Li Songzhan, Wen Jian, Chen Tian, Xiong Liangbin, Wang Jianbo, Fang Guojia
Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education of China, School of Physics and Technology, Wuhan University, Wuhan, 430072, People's Republic of China. School of Electronic and Electrical Engineering, Wuhan Textile University, Wuhan, 430200, People's Republic of China.
Nanotechnology. 2016 Apr 8;27(14):145401. doi: 10.1088/0957-4484/27/14/145401. Epub 2016 Feb 24.
A three-dimensional (3D) CoS/Ni(OH)2 nanocomposite structure based on CoS nanoflakes and two-dimensional (2D) Ni(OH)2 nanosheets were in situ synthesized on Ni foam by a whole hydrothermal reaction and electrodeposition process. The 3D CoS/Ni(OH)2 nanocomposite structures demonstrate the combined advantages of a sustained cycle stability of CoS and high specific capacitance from Ni(OH)2. The obtained CoS/Ni(OH)2 nanocomposite structures on Ni foam can directly serve as a binder-free electrode for a supercapacitor. For the 3D CoS/Ni(OH)2 nanocomposite electrode, the high specific capacitance is 1837 F g(-1) at a scan rate of 1 mV s(-1), which is obviously higher than both the bare CoS electrode and Ni(OH)2 electrode. The galvanostatic charge and discharge measurements illustrate that the 3D CoS/Ni(OH)2 nanocomposite electrode possesses excellent cycle stability, and it keeps a 95.8% retention of the initial capacity after 5000 cycles. Electrochemical impedance spectroscopy measurements also confirm that the 3D CoS/Ni(OH)2 nanocomposite electrode has better electrochemical characteristics. These remarkable performances can be attributed to the unique 3D nanoporous structure of CoS/Ni(OH)2 which leads to a large accessible surface area and a high stability during long-term operation. In addition, 2D Ni(OH)2 nanosheets in 3D nanocomposite structures can afford rapid mass transport and a strong synergistic effect of CoS and Ni(OH)2 as individual compositions contribute to the high performance of the nanocomposite structure electrode. These results may promote the design and implementation of nanocomposite structures in advanced supercapacitors.
通过全水热反应和电沉积过程，在泡沫镍上原位合成了一种基于硫化钴纳米片和二维氢氧化镍纳米片的三维（3D）硫化钴/氢氧化镍纳米复合结构。三维硫化钴/氢氧化镍纳米复合结构展现出了硫化钴的持续循环稳定性和氢氧化镍的高比电容的综合优势。在泡沫镍上获得的硫化钴/氢氧化镍纳米复合结构可直接用作超级电容器的无粘结剂电极。对于三维硫化钴/氢氧化镍纳米复合电极，在扫描速率为1 mV s(-1)时，高比电容为1837 F g(-1)，明显高于裸硫化钴电极和氢氧化镍电极。恒电流充放电测量表明，三维硫化钴/氢氧化镍纳米复合电极具有优异的循环稳定性，在5000次循环后仍保持初始容量的95.8%。电化学阻抗谱测量也证实了三维硫化钴/氢氧化镍纳米复合电极具有更好的电化学特性。这些卓越的性能可归因于硫化钴/氢氧化镍独特的三维纳米多孔结构，该结构导致了较大的可及表面积和长期运行期间的高稳定性。此外，三维纳米复合结构中的二维氢氧化镍纳米片可实现快速的质量传输，并且硫化钴和氢氧化镍作为单独成分产生了强烈的协同效应，有助于纳米复合结构电极的高性能。这些结果可能会促进先进超级电容器中纳米复合结构的设计与应用。
