An investigation of the electrochemically capacitive performances of mesoporous nickel cobaltite hollow spheres. (1st October 2015)

• Record Type: Journal Article
• Authors: Zhu, Yirong; Wu, Zhibin; Jing, Mingjun; Jia, Xinnan; Ji, Xiaobo
• Is Part Of: Electrochimica acta. Volume 178(2015)
• Page Start: 153
• Page End: 162
• Publication Date: 2015-10-01
• Subjects: Spinel nickel cobaltite -- Hollow spheres -- Mesoporous structure -- Soft template method -- Supercapacitor; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2015.08.004
• Languages: English
• ISSNs: 0013-4686

Abstract

Graphical abstract: Highlights: Mesoporous NiCo2 O4 hollow spheres are prepared via a soft template method. Mesoporous NiCo2 O4 hollow spheres manifest enhanced electrochemical performances. Large BET surface area and unique hollow structure give the excellent electrochemical properties. Abstract: Mesoporous NiCo2 O4 hollow spheres are prepared by a soft template method utilizing a hydrothermal route. Three kinds of NiCo2 O4 morphologies can be obtained, including solid sphere, hollow sphere and collapsed hollow sphere with the adjustment of the concentration of hexamethylenetetramine (HMT). Compared with solid spheres and collapsed hollow spheres, the as-prepared NiCo2 O4 hollow spheres show enhanced electrochemical properties, manifesting a high specific capacitance (204.4 mAh g −1 at 2 A g −1 ), exceptional rate capability (62.8% capacity retention at 50 A g −1 ) and good cycling stability (93.2% capacity retention after 1000 cycles). Such remarkable electrochemical properties of the NiCo2 O4 hollow spheres can be primarily ascribed to the high specific surface area and uniform mesoporous hollow structure that can increase the exposure of active sites available for reaction on the surface, shorten transport pathways for both electrons and ions, and alleviate the volume change during charge–discharge process. This work is significant because the unique mesoporous NiCo2 O4 hollow spheres demonstrate the great potential in the development of high-performance electrode materials for supercapacitors. Additionally, this soft template method can be extended to the fabrication of other binary or even ternary metal oxides hollow micro-/nanostructure materials.