Facile deposition of polyaniline on the multi-walled carbon nanotubes/polyvinyl chloride composite films as flexible and robust electrodes for high performance supercapacitors

Fabrication of Coral-like Polyaniline/Continuously Reinforced Carbon Nanotube Woven Composite Films for Flexible High-Stability Supercapacitor Electrodes

The electrochemical performance is significantly influenced by the structure and surface morphology of the electrode materials used in supercapacitors. Using the floating catalytic chemical vapor deposition (FCCVD) technique, a self-supporting, flexible layer of continuously reinforced carbon nanotube woven film (CNWF) was developed. Then, polyaniline (PANI) was formed in the conductive network of CNWF using cyclic voltammetry electrochemical polymerization (CVEP) in various aqueous electrolytes to produce a series of flexible CNWF/PANI composite films. The impacts of the CVEP period, electrolyte type, and electrolyte concentration on the surface morphology, doping degree, and hydrophilicity of CNWF/PANI composite films were thoroughly examined. The CNWF/PANI₁-15C composite electrode, which was created using 15 cycles of CVEP in a solution of 1 M sodium bisulfate, displayed a distinctive coral-like PANI layer with a well-defined sharp nanoprotuberance structure, a 48% doping degree, and a quick reversible pseudocapacitive storage mechanism. At a current density of 1 A g^-1, the energy density and specific capacitance reached 54.9 Wh kg^-1 and 1098.0 F g^-1, respectively, with a specific capacitance retention rate of 75.9% maintained at 10 A g^-1. Both the specific capacitance and coulomb efficiency were maintained at 96.9% and more than 98.1% of their initial values after being subjected to 2000 cycles of galvanostatic charge and discharge, demonstrating excellent electrochemical cycling stability. The CNWF/PANI₁-15C composite film, an ideal electrode material, offers a promising future in the field of flexible energy storage due to its exceptional mechanical properties (127.9 MPa tensile strength and 16.2% elongation at break).

Continuously Reinforced Carbon Nanotube Film Sea-Cucumber-like Polyaniline Nanocomposites for Flexible Self-Supporting Energy-Storage Electrode Materials

The charge storage mechanism and capacity of supercapacitors completely depend on the electrochemical and mechanical properties of electrode materials. Herein, continuously reinforced carbon nanotube film (CNTF), as the flexible support layer and the conductive skeleton, was prepared via the floating catalytic chemical vapor deposition (FCCVD) method. Furthermore, a series of novel flexible self-supporting CNTF/polyaniline (PANI) nanocomposite electrode materials were prepared by cyclic voltammetry electrochemical polymerization (CVEP), with aniline and mixed-acid-treated CNTF film. By controlling the different polymerization cycles, it was found that the growth model, morphology, apparent color, and loading amount of the PANI on the CNTF surface were different. The CNTF/PANI-15C composite electrode, prepared by 15 cycles of electrochemical polymerization, has a unique surface, with a "sea-cucumber-like" 3D nanoprotrusion structure and microporous channels formed via the stacking of the PANI nanowires. A CNTF/PANI-15C flexible electrode exhibited the highest specific capacitance, 903.6 F/g, and the highest energy density, 45.2 Wh/kg, at the current density of 1 A/g and the voltage window of 0 to 0.6 V. It could maintain 73.9% of the initial value at a high current density of 10 A/g. The excellent electrochemical cycle and structural stabilities were confirmed on the condition of the higher capacitance retention of 95.1% after 2000 cycles of galvanostatic charge/discharge, and on the almost unchanged electrochemical performances after 500 cycles of bending. The tensile strength of the composite electrode was 124.5 MPa, and the elongation at break was 18.9%.

An ionic liquid-modified RGO/polyaniline composite for high-performance flexible all-solid-state supercapacitors

An IL-modified RGO/polyaniline composite was obtained by hydrothermal treatment and in situ polymerization, and used for high-performance supercapacitors.

Synthesis and electrochemical properties of various dimensional poly(1,5-diaminoanthraquinone) nanostructures: Nanoparticles, nanotubes and nanoribbons

Nanostructured conducting polymers show their promising potential as electrode materials for supercapacitors. Here, chemical oxidation polymerization of 1,5-diaminoanthraquinone (DAA) was conducted with HClO₄ as initiator and (NH₄)₂S₂O₈ as oxidant in different solvent systems. Due to the different solubilities of its oligomers, different poly(1,5-diaminoanthraquinone) (PDAA) nanostructures were obtained, such as nanoparticles, nanotubes and nanoribbons. As electrode materials, the PDAA nanotubes synthesized in 1:1 CH₃CN/DMF mixture possessed the highest specific capacitance of 353 F/g at 1 A/g and the best rate capability with the capacitance retention of 52% even at 20 A/g in 1 M H₂SO₄ electrolyte, while the PDAA nanoparticles synthesized in DMF showed the best cycling stability of 111% of its initial capacitance after 10,000 CV cycles at 100 mV/s, despite the same chemical structure with different morphologies.