Effect of rapid quenching on electrochemical properties of AB_5and AB_(3.5)-type hydrogen storage alloys

摘要

The energy infrastructure is facing ever moreserious challenges due to limited supplies of oil, environmentalconcerns about C emissions and emissions from fossil fuels,and the ever expanding energy demands of the growingeconomics in Asia. t is widely believed that hydrogen is apotential ma or alternative energy carrier. However, thereremain problems with storage and transportation. An importantaspect in the development of hydrogen as an energy carrierconcerns the use of metal hydrides for hydrogen storage. Amongthe various types of hydrogen storage alloys, LaNi typehydrogen storage alloy has been the most promising materialswhich has been used as metal hydride electrode material for NiMH batteries because of their high capacity, capable ofperforming a high rate charge discharge, high resistance toovercharging and over discharging, a long cycle life,environmental friendliness and compatibility with Ni Cdbatteries, and the nic el metal hydride (Ni MH) rechargeablebatteries have been produced in large industry scale. n thispaper, effect of rapid quenching on the electrochemicalproperties of AB and AB . type hydrogen storage alloys wasstudied. The results indicated that the discharge capacities ofthe rapid quenching MmNi. Co Mn . Al . alloys decrease underand°C with the increase of the quenching rate.Comparatively, the decrease extent of the quenching alloys at °C is lower than that at°C. The result' on the study of thecycle life indicated that the quenching process is favorable to improve the cycle stabilities of the MmNi . CoMn Al . alloys underand°C. Whereas, the effect of the quenchingprocess on the La . Mg . (Ni Co . ) . alloy is different at °C from at °C. Under °C , the cycle life of the alloy wasobviously improved by the quenching process, however, thequenching process did not improve but decreased slightly the cycle life at°C.