알루미늄-공기 전지용 알루미늄 합금 음극의 부식 특성에 미치는 합금원소 및 전해질의 영향

Abstract

Corrosion properties of Al-0.3Ga-0.3Sn, Al-0.3Mn-0.3Ga, and Al-0.3Mn-0.3Sn alloys were examined to develop an anode material for Al-air battery with alkaline aqueous or ethanol electrolyte. The corrosion potential of the Al alloys was -2.04 ～ -1.88 VSCE and the corrosion rate was 8.9×10-3 ～ 1.19×10-2 A/cm2 in aqueous solution. The discharge voltage of Al-air cell with those Al alloys at 50 mA/cm2 was 0.90 ～ 1.29 V, being higher than that of (0.83 V) of the cell with pure Al anode. Ga and Sn appeared to lower the corrosion potential and increase the corrosion rate of Al alloys in aqueous solution. These effects were significant when Ga and Sn were together in the alloy. The effects of Mn in Al alloy were mitigating the effects of Ga and Sn and also stabilizing the cell voltage. The corrosion rate (4.16×10-5 ～ 1.05×10-4 A/cm2) of pure Al and Al alloys was much smaller in ethanol solution than in aqueous solution but the corrosion potentials in both solutions were similar. The discharge voltage of Al-air cell at 0.1 mA/cm2 was 1.5 ～ 1.8 V. Therefore, the ethanol electrolyte proved to have higher cell voltage and lower corrosion rate in comparison with the aqueous solution. Addition of Ga and Sn in the Al alloy resulted in remarkably low corrosion potential, while the corrosion potential of Mn-containing alloys was not so different to that of pure Al. The corrosion rate of Al-Mn-Sn was much lower than that of pure Al. However, Al-Ga-Sn and Al-Mn-Ga showed similar corrosion rates to that of pure Al.