Preparation of Fe3O4@polypyrrole composite materials for asymmetric supercapacitor applications†
Abstract
Although Fe3O4 has high capacity, its low conductivity and poor cycling stability have limited its application in supercapacitors. To address this issue, the core–shell structured Fe3O4@polypyrrole (Fe3O4@PPy) composite materials could be selectively prepared to improve the conductivity of hybrid materials. When used as an electrode material for supercapacitors, the resulting Fe3O4@PPy composite material shows a high specific capacitance of 290.2 F g−1 at a current density of 1 A g−1. To further improve the energy density, the asymmetric coin supercapacitor (Fe3O4@PPy//MoO3) has been assembled and it exhibits a high energy density of 26.6 W h kg−1 as well as a power density of 700 W kg−1, which are much higher than those of the traditional capacitor. Moreover, the asymmetric coin supercapacitor presents excellent cycling stability with 84% of capacity retention after 5000 cycles. Therefore, the present method provides a promising strategy for the production of advanced electrode materials for supercapacitors.