摘要
Nanocrystalline/amorphous LaMg(12)-type alloyNi composites with a nominal composition of LaMg(11)Ni+x wt% Ni(x=100,200) were synthesized by mechanical milling.Effects of Ni content and milling time on the gaseous hydrogen storage thermodynamics and dynamics of alloys were systematically investigated.The hydrogen desorption properties were studied by Sievert apparatus and a differential scanning calorimeter(DSC).Thermodynamic parameters(△H and ΔS) for the hydrogen absorption and desorption of alloys were calculated by Van't Hoff equation.Hydrogen desorption activation energy of alloy hydride was estimated by Arrhenius and Kissinger methods.The increase in Ni content has a slight effect on the thermodynamic properties of alloys,but it significantly enhances the hydrogen absorption and desorption kinetics performance of alloys.Moreover,variation of milling time clearly affects the hydrogen storage properties of alloys.Hydrogen absorption capacity(C(100)~a) and hydrogen absorption saturation ratio(R(10)~a)(a ratio of the hydrogen absorption capacity at 10 min to the saturated hydrogen absorption capacity) have maximum values with milling time varying.But hydrogen desorption ratio(R(20)~d)(a ratio of the hydrogen desorption capacity at 20 min to the saturated hydrogen absorption capacity) always increases with milling time prolonging.Particularly,prolonging milling time from 5 to 60 h makes R(20)~d increase from 10.89% to 16.36% for the x=100 alloy and from 13.93% to 21.68% for the x=200 alloy,respectively.
Nanocrystalline/amorphous LaMg12-type alloyNi composites with a nominal composition of LaMg11Ni+x wt% Ni（x=100,200） were synthesized by mechanical milling.Effects of Ni content and milling time on the gaseous hydrogen storage thermodynamics and dynamics of alloys were systematically investigated.The hydrogen desorption properties were studied by Sievert apparatus and a differential scanning calorimeter（DSC）.Thermodynamic parameters（△H and ΔS） for the hydrogen absorption and desorption of alloys were calculated by Van’t Hoff equation.Hydrogen desorption activation energy of alloy hydride was estimated by Arrhenius and Kissinger methods.The increase in Ni content has a slight effect on the thermodynamic properties of alloys,but it significantly enhances the hydrogen absorption and desorption kinetics performance of alloys.Moreover,variation of milling time clearly affects the hydrogen storage properties of alloys.Hydrogen absorption capacity(C100a) and hydrogen absorption saturation ratio(R10a)（a ratio of the hydrogen absorption capacity at 10 min to the saturated hydrogen absorption capacity） have maximum values with milling time varying.But hydrogen desorption ratio(R20d)（a ratio of the hydrogen desorption capacity at 20 min to the saturated hydrogen absorption capacity） always increases with milling time prolonging.Particularly,prolonging milling time from 5 to 60 h makes R20d increase from 10.89% to 16.36% for the x=100 alloy and from 13.93% to 21.68% for the x=200 alloy,respectively.
出处
《Rare Metals》
SCIE
EI
CAS
CSCD
2019年第12期1144-1152,共9页
稀有金属（英文版）
基金
financially supported by the National Natural Science Foundation of China(Nos.51371094 and 51471054)
作者简介
Yang-Huan Zhang,e-mail:zhangyh59@sina.com。
