Effect of rapid solidification treatment on structure and electrochemical performance of low-Co AB5-type hydrogen storage alloy

(整期优先)网络出版时间:2014-06-16
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TheeffectofrapidsolidificationonstructureandelectrochemicalperformanceoftheLaNi4.5Co0.25Al0.25hydrogenstoragealloywasinvestigatedbyX-raypowderdiffractionandasimulatedbatterytest,includingmaximumcapacity,cyclingstability,self-discharge,andhigh-ratedischargeability(HRD).Allthemelt-spunalloysweresingle-phasewiththeCaCu5-typestructure(spacegroupP6/mmm).Incomparisontotheas-castalloy,therapidlyquenchedalloysmanifestedanimprovedhomogeneityofcompositionandexpandedlatticeparameters.Theelectrochemicalmeasurementsshowedthattheactivationproperty,cyclingstabilityandself-dischargeofthealloyelectrodeswerealsoimprovedfortherapidsolidifiedalloys.TheHRDoftheas-castalloywasbetterthanthoseofalltherapidlysolidifiedalloys.Asthequenchingrateincreased,theHRDandexchangecurrentdensityfirstdecreasedandthenincreased.