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 other-carbon based materials help in creating
complex nano-structural morphology for enhanced energy storage capacity.
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.