β-Ni(OH)_2纳米线的相转化法制备及电化学性能

Preparation by Phase Transformation Method and Electrochemical Performance of β-Ni(OH)_2 Nanowires

采用简单的相转化方法合成出直径为20~30 nm、长度为几微米的β-Ni(OH)_2纳米线.利用XRD和FESEM表征了样品的结构和形貌,并采用循环伏安法、恒流充放电和交流阻抗谱等测试了样品的电化学性能.结果表明,在氢氧化钠溶液中,水热时间为30 min时,Paraotwayite型α-Ni(OH)_2纳米线转化为β-Ni(OH)_2纳米线.在不同扫描速率下,电极材料α-Ni(OH)_2和β-Ni(OH)_2纳米线的可逆性和倍率性能均优于β-Ni(OH)_2纳米片.

β-Nickel hydroxide nanowires with diameters of 20—30 nm and lengths up to several micrometers were prepared via a simple phase transformation method. The structure and morphology of the samples were characterized using X- ray powder diffraction（ XRD） and field emission scanning electron microscopy（ FESEM）. The electrochemical performances were measured using cyclic voltammetry,galvanostatic chargedischarge and electrochemical impedance spectroscopy. The results show that Paraotwayite type α-nickel hydroxide nanowires have successfully transformed to β-nickel hydroxide nanowires in sodium hydroxide solution after being hydrothemally treated for 30 min. The reversibility and rate performance of electrode materialsα-nickel hydroxide and β-nickel hydroxide nanowires are superior to those of β-nickel hydroxide nanosheets at different scan rates.