The Study of Supercapacitive Stability of MnO₂/MWCNT Nanocomposite Electrodes by Fast Fourier Transformation Continues Cyclic Voltammetry

摘要

In this work, the nanostructured MnO2 was uniformly coated on the multi-walled carbon nanotube(MWCNT) by a sonochemical method, and the effect of MWCNT amount on the supercapacitiveperformance of the nanocomposites were investigated. The structure and morphology of thenanocomposites were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA),transition electron microscopy (TEM) and scanning electron microscopy (SEM). Also, the specificcapacitances (SCs) of the MWCNT/MnO2 electrodes were studied by cyclic voltammetry (CV). Theresult shows that the loading the nanocomposite with of MnO2 was 65 wt. %, the electrode has a high-1 -1 SC of 394 F g (at scan rate of 2 mV s in a 0.5 M Na2SO4) indicating a better performance than that-1 -1 of pristine MnO2 electrodes (289 F g at scan rate of 2 mV s ). Fast Fourier transformation continuouscyclic voltammetry (FFTCCV) technique was used to study stability and separation of charge anddischarge curves of the nanocomposite electrodes, over a large number of cycles (at scan rates 200 mV-1 s ). The results indicated SC that the capacitance of the composite electrode decreases only 3.2% ofinitial capacitance, after 4000 cycles. Therefore, the prepared composite could be potential electrodematerials for supercapacitors.