1、ForewordEnergy is the necessary material basis for the survival and development ofhuman society.Oil,coal and natural gas are the main energy resources atpresent.Since the industrial revolution,a huge amount of fossil fuel was quicklyburned in a short-term for driving the rapid development of economy
2、,whichcauses a series of environmental problems including global energy shortage,global warming,air pollution and extreme weather.Of the numerous consumptionforms of energy,the consumption proportion of traffic and transportation is ashigh as 25 percent of the total fossil fuel consumption.More than
3、 that,with thenumber of family vehicles continues to grow,the proportion is increasing everyyear.Energy-saving reduction and developing new clean energy are consideredto be the fundamental ways for solving the above problems.Compared to the other clean energy,such as wind and solar,hydrogen energyha
4、s been used widely due to the higher energy density.Liquid hydrogen is themost commonly used rocket fuel,and compressed hydrogen gas begins to be usedin hydrogen fuel cell vehicles in recent years.However,the high cost in prepar-ing,storing and transporting for liquid hydrogen and the potential secu
5、rity expo-sure for the compressed hydrogen gas make the two kinds of hydrogen storagetechnologies hard to benefit the majority of the people.Hydrogen storage alloysnot only have high hydrogen storage density and safety,but also have excellentcycle life over than 500 cycles.Therefore,considering the
6、factors of energy den-sity,safety and use-cost,hydrogen storage alloys are recognized as the mostsuitable hydrogen storage material for hydrogen fuel cell vehicles.Hydrogen storage alloys have attracted worldwide attention since 1964.Mg2Nialloy,prepared by Brookhaven National Laboratory,has the hydrogen storage ca-
