摘要
为了改善La-Mg-Ni-Co型贮氢合金电极材料的电化学循环稳定性,采用真空中频感应电炉熔炼的方法制备了La0.7Mg0.3(Ni0.85Co0.15)3.5合金,研究了CoO添加剂(添加量分别为0%,2.5%,5%和15%)对其电化学性能的影响。结果表明,当以机械混合的方式在铸态La0.7Mg0.3(Ni0.85Co0.15)3.5合金粉中添加5%CoO时,可使合金电极在高温、低温和室温时的放电容量及室温充放电循环寿命大幅度提高。电化学测试及X射线衍射(XRD)分析结果表明,CoO可能是通过促进La0.7Mg0.3(Ni0.85Co0.15)3.5合金中某个(些)相的电化学反应,及其本身在充放电过程中发生可逆电化学反应,改善La0.7Mg0.3(Ni0.85Co0.15)3.5合金电化学性能。
In order to improve me cycung stability of La-Mg-Ni-Co hydrogen storage alloys, the La0.7Mg0.3 （Ni0.85Co0.15）3.5 alloy was prepared by inductive melting under argon atmosphere. The effect of additive CoO on electrochemical properties of La0.7Mg0.3（Ni0.85 Co0.15）3.5 alloy, which is used as an electrode material was studied. When the addition of CoO is 5%, both the discharge capacity at high-, low- and room-temperature and charge-discharge cycling stability at room temperature can be significantly improved. Electrochemical measurements and X-ray diffraction （XRD） analyses suggest that CoO improves the electrochemical properties of the La0.7Mg0.3（Ni0.85Co0.15）3.5 alloy by promoting the electrochemical reaction of another phase in the alloy and by self electrochemical reversible reaction occurring during the charge-discharge process.
出处
《中国稀土学报》
CAS
CSCD
北大核心
2006年第4期465-469,共5页
Journal of the Chinese Society of Rare Earths
基金
国家"十五"863重大专项(2005AA501160)
关键词
COO
贮氢合金
电化学性能
稀土
CoO
hydrogen-storage alloy
electrochemical property
rare earths
