The reversible hydrogen storage performances of Mg50Co50 and Mg50Co45Pd5 alloys with body-centered cubic phase in electrochemical system
The reversible hydrogen storage performances of Mg50Co50 and Mg50Co45Pd5 alloys with body-centered cubic phase in electrochemical system
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DOI：
10.1016/j.ijhydene.2015.01.133
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发表时间：
2015-03
影响因子：
7.2
通讯作者：
Yao Zhang;Leyu Zhan;Yunfeng Zhu;Xiangyang Zhuang;Xinli Guo;Jian Chen;Zengmei Wang;Liquan Li
中科院分区：
文献类型：
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作者：
Yao Zhang;Leyu Zhan;Yunfeng Zhu;Xiangyang Zhuang;Xinli Guo;Jian Chen;Zengmei Wang;Liquan Li
通过X射线衍射仪和透射电子显微镜/SAED分析，确定了具有体心立方(Bcc)纳米晶结构的镁钴合金和镁钯钴45合金。它们存在于MH-Ni电池体系的负极中，可以进行可逆充放电，最大容量可达458mAhg−1。与它们在固-气体系中的顽强脱氢性能不同，它们具有极大的可逆储氢性能[Y.Zhang等，合金与化合物学报393(2005)147-153]。这一现象可以归因于Mg50Co50基二元和三元体心立方合金在电化学反应中结构的稳定性，以及电催化活性。在镁钴合金中引入钯不仅提高了合金的首次放电容量，而且提高了合金的高倍率放电能力。添加Pd还可以提高三元电极合金的交换电流密度和氢扩散迁移率。
The Mg50Co50and Mg50Pd5Co45alloys with nano-crystalline body-centered cubic (BCC) structure were confirmed by means of XRD and TEM/SAED analyses. They are available in the anode of Ni–MH battery system, which can be reversibly charged and discharged with maximum capacity of 458 mAh g−1. They exhibit greatly enhanced reversible hydrogen storage, differing from their tough dehydrogenation performances in solid–gas system [Y. Zhang et al., Journal of Alloys and Compounds 393 (2005) 147–153]. This phenomenon can be ascribed to the structural stability of Mg50Co50-based binary and ternary BCC alloys in the electrochemical reactions, and also the electro-catalysis activity. Introducing Pd into Mg50Co50alloy lifts not only the initial discharge capacity, but also the high-rate discharge-ability. The exchange current density and hydrogen diffusion mobility can also be improved by the Pd additive in the ternary electrode alloys.