The synthesis of α-nickel hydroxide has been achieved via a facile liquid-phase precipitation approach, using the mixed solvents of ethylene glycol and water as reaction medium at low temperature. The XRD characterization indicates that pure phase α-Ni(OH)2 can be obtained under variable temperature and pH value. The products present a flower-like micro-/nano-structure assembled with curved nanosheets. The nanosheets have the width of 100~500 nm and the thickness of 20~70 nm. The cavities are formed in the structure due to the interconnection of curved nanosheets. The solvents play a key role in the formation of Ni(OH)2 with different forms. Pure phase α-Ni(OH)2 can only be synthesized in the mixed solvents of ethylene glycol and water. Cyclic voltammetry was applied to test the electrochemical activity of the as-synthesized α-Ni(OH)2. The findings suggest that the α-Ni(OH)2 with a micro-/nano-structure exhibits excellent electrochemical activity, which may be considered as a promising candidate of electrode material.