Based on the review of the research and development of the Mg-based hydrogen storage alloys, La2Mg17 hydrogen storage alloy was selected as the study object of the work due to its higher storage capacity than Mg-Ni system alloy. In order to achieve well La2Mg17 alloy gaseous and electrochemical absorption/desorption reversibly by the ball-milling methond in La2Mg17+xwt%Ni(x=50,100,150,200) +ywt%NbF5 / TiF3(y=0, 3, 5) proportion to obtaining amorphous composites. By means of XRD, SEM analyses and the electrochemical test methods including the galvanostatic charge/discharge, EIS, linear polarization, potential-step method etc, the microstructure and electrochemical properties influence on the ball-milled Ni powder, catalyst and milling time composites were systematically studied. The La2Mg17 composite alloy of hydriding kinetics properties were measured by automatically controlled Sieverts apparatus, analysis of the Ni powder, catalyst and milling time controlling on gaseous hydrogen storage composites, and this process of the reaction mechanism is further studied.The study of the influence of Ni powder, catalyst and ball-milling time on the microstructure and gaseous hydrogen absorption / desorption properties of La2Mg17 composite alloys revealed that ball-milling can make excellent La2Mg17 composites hydrogenation/ dehydrogenation invertible. The maximum hydrogen absorption capacity of amorphous 150wt% Ni composites is 7.29wt%H2, respectively, the maximum hydrogen desorption capacity of amorphous 150wt%Ni composites is 2.31wt% H2 at 1MPa. It is found that ball-milling is advantageous for the formation of amorphous structure, thus leading to the improvement of thermodynamic and kinetic properties of the ball-milled composites. The composites kinetics of gaseous hydrogen absorption properties is improve significantly. Besides, the introduction of dynamic model is discussed gaseous hydrogen on the experimental data to estimate the occurrence of various stages of hydrogenation time. Required for the characterization of gaseous hydrogen storage materials study provides a new target parameters.The study of the influence of Ni powder, catalyst and ball-milling time on the microstructure and electrochemical properties of La2Mg17 composite revealed that ball-milling can improve the amorphization degree, and dramatically ameliorate the electrochemical reaction of the composite alloy dynamics. This method can make favorable La2Mg17 composites charge/discharge reversibly at room temperature. The maximum discharge capacity of amorphous 150wt% Ni composites is 787.07 and 775.16mAh/g when added TiF3 and NbF5, respectively. The discharge capacity of the amorphous composite is influenced by the amorphization degree and particle size. But both of them are closely related with Ni powder addition and milling time. The results indicate that the addition of small amounts of metal fluoride can improve the amorphization degree of the composites, thus leading to the improvement of discharge capacity and high-rate discharge ability. Due to metal fluoride cause the decrease of activation energy and electrochemical reaction resistance and then the increase of exchange current density. But the addition of metal fluoride has little effete on the cycling stability. In addition, impedance spectra of alloy (EIS) fitting, polarization current calculation, the introduction of hydrogen diffusion kinetics model, the electrochemical hydrogen storage mechanism are analyzed systematically in detail. |