Construction of novel coaxial electrospun polyetherimide@polyaniline core-shell fibrous membranes as free-standing flexible electrodes for supercapacitors

Designing porous and flexible electrodes with excellent electrochemical properties is crucial to fabricate high-performance flexible supercapacitors. Conductive polymer-based electrospun fibers are expected to be an ideal material for constructing flexible electrodes due to the enormous specific surface area, unique pore structure and inherent flexibility. However, the exploration of such electrospun fibers with facile preparation methods and high areal capacitance remains challenging. Herein, a novel polyetherimide@polyaniline core-shell fibrous membranes (PEI@PANI CFMs) is fabricated via simply coaxial electrospinning and 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) secondary doping. With the aid of polyetherimide, highly concentrated emeraldine base polyaniline (EB-PANI) can be perfectly wrapped on the surface of fibers without any spinning assistants, ensuring the well-developed pore structures, superior hydrophilicity, good electrical conductivity and outstanding mechanical flexibility. Benefiting from the synergistic effect of structure and constituents, such flexible PEI@PANI CFMs as electrode materials can provide more accessible electrochemical active sites and decrease the ion diffusion resistance. Therefore, the PEI@PANI CFMs present outstanding areal capacitance of 1159.9 mF cm−2 and remarkable energy density of 46.91 μW h cm−2 in the electrodes and symmetric supercapacitors, demonstrating great potential for applications in flexible energy storage field. This fabrication strategy provides a simple and practicable way to manufacture polyaniline-based fibrous membranes for high-performance flexible electrode materials.