In this paper, we have studied the electrochemical properties of the LaNi4Fe compound obtained by mechanical alloying (MA) for two durations 5 and 10 h. The properties of hydrogen absorption/desorption in the material are studied by using several characterization methods namely: The cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. The values of the hydrogen diffusion coefficients obtained by cyclic voltammetry for the two alloying durations 5 and 10 h are equal to 2.7 10-9 cm2 S-1 and 5.7 10-9 cm2 S-1 respectively. The chronoamperomety show that the radius “a” of the particles which participate in the electrochemical reaction of the LaNi4Fe compound for the two grinding times 5 and 10 h are respectively estimated at 8 and 11 µm. Impedance spectra from experiments was used to describe the electrochemical processes that occur at the electrode-electrolyte interface. The electrochemical mechanism at the electrode interface of a NiMH battery has been modelled using a Ni-MH battery electrode. The proposed circuit characterizes the processes occurring at the hydride electrode interface. For both grinding times, the values of the diffusion coefficients of hydrogen in α phase (10% state of charge) are greater than those found in β phase (100% state of charge). A few possible causes could be lower number of vacant sites available for hydrogen absorption in beta than in alpha phase as well as more significant H-H repulsion, increasing potential barriers or making some diffusion paths improbable.