高容量长寿命富镧稀土贮氢合金的制备与性能

Preparation and Properties of La-Rich Hydride Alloy Based on LaNi_5 with High Capacity and Long Cyclic Life

通过调整合金的组成,优化其熔炼和热处理过程,制备出一种新组成的富La贮氢合金La0.62Ce0.25Pr0.03Nd0.10Ni3.69Co0.71Mn0.34Al0.29Zr0.005,用扫描电镜、压力-恒温实验、X射线衍射、恒电流充放电和循环伏安扫描方法对合金进行了表征。结果表明:该合金为六方晶系的CaCu5型结构;高温下氢的吸脱附平台低,65℃时压力平台为0.1MPa;初始容量高达335mAh/g,2C经500次循环后,容降仅为18.6%.

A new composition La-rich hydride alloy, La0.62Ce0.25Pr0.03Nd0.10Ni3.69Co0.71Mn0.34Al0.29Zr0.005, was prepared with a casting process. Its performances was characterized by SEM, PCT, XRD, constant current charge-discharge and cyclic voltammetry. Results show that the alloy has hexagonal CaCus-type structure with a crystal particle size of 100 nm-250 nm; the pressure for hydrogen adsorption at high temperature is low, 0.1 MPa at 65℃; the initial discharge capacity of the alloy is up to 335 mAh/g and the capacity loss is only about 18.6% after 500 cycles under 2 C rate.