Structural evolution of multi-walled carbon nanotube/MnO2 composites as supercapacitor electrodes

    Authors

    Q. Li; J. M. Anderson; Y. Q. Chen;L. Zhai

    Comments

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    Abbreviated Journal Title

    Electrochim. Acta

    Keywords

    Multi-walled carbon nanotube; Manganese oxide; Charge/discharge cycles; Structural evolution; Supercapacitor; PERFORMANCE ELECTROCHEMICAL ELECTRODES; CHARGE-STORAGE PROPERTIES; MANGANESE OXIDE; ASYMMETRIC SUPERCAPACITORS; HYDROTHERMAL SYNTHESIS; MNO2 ELECTRODES; HIGH-POWER; CAPACITORS; ALPHA-MNO2; DEPOSITION; Electrochemistry

    Abstract

    Multi-walled carbon nanotube (MWCNT)/MnO2 supercapacitor electrodes containing MnO2 nanoflakes in the MWCNT network are fabricated through the oxidation of manganese acetate with poly(4-styrenesulfonic acid) (PSS) dispersed MWCNTs. The structural evolution of the electrodes under charge/discharge (reduction/oxidation) cycles and its impact on the electrodes' electrochemical properties are evaluated. Structural evolution involves the dissolution of MnO2 upon reduction, the diffusion of the reduced Mn species from the MWCNT network toward the electrolyte solution, and the deposition of MnO2 on the electrode surface upon oxidation. Electrode structural changes, including the electrode dissolution and the growth of the MnO2 crystals, are scan rate dependent and have deteriorating effect on the electrode's electrochemical properties including the specific capacitance and cyclic stability. Published by Elsevier Ltd.

    Journal Title

    Electrochimica Acta

    Volume

    59

    Publication Date

    1-1-2012

    Document Type

    Article

    Language

    English

    First Page

    548

    Last Page

    557

    WOS Identifier

    WOS:000299911500078

    ISSN

    0013-4686

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