Effects Of Ball-milling Process And Catalyst On The Phase Structure And Hydrogen Storage Properties Of La–Mg System Hydrogen Storage Composite Alloys

The Effects of ball-milling time and CeO₂addition on microstructure、hydrogenabsorption and electrochemical of ball-milled La₂Mg₁₇+xwt.%Ni（x=50、100、150、200）composites were investigated.. The study includes the followings:（1） The effects of Niamounts on microstructure、hydrogen absorption and eleetrochemical properties of ball-milled La₂Mg₁₇composites;（2） The effects of ball-milling time and CeO₂addition onmicrostructure and hydrogen absorption properties of La₂Mg₁₇+50wt.%Ni composites;（3）The effects of ball-milled and CeO₂addition on the microstructure and eleetrochemicalproperties of La₂Mg₁₇+200wt.%Ni composites.The influence of Ni amounts on the microstrueture and electrochemical properties of60h ball-milled La₂Mg₁₇composites revealed that certain amount of Ni can change the phasestructure of the alloy to achieve the amorphous alloy. Hydrogen absorbing rate tests foundthat add50wt.%Ni can form a Mg2Ni new phase compare with other Ni content alloys. Thisis La₂Mg₁₇+50wt.%Ni composites hydrogen absorbing rate and hydrogen absorbing quantityhigher than other Ni content composite alloy reasons. The completely amorphous structureLa₂Mg₁₇+200wt.%Ni composites with CeO₂displayed a good electrochemical perform-ance.Effects of CeO₂addition on microstructures and hydrogen absorbing properties ofLa₂Mg₁₇+50wt.%Ni composites were investigated. The hydrogen absorbing propertiesincreased with the prolonging of ball-milling time without or with CeO₂. Hydrogenabsorption capacity of La₂Mg₁₇+50wt.%Ni composites with ball-milling100h was the bestof all the group which was3.569wt.%and the hydrogen absorbing rate was98.91%in2minutes. Hydrogen absorption capacity of La₂Mg₁₇+50wt.%Ni composites with CeO₂higher than without CeO₂.Effects of CeO₂addition on microstructures and electrochemical properties of La₂Mg₁₇+200wt.%Ni composites were investigated.The discharge capacity of the La₂Mg₁₇+200wt.%composites ball-milled with and without CeO₂for different time were353.1mAh/g、326.9mAh/g、352.1mAh/g、352.6mAh/g、390.9mAh/g、373.5mAh/g、398.8mAh/g and409.8mAh/g. with CeO₂higher than that without CeO₂. But CeO₂addition has little effect onthe cycling stability. cycling retention rate of individual samples even can be decrease, thismay be join CeO₂increases the alloy samples of defects and specific surface area, increasedthe alloy contact with alkali solution, to accelerate the corrosion process of alloys.