Cobalt-boron amorphous alloy prepared in water/cetyl-trimethyl-ammonium bromide/n-hexanol microemulsion as anode for alkaline secondary batteries
Cobalt-boron amorphous alloy prepared in water/cetyl-trimethyl-ammonium bromide/n-hexanol microemulsion as anode for alkaline secondary batteries
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DOI：
10.1016/j.electacta.2009.11.082
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发表时间：
2010-02
影响因子：
6.6
通讯作者：
D. Tong;D. Wang;W. Chu;J. Sun;P. Wu
中科院分区：
文献类型：
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作者：
D. Tong;D. Wang;W. Chu;J. Sun;P. Wu
在水/十六烷基三甲基溴化铵/正己醇微乳液体系中，用硼氢化钾还原醋酸钴，首次制备出了具有均匀纳米颗粒的非晶态钴硼（Co-B）。采用X射线衍射、透射电子显微镜、氮气吸附-脱附、X射线光电子能谱、电感耦合等离子体、循环伏安、差示扫描量热、程序升温脱附、扫描电子显微镜、充放电测试和电化学阻抗谱等方法对样品进行了表征。结果表明，合成的Co-B的电化学活性高于在水溶液中制备的常规Co-B。结果表明，Co-B的均匀分布和较大的比表面积有利于其电化学储氢性能的提高。此外，合成的Co-B在50次循环后甚至具有347 mAhg − 1，而在水溶液中制备的常规Co-B在100 mAg −1的电流下30次循环后仅具有254 mAhg − 1。其良好的循环性能可归因于其较小的电极与电解质之间的界面阻抗。
Amorphous cobalt–boron (Co–B) with uniform nanoparticles was prepared for the first time via reduction of cobalt acetate by potassium borohydride in the water/cetyl-trimethyl-ammonium bromide/n-hexanol microemulsion system. The sample was characterized by X-ray diffraction, transmission electron microscopy, nitrogen adsorption–desorption, X-ray photoelectron spectroscopy, inductively coupled plasma, cyclic voltammetry, differential scanning calorimetry, temperature-programmed desorption, scanning electron microscopy, charge–discharge test and electrochemical impedance spectra. The results demonstrate that electrochemical activity of the as-synthesized Co–B was higher than that of the regular Co–B prepared in aqueous solution. It indicates that the homogeneous distribution and large specific surface area helped the electrochemical hydrogen storage of the as-synthesized Co–B. Furthermore, the as-synthesized Co–B even had 347mAhg−1after 50 cycles, while the regular Co–B prepared in aqueous solution only had 254mAhg−1after 30 cycles at a current of 100mAg−1. The better cycling performance can be ascribed to its smaller interfacial impedance between electrode and electrolyte.