Elaboration and electrochemical characterization of LaTi2Cr4Ni5 -based metal hydride alloys

The present paper focuses on the elaboration of LaTi2Cr4Ni5 -based intermetallic compounds by mechanical alloying from LaNi5 and TiCr2 precursors and their characterization as negative electrode materials in Nickel-metal hydride (Ni-MH) batteries. The structural properties of the phases were determined by X-ray diffraction and quantified from the Rietveld refinement data. The increase of the milling time up to 25 h leads to the highest abundance of the LaTi2CLINi5 phase, estimated at 66 wt%, and a complete elimination of the LaNi5 intermetallic precursor. The electrochemical techniques were applied to characterize the electrochemical behavior of prepared LaTi2Cr4Ni5 -based compounds. The maximum discharge capacity was 115 mAh g(-1) and the average capacity retention was equal to 77% upon 60 charge/discharge cycles, indicating a high electrochemical stability in the alkaline solution. The values of the hydrogen diffusion coefficient are equal to 4.18 x 10(-8) and 7.17 x 10(-8) cm(2) s(-1) after 8 h and 20 h of milling durations, respectively. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.