| In this thesis, based on a comprehensive review of the research and development of b.c.c solid solution type hydrogen storage alloys, high-pressure hydrogen storage technology and hybrid hydrogen storage vessel, Ti-V-Mn alloys with high hydrogen storage capacity were chosen as the first object of this study. By mean of microstructure analysis and hydrogen storage properties measurements, the effects of component on the hydrogen storage characteristics of Ti-V-Mn alloys have been investigated systemically, and ball-milling with AB5 type alloys was adopted to enhance the kinetic properties of the alloys. Moreover, with the consideration of the characteristics of high-pressure hydrogen storage vessel, Ti-Cr-V based hydrogen storage alloys which have high plateau pressure were also investigated for the application in hybrid hydrogen storage vessel. Based on the structure of a high-pressure hydrogen storage vessel reported in the literature, the effect of HSA amount on the gravimetric and volumetric hydrogen storage density of the vessel was studied, and the optimum value was found.The influence of substitution of Mn with V on the microstructure and hydrogen storage of TiVxMn2-x(x=0.6-1.6) alloys were investigated. It was found that as x increases, the alloys transform from two-phase structure (Laves and b.c.c phases) into a single b.c.c phase gradually. The alloys with V content of x≥1.2 consists of b.c.c solid solution single phase structure, and a maximum protium absorption capacity of 398ml/g was achieved by TiV1.6Mn0.4 alloy, however, the activation properties degrade and the saturation hydrogenation time extends due to the lack of brittle Laves phase. Moreover, as V content increases, the cell volume of the b.c.c phase increases, thus results in the significant reduction of plateau pressure. However, the hydriding/dehydriding pressure hysteresis also increases with increasing V content.In order to improve the poor activation and kinetic properties of Ti-V-Mn alloys, we modified the alloys by ball-milling with AB5 type rare-earth based alloys. It's found that activation properties of alloys can be enhanced by ball milling for a short time without reduction of hydrogen capacity. This is because more fresh surface and defects are produced during ball milling. The composite can absorb hydrogen saturatedly after 30-minute-ball-milling with addition of Ml0.2Ca0.8Ni5 (Ml isCe-riched rare earth) alloy, and it can be activated after two hydriding/dehydriding cycles. However, when the ball-milling time extends to 2 hours, the intensity of the peaks of X-ray diffraction get broadened and weakened, alloys inclined to amorphization with the extension of milling time. The change of structure results in dramatic decrease of hydrogen storage capacity. In addition, the appearance of a-Ti is also one of the reasons for the hydrogen storage capacity degradation.For TiCr2.^Vx (x=0.2-0.5) alloys, as V content increases, the maximum hydrogen storage capacity increases and the plateau pressure lower dramatically, the hysteresis and the slope of plateaus also increases. TiCri 7V0.3 alloy with the effective desorption capacity of 1.75wt. % was selected as the alloy for the hybrid hydrogen storage vessel. The influence of volume fraction^ of HSA on the gravimetric and volumetric hydrogen storage density of the vessel was studied. The results show that as X increases, the gravimetric density was rapidly decreased with the addition of the alloys, but the volumetric density of the vessel increases linearly with X. With a comprehensive consideration of gravimetric and volumetric density, the optimum value of X =0.15 was found for the present studied system. In ideal state, while the hybrid hydrogen storage vessel absorbs or desorbs hydrogen completely, the temperature of the system will change 89.IK. Under the working pressure of 40MPa, the alloys inside the vessel can absorb or desorb hydrogen without needing heat exchange with the environment.
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