Modified EISA synthesis of NiAl2O4/MWCNT composite mesoporous free-standing film as a potential electrochemical capacitor material

Abstract

Electrochemically active, free-standing mesoporous films of nickel aluminate/ multiwalled carbon nanotubes (NiAl2O4/MWCNT) composite were synthesised by eco-friendly modified evaporation-induced self-assembly process (m-EISA). The high temperature annealed composite material displayed excellent morphological and electrochemical characteristics. The electrochemical performance was evaluated using cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS) analysis for the composite material annealed at 600 °C, 700 °C, 800 °C, and 900 °C. In particular, the composite material annealed at 900 °C, exhibited a specific capacitance of 618 F g−1. The inverse spinel structure prepared by the m-EISA process assembled into a well-configured free-standing film in which MWCNTs facilitated electronic transport across NiAl2O4/MWCNTs interfaces. The m-EISA process employed in the present work was eco-friendly, economical, energy-efficient, time-saving, and provided flexibility in regulating the final mesostructure of the free-standing films.