铝–空气电池用阳极铝合金的掺杂改性

Abstract

在Al-0.5Mg (0.5%Mg)、Al-0.5Mg-0.2In (0.5%Mg 0.2%In)两种合金中添加不同含量的Zn元素，通过多种分析测试方法，来探究Zn、In元素对合金阳极合金组织、腐蚀性能、放电性能、电化学性能的影响，并分析得出最优的合金成分。In元素对于本实验的试样是一种非常重要的元素，加入In后，铝合金阳极活化能力、电化学性能显著提高，开路电位、放电电压快速稳定；铝合金缺陷减少，表面氧化膜变得疏松且不完整；析氢自腐蚀变弱，腐蚀速率明显降低，腐蚀表面平整。Zn则能够细化合金晶粒，使铝合金组织变得致密，减少合金缺陷，抑制铝合金析氢自腐蚀；但会降低铝合金活性，随着Zn含量的增加，开路电位、放电电压正移。当In含量为0.2%，Zn含量为0.2%时，Al-0.5Mg-0.2In-0.2Zn合金具有最好的综合性能，其OCP (Open Circuit Potential)为−1.716 V (vs. Hg/HgO)，腐蚀速率为0.064 mg•cm−2•min−1，10 mA恒流放电单体电池电压可达1.527 V。 In this paper, two alloys of Al-0.5Mg (0.5% Mg) and Al-0.5Mg-0.2In (0.5% Mg 0.2% In) were added with Zn of different contents. Through a variety of analysis methods, the impact of Zn and In ele-ment on alloy structure, corrosion property, discharge performance, and electrochemical perfor-mance of alloy anode, has been explored, and the optimal alloy composition has also been obtained by analysis. In plays an important role in this experiment; after In adding, the activation capacity of aluminum alloy anode and the electrochemical performance were enhanced significantly, while the open circuit potential and the discharge voltage were rapidly stabilized; aluminum alloy defects were reduced, and surface oxide film became loose and incomplete; hydrogen evolution corrosion weakened significantly and corrosion rate lowered. Zn can refine alloy grain, so as to make aluminum alloy organization dense, reduce the alloy defects and inhibit hydrogen evolution corrosion, but at the same time it would reduce aluminum alloy activity, and the open circuit potential and discharge voltage would positively shift as the increasing content of Zn. With the In content of 0.2% and Zn content of 0.2%, Al-0.5Mg-0.2In-0.2Zn alloy has the best overall performance; its Open Circuit Potential (OCP) is −1.716 V (vs. Hg/HgO); the corrosion rate is 0.064 mg•cm−2•min−1; and 10-mA constant discharge cell voltage can reach to 1.527 V.