Hydrogen storage properties of LiBH4
Hydrogen storage properties of LiBH4
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DOI：
10.1016/s0925-8388(02)01253-7
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发表时间：
2003-08
影响因子：
6.2
通讯作者：
A. Züttel;S. Rentsch;P. Fischer;P. Wenger;P. Sudan;P. Mauron;Ch. Emmenegger
中科院分区：
文献类型：
--
作者：
A. Züttel;S. Rentsch;P. Fischer;P. Wenger;P. Sudan;P. Mauron;Ch. Emmenegger
金属氢化物通常每个金属原子吸收1-2个氢原子，并表现出非常大的体积存储密度，可达150 kg H2m−3(例如：Mg2FeH6)。然而，由于过渡金属的大原子质量，氢的重量密度被限制在小于5%的质量%。轻的3族金属，例如Al， B，能够结合四个氢原子并与碱金属形成离子或至少部分共价化合物。这些化合物相当稳定，通常只有在熔点以上才会解吸氢。libh4的重量氢密度为18.5%质量%，体积氢密度为121 kg H2m−3。该化合物最早由Schlesinger和Brown合成[J]。点。化学。Soc. 62(1940) 3429]中的有机溶剂。根据Stasinevich和egrenko的工作[俄国J. Inorg]。化学。13(3)(1968)341]氢在高于470°C的温度下从libh4解吸。我们成功地确定了LiBH4的低温结构：正交，空间群Pnma(#62)，单元胞包含四个分子，在25°c时的尺寸为a=7.1730 Å， b=4.4340 Å， c=6.7976 Å。在100°C左右的结构转变过程中，观察到轻微的氢脱附，在200°C左右，当sio2粉末加入到libh4样品中时，主要的氢脱附开始（13.5质量%）。
Metal hydrides typically absorb 1–2 hydrogen atoms per metal atom and exhibit very large volumetric storage densities of up to 150 kg H2m−3(e.g. Mg2FeH6). However, due to the large atomic mass of the transition metals the gravimetric hydrogen density is limited to less than 5 mass%. Light weight group 3 metals, e.g. Al, B, are able to bind four hydrogen atoms and form together with an alkali metal an ionic or at least partially covalent compound. These compounds are rather stable and often desorb the hydrogen only above their melting temperature. LiBH4has a gravimetric hydrogen density of 18.5 mass% and a volumetric hydrogen density of 121 kg H2m−3. The compound was first synthesized by Schlesinger and Brown [J. Am. Chem. Soc. 62 (1940) 3429] in an organic solvent. According to the work of Stasinevich and Egorenko [Russian J. Inorg. Chem. 13(3) (1968) 341] hydrogen desorbs from LiBH4at temperatures greater than 470°C. We have successfully identified the low temperature structure of LiBH4: orthorhombic, space group Pnma (#62), the unit cell contains four molecules and has the dimensions a=7.1730 Å, b=4.4340 Å, c=6.7976 Å at 25°C. A slight hydrogen desorption was observed during the structure transformation around 100°C and the major hydrogen desorption (13.5 mass%) starts at approximately 200°C when SiO2-powder is added to the LiBH4sample.