Heterostructured Ni(OH)2-Co(OH)2 composites on 3D ordered Ni-Co nanoparticles fabricated on microchannel plates for advanced miniature supercapacitor
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- 作者：Mai Li ; Shaohui Xu ; Yiping Zhu ; Pingxiong Yang ; Lianwei Wang ; Paul K. Chu
- 关键词：Electrochemical capacitors ; Electrodeposition ; Ni&ndash ; Co alloys ; Ordered three-dimensional microchannel plates ; Nanoparticles
- 刊名：Journal of Alloys and Compounds
- 出版年：15 March, 2014
- 年：2014
- 卷：589
- 期：Complete
- 页码：364-371
- 全文大小：2269 K
文摘
Silicon microchannel plates (Si-MCPs) coated with a layer of nickel cobalt alloy (NCA) constitute an excellent substrate for miniature supercapacitors. Nanoscale Ni(OH)2-Co(OH)2 composite particles serving as the active materials are electrodeposited on ordered three-dimensional (3D) NCA/Ni/Si-MCPs and the Ni(OH)2-Co(OH)2 composites have different structures depending on the amount of Co(OH)2 in Ni(OH)2. The nickel hydroxide synthesized from a water-acetone 0.1 M Ni(NO3)2鈰?H2O solvent has a compact structure, but that from a 0.1 M Ni(NO3)2鈰?H2O solvent containing 5% Co(NO3)2鈰?H2O is loosely packed with nanoparticles and that from a 0.1 M Ni(NO3)2鈰?H2O solvent containing 10% Co(NO3)2鈰?H2O contains many nanoparticles. Addition of Co(NO3)2鈰?H2O results in a smooth morphology. The smooth structure is also observed from active materials produced in 20% and 30% Co(NO3)2鈰?H2O solvents. Five types of electrode materials are investigated from the perspective of electrochemical capacitors by conducting cyclic voltammogram, galvanostatic charge-discharge measurements, and electrochemical impedance spectroscopy. In this experiment, the highest specific capacitance of 7.8 F cm鈭? is achieved in the samples prepared in 10% Co(NO3)2鈰?H2O at a discharge current density of 20 mA cm鈭?. It is much better than 1.46 F cm鈭? observed from previous attempts and the materials have excellent capacity retention.