Study On Structur And Electrochenmical Properties Of La-Ni-Mn Hydrogen Storage Alloys

The overall properties of La-Ni-Mn have been investigated on the basis of comprehensive review of the research progress of hydrogen alloys. In this paper, the stoichiometry of La-Ni-Mn base alloy have been studied; The effect of rare earth elements Nd, Ce, Pr, Gd, Er and Y addition on the microstructure and electrochemical properties of the La-Ni-Mn alloy have been investigated; The effect of B addition on the structure and electrochemical performances of the La-Ni-Mn alloy were studied.The results show that the La1.0Ni4.0Mnx(x=0.05~0.5) alloys are composed of La Ni5 phase,La Ni3 and La2Ni7.With the increase of Mn content, the maximum discharge capacity of the alloy electrode increased. High rate capability, cycle stability and high temperature performance of the alloys are all improved. So the La1.0Ni4.0Mn0.5 is choosed as the base alloy.The effects of rare earth element Nd and Ce addition on microstructure and electrochemical properties of La1.0Ni4.0Mn0.5 alloys are studied in this paper. It is found that the comprehensive performance of the La1.0Ni4.0Mn0.5Ndx(x=0.005~0.05) and La1.0Ni4.0Mn0.5Cex(x=0.005~0.05) alloys are the best with x=0.01. The rare earth elements Pr,Gd, Er, and Y have been used as additive element to La1.0Ni4.0Mn0.5 alloy to improve the electrocatalytic activity.The results show that the order priority is as follow: alloy Gd> alloy Pr> alloy Er> alloy Y.Effects of B addition on the microstructure and electrochemical properties of La1.0Ni4.0Mn0.5Bx(x=0.3~0.9) hydrogen storage alloy have been investigated. The results show that the comprehensive performance is the best with x=0.3.