氟化处理对La0.94Mg0.06Ni3.49Co0.73Mn0.12Al0.20储氢合金的性能影响

Effect of Fluorination on Properties of La0.94Mg0.06Ni3.49Co0.73Mn0.12Al0.20 Hydrogen Storage Alloy

摘要:

为了提高La0.94Mg0.06Ni3.49Co0.73Mn0.12Al0.20合金的性能，研究了氟化处理对其电化学性能的影响。X-射线衍射（XRD）和扫描电镜（SEM）分析表明，氟化处理后，合金的相组成发生改变，有新相MgF2生成；合金的表面有一层MgF2颗粒。电化学测试表明，当NH4F浓度为0.3 mol/L时，合金电极的最大放电容量Cmax从346.4 mAh/g提高到378.0 mAh/g，容量保持率S50从69.5% 提高到74.3%，交换电流密度由122.3 mA/g 提高到188.5 mA/g，极限电流密度由891.7 mA/g 提高到1162.1 mA/g，腐蚀电位由-0.895V 提高到-0.849V，电化学反应阻抗减小。

Abstract:

The effect of fluorination treatment on La0.94Mg0.06Ni3.49Co0.73Mn0.12Al0.20 hydrogen storage alloy was studied to improve its electrical chemical properties. The results of X-ray diffraction(XRD) and Scanning electron microscope(SEM) showed that the phase composition of the alloy were changed after fluorination treatment, there is a new phase that is MgF2; some particles of MgF2 were formed on the surface of the alloy, When the concentration of NH4F was 0.3 mol/L, the maximum discharge capacity Cmax of the alloy electrode increased from 346.4 mAh/g to 378.0 mAh/g, the capacity retention rate S50 was improved from 69.5% to 74.3%, the exchange current density was improved from 122.3 mA/g to 188.5 mA/g, the limiting current density was improved from 891.7 mA/g to 1162.1 mA/g, the corrosion potential was improved from -0.895V to -0.849V, electrochemical reaction impedance was reduced.