Facile synthesis of CoAl-LDH/MnO2 hierarchical nanocomposites for high-performance supercapacitors

Abstract

Abstract In this work, MnO 2 /CoAl-layered double hydroxide (CoAl-LDH) nanocomposites were prepared through a simple redox reaction between Co 2+ species and MnO 4 − . The structure and morphology of these nanocomposites were investigated by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), focused ion beam scanning electron microscopy (FIB/SEM) and high-resolution transmission electron microscopy (HRTEM). CoAl-LDH/MnO 2 nanocomposites presented their platelet-like structures with MnO 2 nanocrystals decorating the LDH host layer. Furthermore, the electrochemical properties of composites were evaluated by cycle voltammetric (CV) and galvanostatic charge–discharge measurements. Surprisingly, the hierarchical CoAl-LDH/MnO 2 composites displayed a high specific capacitance (1088 F g −1 at 1 A g −1 ), high rate capability, and excellent long-term cycling life. In principle, these findings suggested that CoAl LDHs-based nanocomposites could be promising candidates for supercapacitors electrode with enhancive electrochemical behavior.