Fabrication of nanocomposite electrode with MnO2 nanoparticles distributed in polyaniline for electrochemical capacitors

We proposed an in situ method for the synthesis of polyaniline (PANI)/MnO2 nanocomposite by using an in situ polymerization reaction. Morphology analysis showed a porous structure of PANI/MnO2 nanocomposite with MnO2 particles (range from 5 to 15 nm) uniformly dispersed in the polyaniline support. Thermogravimetric analysis and Fourier transform infrared spectrum revealed that the components of PANI and MnO2 in the nanocomposite can be controlled through changing the polymerization time. Toward the utility in supercapacitors, the electrochemical properties of the nanocomposite were studied using cyclic voltammetry and chronopotentiometry tests in 0.5 M Na2SO4 neutral solution. The results showed that the materials had a specific capacitance as large as 510 F g−1 in the potential range from 0.0 to 0.65 V (vs. SCE) at a charge–discharge current density of 1.0 A g−1, greatly improved compared to those of pure PANI and MnO2 materials.