Structural and Electrochemical Hydrogen Storage Properties of AB<sub>4</sub>-type La<sub>2</sub>YNi<sub>12</sub><sub>-</sub><italic

The forming regularities and electrochemical hydrogen storage properties of AB₄-type superlattice phases in the La-Y-Ni-Mn system were explored. AB₄-type La₂YNi₁₂<italic>_-x</italic>Mn<italic>_x</italic>(<italic>x</italic> =0.5, 1.0, 1.5) hydrogen storage alloys were designed, and 3R-AB₄-type La₂YNi₁₁Mn single-phase alloy was prepared by optimizing the quenching temperature. The study found that as the quenching temperature increased, the A₅B₁₉ phase transforms into AB₄ phase, and the AB₄ single-phase alloy could be obtained at 997 ℃. The substitution of Mn for Ni increases the cell volume of the phase and the volume of the [A₂B₄] subunit, which enhances the structural stability and the electrochemical properties of the alloy. The maximum discharge capacity of AB₄ single-phase alloy is 346 mAh/g, and the cyclic capacity is 216.6 mAh/g after 300 charge/discharge cycles.