Effect of polymerization conditions on the physicochemical and electrochemical properties of SnO2/polypyrrole composites for supercapacitor applications

Montmorillonite/Poly(Pyrrole) for Low-Cost Supercapacitor Electrode Hybrid Materials

Conductive polymers such as polypyrrole have been widely used as pseudo-capacitive electrodes for supercapacitors. This work demonstrates a simple method to improve the performance of conductive polymer electrodes by adding montmorillonite in order to perform capacitive behavior. Conductive composite polymers (CCPs) based on montmorillonite/polypyrrole (MMT/PPy(Cl)) have been synthesized by polymerization using FeCl3 as an oxidizing agent. During the preparation of CCP, the effect of MMT/pyrrole mass ratio and the influence of the amount of added H+ and temperature of the synthesis medium on the electrochemical performance of the composite have been investigated. The investigation associated with conductivity measurement allowed us to determine the best conditions to reach a high specific capacitance of 465 F gr-1 measured by cyclic voltammetry with respect to the CCP synthesized at ambient temperature (220 F gr-1) and a 35% increase in capacity compared to its homologue synthesized in neutral conditions at a low temperature. These performances have been advantageously correlated both to the edge acidity of the host material and to the evolution of its conductivity according to the preparation conditions. The galvanostatic charge/discharge tests also confirm the stability of the obtained composite, and a capacitance of 325 F g-1 for the best CCP is recorded with a regime of 1 A g-1. In addition, the durability of the device shows that the proposed material has a relatively good stability during cycling.

Ameliorated optical, luminescent and thermo-chemical features of polymer derived PPy-SnO2 nanocomposite as efficient emissive layer material (EML)

PPy-SnO2 (PS) nanocomposite was synthesized with varying doses of SnO2 through in-situ oxidative polymerization technique. Morphological study was performed through FESEM analysis. Particle size of the 15% PS nanocomposite was estimated in the 13-35 nm range by XRD analysis. Elemental presence and its deconvoluted states in the 15% PS nanocomposite were confirmed by XPS analysis. Optical band gap for optimized 15% PS was calculated ∼1.83 eV. PL intensity increases with increase in the concentration of SnO2. Its value was found highest for 15% PS laid in the light blue region (close to white light). CIE color coordinate study of the nanocomposites elucidated that optimized 15% PS could be used as efficient emissive layer material for WLED application. A comparative TGA study of the PPy and 15% PS illustrated that optimized 15% PS nanocomposite proved to have better thermal stability.

Cattail-Grass-Derived Porous Carbon as High-Capacity Anode Material for Li-Ion Batteries

Cattail-grass-derived porous carbon as high-capacity anode materials were prepared via high-temperature carbonization and activation with KOH. The samples exhibited different structures and morphologies with increasing treatment time. It was found that the cattail grass with activation treatment-1 (CGA-1) sample obtained at 800 °C for 1 h presented excellent electrochemical performance. As an anode material for lithium-ion batteries, CGA-1 showed a high charge-discharge capacity of 814.7 mAh g-1 at the current density of 0.1 A g-1 after 400 cycles, which suggests that it has a great potential for energy storage.