Electrochemical properties of aluminum-substituted α-Ni(OH)_2

The essential conditions under which a stable inorganic metal element-substituted α-Ni（OH）2 with a turbostratic structure can be prepared were discussed. The electrochemical properties of aluminum-substituted α-Ni（OH）2 were investigated systematically using galvanostatic charging/discharging method, voltammetric technique and AC impedance method, and compared with that of β-Ni（OH）2. The results show that its maximum discharge capacity is 275 mAh/g at 68.3 mA/g and its high-rate discharge behavior is excellent. Compared with β-Ni（OH）2, the Al-substituted α-Ni（OH）2 has a higher and flatter discharge plateau, higher charge efficiency and reversibility.