Core-shell N-doped carbon nanotube/alginate@polyaniline fibrous electrodes via in situ polymerization for supercapacitors

In this work, we developed a novel strategy to fabricate core-shell structured nitrogen-doped carbon nanotube/alginate@polyaniline (NCNT/Alg@PANI) composite fibers. First, nitrogen-doped carbon nanotubes (NCNTs) were dispersed in sodium alginate (SA) solution, and the resulting mixture was processed into wrinkled NCNT/Alg fibers via wet-spinning. Subsequently, polyaniline (PANI) was in situ polymerized on the fiber surface, which can significantly enhance the electrochemical performance of the fibers. By tuning the PANI loading, the morphology and specific capacitance of the NCNT/Alg@PANI fibers were optimized. The specific capacitance initially increases and then decreases as the amount of aniline used is raised from 0.2 mL to 0.5 mL. An optimal specific capacitance of 1661.7 mF cm −2 (221.6 F cm −3 ) was achieved in 1 M H 2 SO 4 electrolyte. The electrode exhibited excellent rate capability and cycling stability, retaining 73.7% of the capacitance when the current density was increased from 1 to 10 mA cm −2 , and maintaining 69.72% of the initial capacitance after 5000 charge-discharge cycles at a high current density of 20 mA cm −2 . Furthermore, a fiber-based supercapacitor was assembled using the NCNT/Alg@PANI fiber and delivered an energy density of 18.6 μWh cm −2 at a power density of 80 μW cm −2 . This work presents a promising and effective approach for developing high-performance energy storage devices. Download: Download high-res image (124KB) Download: Download full-size image