Facial Synthesis of Fe3O4/PPy Core–Shell Composite Electrode Material for Boosted Supercapacity

Polypyrrole (PPy) has great potential for applications as a supercapacitor electrode owing to its excellent pseudocapacitance. However, the large volume changes during the rapid charge and discharge process lead to damage to the structure, which is the main obstacle to practical applications. Here, the core–shell structure composite composed of magnetic ferroferric oxide (Fe3O4) nanoparticles and PPy was prepared by solution polymerization. In the Fe3O4/PPy composite, Fe3O4 nanoparticles play the role of reaction template, which can be arranged in a line under a magnetic field, thereby starting the adhesion polymerization of PPy to form a stable core–shell structure with excellent capacitance. The as-synthesized Fe3O4/PPy electrode presents a significantly enhanced specific capacitance of 697 F g–1 at 1.0 A g–1. In particular, the as-synthesized Fe3O4/PPy composite achieved a high energy density of 96.8 Wh kg–1 at 500 W kg–1. This study paves a way to develop materials with high electrochemical performance and may promote the practical application of high-capacity energy storage materials.