摘要
采用富La混合稀土与Ni、Co、Mg等元素组合,获得了一种非化学计量LaNi5型储氢合金.用金相、XRD和SEM-EDX等方法分析了该合金的组织结构,研究了合金的气相储氢特性以及电化学性能,结果表明:在1.6 MPa氢压和温度29℃下,该合金的储氢量达到1.58％（质量分数）.该合金的放电容量为380mAh/g;经300次循环后容量保持率为55％.该合金的基体是CaCu5型结构的LaNi5相,但有第二相（LaMg）Ni3析出,这种第二相的形成是导致该合金大容量的关键.
A non-stoichiometric LaNi5 type hydrogen storage alloy was obtained by combining La-rich mischmetal with some other elements such as Ni, Co and Mg. The microstructure of the alloy was analyzed using optic metallography, XRD and SEM-EDX. The hydrogen storage characteristics and the electrochemical properties of the alloy were investigated. The results showed that the alloy absorbed hydrogen by 1.58% (mass fraction) at 1.6 MPa H2 pressure and 29°C. The discharge capacity of the alloy reached 380 mAh/g. 55% of the discharge capacity remained after 300 charging/discharging cycles. The matrix of the alloy was LaNi5 phase with CaCu5 type structure but (LaMg)Ni3 secondary phase was precipitated. The secondary phase is the key factor to the high capacity of the alloy.
出处
《材料研究学报》
EI
CAS
CSCD
北大核心
2002年第4期395-398,共4页
Chinese Journal of Materials Research
基金
国家教育部骨干教师基金资助项目
