Effects of doping content of potassium fluoride on hydrogen storage properties of MgH2-2LiNH2

MgH2-2LiNH2-xKF(x=0, 0.015, 0.025, 0.050, 0.100)samples were prepared by high energy ball milling. The phases and hydrogen desorption characteristics of the samples were analyzed by using X-ray diffraction(XRD), differential scanning calorimetry-mass spectrometry(DSC-MS) and Sievert's type apparatus. The experimental results showed that the transformation from (MgH2-2LiNH2) to (Mg(NH2)2-2LiH) was improved efficiently by KF dopant after ball-milling, the diffraction peaks of KH were observed after dehydrogenation for the KF doped sample. The onset dehydrogenation temperature and activation energy of KF doped MgH2-2LiNH2 samples were greatly decreased, and the level of NH3 desorbed during the hydrogen desorption process was also effectively decreased. The optimal doping content of the KF dopant for the MgH2-2LiNH2 system was 0.05 mol.