电镀镍-钴合金对La-Mg-Ni基贮氢合金电化学性能的影响  

Electrochemical Performance Studies on Nickel-cobalt Electroplated La-Mg-Ni-based Hydrogen Storage Alloys

作　　者：丁慧玲[1,2] 蒿建生[1,3] 朱惜林[2,3] 李媛[2] 韩树民[1,2] 张静武[1] 

机构地区：[1]燕山大学亚稳材料制备技术与科学国家重点实验室,秦皇岛066004 [2]燕山大学环境与化学工程学院,秦皇岛066004 [3]内蒙古稀奥科贮氢合金有限公司,包头014030

出　　处：《无机材料学报》2010年第6期647-652,共6页Journal of Inorganic Materials

基　　金：国家自然科学基金(20673093);河北省自然科学基金(B2007000303)

摘　　要：为了改善La-Mg-Ni基贮氢合金的循环稳定性和综合电化学性能,研究了电镀镍-钴合金对La0.88Mg0.12Ni2.95Mn0.10Co0.55Al0.10贮氢合金粉末表面形貌和电极电化学性能的影响.FESEM表明,电镀处理后合金粉末表面沉积了球状的镍-钴合金颗粒.电化学性能测试表明,贮氢合金电极的放电容量、高倍率放电性能和循环稳定性均得到了显著改善.200周循环时合金电极的容量保持率从未处理合金电极的60%提高到镀覆镍-钴合金的80%,在放电电流密度1080mA/g下的高倍率放电性能提高了23%.线性极化曲线和电化学阻抗分析结果显示,包覆镍-钴合金后贮氢合金电极表面的电荷转移速率加快,电催化活性提高.In order to improve cycling stability and overall electrochemical properties of La-Mg-Ni-based hydrogen storage alloys,an electroplating treatment was applied on La0.88Mg0.12Ni2.95Mn0.10Co0.55Al0.10 alloy powders.The effect of cobalt-nickel coating on the morphological and electrochemical properties was studied.FESEM results show that spherical nickel-cobalt alloy particles are deposited on the surface of the alloys.Electrochemical tests indicate that the maximum discharge capacity,the cycling stability and the high rate dischargeability（HRD） are remarkably improved.After 200 charge/discharge cycles,the capacity retention rate increases from 60%（uncoated） to 80%（nickel-cobalt coated）.The HRD at 1080mA/g rises by 23% for the nickel-cobalt coated alloy electrodes.Linear polarization and Electrochemical Impedance Spectroscope（EIS） results reveal that the surface of alloy electrodes with cobalt-nickel coatings is more catalytic for the electrochemical charge transfer reactions.

关 键 词：La-Mg-Ni基贮氢合金 表面处理 电镀 镍-钴合金 电化学性能 

分 类 号：TM912[电气工程—电力电子与电力传动]