Facile synthesis of 3D porous polyaniline composite with MnO2-decorated fiber morphology and enhanced electrochemical performance

Abstract

3D porous polyaniline (PANI) with the inherent characteristics of nanoporous structure, large specific surface area, and fast electron/ion transport is an ideal candidate of electrochemical electrode. Herein, in an effort to further enhance the electrochemical performance, manganese sulfate was added into precusor solution of PANI gel, and the PANI/MnO2 composite with porous structure constructed by MnO2 decorated PANI nanofibers was formed via self-assembly, in situ reaction and hydrothermal treatment. As a result, the specific capacitance of PANI/MnO2 (328 F g−1, 0.5 A g−1) increased by 35.5% compared with 3D porous bare PANI (242 F g−1, 0.5 A g−1), and the superb charge transfer behavior was also retained. In addition, the quantitative analysis of kinetics on PANI/MnO2 showed that both capacitive and diffusion-controlled behaviors contributed to the electrochemical performance. Moreover, the symmetric supercapacitor (SSC) assembled by two identical PANI/MnO2 electrodes exhibited an ultra-high potential window (2.2 V), so that it achieved high energy density of 25.5 Wh kg−1 at power density of 499 W kg−1. The enhanced electrochemical should be attributed to superior ion/electron conduction and structural stability enable by the nanoporous structure and continuous fiber conductive framework, and the synergistically electrochemical behavior between PANI and MnO2. The present work well promoted the development of 3D porous polyaniline composite electrode materials with the ideal nanostructure and electrochemical activity for high-performance supercapacitors.