Solvothermal synthesis of Ni(HCO₃)₂/graphene composites toward supercapacitors and the faradiac redox mechanism in KOH solution

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• 作者：Jinfeng Sun ; Zhangpeng Li ; Jinqing Wang ; Zhaofeng Wang ; Lengyuan Niu ; Peiwei Gong ; Xiaohong Liu ; Honggang Wang ; Shengrong Yang
• 关键词：Solvothermal synthesis ; Ni(HCO3)2/graphene composite ; Supercapacitors ; Faradiac redox mechanism
• 刊名：Journal of Alloys and Compounds
• 出版年：2013
• 出版时间：25 December, 2013
• 年：2013
• 卷：581
• 期：Complete
• 页码：217-222
• 全文大小：1449 K

文摘

In this work, a series of composites consisting of Ni(HCO₃)₂ and graphene nanosheets (GS) have been prepared by a facile solvothermal method, and then their application as electrode materials for supercapacitors has been investigated by cyclic voltammetry (CV) and galvanostatic charge-discharge tests. Morphological and structural analyses by field-emission scanning electron microscopy, high resolution transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy indicated that Ni(HCO₃)₂ particles deposited on the GS and formed a loosely packed microstructure, actualizing the successful combination of Ni(HCO₃)₂ particles with GS. Among the prepared composites, the sample of Ni(HCO₃)₂/GS2 exhibited the highest capacitance of 1200 F g^?1 at a current density of 4 A g^?1, illustrating that such composite is a promising candidate as electrode material for supercapacitors. Moreover, the Faradic redox mechanism of the Ni(HCO₃)₂/GS composite was further studied in virtue of XRD analysis, which revealed that the Ni(HCO₃)₂ phase could be quickly transformed into Ni(OH)₂ phase by an electrochemically induced phase transformation process during the galvanostatic charge-discharge tests.