A comparative study of the hydrogen storage properties of LiBH4 doping with CaHCl and CaH2

作者：Jiang, Kun; Xiao, Xuezhang; Chen, Lixin^*; Han, Leyuan; Li, Shouquan; Ge, Hongwei; Wang, Qidong

来源：Journal of Alloys and Compounds, 2012, 539: 103-107.

DOI：10.1016/j.jallcom.2012.06.039

• LiBH4
• CaHCl additive
• Hydrogen storage properties
• De/rehydrogenation mechanism

In the present work, CaHCl was synthesized as an additive for the LiBH4 complex hydride. The hydrogen storage properties of LiBH4 doping with CaHCl was firstly investigated and compared to LiBH4 doping with CaH2. It is found that LiBH4 doping with CaHCl exhibits more promising catalytic properties than that of CaH2: doping with CaHCl can decrease the thermodynamic stability of LiBH4 and improve the low temperature dehydrogenation kinetics of LiBH4 greater than CaH2 do. The activation energy of the dehydriding step of LiBH4 decreases from 160.11 kJ/mol in 6LiBH(4) + CaH2 system to 112.39 kJ/mol in 6LiBH(4) + CaHCl system. The dehydrogenation scheme of 6LiBH(4) + CaHCl system is different from 6LiBH(4) + CaH2 system, and its dehydrogenation reaction is 6LiBH(4) + CaHCl -> 5LiH + LiCl + CaB6 + 10H(2)dagger. However, due to the stable LiCl formed after dehydrogenation, the rehydrogenation route of 6LiBH(4) + CaHCl system is the same as 6LiBH(4) + CaH2 system to regenerate LiBH4 and CaH2 (in molar ratio of 6:1), which indicates that 6LiBH(4) + CaHCl system cannot be fully rehydrogenated. It is also observed that 6LiBH(4) + CaHCl system has more stable cyclic dehydrogenation properties than 6LiBH(4) + CaH2 system.

• 出版日期2012-10-25
• 单位浙江大学