8-羟基喹啉对空气电池用AP65镁阳极腐蚀及放电性能的影响

Effects of 8-hydroxyquinoline on corrosion and discharge performance of AP65 alloy as anode for Mg-air battery

通过失重、电化学测试和腐蚀产物分析,研究氯化钠溶液中添加8-羟基喹啉对空气电池用AP65镁合金阳极腐蚀及放电性能的影响。结果表明:在3.5%NaCl(质量分数)溶液中添加8-羟基喹啉能使AP65镁合金的腐蚀速率由(0.36±0.1)mg·cm^2/h降至(0.028±0.0.5)mg·cm^2/h、腐蚀电位正移、腐蚀电流密度由(46.95±3.3)μA/cm^2降至(18.37±4.8)μA/cm^2。组装成单体空气电池在2 mA/cm^2电流密度下放电时,添加8-羟基喹啉的电解液可使AP65镁阳极的电流效率从21.4%提高到62.4%;在15 mA/cm^2电流密度下放电时放电电压从0.89 V提高到0.96 V。AP65镁合金在含有8-羟基喹啉的氯化钠电解液中的放电产物主要为Mg(HQ)2和Mg(OH)2,腐蚀膜层薄且均匀,有利于Cl?渗透。腐蚀层与镁基体之间沉积PbO2,可剥离腐蚀产物,促进基体全面均匀的活化溶解,增强阳极的放电活性。

The effects of 8-hydroxyquinoline on the corrosion and discharge performance of AP65 magnesium alloy as anode for Mg-air battery were studied by the mass loss test,electrochemical measurements and corrosion product analysis.The results show that the addition of 8-HQ in 3.5%NaCl(mass fraction)solution decreases the corrosion rate of AP65 alloys from(0.36±0.1)mg·cm^2/h to(0.028±0.0.5)mg·cm^2/h,shifts the corrosion potential to the positive direction,and decreases the corrosion current density from(46.95±3.3)μA/cm^2to(18.37±4.8)μA/cm^2.When being assembled as single Mg-air battery and discharged at a current density of 2 mA/cm^2,AP65 alloys express an improved current efficiency from 21.4%to 62.4%with the addition of 8-hydroxyquinoline into 3.5%NaCl solution.When being discharged at a current density of 15 mA/cm^2,the discharge voltage of single Mg-air battery increases from 0.89 V to 0.96 V with the addition of 8-hydroxyquinoline.The discharge products of AP65 magnesium alloy in 3.5%NaCl electrolyte containing 8-hydroxyquinoline are mainly Mg(HQ)2 and Mg(OH)2.The thin and uniform corrosion film is beneficial to the penetration of Cl?ion.Meanwhile,PbO2 compound is deposited between the corrosion film and the substrate.It can peel off the corrosion product and enhance the comprehensive activation dissolution as well as the discharge activity of AP65 alloy matrix.