Electrochemical properties of the CaNi4.8M0.2(M=Mg, Zn, and Mn) mechanical milling alloys used as anode materials in nickel-metal hydride batteries

The present research work examines the electrochemical properties of CaNi4.8M0.2(M=Mg, Zn) type alloy applied as an anode in nickel metal hybrid batteries. Based on an extensive study of the CaNi4.8Mn0.2 compound prepared by mecano-synthesis; under an argon atmosphere, with a variation of milling time and weigh ratio, using a Retsch PM400 type ball mill. The experimental results show that the excellent electrochemical properties were obtained for a milling time of 40 h and a ball-to-powder weight ratio equal to 8:1. Based on this study, we examined electrochemically the CaNi4.8M0.2(M=Mg, Zn, and Mn) compound according to the optimized parameters. Several methods, such as galvanostatic polarization and potentiodynamic polarization, were applied to characterize these electrodes. CaNi4.8M0.2(M=Mg, Zn, and Mn) electrodes were activated, respectively, during the first, second, and third cycles. The maximum discharge capacity was about 87, 60, and 96 mAhg(-1) at ambient temperature. These electrochemical findings correlate with the kinetic results provided during a long cycle.