氟化处理对La0.67Mg0.33Ni2.25Co0.75贮氢合金电化学性能的影响

Effects of Fluorination Treatment on Electrochemical Properties of La0.67Mg0.33Ni2.25Co0.75 Hydrogen Storage Alloy

摘要:

采用扫描电镜、充放电测试、线性极化和电位阶跃等方法研究了氟化处理对La0.67Mg0.33Ni2.25Co0.75贮氢合金电化学性能的影响。结果表明，氟化处理提高了合金电极的循环稳定性，合金电极50次充放电循环后的容量保持率显著提高。同时，氟化处理也提高合金电极的交换电流密度，降低极化电阻，并且有利于氢在合金中的扩散，从而显著改善合金的高倍率放电性能 (HRD)

Abstract:

Effects of fluorination treatment on electrochemical properties of La0.67Mg0.33Ni2.25Co0.75 hydrogen storage alloy were investigated, using scanning electron microscopy, charge and discharge testing, linear polarization and potential-step measurement. The results show that cycling stability is improved by fluorination treatment. The cycling capacity retention rate S50 increases greatly after fluorination treatment. Moreover, fluorination treatment contributes to an increase in exchange current density, a decrease in charge- transfer resistance and the facility of hydrogen diffusion within the bulk alloy, leading to an obvious improvement on high rate dischargeability (HRD).