Self-discharge performance is one of the key indexes of nickel-metal hydride batteries. In this work, single-phase Ce2Ni7-type La-Nd-Mg-Ni-based alloy with great application potential in long-term storage Ni/MH batteries are prepared by step-wise annealing. The as-cast alloy contains CaCu5-, Gd2Co7- and Ce5Co19-type phases. After annealed at 1248 K, CaCu5- and Ce5Co19-type phases disappear and a single-phase Gd2Co7-type structure is obtained. With the temperature increase, Gd2Co7-type structure begins to transform into Ce2Ni7-type structure. As annealed at 1323 K, the alloy shows a Ce2Ni7-type single-phase structure. The C-60 (discharge capacity at 60 mA g(-1)) of Ce2Ni7-type electrode reaches 405 mAh g(-1), and the C-1900 is even high to 210 mAh g(-1). The Ce2Ni7-type electrode also shows superior self-discharge properties and the charge retention rate for 1 d (CRT1d) is 96.5%. Moreover after 150 cycles, the CRT1d is even high to 97.7% and CRT7d is 81.5%. While those of the as-cast electrodes are only 79% and 36%, respectively. Electrochemical pressure-composition isotherms show that Ce2Ni7-type electrode has relatively lower hydrogen desorption plateau pressure, indicating more stable hydride and less reversible self-discharge. After 150 cycles, the plateau pressure gets even lower. Moreover Ce2Ni7-type electrode possesses smaller corrosion current density, indicating minor oxidation/corrosion degree. (c) 2018 The Electrochemical Society.