Synthesis and characterization of novel polyindole/metal oxide nanocomposites and its evaluation for lithium ion rechargeable battery applications

Two novel conducting polyindole (PIn) based on gamma-Fe2O3 and gamma-Al2O3 nanocomposites with LiClO4 on Au electrode (Au/PIn/ClO4-@gamma-Al2O3 and Au/PIn/ClO4-@gamma-Fe2O3) as cathode materials for lithium-ion rechargeable batteries were fabricated via an in situ electropolymerization approach. The PIn and polymer nanocomposites were characterized by FT-IR, SEM, TEM, EDX, and TGA. The electrochemical properties of PIn and polymer nanocomposites were studied by cyclic voltammetry (CV), in situ conductivity measurements, electrochemical impedance spectroscopy and charge-discharging test. The optical properties of the samples were also investigated by in situ UV-Visible spectroscopy. The CV results show better reversibility for polymer nanocomposites in compered PIn. The intermolecular interaction between nanoparticles and PIn were confirmed by FT-IR. The TEM images of polymer nanocomposites show that gamma-Fe2O3 and gamma-Al2O3 are embedded in PIn matrix. The thermal stability of the polymer nanocomposites has increased compared to that of PIn. The in situ conductivity of polymer nanocomposites were increased at about 0.20 order of magnitudes in compared to PIn. The electrochemical properties and charge-discharging behavior of the materials were measured with Li/LiClO4+ACN/Au-PIn, Li/LiClO4+ACN/Au-PIn-gamma-Al2O3, and Li/LiClO4+ACN/Au-PIn-gamma-Fe2O3 cells using a constant current of 0.5 mA/cm(2). The results for polymer nanocomposites cells indicated better discharging characteristics at about 116-124 mAh/g with very good cyclic properties in compered to PIn cell. The discharge capacities achieve the best value after 30-40 cycles with around drops 3-6% after 20,000 times. POLYM. COMPOS., 40:496-505, 2019. (c) 2017 Society of Plastics Engineers