高等学校化学学报 ›› 2012, Vol. 33 ›› Issue (09): 2030.doi: 10.3969/j.issn.0251-0790.2012.09.027

• 物理化学 • 上一篇    下一篇

化学计量比和放氢背压对LiBH4+xMg2NiH4体系放氢性能的影响

邓帅帅, 肖学章, 陈立新, 韩乐园, 李寿权, 葛红卫, 王启东   

  1. 浙江大学材料科学与工程学系, 杭州 310027
  • 收稿日期:2011-12-26 出版日期:2012-09-10 发布日期:2012-08-14
  • 通讯作者: 陈立新,男,博士,教授,博士生导师,主要从事储氢材料研究.E-mail:lxchen@zju.edu.cn E-mail:lxchen@zju.edu.cn
  • 基金资助:

    国家"九七三"计划项目(批准号: 2010CB631300)和国家自然科学基金(批准号: 51171173, 51001090)资助.

Effects of Stoichiometry and Dehydrogenation Back-pressure on the Dehydrogenation Behavior of LiBH4+xMg2NiH4 Composites

DENG Shuai-Shuai, XIAO Xue-Zhang, CHEN Li-Xin, HAN Le-Yuan, LI Shou-Quan, GE Hong-Wei, WANG Qi-Dong   

  1. Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China
  • Received:2011-12-26 Online:2012-09-10 Published:2012-08-14

摘要:

研究了不同化学计量比(x=0.25, 0.5, 0.75, 1.0, 1.25)和放氢背压(1×10-4和0.4 MPa)对LiBH4+xMg2NiH4复合体系吸放氢性能的影响. 结果表明, 随着化学计量比(x)的增加, 复合体系的放氢温度逐渐降低, 放氢动力学性能得到提高, 但放氢容量逐渐降低; 其中, 在1×10-4和0.4 MPa初始放氢背压下, LiBH4+0.75Mg2NiH4体系具有最佳放氢动力学性能和较高的储氢容量. 结果表明, 放氢背压和化学计量比均会对高温下液相LiBH4 与固态Mg2NiH4 的润湿性产生影响, 进而影响复合体系的放氢路径和放氢动力学性能.

关键词: 储氢材料, 储氢性能, 化学计量比, LiBH4, Mg2 NiH4

Abstract:

The effects of stoichiometry (x=0.25, 0.5, 0.75, 1.0, 1.25) and hydrogen back pressure on the dehydrogenation behavior of LiBH4+xMg2NiH4 composites were investigated systematically by methods of X-ray diffraction(XRD) and temperature programmed desorption(TPD) analysis. The results show that the stoichiometry x has a great effect on the dehydriding kinetics of LiBH4+xMg2NiH4 composites. With the increase of x value for the LiBH4+xMg2NiH4 composites, the decrease of the dehydrogenation temperature and the improvement of the dehydriding kinetics are observed but with a loss of dehydrogenation capacity. Thereinto, LiBH4+0.75Mg2NiH4 composite has the best dehydriding kinetics and a relatively high hydrogen storage capacity under initial hydrogen back pressure of 1×10-4 or 0.4 MPa. The analysis shows that both the stoichiometry x of the LiBH4+xMg2NiH4 mixtures and hydrogen back pressure can influence the wetting between liquid LiBH4 and solid Mg2NiH4, and have a great effect on the dehydrogenation path and kinetics furthermore.

Key words: Hydrogen storage material, Hydrogen storage property, Stoichiometry, LiBH4, Mg2NiH4

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