An Investigation On The Configuration And Electrochemical Performance Of Aluminum/Magnesium-Air Battery

The aluminum-air battery with open configuration was successfully assembled using Al alloy as anode, air electrode as cathode and NaCl solution as electrolyte. The magnesium-air battery with close configuration was also prepared with pure Mg anode. The electrochemical performance of Al alloy and Mg anodes and the effects of different configuration parameters on the discharge performance were systematically investigated by hydrogen evolution, polarization, discharge performance and SEM, based on which the best configuration parameters and electrochemical performance of aluminum / magnesium-air battery were obtained.The experiment results showed that the aluminum-air battery with open configuration, using high-activity Al alloy as anode and air electrode as cathode, could achieve an open circuit voltage of 1.5 V and a working voltage of 1.1 V on constant resistance of 4Ω, when its space between electrodes was 8 mm and discharging at the current density of 2 mA/cm2 in 3.5% NaCl solution at 20℃. The consumption and utilizing ratio of anode could reach 95% and 44.97%, respectively. The practical specific capacity of Al alloy anode could reach 1.34 Ah/g (1540 Wh/kg). The reaction products could get off from the cell by itself, thus preventing the rising of internal resistance caused by deposited. The aluminum-air battery pack assembled by four cells in series could light a light-emitting diode for more than 100 h, and the working voltage could maintain at 4.0 V for 80 h.The magnesium-air battery with close configuration was assembled with pure Mg as anode and high-activity air electrode as cathode. The reaction product of Mg(OH)2 could fall off from the Mg anode sheet, thus leading to the prolonging of discharging duration. The optimal cell gap was set at 6 mm. The frequency of changing anode sheet and electrolyte could be the same when the weight ratio of Mg anode to electrolyte was 1:16. The open circuit voltage of the cell could be over 1.8 V. The utility ratio of Mg anode was beyond 50% at the current density of 20 mA/cm2, that is, the practical specific capacity of Mg anode could reach 1.1 Ah/g. And the utilizing ratio of Mg anode was 23% at the discharge current density of 2 mA/cm2. The magnesium-air battery pack that was assembled by two cells in series could light a bulb (2.2 V / 0.3 W) for more than 50 h.