Advanced sustainable solid state energy storage devices based on FeOOH nanorod loaded carbon@PANI electrode: GCD cycling and TEM correlation

Abstract

A cost-effective, environment-friendly polyaniline-wrapped activated carbon-FeOOH ternary composite electrode is developed by two steps facile method for the efficient and sustainable energy storage device. The HR-TEM analysis before and after cyclic stability (20 k cycles of charging-discharging) shows electrode structural stability and potentiality as an energy storage device. The ternary composite utilizes polyaniline (PANI) maximum, which reflects an increase in voltage window, and electrochemical performance. The voltammetry (cyclic) and galvanostatic charge-discharge (GCD) examination display specific capacitance of 213 F g−1 at 10 mV s−1 and 234 F g−1 at 2 mA sec−1 for 20 wt%. The drastic variation through EIS (electrochemical impedance spectroscopy) in equivalent series resistance is seen by the nyquist plot before and after cycling. The specific capacitance is 234.5 F g−1 at 1 Ag−1 for 20 wt% PANI composite. The energy(Ed) and power density (Pd) of the device are 45 W h kg−1 and 5997 W kg−1 at 2 mA and 20 mA, respectively. The fabricated device shows very advanced capacity retention of up to 89% and coulombic efficiency of 100% till the last 20 k cycles with a stable potential window. The fabricated device can glow LED panels (consisting of 26 LEDs) for up to 5.30 min. The device retention profile and stable potential window show its advanced structural stability up to commercial-scale cycling, which signifies the additional role of PANI. The HR-TEM and electrochemical results after cyclic stability are in correlation.