Electrochemical properties of the LaY2Ni9 hydrogen storage alloy

The electrochemical properties of LaY₂Ni₉ hydrogen storage alloy have been studied through chronopotentiometric, chronoamperometric and cyclic voltammetry measurements. At the C/5 rate the maximum capacity is obtained after 5 cycles of activation and reached 224 mAh g^-1, the discharge capacity loss (ratio of the discharge capacity at a given cycle n by the maximum discharge capacity) tends to 46% after 100 cycles. The value of the hydrogen diffusion coefficient obtained through chronoamperometric technic, after a long cycling, is 1.3 10^-7 cm².s^-1. The corrosion paramètres, such as the corrosion potential and the corrosion current density, are determined by cyclic voltammetry with a potential scanning rate of 1mVs^-1. The evolution of the corrosion potential and the corrosion current density after a long cycling stabilize around an oscillating value of 1020 mV and 1.54 mA.cm^-2, respectively.