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以硫酸镍为镍源,尿素为沉淀剂,水热水解制备了纳米花瓣状β-Ni(OH)2,其制备方法简单易行。利用X射线衍射(XRD)、扫描电镜(SEM)和恒电流充放电测试技术测试了制备样品的相结构、微观形貌和电化学性能。研究结果表明:随着镍尿素摩尔比的增加,制备样品逐渐由α相过渡到β相。镍尿素摩尔比为1∶5时,制备的样品为花瓣状β-Ni(OH)2。扫描电镜谱图表明制备的微球是由几十个相互连接的纳米片所构成的,花瓣厚度均匀结构清晰,平均粒径约为5.4μm,纳米片层长度约为0.55μm,厚度约为20 nm。和普通球形Ni(OH)2相比,花瓣状Ni(OH)2在0.2 C和1.0 C倍率放电容量分别提高23%和14.8%,具有更好的充放电性能和循环稳定性。通过观察镍尿素摩尔比和水热时间对生成产物微观形态的影响,探讨了Ni(OH)2花瓣状微球的生长机制。
Nano petaloid β-Ni (OH) 2 was prepared by hydrothermal hydrolysis using nickel sulfate as nickel source and urea as precipitating agent. The preparation method was simple and easy. The phase structure, microstructure and electrochemical properties of the samples were tested by X-ray diffraction (XRD), scanning electron microscopy (SEM) and galvanostatic charge-discharge test. The results show that: with the increase of molar ratio of nickel to urea, the prepared sample gradually transition from α phase to β phase. NiMH molar ratio of 1: 5, the sample was prepared petal-like β-Ni (OH) 2. Scanning electron micrographs showed that the prepared microspheres consisted of dozens of interconnected nanosheets. The petal thickness was uniform and the structure was clear. The average particle size was about 5.4μm. The length of nanosheets was about 0.55μm and the thickness was about 20 nm. Compared with the common spherical Ni (OH) 2, the discharge capacity of petal Ni (OH) 2 increased by 23% and 14.8% at 0.2 C and 1.0 C, respectively, which has better charge and discharge performance and cycle stability. The growth mechanism of Ni (OH) 2 petaloid microspheres was discussed by observing the effect of Ni / Mo molar ratio and hydrothermal time on the microstructure of the product.