Synthesis and Electrochemical Capacity of MnO2/SMWCNT/PANI Ternary Composites

Binary MnO2/acidified multi-walled carbon nanotube (SMWCNT) and ternary MnO2/SMWCNT/ polyaniline (PANI) composites were prepared by liquid-phase precipitation method. SEM images show that the morphology of the materials presents a typical porous structure. The electrochemical capacitive performance of the prepared samples in 0.1 mol/L K2SO4 solution was investigated by cyclic voltammetry and galvanostatic charge/discharge tests. The binary MnO2/SMWCNT composites exhibits improved capacitance compared with the SMWCNT. Further, the ternary MnO2/SMWCNT/PANI composites display quasi-rectangular voltammogram shapes and high capacitor properties. The sample with the mass ratio of MnO2:SMWCNT:PANI=1:1:0.4 displays the best performance in all electrode materials. The specific capacitance of the sample reaches 318.6 F/g at the current density of 0.1 A/g, and its oxidation current density reaches 6.02 A/g. 92.7% current value is maintained after 100 cycles. The high electrochemical capacitors of the ternary MnO2/SMWCNT/PANI composites may be ascribed to their porous morphological structure and well-dispersed MnO2 particles on SMWCNT and PANI.