Background: A tremendous amount of research work has been done over the past decade to
explore the potential of graphene for energy applications including its use in supercapacitors because of
its unique characteristics such as: novel charge transport behavior, superior electrical and thermal conductivity,
good chemical stability, outstanding mechanical behavior, and above all its tunable interlayer
spacing. A variety of ions has intercalated into the graphene layers without damaging its structure suggesting
structural stability and durability for energy storage applications. Although the energy storage
capacity of pure graphene is low, its charge storage capacity can be improved by synthesizing nanocomposites
of graphene with polymers, metal oxides, and carbon-based materials. Nanocomposites with
conducting polymers such as polyaniline, polypyrrole and polythiophenes can provide various nanostructures
with improved electrochemical properties compared to pure graphene and conducting polymers.
On the other hand, metal oxides provide ultra-high faradic capacitive performance and othercarbon
based materials help in creating complex nano-structural morphology for enhanced energy storage
Objective: The purpose of this review article is to provide both a comprehensive and critical scientific
progress that has so far been made on nanocomposites of graphene. We will especially focus on topics
such as the supercapacitive performance in terms of specific capacitance, energy density, power density,
cycling life, rate capability and the working principles of supercapacitive nanocomposites.