Abstract:

The Al-Co, Al-Yb, Yb-Co and Al-Yb-Co multiple doping are respectively used. By controlling the amount of sodium carbonate, the α-Ni(OH)₂ is prepared by ultrasonic-assisted precipitation. And the influence of sodium carbonate on the crystalline phase and structure stability for alpha nickel hydroxide is studied. The results demonstrate that with the amount increasing, the bi-phase nickel hydroxide gradually transforms to pure alpha nickel hydroxideand, the structural stability is also improved. For Al-Yb-Co-Ni(OH)₂, when the amount of sodium carbonate is 2.0 g, the sample still keeps α-Ni(OH)₂ 30 d after being aged. And when the amount is less than 2.0 g, the phase transformation exists in the samples with different extent. These results demonstrate that the amount of sodium carbonate is a critical factor in maintaining the structural stability of α-Ni(OH)₂.

Key words: sodium carbonate; nickel hydroxide crystalline; structural stability; multiple doping