膨胀石墨/LiBH_4复合储氢材料脱氢性能研究

Hydrogen desorption property of LiBH_4-loaded expended graphite hydrogen storage composites

研究了多孔膨胀石墨(EG)负载Li BH_4复合储氢材料(EG/Li BH_4)的脱氢性能。使用溶液浸渍的方法,成功制备了EG/Li BH_4复合储氢材料。使用物理吸附仪、X射线衍射(XRD)、热重(TG)、压力-组份-等温测试仪(PCT)、电感耦合等离子体发射光谱仪(ICP-OES)及扫描电子显微镜(SEM)对其进行表征,分析了其脱氢温度和脱氢动力学性能改善的原因。结果表明,膨胀石墨负载的Li BH_4的脱氢温度和放氢动力学性能均得到有效的改善。其脱氢温度较球磨后的纯Li BH_4降低了100℃。Li BH_4在膨胀石墨中的负载量为46.9%(质量分数)时,360℃、真空条件下1 h内就能释放8.4%(质量分数)的H_2。

LiBH4-loaded expanded graphite （LiBH4-EG） composite was synthesized by impregnation method in tetrahydrofuran （THF） solution. The performance and mechanisms of the hydrogen desorption of LiBH4-EG composite were characterized by X-ray diffraction （XRD）, thermogravimetry （TG）, pressure composition isotherm measurement system （PCT）, inductively coupled plasma-optical emission spectroscopy （ICP-OES） and scanning electron microscope （SEM）. The results show that the desorption temperature and dehydrogenation kinetic of LiBH4 are improved by employing expanded graphite as the support. The main dehydrogenation temperature of LiBH4-EG composite is decreased by 100 ℃ compared with pure ball-milled LiBH4. Furthermore, the expanded graphite loading 46.9% LiBH4 can release 8.4% H2 in 1 h under 360 ℃ and vacuum condition.