AC-MnO2-CNT composites for electrodes of electrochemical supercapacitors

Abstract

Electrodes for electrochemical supercapacitors were fabricated by doctor blade method of composite of activated carbon (AC), MnO2 and carbon nanotubes (CNTs). The AC-MnO2-CNTs composites were synthesized by solution processing method with pH variation of 3, 7 and 11. The composites were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and impedance spectroscopy. The XRD pattern shown the crystalline structure and the SEM image observed that the distribution of CNTs was homogeneous between carbon particles. The electrodes were fabricated for supercapacitor cells with 316L stainless steel as current collector and 1 M Na2SO4 as electrolyte. An electrochemical characterization was performed by using an electrochemical impedance spectroscopy (EIS) method using a LCR Hi-Tester HIOKI 3522 instrument and the results showed an increase in the value of specific capacitance at the AC-MnO2-CNT on the acid reaction condition.