Synthesis and physico-chemical property evaluation of PANI-NiFe2O4 nanocomposite as electrodes for supercapacitors

Nanosized PANI-NiFe2O4 composites were prepared by in situ-chemical oxidative polymerization method, whereas NiFe2O4 was synthesized by solution combustion synthesis (SCS) technique. Structural, morphological and electrochemical properties of NiFe2O4, PANI and PANI-NiFe2O4 composites were characterized by XRD, FT-IR, TGA, SEM, TEM, cyclic voltammetry, and galvanostatic charge-discharge techniques. The crystalline nature of NiFe2O4 and PANI-NiFe2O4 composites was elucidated by X-ray diffraction. FT-IR spectra inferred the polymerization of aniline and revealed the corresponding functional groups of PANI. Cyclic voltammetry and galvanostatic charge-discharge experiments were carried out to study the electrochemical capacitive properties. The PANI-NiFe2O4 composites (NP1, NP2 and NP3) exhibited enhanced capacitive performance due to the increase in conducting network of PANI. The composite NP1 was provided higher SC of 448 F/g compared to PANI (292 F/g) and other PANI-NiFe2O4 composites. For the sample NP1, maximum energy density of 50.4 Wh/kg was observed at a current density of 1 mA/cm(2). Above 80% of capacitance was maintained after 1000 cycles at a higher current density of 10 mA/cm(2). Hence, the prepared PANI-NiFe2O4 composites can be used as suitable electrode materials for redox supercapacitors. (C) 2012 Elsevier B.V. All rights reserved.