For improving the electrochemical properties of nonstoichiometric AB3-type La0.78Mg0.22Ni2.67Mn0.11Al0.11Co0.52 alloy as negative electrode of Ni-MH battery, its related composites La0.78Mg0.22Ni2.67Mn0.11Al0.11Co0.52-x wt.% M1Ni3.5Co0.6Mn0.4Al0.5 (x = 0, 10, 20, 30) were prepared. Analysis by X-ray diffractometry (XRD) revealed that the composites consist mainly of LaNi5 and La2Ni7 phases. Despite the small decrease in the maximum discharge capacity, the cycle performance was significantly enhanced. Linear polarization (LP), anodic polarization (AP) and potential step discharge experiments revealed that the electrochemical kinetics increases first and then decreases with increasing x.
AB3-type alloy; composite electrode material; cycle stability
