(西安交通大学 金属材料强度国家重点实验室， 西安 710049)
摘 要: 研究了储氢合金 (MlMg)Ni4-xCo0.7Znx(0≤x≤0.3) 的气相储氢特性和电化学性能。 结果表明， 随着Zn含量的增加， 合金吸、 放氢 (室温下) 的平台压力降低， 最大储氢量减少， 分别从1.58% (x=0) 减少到1.44%(x=0.2)、 1.19% (x=0.3)；合金的放电容量减少， 分别从380mAh/g (x=0) 减少到366mAh/g (x=0.1)、 345mAh/g (x=0.2)、 271mAh/g (x=0.3)， 但循环稳定性得到提高，经100次充放电循环后的容量衰减率从16% (x=0) 降低到4% (x=0.3)；适当控制Zn含量， 既对合金的放电容量无大的影响， 又可提高合金放电的稳定性，尤其是在大电流下放电的稳定性。
关键字: 储氢合金； P-C-T曲线； 放电容量； 循环稳定性
（State Key Laboratory for Mechanical Behavior of Materials,
Xi′an Jiaotong University, Xi′an 710049, China）
Abstract:The gas hydrogen storage characteristics and electrochemical properties of (MlMg)Ni4-xCo0.7Znx (0≤x≤0.3) were studied. The results indicate that the absorption/desorption plateau pressures of the alloys lower and the highest hydrogen contents decrease from 1.58% (x=0) to 1.44% (x=0.2) and 1.19% (x=0.3) respectively with the increase of Zn in the alloys. The discharge capacities of the alloys decrease to a certain extent from 380mAh/g (x=0) to 366mAh/g (x=0.1), 345mAh/g (x=0.2) and 271mAh/g (x=0.3) respectively with the increase of Zn in the alloys, but their cycle stabilities are improved. The attenuation rate of capacity decreases from 16%(x=0) to 4%(x=0.3) after 100 charge/discharge cycles. The proper content of Zn influences the discharge capacity of the alloys a little， but promotes the discharge stability, especially at high current density.
Key words: hydrogen storage alloy; P-C-T curve; discharge capacity;cycle stability
