Electrospinning Preparation of Fe₃O₄/Porous Carbon Nanofibres for use as Supercapacitor Electrode Materials

A Fe₃O₄/porous carbon nanofibre (Fe₃O₄/CNF) was prepared by carbonization of electrospun polyacrylonitrile (PAN)/polymethylmethacrylate (PMMA) composite nanofibres and used as electrode materials for supercapacitors. The introduction of PMMA as a pore-forming agent in PAN results in an optimum pore distribution and a more suitable specific surface area for Fe₃O₄/CNF; the improved pores and surface area contribute to the diffusion of the electrolyte from the surface to the inside of the electrode material. Electrochemical measurements of the Fe₃O₄/CNF in three-and two-electrode systems reveal a maximum specific capacitance of 540 F g^-1 in the three-electrode system and a capacitance retention of 76.3 % after 5000 continuous cycles in the two-electrode system. Due to the synergistic effect of redox pseudocapacitance behaviour and bilayer capacitance, the excellent electrochemical performance of the Fe₃O₄/CNF electrode highlights the importance of adding PMMA into composite materials.