机械球磨合成LiNH_2及LiNH_2+LiH的放氢性能  

Synthesis of LiNH_2 by mechanical ballmilling and hydrogen discharging performance of LiNH_2+LiH

作　　者：罗永春[1] 李宗厚[1] 阎汝煦[1] 毛松科[1] 康龙[1] 

机构地区：[1]兰州理工大学甘肃省有色金属新材料省部共建国家重点实验室,甘肃兰州730050

出　　处：《兰州理工大学学报》2007年第5期1-5,共5页Journal of Lanzhou University of Technology

基　　金：甘肃省自然科学基金(3ZS041-B25-017)

摘　　要：以LiH为初始原料,在室温下用LiH与氨气进行机械球磨原位化学合成LiNH2.将合成产物LiNH2与LiH按摩尔比1∶1球磨混合和改性,通过恒温放氢性能测试和TG及DSC热分析方法分析机械球磨改性后LiNH2＋LiH储氢材料体系的放氢规律;用X-射线衍射和Rietveld全谱拟合方法分析合成产物和放氢后固体产物.研究表明,球磨改性后的LiNH2＋LiH试样在230℃即开始放氢,在230~340℃放氢迅速,放氢过程属于LiNH2与LiH直接反应放氢;经吸放氢循环的LiNH2＋LiH从320℃开始放氢,在340～440℃放氢迅速,放氢时LiNH2首先分解出氨气,氨气与LiH发生反应生成氢气析出.LiNH2 was chemically synthesized in situ by means of mechanical ballmilling the LiH as raw material in the atmosphere of ammonia at room temperature. The synthesized product was then ballmilled and modified together with LiH in molar ratio 1 ： 1. The hydrogen discharging regularity of this hydrogen storage material system was analyzed by means of hydrogen discharging test at constant temperature and TG/DSC thermal analysis methods. Combine XRD and Rietveld all-spectrum fitting method were used to analyze the synthezed product as well as the hydrogen discharging solid product. It was found that the sample of ballmilled and modified LiNH2 ＋ LiH began to discharge hydrogen at 230 ℃ and reached the highest reaction rate at 230～340 ℃, being a kind of direct reaction between LiNH2 and LiH. In the cycle of hydrogen absorption-desorption of LiNH2 ＋LiH the hydrogen discharge began at 320℃ and reached the highest reaction rate at 340～440 ℃, the NH3 being first decomposed from the LiNH2 and then the hydrogen being separated out through the reaction between the NH3 and LiH.

关 键 词：储氢材料 LiNH2 LIH 放氢性能 循环稳定性 热分析 

分 类 号：TG146.4[一般工业技术—材料科学与工程]