Asymmetric Hybrid Capacitor Based on NiCo2O4 Nanosheets Electrode

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	Asymmetric Hybrid Capacitor Based on NiCo2O4 Nanosheets Electrode
	Tong Yongli; Dai Meizhen; Xing Lei; Liu Hengqi; Sun Wanting; Wu Xiang
刊名	ACTA PHYSICO-CHIMICA SINICA
	2020
卷号	36 期号:7
关键词	FLEXIBLE CARBON-FIBERS HIGH-PERFORMANCE ENERGY-STORAGE SUPERCAPACITOR ELECTRODES NANONEEDLE ARRAYS PHOTOCATALYSTS TRANSITION NANORODS NI NiCo2O4 nanosheet Electrochemical performance Asymmetrical supercapacitor Cathode material Cycle stability
ISSN号	1000-6818
英文摘要	The looming global energy crisis and ever-increasing energy demands have catalyzed the development of renewable energy storage systems. In this regard, supercapacitors (SCs) have attracted widespread attention because of their advantageous attributes such as high power density, excellent cycle stability, and environmental friendliness. However, SCs exhibit low energy density and it is important to optimize electrode materials to improve the overall performance of these devices. Among the various electrode materials available, spinel nickel cobaltate (NiCo2O4) is particularly interesting because of its excellent theoretical capacitance. Based on the understanding that the performances of the electrode materials strongly depend on their morphologies and structures, in this study, we successfully synthesized NiCo2O4 nanosheets on Ni foam via a simple hydrothermal route followed by calcination. The structures and morphologies of the as-synthesized products were characterized by X-ray diffraction, scanning electron microscopy, and Brunauer-Emmett-Teller (BET) surface area analysis, and the results showed that they were uniformly distributed on the Ni foam support. The surface chemical states of the elements in the samples were identified by X-ray photoelectron spectroscopy. The as-synthesized NiCo2O4 products were then tested as cathode materials for supercapacitors in a traditional three-electrode system. The electrochemical performances of the NiCo2O4 electrode materials were studied and the area capacitance was found to be 1.26 C.cm(-2) at a current density of 1 mA.cm(-2). Furthermore, outstanding cycling stability with 97.6% retention of the initial discharge capacitance after 10000 cycles and excellent rate performance (67.5% capacitance retention with the current density from 1 to 14 mA.cm(-2)) were achieved. It was found that the Ni foam supporting the NiCo2O4 nanosheets increased the conductivity of the electrode materials. However, it is worth noting that the contribution of nickel foam to the areal capacitance of the electrode materials was almost zero during the charge and discharge processes. To further investigate the practical application of the assynthesized NiCo2O4 nanosheets-based electrode, a device was assembled with the as-prepared samples as the positive electrode and active carbon (AC) as the negative electrode. The assembled supercapacitor showed energy densities of 0.14 and 0.09 Wh.cm(-3) at 1.56 and 4.5 W.cm(-3), respectively. Furthermore, it was able to maintain 95% of its initial specific capacitance after 10000 cycles. The excellent electrochemical performance of the NiCo2O4 nanosheets could be ascribed to their unique spatial structure composed of interconnected ultrathin nanosheets, which facilitated electron transportation and ion penetration, suggesting their potential applications as electrode materials for high performance supercapacitors. The present synthetic route can be extended to other ternary transition metal oxides/sulfides for future energy storage devices and systems.
资助项目	[Research Project of Guangdong Province Key Laboratory of Display Material and Technology, China]
语种	英语
CSCD记录号	CSCD:6759760
内容类型	期刊论文
源URL	[http://ir.imr.ac.cn/handle/321006/145257]
专题	金属研究所_中国科学院金属研究所
作者单位	中国科学院金属研究所
推荐引用方式 GB/T 7714	Tong Yongli,Dai Meizhen,Xing Lei,et al. Asymmetric Hybrid Capacitor Based on NiCo2O4 Nanosheets Electrode[J]. ACTA PHYSICO-CHIMICA SINICA,2020,36(7).
APA	Tong Yongli,Dai Meizhen,Xing Lei,Liu Hengqi,Sun Wanting,&Wu Xiang.(2020).Asymmetric Hybrid Capacitor Based on NiCo2O4 Nanosheets Electrode.ACTA PHYSICO-CHIMICA SINICA,36(7).
MLA	Tong Yongli,et al."Asymmetric Hybrid Capacitor Based on NiCo2O4 Nanosheets Electrode".ACTA PHYSICO-CHIMICA SINICA 36.7(2020).