Sintesis dan Karakteristik CeNi5 dari Oksida Logam Tanah Jarang dengan Metode Solid State

Abstract

RENi₅ (RE = La, Ce, Pr, Nd, Gd, Mm, etc) intermetallic compounds have been widely investigated as anode materials of Ni-MH batteries because of the excellent properties such as attractive hydrogen storage, moderate plateau pressures, and easy activation. RENi₅-type compounds are commonly prepared by a complicated method, which involves several steps of melting, alloying, casting, annealing and making it into powders. This study aims to examine synthesis CeNi₅ by solid state reaction. Commercial product of rare-earth oxide (CeO₂) and nickel oxide (NiO) as the raw material were mixed to prepare CeNi₅ by mechanical milling. The powders were mechanically milled at 400 rpm for 4 hours using ball mill. To study the calcination behaviours, calcination temperature was varied of 850°C and 1150°C for 4 hours.The powders properties were characterized by XRD, SEM-EDX, and TGA.  Non calcine powder shows no difference color with the raw oxide. It means there was an oxide in milling powder. The calcination temperature affect the electrode material and produced the difference color between powder with calcinations and without calcinations. This difference was caused by a phase change, decomposition of organic compounds, or may be due to oxidation. The oxidation process can also be seen from the increase in mass when conducted calcination on powder CeNi₅. Physical properties show that the higher calcination temperature the higher intensity phase of the CeNi₅. This means the higher calcination temperature made CeNi₅more crystalize.