Nanocrystalline Mg2Ni-type alloys with nominal compositions of Mg20Ni10–xCux(x=0,1,2,3,4,mass fraction,%) were synthesized by rapid quenching technique.The microstructures of the as-cast and quenched alloys were char...Nanocrystalline Mg2Ni-type alloys with nominal compositions of Mg20Ni10–xCux(x=0,1,2,3,4,mass fraction,%) were synthesized by rapid quenching technique.The microstructures of the as-cast and quenched alloys were characterized by XRD,SEM and HRTEM.The electrochemical hydrogen storage performances were tested by an automatic galvanostatic system.The hydriding and dehydriding kinetics of the alloys were measured using an automatically controlled Sieverts apparatus.The results show that all the as-quenched alloys hold the typical nanocrystalline structure and the rapid quenching does not change the major phase Mg2Ni.The rapid quenching significantly improves the electrochemical hydrogen storage capacity of the alloys,whereas it slightly impairs the cycling stability of the alloys.Additionally,the hydrogen absorption and desorption capacities of the alloys significantly increase with rising quenching rate.展开更多
Gas with high pressure is widely used at present as fuel storage mode for different hydrogen vehicles. Differenttypes of materials are used for constructing these hydrogen pressure vessels. An aluminum lined vessel an...Gas with high pressure is widely used at present as fuel storage mode for different hydrogen vehicles. Differenttypes of materials are used for constructing these hydrogen pressure vessels. An aluminum lined vessel and typicallycarbon fiber reinforced plastic (CFRP) materials are commercially used in hydrogen vessels. An aluminumlined vessel is easy to construct and posses high thermal conductivity compared to other commercially availablevessels. However, compared to CFRP lined vessel, it has low strength capacity and safety factors. Therefore,nowadays, CFRP lined vessels are becoming more popular in hydrogen vehicles. Moreover, CFRP lined vesselhas an advantage of light weight. CFRP, although, has many desirable properties in reducing the weight and inincreasing the strength, it is also necessary to keep the material temperature below 85 ℃ for maintaining stringentsafety requirements. While filling process occurs, the temperature can be exceeded due to the compression worksof the gas flow. Therefore, it is very important to optimize the hydrogen filling system to avoid the crossing of thecritical limit of the temperature rise. Computer-aided simulation has been conducted to characterize the hydrogenfilling to optimize the technique. Three types of hydrogen vessels with different volumes have been analyzed foroptimizing the charging characteristics of hydrogen to test vessels. Gas temperatures are measured inside representativevessels in the supply reservoirs (H2 storages) and at the inlet to the test tank during filling.展开更多
基金Project(2007AA03Z227) supported by High-tech Research and Development Program of ChinaProjects(50871050,50701011) supported by the National Natural Science Foundation of China+1 种基金Project(200711020703) supported by the Natural Science Foundation of Inner Mongolia,ChinaProject(NJzy08071) supported by High Education Science Research Project of Inner Mongolia,China
文摘Nanocrystalline Mg2Ni-type alloys with nominal compositions of Mg20Ni10–xCux(x=0,1,2,3,4,mass fraction,%) were synthesized by rapid quenching technique.The microstructures of the as-cast and quenched alloys were characterized by XRD,SEM and HRTEM.The electrochemical hydrogen storage performances were tested by an automatic galvanostatic system.The hydriding and dehydriding kinetics of the alloys were measured using an automatically controlled Sieverts apparatus.The results show that all the as-quenched alloys hold the typical nanocrystalline structure and the rapid quenching does not change the major phase Mg2Ni.The rapid quenching significantly improves the electrochemical hydrogen storage capacity of the alloys,whereas it slightly impairs the cycling stability of the alloys.Additionally,the hydrogen absorption and desorption capacities of the alloys significantly increase with rising quenching rate.
文摘Gas with high pressure is widely used at present as fuel storage mode for different hydrogen vehicles. Differenttypes of materials are used for constructing these hydrogen pressure vessels. An aluminum lined vessel and typicallycarbon fiber reinforced plastic (CFRP) materials are commercially used in hydrogen vessels. An aluminumlined vessel is easy to construct and posses high thermal conductivity compared to other commercially availablevessels. However, compared to CFRP lined vessel, it has low strength capacity and safety factors. Therefore,nowadays, CFRP lined vessels are becoming more popular in hydrogen vehicles. Moreover, CFRP lined vesselhas an advantage of light weight. CFRP, although, has many desirable properties in reducing the weight and inincreasing the strength, it is also necessary to keep the material temperature below 85 ℃ for maintaining stringentsafety requirements. While filling process occurs, the temperature can be exceeded due to the compression worksof the gas flow. Therefore, it is very important to optimize the hydrogen filling system to avoid the crossing of thecritical limit of the temperature rise. Computer-aided simulation has been conducted to characterize the hydrogenfilling to optimize the technique. Three types of hydrogen vessels with different volumes have been analyzed foroptimizing the charging characteristics of hydrogen to test vessels. Gas temperatures are measured inside representativevessels in the supply reservoirs (H2 storages) and at the inlet to the test tank during filling.
