Enhancing the supercapacitor performance of flexible MnOxCarbon cloth electrodes by Pd-decoration. (10th May 2018)

• Record Type: Journal Article
• Authors: Babkova, T.A.; Fei, H.; Kazantseva, N.E.; Sapurina, I.Y.; Saha, P.
• Is Part Of: Electrochimica acta. Volume 272(2018)
• Page Start: 1
• Page End: 10
• Publication Date: 2018-05-10
• Subjects: Manganese oxide -- Palladium -- Carbon cloth -- Electrodeposition -- Nucleation and growth -- Supercapacitor; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2018.03.143
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: Manganese oxide (MnOx )-based hybrid electrode materials have been designed by electrochemical deposition on carbon cloth preliminary activated by palladium (Pd) nanoparticles. The synthesis conditions (current density, deposition time) were chosen in such a way as to achieve a stable structure of MnOx with a large surface area. The structural parameters and surface morphology of materials obtained are characterized by Scanning Electron and Transmission Electron Microscopy (SEM, TEM), Raman spectroscopy, X-ray Photoelectron Spectroscopy (XPS), etc. The electrochemical behavior was investigated by cyclic voltammetry, galvanostatic charge/discharge and impedance spectroscopy. The attained results indicate that MnOx deposits reviled birnessite-type structural feature. Apart from that, the morphology of MnOx transformed with increasing of current density from needlelike structure to loosely-packed thin sheets and then to closed-packed thicker sheets structures. Different morphology exhibits different specific surface area and electrochemical efficiency. Hence electrochemical analysis reviled the highest specific capacitance (186 F g −1 ) and cyclic stability for MnOx PdCC with obtained at current density of 1 mA cm −2 . It can be explained by the formation of a less dense structure of MnOx (loosely-packed thin sheets) with large specific surface area and thus better permeability for Na + and SO4 −2 ions. As to the role of Pd, its nanoparticles deposited on CC can play a dual role, namely electron conducting passway between CC and MnOx and structure–guiding agent of manganese oxides nucleation and grows.