABs) are studied with respect to their influence on electrochemical performance. Copper is deposited on the surface of aluminium alloy by electrodeposition, and the morphology is characterized by scanning electron microscope (SEM). Four different trials are conducted with copper coating to aluminium anode and each trial contained mixed solution of different composition. The current supply for each trial is maintained at 0.3A and the deposition time for trial 1 to trial 4 are 15 min at 35 °C, 30 min at 60 °C, 1 h at 45 °C and 1 h at 55 °C respectively. The deposition efficiency of the sample 4 is 80.75% and the coating thickness is 1.1014 cm. The investigation on the electrochemical behaviour of the coated and non-coated anodes is obtained by open-circuit potential (OCP), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), hydrogen evolution, and corrosion rate tests. The scan rate of Cyclic voltammetry (CV) measurement is 10 mV s -1 . Potentio-dynamic polarization of the samples range from − 250 mV to + 250 mV with respect to the stabilized OCP at a scan rate of 1 mV s -1 . The open circuit potential of the bare AA5083 aluminium-air battery and copper-coated AA5083 battery are 1.42042 V and 1.20145 V, respectively. FESEM analysis confirmed copper deposition on the surface of AA5083. Electrochemical test showed that the non-coated anode had better corrosion resistance than copper-coated anode. The Icorr value increases from 3.24 µA cm⁻ 2 to 6.10 µA cm⁻ 2 after copper coating, indicating enhanced anodic dissolution. The corrosion rate measurements are 0.0358 mm y -1 for the bare alloy and 0.0675 mm y -1 for the copper-coated alloy. The corrosion rate of coated anode is higher than bare aluminium anode. EIS analysis revealed a significant reduction in the impedance of AA5083 after copper coating. The charge-transfer resistance decreased from 68Ω to 4.2 Ω corresponding to an approximately 94% reduction, showing enhanced interfacial electron transfer kinetics in coated anode. The solution resistance also decreased from 11 Ω to 3.8 Ω, indicating improved electrolyte/electrode conductivity. The total impedance decreased from 79 Ω to 9.8 Ω, corresponding to an 87.6% reduction, demonstrating that copper coating effectively improves the electrochemical performance of AA5083 and promotes its suitability as an anode material for aluminium–air battery applications. The hydrogen evolution rate of copper-coated anode is 29.98 mL cm -2 h -1 . In short, the performance improvement is due to a copper barrier layer that forms to control aluminium dissolution and inhibit unwanted parasitic corrosion reactions. It illustrates the potential of low-cost surface modification method, such as copper electrodeposition for the durability and electrochemical performance enhancement of AA5083 alloy anodes in aluminium-air battery applications.