Synergistic effect of control parameters and morphology on synthesis and performance of the Al2O3/MWCNT composite as a promising capacitor material

Abstract

The functional ceramic/CNT composites were investigated using the alumina (Al2O3)/multiwall carbon nanotube (MWCNT) composite as a promising capacitor material based on its electrochemical properties, mesoporous morphology, and aligned MWCNT network. The aligned morphology of the carbon nanotubes in alumina matrix annealed at 900 °C resulted in increased surface area (609.55 m2 g−1), hardness (11 GPa), and Young’s modulus (85.88 GPa). The electrochemical properties of the Al2O3/MWCNT composite were investigated by galvanostatic charge–discharge, cyclic voltammetry, and electrochemical impedance spectroscopy measurements. The MWCNT/Al2O3 composite displays appreciable specific capacitance (183.33 F g−1), energy density (9.16 Wh kg−1), and power density (2.99 kW kg−1) with the addition of 5 wt.% MWCNT. The cycling characteristics of the electrode material show excellent stability up to 1000 charge/discharge cycles with MWCNTs playing the role of the current collector while mesoporous alumina adds to the capacitive performance of the electrode. The alignment of MWCNTs within the alumina matrix changed into accountable for the electrochemical properties of the composite. The results obtained and the ceramic film fabrication technique used in this work provide unflinching confidence that this composite material will be utilized for the fabrication of cost-effective devices for energy storage applications.