Morphological, structural and electrochemical properties of the LaNi4Fe compound elaborated by mechanical alloying

Abstract

In this paper, we have studied the morphologic, the structural and the electrochemical properties of the LaNi4Fe compound elaborated by mechanical alloying (MA) for two durations 5 and 10 h. These properties are determined by various methods, such as XRD, SEM and galvanostatic cycling. The results show that the LaNi4Fe compound crystallizes in the hexagonal CaCu5 type structure for the two alloying durations 5 and 10 h. The particles obtained by mechanical alloying are in the order of 6 to 7 nm. The chemical microanalysis by EDX shows that the nominal and actual compositions are very close for the two grinding times. The maximum discharge capacity, of 180 and 200 mAh / g respectively for 5h and 10 h, is obtained from the first two cycles, which shows that the activation of nano compounds is easier than that obtained for bulk material obtained by melting since the reaction surface is larger. A decrease in capacity is observed after about thirty cycles: A loss of around 15% of maximum capacity is observed.