Crystal structure and cyclic properties of hydrogen absorption–desorption in Pr2MgNi9
Crystal structure and cyclic properties of hydrogen absorption–desorption in Pr2MgNi9
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DOI：
10.1016/j.ijhydene.2012.09.034
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发表时间：
2012-12
影响因子：
7.2
通讯作者：
K. Iwase;N. Terashita;K. Mori;S. Tsunokake;T. Ishigaki
中科院分区：
文献类型：
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作者：
K. Iwase;N. Terashita;K. Mori;S. Tsunokake;T. Ishigaki
我们研究了Pr2MgNi9的晶体结构和循环吸放氢性能。结构模型基于PuNi3型结构，假定镁原子替代了镁锌2型电池中的Pr位。用X射线衍射法测定了精制后的晶格参数。在298K的P-C(压力组成)等温线上观察到一个较宽的平台区。当氢气压力为2.0 Mpa时，最大吸氢量达到1.12H/M(1.62%)。经1000次吸放氢循环后，其吸放氢能力优于LaNi5(82%)。氢化过程中产生了各向异性的晶格应变。确定各向异性展宽矢量为<；001>；。计算的初始循环和1000循环后的各向异性晶格应变远小于LaNi5。
We investigated the crystal structure and cyclic hydrogen absorption–desorption properties of Pr2MgNi9. The structural model is based on the PuNi3-type structure; the Mg atom is assumed to substitute for the Pr site in an MgZn2-type cell. The refined lattice parameters were determined from X-ray diffraction. A wide plateau region was observed in the P–C (pressure composition) isotherm at 298K. The maximum hydrogen capacity reached 1.12H/M (1.62 mass%) under a hydrogen pressure of 2.0MPa. After 1000 hydrogen absorption–desorption cycles, the hydrogen capacity was superior to that of LaNi5(82%). Anisotropic lattice strain occurred in the hydriding process. The anisotropic peak-broadening vector was determined to be <001>. The calculated anisotropic lattice strains of the initial cycle and after 1000 cycles were far smaller than those of LaNi5.