Microfluidic-Spinning-Directed Conductive Fibers toward Flexible Micro-Supercapacitors

The large-scale fabrication of the flexible fiber-shaped micro-supercapacitors has received major attention from both industrial and academic researchers. Herein, conductive and robust polyaniline-wrapped multiwall carbon tubes reduced graphene oxide/thermoplastic polyurethane (PANI/MCNTs-rGO/TPU) composite fibers are successfully fabricated on a large scale via the combination of facile microfluidic-spinning process and in situ polymerization of aniline. Initially, MCNTs-rGO/TPU fibers are formed in a T-shape microfluidic chip, relying on the fast material diffusion and exchange in the microfluidic channel. Then, PANI/MCNTs-rGO/TPU hybrid fibers are synthesized through an in situ chemical oxidative polymerization of aniline. With the assistance of polyaniline, these PANI/MCNTs-rGO/TPU hybrid fibers exhibit enhanced electrochemical properties in comparison with pure MCNTs-rGO/TPU fibers, especially in high specific capacitance, which is dramatically increased from 42.1 to 155.5 mF cm⁻². Moreover, the PANI/MCNTs-rGO/TPU hybrid fibers can endure various blending stresses, contributing to its outperforming flexibility and weavability. The best of the excellent electrochemical and mechanical properties of these conductive fibers is made to construct the flexible supercapacitors and various complicated functional fabrics.