Sandwich-like NiCo layered double hydroxide/reduced graphene oxide nanocomposite cathodes for high energy density asymmetric supercapacitors. Issue 16 (21st March 2019)

• Record Type: Journal Article
• Authors: Le, Kai; Wang, Zhou; Wang, Fenglong; Wang, Qi; Shao, Qian; Murugadoss, Vignesh; Wu, Shide; Liu, Wei; Liu, Jiurong; Gao, Qiang; Guo, Zhanhu
• Is Part Of: Dalton transactions. Volume 48:Issue 16(2019)
• Page Start: 5193
• Page End: 5202
• Publication Date: 2019-03-21
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/c9dt00615j
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : Lab-synthesized sandwich-like LDH/rGO composites were assembled into asymmetric supercapacitors exhibiting high energy density and excellent cycling stability. Abstract : Nanocomposites with a well-defined sandwich-like nanostructure were prepared via in situ growing NiCo-layered double hydroxide nanosheets with tunable Ni/Co ratios on reduced graphene oxide (rGO). Electrochemical impedance spectra and N2 adsorption/desorption isotherms confirmed that these sandwich nanostructures effectively promoted charge transport and enlarged the specific surface area. The nanocomposites with Ni : Co = 2 : 1 exhibited a maximum specific capacitance of 2130 F g −1 at 2 A g −1, excellent rate capability (72.7% retention at 15 A g −1 ), and cycling stability. Asymmetric supercapacitors were assembled with these nanocomposite cathodes and rGO as a negative electrode (anode), and demonstrated an energy density of 34.5 W h kg −1 at a power density of 772 W kg −1, while maintaining a capacity retention of 86.7% after 10 000 cycles at 5 A g −1 . The robust electrochemical properties indicate the composites as promising electrodes for electrochemical energy storage devices.