Preparation of ternary composite CF@γ-MnO2/PANI material in electrochemical supercapacitors

In this paper, a ternary hybrid material carbon fiber/manganese dioxide/polyaniline (CF@γ-MnO2/PANI) is synthesized for its utility in supercapacitor application. γ-MnO2 nanoparticles are loaded on the surface of CF under hydrothermal conditions to prepare CF@γ-MnO2. Subsequently, PANI in situ polymerized on the surface of CF@γ-MnO2 to form CF@γ-MnO2/PANI ternary composite. The electrochemical performance of CF@γ-MnO2/PANI is investigated using cyclic voltammetry (CV), galvanostatic charge–discharge measurement (GCD), and electrochemical impedance spectroscopy (EIS). Compared with CF/PANI and PANI, the as-prepared ternary hybrid material exhibits the highest capacitance of 654.3 F g−1 at a current density of 1 A g−1, its rate performance is 78.1% (10 A g−1), and 75.94% of the initial capacitance after 4000 charge–discharge cycles. The asymmetric supercapacitor shows a specific capacitance of 260 F g −1 and high energy density 30.9 Wh kg−1 at a power density of 750 W kg−1, good cycling stability by maintaining 73.2% initial capacitance after 5000 cycles. The good capacitive behaviors demonstrated that the low-cost CF provides an excellent base for γ-MnO2 and PANI. The nanoparticles γ-MnO2 is supported on the surface of CF and coated by PANI, which effectively improves the utilization rate of MnO2 and PANI. It could be a promising material for supercapacitors applications.