Al-Ga-Mg-Sn-xSi阳极合金电化学性能研究

Research on electrochemical performance of Al-Ga-Mg-Sn-xSi anode alloy

熔炼并制备了铝空气电池用阳极材料Al-0.02Ga-0.5Mg-0.1Sn-x Si[x=0~0.2%（质量分数）]合金,通过测试合金的自腐蚀速率、开路电位（OCP）、极化曲线（Tafel）以及电化学阻抗（EIS）等,研究了其在4 mol/L Na OH溶液中的电化学性能;采用能量散射X射线谱（EDX）分析了合金中偏析相元素成分,并结合扫描电镜（SEM）观察了合金的腐蚀形貌。结果表明：合金中添加Si可降低自腐蚀速率,提高其电化学性能;但过量的Si会加剧合金点蚀。随着Si含量增加,合金开路电位负移,放电电压升高;当Si含量为0.1%时,合金具有最佳的综合性能,自腐蚀速率最小[0.113 mg/（cm^2·min）],开路电位最负（-1.80 V）,20 m A恒流放电时单电池电压达1.50 V。

Al-0.02Ga-0.5Mg-0.1Sn-x Si（x=0~0.2%） anode alloy used for aluminum-air batteries were smelted. The electrochemical performance was studied by the measurement technique of self-corrosion rate, open circuit potential（OCP）, polarization curives（Tafel） and electrochemical impedance spectroscopy（EIS） in 4 mol/L Na OH electrolyte.The segregation phase composition and corrosion morphology were researched by energy dispersive x-ray detector（EDX） and scanning electron microscope（SEM）. The results show that the self-corrosion rate is lower through adding Si element, but adding more ones aggravate pitting. The electrochemical performance of anode alloys was improved,the OCP was more negative and discharge voltage rising. When 0.1% Si element was added, the best combination property could be obtained, the lowest self-corrosion rate[0.113 mg/（cm2·min）] and the negativest OCP（-1.80 V）.The discharge voltage was 1.50 V at 20 m A constant current discharge.