Electrical and electrochemical studies of core–shell structured nanorods of LiMn2O4@PANI composite

Abstract

Polyaniline has received much concentration in both basic and applied studies because it has electrical and electrochemical properties comparable to those of both conventional semiconductors and metals. In this work, PANI was used as a conducting additive to formulate a nanocomposite as a high functioning cathode material for Li-ion batteries. PANI, spinel cathode materials of LiMn2O4, and LMO@PANI were synthesized and characterized via scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). SEM of the composite illustrated the formation of long rods of LiMn2O4 covered by PANI layers. The electrical and electrochemical properties of the prepared materials were studied by electrochemical impedance spectroscopy as well as cyclic voltammetry. The composite sample showed higher electrical conductivity (5.5 × 10–2 S/cm) compared with that of PANI (9.1 × 10–4 S/cm) and also showed improving in its specific electrical capacity with a value of 75 mAh/g at a scan rate of 5 mV/s in 1 M LiNO3 electrolyte compared with that of PANI (33 mAh/g). The cycling stability of the composite electrode was significantly improved and showed cycling performance, with ~ 86.2% capacity retained over 1000 cycles. Results predict that the developed LMO@PANI nanocomposite could be used in an electrochemical energy storage device.