Investigation of the structure, phase composition, and electrochemical characteristics of hydrogen-sorbing intermetallics of the La–Мg–Ni system obtained by the sintering method

The crystal structure, phase composition, and electrochemical properties of the materials obtained by sintering of (LaNi 3 +Mg+Ni) powder mixture in the temperature range 640–1020°С have been investigated. Experimental results show that, at temperatures of ≤850°С, the sintered multiphase material, whose major phases are phases with PuNi 3 -type structure (LaMg 2 Ni 9 and LaNi 3 ) and CaCu 5 -type structure (LaNi 5 ), is formed. With increase in temperature, the number of phases in the sintered material decreases to a single major phase LaNi 5, and the content of the LaMg 2 Ni 9 phase practically does not change. It has been established that increase in sintering temperature deteriorates the activation of the electrode materials and slows down the hydrogen absorption process. At the same time, the maximum discharge capacity and cyclic stability of electrodes increase.