摘要
A new type of AB_5-x%LaMg_3(x=2, 3, 4, 5, 6, 7, 8)composite hydrogen storage alloys were prepared by sintering the powder mixtures of a commercial AB_5 alloy and LaMg_3 alloy. The phase structure and electrochemical characteristics of the composite hydrogen storage alloys were also studied. It is shown that AB_(5)-x%LaMg_3(x=2, 3, 4, 5, 6, 7, 8)composites have mult; phase structure. The matrix phase has CaCu_5 structure, the second phase is LaNi_3 phase. The maximum discharge capacity, discharge capacity at low temperature and HRD of AB_5 alloy electrodes are greatly improved after the composite. The maximum discharge capacity of the composite electrodes increases from 325 mAh·g^(-1) for x=0 to 358 mAh·g^(-1) for x=5, and the HRD of the composites for x=5 at the current density of 1200 mA·g^(-1)30% of that of the alloy at 60 mA·g^(-1). The discharge capacity of AB_5-x%LaMg_3 composite alloy electrode at 233 K is up to 174 mAh·g^(-1). The improvement of the electrochemical characteristics of the composite electrodes seems to be related with formation of the LaNi_3 second phase.
A new type of AB_5-x%LaMg_3(x=2, 3, 4, 5, 6, 7, 8)composite hydrogen storage alloys were prepared by sintering the powder mixtures of a commercial AB_5 alloy and LaMg_3 alloy. The phase structure and electrochemical characteristics of the composite hydrogen storage alloys were also studied. It is shown that AB_(5)-x%LaMg_3(x=2, 3, 4, 5, 6, 7, 8)composites have mult; phase structure. The matrix phase has CaCu_5 structure, the second phase is LaNi_3 phase. The maximum discharge capacity, discharge capacity at low temperature and HRD of AB_5 alloy electrodes are greatly improved after the composite. The maximum discharge capacity of the composite electrodes increases from 325 mAh·g^(-1) for x=0 to 358 mAh·g^(-1) for x=5, and the HRD of the composites for x=5 at the current density of 1200 mA·g^(-1)30% of that of the alloy at 60 mA·g^(-1). The discharge capacity of AB_5-x%LaMg_3 composite alloy electrode at 233 K is up to 174 mAh·g^(-1). The improvement of the electrochemical characteristics of the composite electrodes seems to be related with formation of the LaNi_3 second phase.
基金
ProjectsupportedbytheNaturalScienceFoundationofHebeiProvince(B2 0 0 40 0 0 188)
theChinaPostdoctoralScienceFounda tion(2 0 0 40 3 5 0 5 8)
