Investigation on the structure, thermodynamic and electrochemical properties of the MmNi3.55Mn0.4Al0.3Fe0.75 compound used as negative electrode in Ni-MH batteries

AbstractThe structure, thermodynamic and electrochemical properties of the hydride poly-substituted MmNi3.55Mn0.4Al0.3Fe0.75 alloy used as material for negative electrode in Ni-MH batteries investigated. The solid-gas capacity and pressure equilibrium measurement at room temperature are respectively 3.93 H/mol and 0.024 bars. The chronoamperometry method shows the size of the particles (a) participating in the electrochemical reaction decrease of cycle number. The hydrogen diffusion coefficient determined by electrochemical impedance spectroscopy (EIS) increase of the number of cycles from 3.5 × 10−12 cm2 s−1 before cycling to 7.29 × 10−10 cm2 s−1 after 13 cycles charge-decharge.