Novel cuboid-like cobalt nickel phosphate/manganese dioxide/Multi-walled carbon nanotubes composites as binder-free electrodes for high-performance supercapacitors

Publication date: Available online 1 February 2020Source: Inorganic Chemistry CommunicationsAuthor(s): Shi-wen Wang, Ming Mao, Yang Cao, He-wei Luo, Heng Wang, Dong-jie GuoAbstractUsing NiCl2·6H2O, CoCl2·6H2O, Na2HPO4, manganese dioxide (MnO2) and Multi-walled carbon nanotubes (MWCNTs) as the main raw materials, the cuboid-like cobalt nickel phosphate/MnO2/MWCNTs (CNPMM) composites were successfully prepared by a simple hydrothermal method. The morphology, composition and structure of the composites were studied by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectrum, specific surface area analyzer and particle size analysis. SEM images showed that the composite material presented a cuboid-like morphology. The width, length and height of cuboids are 0.3-0.8 µm, 2-3 µm and 8-10µm, respectively. The special structure and morphology of the sample provide more active sites, making it exhibit superior pseudocapacitance. The electrochemical performance of the three-electrode system supercapacitor was systematically studied by cyclic voltammetry, constant current charge-discharge and electrochemical impedance spectroscopy. When the mass ratio of MnO2 to MWCNTs is 1:1 with the total doping amount of 3.9 wt%, the as-prepared CNPMM1:1 composite shows the best capacitance performance. With 3 mol·L-1 KOH as the electrolyte, it exhibits a specific capacitance as high as 2334 F ...
Source: Inorganic Chemistry Communications - Category: Chemistry Source Type: research