Highly Crosslinked Conductive Polymer Nanofibrous Films for High-Rate Solid-State Supercapacitors and Electromagnetic Interference Shielding

With their low cost and unique physicochemical properties, conductive polymer- based film electrodes drew much attention in flexible electronic devices. However, their poor intrinsic conductivities limit their applications in high-rate supercapacitors or high electromagnetic interference (EMI) shielding performance. It is meaningful to deal with the issue through the rational design of the film nanostructure. Herein, using specially treated PEDOT:PSS coated polyacrylonitrile (PAN) nanofibrous films (PPNFs) as a current collector, polyaniline (PANI) or polypyrrole (PPy) based highly crosslinked conductive nanofibrous films (HCC-NFs), named as PANI@PPNF and PPy@PPNF, are fabricated. The PANI@PPNF electrodes exhibit a specific capacitance of 156 mF cm^–2 at a current density of 1 mA cm^–2. Meanwhile, 41% capacity (64 mF cm^–2) remained even at 20 mA cm^–2. The remarkable rate performance of PANI@PPNFs demonstrates the HCC-NF structure brings a high-rate character for pseudocapacitive material. Furthermore, the solid-state supercapacitor shows long-term cycle stability at a high scan rate of 1 V s^–1 for 5 000 cycles and over 75% of the specific capacitance is retained, suggesting excellent cycle stability of PANI@PPNF. Besides, PANI or PPy based HCC-NFs show high performance in EMI shielding. This conductive polymer-based HCC-NF structure offers a promising platform for designing multi-functional flexible electronic devices.