(内蒙古科技大学 内蒙古自治区白云鄂博矿多金属资源综合利用重点实验室，包头 014010)
摘 要: 研究了La2Mg(Ni1-xZnx)9 (x=0.1, 0.15, 0.2)合金的组织结构、储氢性能及失效行为特征。Zn倾向于在AB5型相中固溶，显著促进了AB5和AB2型相含量的提高。虽然Zn降低了合金的电化学放电容量和高倍率性能，但适量的Zn能够显著提高合金的电化学循环稳定性。100次充放电循环后La2Mg(Ni0.9Zn0.1)9合金的容量保持率可达94%。原因在于Zn有利于合金结构稳定性的保持和抗粉化能力，特别是Zn能在合金表面形成致密钝化膜，显著提高了合金的耐腐蚀性。通过上述研究结果，提出含Zn合金性能改进的关键在于降低合金吸放氢平台压并抑制AB2型相的含量。
关键字: La-Mg-Ni系储氢合金；Zn；电化学性能；失效行为
（Key Laboratory of Integrated Exploitation of Bayan Obo Multi-Metal Resources, Inner Mongolia University of Science and Technology, Baotou 014010, China）
Abstract:Effect of Zn substitution on the microstructure, hydrogen storage properties and degradation characters of AB3 type La-Mg-Ni alloys was studied in the present work. Zn prefers to dissolve in AB5-type phase, leading to disappearance of AB3-type phase, elevation of abundance of AB5 and AB2-type phase. While the content of A2B7-type phase first increases and then decreases with the increasing of Zn. Although the discharge capacity and high rate dischargeability are weakened, the cycling stability can be dramatically improved by proper Zn substitution. The capacity retention of the La2Mg(Ni0.9Zn0.1)9 alloy after 100 charge/discharge cycles reaches to 94%, which can be ascribed to improvement of the structural stability, anti-pulverization and corrosion resistant caused by Zn addition. Based on these results, reducing the hydrogen absorption/desorption plateau and abundance of the AB2-type phase is considered to be the key issue to further improvement of the Zn-contained La-Mg-Ni alloys.
Key words: La-Mg-Ni-based hydrogen storage electrode alloys; Zn; electrochemical performances; degradation characters
