Abstract: The hollowed-out tubular carbon@MnO2 hybrid composites with hierarchical morphology have been successfully prepared via the redox reaction between MnO4 and tubular carbonized kapok fiber. The morphology and electrochemical performance of the as-prepared hybrid composites can be facilely controlled by adjusting the concentration of MnO4 . The carbon@MnO2 electrode with tubular structure of the assembled MnO2 nanosheets possess the highest specific capacitance of 321 Fg(-1) at a current density of 0.5 Ag-1 with the capacitance retention of 94% at a scan rate of 100 mV s(-1) for 800 cycles in 1.0M Na2SO4 solution. The studies on the temperature dependence indicated that the specific capacitance increased with the increase in the testing temperature. The results reveal that the introduction of the highly conductive carbon in hybrid structure is one of the effective methods to improve the electrochemical performance of MnO2 electrodes whose poor conductivity limit their capacitance, cycling life and rate performance. It also can be concluded that it is crucial to design and control the morphology of materials in practical application for supercapacitor. (C) 2015 Elsevier Ltd. All rights reserved.

KeyWords Plus:HIGH-PERFORMANCE SUPERCAPACITORS; ELECTROCHEMICAL CAPACITORS; ASYMMETRIC SUPERCAPACITORS; MNO2 NANOSHEETS; ENERGY-STORAGE; CARBON-FIBERS; OXIDE; SHELL; ARRAYS; FABRICATION

Published in ELECTROCHIMICA ACTA, 178 709-720; 10.1016/j.electacta.2015.08.091 OCT 1 2015