为改善LiBH4的储氢性能,采用球磨法制备2LiBH4/LiAlH4/0.5CaC2复合体系,利用X射线衍射仪(XRD)、傅里叶变换红外光谱仪(FTIR)和压力?组成?温度测试仪(PCT),研究复合体系的放/吸氢性能及反应机制.结果表明:2LiBH4/LiAlH4/0.5CaC2复合体系在440℃前结束放氢,总放氢量约为6.2%(质量分数);放氢过程中CaC2直接参与反应,使体系反应失稳而改善放氢性能;复合体系在450℃、9 MPa条件下再吸氢12 h的吸氢量为5.4%(质量分数),与纯LiBH4相比,可逆再吸氢性能得到明显改善.
In order to improve the hydrogen storage property of LiBH4, 2LiBH4/LiAlH4/0.5CaC2 composite was prepared with ball-milling method.The de-rehydrogenation properties and reaction mechanism were investigated with X-ray diffraction(XRD),Fourier transform infrared spectrometer(FTIR)and pressure-composite-tempera-ture testing apparatus(PCT). The results show that dehydrogenation of the 2LiBH4/LiAlH4/0.5CaC2 composite accomplishes at approximately 440℃,with about 6.2%(mass fraction)of hydrogen totally desorbed.In the process of hydrogen desorption,CaC2 is directly involved in the reaction to cause the destabilization of the reaction,thus improving the dehydrogenation property.After rehydrogenation at 450℃and 9 MPa for 12 h,5.4%(mass fraction) of hydrogen can be absorbed. The reversible hydrogen storage property is improved obviously with respect to pristine LiBH4.